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Sample records for ophthalmia sympathetic

  1. Immunopathology of sympathetic ophthalmia.

    Science.gov (United States)

    Marak, G E

    1976-01-01

    The long held notion that sympathetic ophthalmia represents an autoimmune reaction to uveal pigment is no longer tenable. Pigmentation influences the histopathologic picture of sympathetic ophthalmia but no evidence supports the role of uveal pigment as inciting antigen. Several recent studies have confirmed our initial report of the participation of cellular hypersensitivity to ocular tissues in the pathogenesis of this disease. Both clinical and experimental studies implicate retinal tissue as being more immunogenic than uveal antigens. The recent histopathologic observation that eosinophils concentrate near the choriocapillaris suggests that outer retina and retinal pigment epithelium should not be overlooked as a potential source of the stimulating antigen in sympathetic ophthalmia.

  2. Recent advances in sympathetic ophthalmia.

    Science.gov (United States)

    Marak, G E

    1979-01-01

    Recent advances in understanding the pathogenesis of sympathetic ophthalmia are helping to remove the pigmented cloud which has obstructed the view of researchers on this disease for many years. Clinical features, diagnostic testing, histopathologic variations and principles of treatment are evaluated in the context of our increasing understanding of the pathogenesis of this disease. The relationship of sympathetic ophthalmia to Harada's disease and phacoantigenic uveitis are reviewed.

  3. Pigmentation associated histopathological variations in sympathetic ophthalmia.

    Science.gov (United States)

    Marak, G E; Ikui, H

    1980-01-01

    The severity of inflammation in sympathetic ophthalmia is related to the degree of pigmentation, and the granulomatous response seems to be related to pigmentation. Eosinophilia is also associated with pigmentation, but this association appears to be fortuitous and is a result of the association of eosinophilia with severity of the inflammation. PMID:7387955

  4. Development of sympathetic ophthalmia following globe injury

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; ZHANG Mao-nian; JIANG Cai-hui; YAO Yi

    2009-01-01

    Background Sympathetic ophthalmia (SO), a rare, bilateral, diffuse granulomatous uveitis, usually occurs after open globe injury or intraocular surgery. We sought to identify the risk factors for the development of SO after open globe injury and describe their demographic and clinical features and outcomes of treatments.Methods A retrospective study of inpatients with globe injury in 15 tertiary referral hospitals of China from January 2001 to December 2005 was conducted. The information of demography, nature and mechanism of injury, time and ways of treatments and outcomes was reviewed. Diagnosis of SO was made based on a history of ocular trauma or surgery and subsequent development of bilateral or contralateral uveitis consistent with SO. Any association between related parameters and development of SO was analyzed.Results Among 9103 patients (9776 eyes) of globe injury, SO occurred after open globe injury in 18 cases with an occurrence rate of 0.37%, vitrectomy of closed globe injury in 2 (0.37%) and perforation of burned eyes in another 2. For open globe injury, the median age ((36.72±13.59) years, P=0.01) was higher in patients with SO; there were no significant effects of sexes, injury type, uvea proplaps, once or multi-intraocular surgery, once or multi-vitrectomy and endophthalmitis on incidence of SO; 0.70% endophthalmitis concurred with SO; 83.33% of SO occurred within 1 year after injury or last ocular surgery. SO developed in a fellow eye one week after evisceration of the perforating burned eye. Good final visual acuity was obtained in sympathizing eyes with prompt treatment.Conclusions For open globe injuries, SO sufferers were relatively older and any injury type could induce SO with equal possibility. The initial open globe injury was more likely to be the trigger of SO than subsequent intraocular surgeries including vitrectomy. Prophylactic enucleation after injury is not recommended.

  5. Sympathetic ophthalmia after 23-gauge transconjunctival sutureless vitrectomy

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    Masatoshi Haruta

    2010-11-01

    Full Text Available Masatoshi Haruta1, Hirokazu Mukuno2, Kazuaki Nishijima3, Hitoshi Takagi4, Mihori Kita51Department of Ophthalmology, Kurume University School of Medicine, Kurume, Fukuoka, Japan; 2Department of Ophthalmology, Konan Hospital, Kobe, Hyogo, Japan; 3Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Kyoto, Japan; 4Department of Ophthalmology, St Marianna University School of Medicine, Kawasaki, Kanagawa, Japan; 5Department of Ophthalmology, Hyogo Prefectural Amagasaki Hospital, Amagasaki, Hyogo, JapanPurpose: We report a case of a sympathetic ophthalmia that occurred after 23-gauge transconjunctival sutureless vitrectomy for a retinal detachment.Case report: A 41-year-old Japanese woman underwent combined phacoemulsification with intraocular lens implantation and 23-gauge transconjunctival sutureless vitrectomy for a rhegmatogenous retinal detachment in the right eye. Endolaser photocoagulation and silicone oil tamponade were used to manage inferior retinal holes. Four weeks after the surgery, she returned with a 5-day history of reduced vision and metamorphopsia in her left eye. Slit-lamp examination showed a shallow anterior chamber in the right eye and moderate anterior uveitis bilaterally. Silicone oil bubbles and pigment dispersion were observed in the subconjunctival space adjacent to the right eye’s superonasal sclerotomy site. Fundus examination showed multifocal serous retinal detachments in both eyes. A diagnosis of sympathetic ophthalmia was made and the patient was treated with intensive topical and systemic steroids. The subretinal fluid cleared in both eyes following treatment. Twelve months after the onset of inflammation, the patient’s condition was stable on a combination of oral cyclosporine and topical steroids. Sunset glow retinal changes remain, but there has been no evidence of recurrent inflammation.Conclusion: Sympathetic ophthalmia can develop after 23-gauge

  6. Reversible alopecia in Vogt-Koyanagi-Harada disease and sympathetic ophthalmia

    Science.gov (United States)

    2013-01-01

    Background Vogt-Koyanagi-Harada (VKH) disease and sympathetic ophthalmia (SO) are both autoimmune disorders targeting melanin-bearing cells, even though their etiologies are different. Both shared many ocular and systemic manifestations, including integumentary findings. Most of the literature focused on the ocular manifestations and related treatment. Alopecia was seldom mentioned. Findings We report one case of VKH disease and one case of SO. Both developed severe alopecia and early sunset glow fundus, which are probably due to incomplete treatment. Fortunately, the alopecia improved soon after systemic steroid treatment. Conclusions Early and complete treatments are important in the management of VKH or SO and prevent integumentary manifestation. Alopecia can be reversible after steroid treatment in time. PMID:23514340

  7. Massive choroidal hemorrhage after intravitreal administration of bevacizumab (Avastin® for AMD followed by controlateral sympathetic ophthalmia

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    Dimitrios Brouzas

    2009-08-01

    Full Text Available Dimitrios Brouzas, Chryssanthi Koutsandrea, Marilita Moschos, Spiros Papadimitriou, Ioannis Ladas, Michael Apostolopoulos1st Eye Department , University of Athens, Athens, GreecePurpose: To report a severe ocular complication initiated ten days after intravitreal administration of bevacizumab (Avastin®, in a patient with exudative age-related macular degeneration (AMD.Patients and method: Case report.Results: Ten days after intravitreal injection of 1.25 mg Avastin®, the patient manifested acute loss of vision with excruciating pain. An extensive choroidal detachment was evident in close contact with the lens, which necessitated an emergency sclerotomy with reconstruction of the anterior chamber. Four months later, the eye proceeded to phthisis bulbi. Five months after the injection, the patient complained of mild pain, photophobia, and visual acuity deterioration from the fellow eye. The diagnosis of sympathetic ophthalmia was suggested and treated with intravitreal injections of triamcinolone acetonide every three months with good response, complicated by elevation of intraocular pressure which we managed with Ahmet valve implantation.Conclusion: Serious ocular complications after intravitreal of Avastin® can not be excluded, including massive choroidal hemorrhage and sympathetic ophthalmia of the fellow eye.Keywords: Avastin® complication, intravitreal injection, choroidal detachment, Phthisis bulbi, sympathetic ophthalmia

  8. Gender Differences in Vogt-Koyanagi-Harada Disease and Sympathetic Ophthalmia

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    Yujuan Wang

    2014-01-01

    Full Text Available Vogt-Koyanagi-Harada disease (VKH and sympathetic ophthalmia (SO are types of T-cell mediated autoimmune granulomatous uveitis. Although the two diseases share common clinical features, they have certain differences in gender predilections. VKH classically has been reported as more prevalent in females than males, yet some studies in Japan and China have not found differences in gender prevalence. Male patients have a higher risk of chorioretinal degeneration, vitiligo, and worse prognosis. Conversely, the changing levels of estrogen/progesterone during pregnancy and the menstrual cycle as well as higher levels of TGF-β show a protective role in females. Potential causes of female predilection for VKH are associated with HLA-DR and HLA-DQ alleles. SO, a bilateral granulomatous uveitis, occurs in the context of one eye after a penetrating injury due to trauma or surgery. In contrast to the female dominance in VKH, males are more frequently affected by SO due to a higher incidence of ocular injury, especially during wartime. However, no gender predilection of SO has been reported in postsurgical cases. No clinically different manifestations are revealed between males and females in SO secondary to either ocular trauma or surgery. The potential causes of the gender difference may provide hints on future treatment and disease evaluation.

  9. Enhanced depth imaging OCT (EDI-OCT) findings in acute phase of sympathetic ophthalmia.

    Science.gov (United States)

    Behdad, Bahareh; Rahmani, Safa; Montahaei, Talieh; Soheilian, Roham; Soheilian, Masoud

    2015-06-01

    The purpose of this study was to describe the EDI-OCT findings in an acute phase of sympathetic ophthalmia (SO). A 24-year-old gentleman was referred to clinic complaining of progressive blurry vision of his right eye within last 3 days. He had a history of repaired corneoscleral laceration in his left eye followed by lensectomy and anterior vitrectomy approximately 1 month before his recent right eye discomfort. Physical examination revealed a granulomatous uveitis with an exudative RD of the right eye consistent with SO. EDI-OCT was done at initial exam and repeated 1 and 15 months after therapy. EDI-OCT 1 month following therapy showed significant improvement in choroidal thickening and outer retinal cell layers. The choroidal thickness in the right sympathizing eye decreased from 617 to 568 μm and in the left exciting eye from 539 to 521 μm. After 15 month follow-up, choroidal thickness that is reported in EDI-OCT is 436 μm in the right and 382 μm in the left eye. SO should be added to the list of choroidopathies that cause an increase in choroidal thickness in acute phase of disorder with subsequent decrease after therapy, so help us in assessing and estimation of response to treatment.

  10. High-dose short-term chlorambucil for intractable sympathetic ophthalmia and Behçet's disease.

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    Tessler, H H; Jennings, T

    1990-01-01

    We treated five patients with intractable sympathetic ophthalmia and six patients with severe Behçet's disease by high-dose, short-term chlorambucil therapy. We used a total dose ranging from 306 mg to 4.2 g and a duration of therapy no longer than 36 weeks and in most cases less than 24 weeks. After termination of therapy all 11 patients had a sustained remission of their eye disease. Unless subretinal neovascularisation was present, all had a final visual acuity of 20/50 or better. Malignancy has not developed in any of our cases, with a follow-up ranging from 6 months to 12 years (mean, 4.5 years). Although 30- and 40-year follow-ups and larger numbers of patients may be necessary fully to realise the risks of chlorambucil, we believe that our high-dose, short-term regimen (Behçet's disease: average duration, 23 weeks; average total dose 2.2 g; sympathetic ophthalmia: average duration, 11 weeks; total average dose, 0.9 g) may be safer than previously reported chlorambucil regimens of one to two years or longer. In addition we fulfilled our aim of discontinuing all concomitant systemic corticosteroids within a relatively short time (usually six to eight weeks). PMID:2378842

  11. Aspectos da tomografia de coerência óptica na oftalmia simpática: relato de caso Optical coherence tomography aspects of sympathetic ophthalmia: case report

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    Magno Antônio Ferreira

    2009-06-01

    Full Text Available A oftalmia simpática é uma panuveíte granulomatosa que se inicia após trauma ocular. O prognóstico é reservado e depende do diagnóstico e tratamento precoces. Os autores descrevem um caso de paciente portador de oftalmia simpática no qual foi realizada tomografia de coerência óptica e instituído tratamento precoce, e sugerem que a tomografia de coerência óptica possa corroborar como exame subsidiário no estudo das características da retina de pacientes portadores dessa doença, especialmente em casos de apresentação rara, com descolamento seroso da retina, como manifestação oftalmológica isolada.The sympathetic ophthalmia is a granulomatous panuveitis that starts after ocular trauma. The prognosis is poor and depends of both early diagnosis and treatment. The authors describe one case of a patient with sympathetic ophthalmia using optical coherence tomography who was submitted to early treatment, and it suggests that the optical coherence tomography can corroborate as a ancillary method in the study of retina characteristics in sympathetic ophthalmia disease specially in cases of rare presentation, with serous retinal detachment as an isolated ophthalmological manifestation.

  12. Long-term, drug-free remission of sympathetic ophthalmia with high-dose, short-term chlorambucil therapy.

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    Patel, Sarju S; Dodds, Emilio M; Echandi, Laura V; Couto, Cristobal A; Schlaen, Ariel; Tessler, Howard H; Goldstein, Debra A

    2014-02-01

    To evaluate the safety and effectiveness of short-term, high-dose chlorambucil therapy in achieving long-term, drug-free remission in the treatment of sympathetic ophthalmia (SO). Retrospective case series. Sixteen patients with SO treated with high-dose, short-term chlorambucil therapy between 1970 and 2010. Descriptive and bivariate analyses were used to characterize disease and outcomes. Months of disease-free remission, prevalence rate of relapse, and prevalence of serious treatment-related adverse events. Sixteen patients with SO treated with short-term, high-dose chlorambucil were identified. Patients were treated with chlorambucil for a median of 14.0 weeks (mean, 14.5 weeks; range, 12.0-19.0 weeks). Median follow-up was 98.5 months (mean, 139.1 months; range, 48-441 months) from initiation of chlorambucil therapy. Control of inflammation was achieved in 100% of patients. Thirteen patients (81.3%) maintained vision of 20/40 or better in the sympathizing eye. Four patients (25%) relapsed after a median of 83 months (mean, 131 months) after cessation of systemic therapy. Seventy-five percent of relapses were controlled with topical therapy only. Conjunctival Kaposi's sarcoma developed in 1 patient. No patient demonstrated systemic malignancy. Short-term, high-dose chlorambucil therapy provides sustained periods of drug-free remission. With median follow-up of more than 8 years (mean, 11.6 years; range, 4-37 years), there was a low rate of recurrence and minimal long-term serious health consequences or adverse events. Because SO may be a lifelong condition and because chlorambucil therapy may offer long-term, drug-free remission, this treatment may be worth considering early in the decision-making process for severe sight-threatening disease. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  13. A case of Vogt-Koyanagi-Harada disease mimicking sympathetic ophthalmia

    Institute of Scientific and Technical Information of China (English)

    Syed Shoeb Ahmad; Faisal Ariff Hassan

    2015-01-01

    A 34 years old male patient presented to us on 15th February 2015, with complaints of mild pain in right eye and a foreign body sensation to the left eye, associated with redness, discomfort and blurring of vision with 4 days duration. There was history of a penetrating eye injury to his right eye 20 years ago. Examination showed bilaterally inflamed eyes. The right eye was going into phthisis bulbi. Fundus examination of the left eye showed blurred optic disc with hemorrhagic areas, macular edema and exudative retinal detachments. Systemic review did not show any gross skin changes, neurological signs or dysmorphism. He was initially treated as sympathetic ophthalmitis, but the history and examination noted that he had bilateral sensory neural hearing loss. Fundus fluorescein angiography showed that he had hyperfluorescent spots in the fundus. Thus, the diagnosis was changed to Vogt-Koyanagi-Harada disease. The patient was treated with oral steroids (1 mg/kg per day) and subsequent follow up showed a marked improvement in the ocular findings.

  14. Experimental Studies of Melanin Associated Antigen and Its Relationship with Sympathetic Ophthalmia and Vogt-Kayanagi-Harada Syndrome

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng Lin; Shaozhen Li; Chufeng Xie; Xiangkun Huang; Zhigang Fan

    2003-01-01

    Purpose: To discuss the relationship of Bovine Melanin-Associated Antigen (BMAA) to Sympathetic Ophthalmia (SO) and Vogt-Kayanagi-Harada (VKH) syndrome.Methods:BMAA was isolated and purified from bovine iris and ciliary body and MTT method was used to measure the peripheral lymphocyte reactions of SO and VKH syndrome patients to BMAA. 15 cases of SO were included in the SO group with 11 males and 4 females. The average age was 37.5, ranging from 23 to 56 years; 15 patients with VKH syndrome were included in the VHK group with 7 males and 8 females. Their average age was 37.2 years, ranging from 24 to 69 years; 20 normal individuals without ocular and systemic autoimmune diseases were included in the control group.These included 9 males and 11 females, aging from 14 to 28 with an average of 23.8 years.Results: The OD values of each group were as follows: SO controls 0.327+0.032; SO+ BMAA 0.490+0.758; SO+PHA 0.5310+0.918; VKH controls 0.328+0.503; VKH+BMAA 0.430 +0.530; VKH +PHA 0.328 +0.484;Normal controls 0.304 +0.267; Normal +BMAA 0.343+0.326; Normal+PHA 0.477+0.598. The average OD values of peripheral lymphocytes to BMAA stimulation in SO patients and normal controls were 0.490 and 0.343 respectively. The difference was statistically significant, P< 0.001; The average OD values of peripheral lymphocytes to BMAA stimulation in SO and VKH syndrome patients were 0.470 and 0.430 respectively. The difference was not statistically significant,P > 0.05.Conclusions:BMAA effectively stimulate the proliferative reaction of peripheral lymphocytes in SO patients and BMAA may act as an antigen and contribute in the pathological process of SO.No difference in proliferative reaction of peripheral lymphocytes was found between SO and VKH syndrome patients after BMAA stimulations and BMAA may be involved in the development of both SO and VKH yndrome.

  15. Choroidal neovascularization associated with sympathetic ophthalmia: case report Neovascularização coroidiana associada à oftalmia simpática: relato de caso

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    Raul Nunes Galvarro Vianna

    2005-06-01

    Full Text Available A 7-year-old boy with sympathetic ophthalmia secondary to penetrating ocular trauma developed choroidal neovascularization in the macular region of the sympathizing eye. Posterior segment biomicroscopy disclosed a single, round, small, slightly elevated yellow-white lesion temporal to the fovea, linked to the temporal edge of the optic disc by a fibrotic band. On fluorescein angiography the round lesion showed a gradual hyperfluorescence, with late staining and leakage, and was interpreted as a fibrovascular scar from previous choroidal neovascularization. Despite intense immunosuppressive therapy, the patient's final visual acuity was 20/400. Although rarely associated with sympathetic ophthalmia, choroidal neovascularization and its cicatricial stages can occur and compromise the visual prognosis of an already debilitated eye. The best course of treatment for choroidal neovascularization in these types of cases has not yet been determined.Paciente com oftalmia simpática (OS desenvolveu neovascularização coroidiana (NVC na região macular do olho simpatizado. A biomicroscopia do segmento posterior do olho afetado revelou uma pequena lesão branco-amarelada, discretamente elevada, localizada na região temporal à fóvea. Uma banda fibrosa ligava o disco óptico à lesão foveal. À angiografia fluoresceínica, a lesão revelou hiperfluorescência progressiva, com impregnação e extravazamento tardio do corante, achados esses característicos de uma cicatriz fibrovascular. Apesar de intenso tratamento com medicação imunossupressora, a acuidade visual final do paciente foi de 20/400. Embora raramente associada à oftalmia simpática a neovascularização coroidiana pode ocorrer e comprometer o prognóstico visual de um olho já debilitado. A melhor opção para o tratamento da neovascularização coroidiana em casos de oftalmia simpática ainda não está determinada.

  16. Preventing Ophthalmia Neonatorum

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    Dorothy L Moore

    2015-01-01

    Full Text Available The use of silver nitrate as prophylaxis for neonatal ophthalmia was instituted in the late 1800s to prevent the devastating effects of neonatal ocular infection with Neisseria gonorrhoeae. At that time – during the preantibiotic era – many countries made such prophylaxis mandatory by law. Today, neonatal gonococcal ophthalmia is rare in Canada, but ocular prophylaxis for this condition remains mandatory in some provinces/ territories. Silver nitrate drops are no longer available and erythromycin, the only ophthalmic antibiotic eye ointment currently available for use in newborns, is of questionable efficacy. Ocular prophylaxis is not effective in preventing chlamydial conjunctivitis. Applying medication to the eyes of newborns may result in mild eye irritation and has been perceived by some parents as interfering with mother-infant bonding. Physicians caring for newborns should advocate for rescinding mandatory ocular prophylaxis laws. More effective means of preventing ophthalmia neonatorum include screening all pregnant women for gonorrhea and chlamydia infection, and treatment and follow-up of those found to be infected. Mothers who were not screened should be tested at delivery. Infants of mothers with untreated gonococcal infection at delivery should receive ceftriaxone. Infants exposed to chlamydia at delivery should be followed closely for signs of infection.

  17. 细胞因子信号抑制因子在交感性眼炎患者外周血单个核细胞内的表达%Expression of suppressor of cytokine signaling in peripheral blood monocular cells of patients with sympathetic ophthalmia

    Institute of Scientific and Technical Information of China (English)

    周增超; 王启常

    2012-01-01

    Objective To investigate the mRNA and protein expression of suppressor of cytokine signaling (SOCS) in peripheral blood mononuclear cells(PBMC) of patients with sympathetic ophthalmia.Methods Blood samples were taken from 14 sympathetic ophthalmia patients with active uveitis,13 quiescent patients,and 15 healthy individuals.IFN-γ,IL-12 and IL-4 in the serum were measured by ELISA.PBMC were subjected to analysis of SOCS mRNA and protein expression using quantitative RT-PCR and western blot,respectively.Results The level of IFN-γ,IL-12 and IL-4 were all significantly higher in the serum of sympathetic ophthalmia patients with active uveitis than that in controls and quiescent patients(P <0.05).There were no significant differences between the quiescent patients and the controls(P > 0.05).Compared to healthy volunteers,the expressions of cytokine inducible SH2 containing protein (CIS),SOCS1,SOCS3 and SOCS5 mRNA and protein were significantly increased.There were no significant differences in expression of CIS,SOCS1,SOCS3 mRNA and protein in quiescent patients,but SOCS5 mRNA and protein were significantly increased.Conclusion Up regulation of SOCS1 and SOCS5 expression may involve in the development of a Th1 mediated immune response in sympathetic ophthalmia patients with active uveitis.CIS and SOCS3 may play important roles in mitigating the pathogenic effects of proinflammatory cytokines.It were kept balance in quiescent patients,and up-regulation of SOCS5 may have protective functions.%目的 探讨细胞因子信号抑制因子(SOCS)在交感性眼炎患者外周血单个核细胞(PB-MC)内的表达及意义.方法 抽取14例交感性眼炎活动期患者、13例静止期患者和15例正常人的外周血,用酶联免疫吸附测定方法检测血清中细胞因子IL-4、IL-12、IFN-γ的水平;用实时荧光定量PCR和蛋白免疫印迹法检测PBMC内SOCSmRNA和蛋白的表达.结果 活动期患者IFN-γ、IL-12和IL-4水平较对照

  18. Ophthalmia neonatorum caused by Neisseria cinerea.

    OpenAIRE

    Bourbeau, P; Holla, V; Piemontese, S

    1990-01-01

    Neisseria cinerea is an organism that has only recently been implicated as a human pathogen. In this case, N. cinerea was identified as the cause of ophthalmia neonatorum (conjunctivitis) in a 2-day-old girl.

  19. Ophthalmia neonatorum caused by Neisseria cinerea.

    Science.gov (United States)

    Bourbeau, P; Holla, V; Piemontese, S

    1990-07-01

    Neisseria cinerea is an organism that has only recently been implicated as a human pathogen. In this case, N. cinerea was identified as the cause of ophthalmia neonatorum (conjunctivitis) in a 2-day-old girl.

  20. John Vetch and the Egyptian ophthalmia.

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    Feibel, R M

    1983-01-01

    During the Napoleonic Wars from 1798-1815, severe epidemics of keratoconjunctivitis affected the military and civilian populations of Western Europe. This disease was known as the Egyptian ophthalmia because it was first described in troops stationed in Egypt. Most physicians believed this condition was not infectious, but caused by various climatological factors. John Vetch, a British physician, emphasized that this disease was spread by direct conveyance of pus from the diseased to the healthy eye. His insistence that the ophthalmia was contagious, and his suggestions for prevention and treatment were milestones in the history of ophthalmology.

  1. Sympathetic ophthalmia - histopathological correlation with fluorescein and indocyanine green angiography: case report Oftalmia simpática - correlação da histopatologia com a angiografia por fluoresceína e indocianina verde: relato de caso

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    Antônio Marcelo Barbante Casella

    2008-12-01

    Full Text Available This study correlates fluorescein angiography (FA and indocyanine green angiography (ICGA to histopathologic findings in a patient with sympathetic ophtalmia. A male with a perforated trauma in right eye presented after two months a decrease in visual acuity of the left eye. FA and ICGA were performed and the images were correlated with the histopathologic findings of the enucleated eye; FA showed background areas of homogeneous hypofluorescence in the arterial and venous phases, as well as areas of granular progressive hyperfluorescence and leakage from the optic disc. ICGA showed areas of hypofluorescence in the early and intermediate phases of the examination, which persisted until the late phase. During the early phase, there was also diffuse hypofluorescence caused by blockage that allowed observation of areas of partial choroidal circulation. The histopathology of the enucleated right eye showed diffuse choriocapillaris edema and inflammation of the choroids, focal areas of hyperplasia of the retinal pigment epithelium (RPE as well as foci of epithelioid cells located between the choroid and the RPE. Furthermore, lymphocytic infiltration of the episcleral veins and retinal detachment were present. The hyperfluorescence observed on FA was correlated to retinal detachment and optic nerve inflammation. The hypofluorescence noted on FA and ICGA corresponded to the presence of blocking inflammatory cells (Dalen-Fuchs-like nodules and to diffuse choriocapillaris edema.O objetivo deste relato de caso foi correlacionar achados da histopatologia com a angiografia por fluoresceína (AF e por indocianina verde (AIV em um paciente com oftalmia simpática. Após dois meses de trauma perfurante no olho direito, o paciente apresentou baixa acuidade visual no olho esquerdo (OE. A AF do OE mostrou áreas de hipofluorescência homogênea na fase arterial e venosa, áreas de progressiva hiperfluorescência granular e vazamento do disco. A AIV mostrou

  2. A Survey on Ophthalmia Neonatorum in Benin City, Nigeria (Emphasis on gonococcal ophthalmia

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    Enabulele Onaiwu

    2003-08-01

    Full Text Available The purpose of the study was to investigate the incidence of gonococcal ophthalmia neonatorum considering its ability to lead to childhood blindness through corneal ulceration and scarification. Eye swabs were obtained from 330 neonates of 1-5 days in the hospitals of study. Of these, 248 yielded growth and six bacterial genera were identified using standard techniques. Staphylococcus aureus was the most prevalent (60.5% while Neisseria gonorrhoeae accounted for 1.7%. Susceptibility patterns of bacterial isolates to four antibiotics were determined using Disk-diffusion tests. Staphylococcus aureus and Neisseria gonorrhoeae showed 62.5 and 100% susceptibility to Erythromycin while 66.7% of Escherichia coli and Klebsiella and 62.5% of Pseudomonas aeruginosa were susceptible to Gentamicin. The incidence of gonococcal ophthalmia neonatorum for the period of study was 8.9 (cases per 1,000 live births. Prevention is through ocular prophylaxis by the application of either 1% silver nitrate ophthalmic solution or 0.5% erythromycin ointment to the neonates? eyes some hours after birth. This would help to preserve vision and reduce to the barest minimum the incidence of childhood blindness.

  3. Ophthalmia due to spitting cobra venom in an urban setting - A report of three cases

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    Leslie Jonathan Ang

    2014-01-01

    Full Text Available To describe three presentations of spitting cobra venom induced ophthalmia in urban Singapore. Case notes and photographs of three patients with venom ophthalmia who presented to our clinic between 2007 and 2012 were reviewed. Two patients encountered the spitting cobra while working at a job site while the third patient had caught the snake and caged it. The venom entered the eyes in all 3 cases. Immediate irrigation with tap water was carried out before presenting to the Accident and Emergency department. All patients were treated medically with topical antibiotic prophylaxis and copious lubricants. The use of anti-venom was not required in any case. All eyes recovered with no long-term sequelae. If irrigation is initiated early, eyes can recover with no significant complications or sequelae.

  4. Management of gonococcal ophthalmia neonatorum with single-dose kanamycin and ocular irrigation with saline.

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    Latif, A; Mason, P; Marowa, E; Paraiwa, E; Dhamu, F; Tambo, J; Gwanzura, L; Mapeta, D; Jongeling, G

    1988-01-01

    Two hundred nineteen neonates with gonococcal ophthalmia neonatorum, including 40 infected with penicillinase-producing strains, were treated as outpatients with a single intramuscular injection of 100 mg of kanamycin and hourly ocular irrigation with saline. Neisseria gonorrhoeae was isolated from three (1.4%) of the 212 babies attending for follow-up, and post-gonococcal conjunctivitis developed in 22 (10.4%) of those who returned for follow-up.

  5. Prevention of Ophthalmia Neonatorum Caused by Neisseria gonorrhoeae Using a Fatty Acid-Based Formulation

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    Colin P. Churchward

    2017-07-01

    Full Text Available Ophthalmia neonatorum, also called neonatal conjunctivitis, acquired during delivery can occur in the first 28 days of life. Commonly caused by the bacterial pathogen Neisseria gonorrhoeae, infection can lead to corneal scarring, perforation of the eye, and blindness. One approach that can be taken to prevent the disease is the use of an ophthalmic prophylaxis, which kills the bacteria on the surface of the eye shortly after birth. Current prophylaxes are based on antibiotic ointments. However, N. gonorrhoeae is resistant to many antibiotics and alternative treatments must be developed before the condition becomes untreatable. This study focused on developing a fatty acid-based prophylaxis. For this, 37 fatty acids or fatty acid derivatives were screened in vitro for fast antigonococcal activity. Seven candidates were identified as bactericidal at 1 mM. These seven were subjected to irritation testing using three separate methods: the bovine corneal opacity and permeability (BCOP test; the hen’s egg test—chorioallantoic membrane (HET-CAM; and the red blood cell (RBC lysis assay. The candidates were also tested in artificial tear fluid to determine whether they were effective in this environment. Four of the candidates remained effective. Among these, two lead candidates, monocaprin and myristoleic acid, displayed the best potential as active compounds in the development of a fatty acid-based prophylaxis for prevention of ophthalmia neonatorum.

  6. Toxin ophthalmia caused by nuchal gland secretion of the Taiwan tiger keelback (Rhabdophis tigrinus formosanus

    Directory of Open Access Journals (Sweden)

    Yen-Chia Chen

    2014-10-01

    Full Text Available Rhabdophis tigrinus is a common colubrid snake that can be found in an extensive geographical region in East Asia. It consists of two subspecies: R.t. tigrinus (yamakagashi and R.t. formosanus (Taiwan tiger keelback. R. tigrinus possesses two different sets of poisonous glands: the Duvernoy's glands in the maxilla, and the nuchal glands in the dorsal skin of the neck. We report the first case in current English literature of toxin ophthalmia caused by the nuchal gland secretion of R.t. formosanus. The patient was a 40-year-old man whose right eye was sprayed by the nuchal gland fluid of R.t. formosanus. He presented with symptoms of foreign body sensation, progressive burning pain, and blurred vision. Ophthalmologic examination revealed diffuse superficial punctate keratitis, corneal stromal edema with Descemet folds, and conjunctival congestion. The patient responded well to topical treatment with a corticosteroid, antihistamine, and antibiotic, and had a favorable clinical course and outcome.

  7. First Attempt to Implement Ophthalmia Neonatorum Prophylaxis in Angola: Microorganisms, Efficacy, and Obstacles

    Directory of Open Access Journals (Sweden)

    Isabel Alexandre

    2015-01-01

    Full Text Available Purpose. To determine the efficacy of povidone-iodine (P-I prophylaxis for ophthalmia neonatorum (ON in Angola and to document maternal prevalence and mother-to-child transmission rates. Methods. Endocervical samples from mothers n=317 and newborn conjunctival smears n=245 were analysed by multiplex polymerase chain reaction (PCR for Chlamydia trachomatis (CT, Neisseria gonorrhoeae (NG, and Mycoplasma genitalium (MG. Newborns were randomized into a noninterventional group and an interventional group that received a drop of P-I 2.5% bilaterally after conjunctival smear collection. Mothers were trained to identify signs of ON and attend a follow-up visit. Results. Forty-two newborns had ocular pathology, and 11 (4.4% had clinical signs of ON at the time of delivery. Maternal PCR was positive for MG n=19, CT n=8, and NG n=2. Six newborns were positive for CT n=4, MG n=2, and NG n=1. Mother-to-child transmission rates were 50% for CT and NG and 10.5% for MG. Only 16 newborns returned for follow-up. Conclusions. Lack of maternal compliance prevented successful testing of prophylactic P-I efficacy in ON prevention. Nevertheless, we documented the prevalence and mother-to-child transmission rates for CT, NG, and MG. These results emphasize the need to develop an effective Angolan educational and prophylactic ON program.

  8. Venom ophthalmia caused by venoms of spitting elapid and other snakes: Report of ten cases with review of epidemiology, clinical features, pathophysiology and management.

    Science.gov (United States)

    Chu, Edward R; Weinstein, Scott A; White, Julian; Warrell, David A

    2010-09-01

    Venom ophthalmia caused by venoms of spitting elapid and other snakes: report of ten cases with review of epidemiology, clinical features, pathophysiology and management. Chu, ER, Weinstein, SA, White, J and Warrell, DA. Toxicon XX:xxx-xxx. We present ten cases of ocular injury following instillation into the eye of snake venoms or toxins by spitting elapids and other snakes. The natural history of spitting elapids and the toxinology of their venoms are reviewed together with the medical effects and management of venom ophthalmia in humans and domestic animals including both direct and allergic effects of venoms. Although the clinical features and management of envenoming following bites by spitting elapids (genera Naja and Hemachatus) are well documented, these snakes are also capable of "spraying" venom towards the eyes of predators, a defensive strategy that causes painful and potentially blinding ocular envenoming (venom ophthalmia). Little attention has been given to the detailed clinical description, clinical evolution and efficacy of treatment of venom ophthalmia and no clear management guidelines have been formulated. Knowledge of the pathophysiology of ocular envenoming is based largely on animal studies and a limited body of clinical information. A few cases of ocular exposure to venoms from crotaline viperids have also been described. Venom ophthalmia often presents with pain, hyperemia, blepharitis, blepharospasm and corneal erosions. Delay or lack of treatment may result in corneal opacity, hypopyon and/or blindness. When venom is "spat" into the eye, cranial nerve VII may be affected by local spread of venom but systemic envenoming has not been documented in human patients. Management of venom ophthalmia consists of: 1) urgent decontamination by copious irrigation 2) analgesia by vasoconstrictors with weak mydriatic activity (e.g. epinephrine) and limited topical administration of local anesthetics (e.g. tetracaine) 3) exclusion of corneal abrasions

  9. Cyclosporine-Associated Leukoencephalopathy in a Case of Sympathetic Ophthalmitis

    Directory of Open Access Journals (Sweden)

    Mizuki Tagami

    2016-01-01

    Full Text Available Purpose: Cyclosporine (CsA is currently widely used as a primary immunosuppressive agent in ocular disease, particularly in severe uveitis. Posterior reversible encephalopathy syndrome (PRES is a significant complication of CsA therapy. However, there are no reports of the occurrence of PRES in response to the treatment of uveitis in the ophthalmological area. Case Presentation: We report a case with CsA-associated PRES. A 70-year-old woman with sympathetic ophthalmitis was treated with 50 mg/day of CsA for 1 week. However, the trough level in her blood was too low; thus, we increased the dose to 100 mg/day of CsA with prednisolone. She had headaches, hypertension (systolic blood pressure 180-200 mm Hg, loss of consciousness for several hours, and reduced limb movement, and her MRI showed a high signal intensity in both posterior lobes, consistent with PRES. Examination of the cerebrospinal fluid indicated that it was within normal limits. Her CsA trough level in the blood was within normal ranges on the day of the attack. Her symptoms gradually improved over the next several days; however, she presented with cortical blindness, which lasted for several weeks. Finally, she returned to her baseline values from before the attack. Her MRI findings showed that PRES had essentially disappeared. Conclusion: PRES is not directly associated with the dosage of CsA administered; however, in general, it is well known that PRES can affect strongly immunosuppressed cases undergoing organ and bone marrow transplantation. Nevertheless, our CsA dose was only 100 mg (1.8 mg/kg. In this study, we report on the occurrence of PRES after the administration of CsA to treat sympathetic ophthalmia. To our knowledge, PRES can also occur after the administration of a small dose of CsA; thus, ophthalmologists using CsA should carefully observe the systemic conditions of CsA-treated patients.

  10. AMPUTATION AND REFLEX SYMPATHETIC DYSTROPHY

    NARCIS (Netherlands)

    GEERTZEN, JHB; EISMA, WH

    Reflex sympathetic dystrophy is a chronic pain syndrome characterized by chronic burning pain, restricted range of motion, oedema and vasolability. Patients are difficult to treat and the prognosis is very often poor. This report emphasizes that an amputation in case of a reflex sympathetic

  11. The History of Sympathetic Surgery.

    Science.gov (United States)

    Hashmonai, Moshe

    2016-11-01

    At present, primary hyperhidrosis is the main indication for sympathectomy. For upper thoracic sympathetic ablation, excision of the second thoracic ganglion alone or with the first and/or third ganglia was the standard during the open surgery era. With the advent of thoracoscopy, modifications related to the level, extent, and type of ablation were proposed to attenuate compensatory hyperhidrosis. The ideal operation for sympathetic denervation of the face and upper limbs remain to be defined. Controlled double-blind studies with quantitave measurements of sweat production are required. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. The sympathetic nervous system in obesity hypertension.

    Science.gov (United States)

    Lohmeier, Thomas E; Iliescu, Radu

    2013-08-01

    Abundant evidence supports a role of the sympathetic nervous system in the pathogenesis of obesity-related hypertension. However, the nature and temporal progression of mechanisms underlying this sympathetically mediated hypertension are incompletely understood. Recent technological advances allowing direct recordings of renal sympathetic nerve activity (RSNA) in conscious animals, together with direct suppression of RSNA by renal denervation and reflex-mediated global sympathetic inhibition in experimental animals and human subjects have been especially valuable in elucidating these mechanisms. These studies strongly support the concept that increased RSNA is the critical mechanism by which increased central sympathetic outflow initiates and maintains reductions in renal excretory function, causing obesity hypertension. Potential determinants of renal sympathoexcitation and the differential mechanisms mediating the effects of renal-specific versus reflex-mediated, global sympathetic inhibition on renal hemodynamics and cardiac autonomic function are discussed. These differential mechanisms may impact the efficacy of current device-based approaches for hypertension therapy.

  13. Sympathetic crashing acute pulmonary edema.

    Science.gov (United States)

    Agrawal, Naman; Kumar, Akshay; Aggarwal, Praveen; Jamshed, Nayer

    2016-12-01

    Sympathetic crashing acute pulmonary edema (SCAPE) is the extreme end of the spectrum of acute pulmonary edema. It is important to understand this disease as it is relatively common in the emergency department (ED) and has better outcomes when managed appropriately. The patients have an abrupt redistribution of fluid in the lungs, and when treated promptly and effectively, these patients will rapidly recover. Noninvasive ventilation and intravenous nitrates are the mainstay of treatment which should be started within minutes of the patient's arrival to the ED. Use of morphine and intravenous loop diuretics, although popular, has poor scientific evidence.

  14. Sympathetic vasoconstrictor nerve function in alcoholic neuropathy

    DEFF Research Database (Denmark)

    Jensen, K; Andersen, K; Smith, T;

    1984-01-01

    The peripheral sympathetic vasomotor nerve function was investigated in 18 male chronic alcoholics admitted for intellectual impairment or polyneuropathy. By means of the local 133Xenon washout technique, the sympathetic veno-arteriolar axon-reflex was studied. This normally is responsible for a ...

  15. Sympathetic actions on the skeletal muscle.

    Science.gov (United States)

    Roatta, Silvestro; Farina, Dario

    2010-01-01

    The sympathetic nervous system (SNS) modulates several functions in skeletal muscle fibers, including metabolism, ionic transport across the membrane, and contractility. These actions, together with the sympathetic control of other organ systems, support intense motor activity. However, some SNS actions on skeletal muscles may not always be functionally advantageous. Implications for motor control and sport performance are discussed.

  16. Sympathetic rhythms and cardiovascular oscillations.

    Science.gov (United States)

    Montano, N; Cogliati, C; Dias da Silva, V J; Gnecchi-Ruscone, T; Malliani, A

    2001-07-20

    Spectral analysis of heart rate and arterial pressure variabilities is a powerful noninvasive tool, which is increasingly used to infer alterations of cardiovascular autonomic regulation in a variety of physiological and pathophysiological conditions, such as hypertension, myocardial infarction and congestive heart failure. A most important methodological issue to properly interpret the results obtained by the spectral analysis of cardiovascular variability signals is represented by the attribution of neurophysiological correlates to these spectral components. In this regard, recent applications of spectral techniques to the evaluation of the oscillatory properties of sympathetic efferent activity in animals, as well as in humans, offer a new approach to a better understanding of the relationship between cardiovascular oscillations and autonomic regulation.

  17. A model for magnetically coupled sympathetic eruptions

    CERN Document Server

    Torok, T; Titov, V S; Mikic, Z; Reeves, K K; Velli, M; Linker, J A; De Toma, G

    2011-01-01

    Sympathetic eruptions on the Sun have been observed for several decades, but the mechanisms by which one eruption can trigger another one remain poorly understood. We present a 3D MHD simulation that suggests two possible magnetic trigger mechanisms for sympathetic eruptions. We consider a configuration that contains two coronal flux ropes located within a pseudo-streamer and one rope located next to it. A sequence of eruptions is initiated by triggering the eruption of the flux rope next to the streamer. The expansion of the rope leads to two consecutive reconnection events, each of which triggers the eruption of a flux rope by removing a sufficient amount of overlying flux. The simulation qualitatively reproduces important aspects of the global sympathetic event on 2010 August 1 and provides a scenario for so-called twin filament eruptions. The suggested mechanisms are applicable also for sympathetic eruptions occurring in other magnetic configurations.

  18. Sympathetic nervous system and chronic renal failure.

    Science.gov (United States)

    Boero, R; Pignataro, A; Ferro, M; Quarello, F

    2001-01-01

    The aim of this work was to review evidence on the role of the sympathetic nervous system (SNS) in chronic renal failure (CRF). Three main points are discussed: 1) SNS and pathogenesis of arterial hypertension; 2) SNS and cardiovascular risk; 3) implication of SNS in arterial hypotension during hemodialysis. Several lines of evidence indicate the presence of a sympathetic hyperactivity in CRF, and its relationship with arterial hypertension. It is suggested that diseased kidneys send afferent nervous signals to central integrative sympathetic nuclei, thus contributing to the development and maintenance of arterial hypertension. The elimination of these impulses with nephrectomy could explain the concomitant reduction of blood pressure. Several experiments confirmed this hypothesis. Regarding SNS and cardiovascular risk, some data suggest that reduced heart rate variability identifies an increased risk for both all causes and sudden death, independently from other recognized risk factors. Symptomatic hypotension is a common problem during hemodialysis treatment, occurring in approximately 20-30% of all hemodialysis sessions and is accompanied by acute withdrawal of sympathetic activity, vasodilation and relative bradicardia. This reflex is thought to be evoked by vigorous contraction of a progressively empty left ventricle, activating cardiac mechanoceptors. This inhibits cardiovascular centers through vagal afferents, and overrides the stimulation by baroreceptor deactivation. Alternative explanations include cerebral ischemia and increased production of nitric oxide, which inhibit central sympathetic activity. It is hoped that therapies aimed at modulating sympathetic nerve activity in patients with CRF will ameliorate their prognosis and quality of life.

  19. Morphology of sympathetic chain in Saguinus niger

    Directory of Open Access Journals (Sweden)

    MARINA P.E. PINTO

    2013-03-01

    Full Text Available Saguinus niger popularly known as Sauim, is a Brazilian North primate. Sympathetic chain investigation would support traumatic and/or cancer diagnosis which are little described in wild animals. The aim of this study was to describe the morphology and distribution of sympathetic chain in order to supply knowledge for neurocomparative research. Three female young animals that came death by natural causes were investigated. Animals were fixed in formaldehyde 10% and dissected along the sympathetic chain in neck, thorax and abdomen. Cranial cervical ganglion was located at the level of carotid bifurcation, related to carotid internal artery. In neck basis the vagosympathetic trunk divides into the sympathetic trunk and the parasympathetic vagal nerve. Sympathetic trunk ran in dorsal position and originated the stellate ganglia, formed by the fusion of caudal cervical and first thoracic ganglia. Vagal trunk laid ventrally to heart and formed the cardiac plexus. In abdomen, on the right side, were found the celiac ganglion and cranial mesenteric ganglion; in the left side these ganglia were fusioned into the celiac-mesenteric ganglion displaced closely to the celiac artery. In both sides, the caudal mesenteric ganglion was located near to the caudal mesenteric artery.

  20. Sympathetic vasoconstriction takes an unexpected pannexin detour

    DEFF Research Database (Denmark)

    Schak Nielsen, Morten

    2015-01-01

    Sympathetic vasoconstriction plays an important role in the control of blood pressure and the distribution of blood flow. In this issue of Science Signaling, Billaud et al. show that sympathetic vasoconstriction occurs through a complex scheme involving the activation of large-pore pannexin 1 cha...... abrogates sympathetic vasoconstriction in skeletal muscle. Because pannexin 1 channels are inhibited by nitric oxide, they may function as a switch to turn off adrenergic signaling in skeletal muscle during exercise.......Sympathetic vasoconstriction plays an important role in the control of blood pressure and the distribution of blood flow. In this issue of Science Signaling, Billaud et al. show that sympathetic vasoconstriction occurs through a complex scheme involving the activation of large-pore pannexin 1...... channels and the subsequent release of adenosine triphosphate that promotes contraction in an autocrine and paracrine manner. This elaborate mechanism may function as a point of intercept for other signaling pathways-for example, in relation to the phenomenon "functional sympatholysis," in which exercise...

  1. [Effectiveness of sympathetic block using various technics].

    Science.gov (United States)

    Weissenberg, W

    1987-07-01

    Blocking of sympathetic conduction aims at permanent or temporary elimination of those pain pathways conducted by the sympathetic nervous system. In order to provide an objective evaluation of sufficient blocking effect, earlier inquiries referred to parameters such as: (1) observation of clinical signs such as Horner's syndrome, Guttman's sign, anhidrosis, extended venous filling; (2) difference in skin temperature of at least 1.5 degrees C between blocked and unblocked side; (3) increase in amplitude of the pulse wave; and (4) depression of the psychogalvanic reflex (PGR) on the blocked side (Fig. 1). In clinical practice, these control parameters are effective because they are time-saving, technically simple, and highly evidential. Further parameters for evaluating sympathetic blockade are examination of hydrosis by means of color indicators such as bromocresol and ninhydrin, oscillometry, and plethysmography. The effectiveness of sympathetic blockade after stellate ganglion and sympathetic trunk blocks has been verified by various authors. In a clinical study, 16 patients were divided into four groups in order to test the effectiveness of sympathetic blockade after spinal anesthesia with 3 ml 0.75% bupivacaine (group I) and 4 ml 0.75% bupivacaine (group II) and after peridural anesthesia with 15 ml 0.75% bupivacaine (group III) and 20 ml 0.75% bupivacaine (group IV) by means of temperature difference, response of pulse wave amplitude and PGR between blocked lower and unblocked upper extremity, and sensory levels of block. The patients were classified as ASA I and II; their ages varied from 20 to 63 years.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Sympathetic hyperactivity in patients with chronic kidney disease

    NARCIS (Netherlands)

    Neumann, N.

    2007-01-01

    Sympathetic hyperactivity in patients with chronic kidney disease Chronic kidney disease (CKD) is often characterized by the presence of sympathetic hyperactivity. This contributes to the pathogenesis of renal hypertension. It is also associated with cardiovascular (CV) morbidity and mortality indep

  3. Sympathetic reflex control of blood flow in human peripheral tissues

    DEFF Research Database (Denmark)

    Henriksen, O

    1991-01-01

    Sympathetic vasoconstrictor reflexes are essential for the maintenance of arterial blood pressure in upright position. It has been generally believed that supraspinal sympathetic vasoconstrictor reflexes elicited by changes in baroreceptor activity play an important role. Recent studies on human ...... to collision of normodromically and antidromically conducted impulses in efferent sympathetic vasoconstrictor fibers. The evidence obtained suggests that sympathetic vasoconstrictor reflexes to postural changes are complex and highly differentiated....

  4. Renal Sympathetic Denervation: Hibernation or Resurrection?

    Science.gov (United States)

    Papademetriou, Vasilios; Doumas, Michael; Tsioufis, Costas

    2016-01-01

    The most current versions of renal sympathetic denervation have been invented as minimally invasive approaches for the management of drug-resistant hypertension. The anatomy, physiology and pathophysiology of renal sympathetic innervation provide a strong background supporting an important role of the renal nerves in the regulation of blood pressure (BP) and volume. In addition, historical data with surgical sympathectomy and experimental data with surgical renal denervation indicate a beneficial effect on BP levels. Early clinical studies with transcatheter radiofrequency ablation demonstrated impressive BP reduction, accompanied by beneficial effects in target organ damage and other disease conditions characterized by sympathetic overactivity. However, the failure of the SYMPLICITY 3 trial to meet its primary efficacy end point raised a lot of concerns and put the field of renal denervation into hibernation. This review aims to translate basic research into clinical practice by presenting the anatomical and physiological basis for renal sympathetic denervation, critically discussing the past and present knowledge in this field, where we stand now, and also speculating about the future of the intervention and potential directions for research. © 2016 S. Karger AG, Basel.

  5. Trapping and Sympathetic Cooling of Boron Ions

    CERN Document Server

    Rugango, Rene; Shu, Gang; Brown, Kenneth R

    2016-01-01

    We demonstrate the trapping and sympathetic cooling of B$^{+}$ ions in a Coulomb crystal of laser-cooled Ca$^{+}$, We non-destructively confirm the presence of the both B$^+$ isotopes by resonant excitation of the secular motion. The B$^{+}$ ions are loaded by ablation of boron and the secular excitation spectrum also reveals features consistent with ions of the form B$_{n}^{+}$.

  6. Sympathetic reflex control of blood flow in human peripheral tissues

    DEFF Research Database (Denmark)

    Henriksen, O

    1991-01-01

    Sympathetic vasoconstrictor reflexes are essential for the maintenance of arterial blood pressure in upright position. It has been generally believed that supraspinal sympathetic vasoconstrictor reflexes elicited by changes in baroreceptor activity play an important role. Recent studies on human...... sympathetic vasoconstrictor reflexes are blocked. Blood flow has been measure by the local 133Xe-technique. The results indicate the presence of spinal as well as supraspinal sympathetic vasoconstrictor reflexes to human peripheral tissues. Especially is emphasized the presence of a local sympathetic veno...

  7. Sympathetic adaptations to one-legged training

    Science.gov (United States)

    Ray, C. A.

    1999-01-01

    The purpose of the present study was to determine the effect of leg exercise training on sympathetic nerve responses at rest and during dynamic exercise. Six men were trained by using high-intensity interval and prolonged continuous one-legged cycling 4 day/wk, 40 min/day, for 6 wk. Heart rate, mean arterial pressure (MAP), and muscle sympathetic nerve activity (MSNA; peroneal nerve) were measured during 3 min of upright dynamic one-legged knee extensions at 40 W before and after training. After training, peak oxygen uptake in the trained leg increased 19 +/- 2% (P leg exercise and indicates that attenuation of MSNA to exercise reported with forearm training also occurs with leg training.

  8. Sympathetic blocks for visceral cancer pain management

    DEFF Research Database (Denmark)

    Mercadante, Sebastiano; Klepstad, Pal; Kurita, Geana Paula

    2015-01-01

    The neurolytic blocks of sympathetic pathways, including celiac plexus block (CPB) and superior hypogastric plexus block (SHPB) , have been used for years. The aim of this review was to assess the evidence to support the performance of sympathetic blocks in cancer patients with abdominal visceral...... pain. Only comparison studies were included. All data from the eligible trials were analyzed using the GRADE system. Twenty-seven controlled studies were considered. CPB, regardless of the technique used, improved analgesia and/or decrease opioid consumption, and decreased opioid-induced adverse...... effects in comparison with a conventional analgesic treatment. In one study patients treated with superior hypogastric plexus block (SHPB) had a decrease in pain intensity and a less morphine consumption, while no statistical differences in adverse effects were found. The quality of these studies...

  9. [Sympathetically maintained pain (SMP): phentolamine test vs sympathetic nerve blockade. Comparison of two diagnostic methods].

    Science.gov (United States)

    Wehnert, Y; Müller, B; Larsen, B; Kohn, D

    2002-11-01

    The objective of our study was to clarify whether the phentolamine test is as suitable as sympathetic blockade in diagnosing cases of sympathetically maintained pain. The specificity and the sensitivity of both procedures were examined within a prospective and randomized study. Both a local sympathetic blockade and an intravenous phentolamine infusion were carried out in 29 patients with persistent pain in the area of the upper or lower extremities. A significant improvement was defined as reduction of pain of at least 50%. There were no complications in either test procedure. The phentolamine test registers sympathetically maintained pain well when it has a positive result (specificity of 83%). However, the phentolamine test shows only a low sensitivity of 69%. The phentolamine test, on the other hand, can be realized very easily and safely. Therefore, based on the results obtained, it is recommended that the phentolamine test be applied for primary diagnosis. In case of a negative result, further diagnosis should follow subsequently, for example with local sympathetic blockade.

  10. Increased sympathetic tone in forearm subcutaneous tissue in primary hypothyroidism

    DEFF Research Database (Denmark)

    Vagn Nielsen, H; Hasselström, K; Feldt-Rasmussen, U

    1987-01-01

    Sympathetic reflex regulation of subcutaneous blood flow (SBF) in the forearm was studied in eight patients with primary hypothyroidism. Diastolic arterial pressure was greater than or equal to 95 mmHg in five patients. SBF was determined by local clearance of Na99mTcO4. Sympathetic vasoconstrict......Sympathetic reflex regulation of subcutaneous blood flow (SBF) in the forearm was studied in eight patients with primary hypothyroidism. Diastolic arterial pressure was greater than or equal to 95 mmHg in five patients. SBF was determined by local clearance of Na99mTcO4. Sympathetic.......02)). In conclusion sympathetic vasoconstrictor activity in adipose tissue is markedly increased in primary hypothyroidism. Sympathetic tone and arterial pressure are reduced during treatment....

  11. The sympathetic nervous system alterations in human hypertension.

    Science.gov (United States)

    Grassi, Guido; Mark, Allyn; Esler, Murray

    2015-03-13

    Several articles have dealt with the importance and mechanisms of the sympathetic nervous system alterations in experimental animal models of hypertension. This review addresses the role of the sympathetic nervous system in the pathophysiology and therapy of human hypertension. We first discuss the strengths and limitations of various techniques for assessing the sympathetic nervous system in humans, with a focus on heart rate, plasma norepinephrine, microneurographic recording of sympathetic nerve traffic, and measurements of radiolabeled norepinephrine spillover. We then examine the evidence supporting the importance of neuroadrenergic factors as promoters and amplifiers of human hypertension. We expand on the role of the sympathetic nervous system in 2 increasingly common forms of secondary hypertension, namely hypertension associated with obesity and with renal disease. With this background, we examine interventions of sympathetic deactivation as a mode of antihypertensive treatment. Particular emphasis is given to the background and results of recent therapeutic approaches based on carotid baroreceptor stimulation and radiofrequency ablation of the renal nerves.

  12. Clinical utility of sympathetic blockade in cardiovascular disease management.

    Science.gov (United States)

    Park, Chan Soon; Lee, Hae-Young

    2017-04-01

    A dysregulated sympathetic nervous system is a major factor in the development and progression of cardiovascular disease; thus, understanding the mechanism and function of the sympathetic nervous system and appropriately regulating sympathetic activity to treat various cardiovascular diseases are crucial. Areas covered: This review focused on previous studies in managing hypertension, atrial fibrillation, coronary artery disease, heart failure, and perioperative management with sympathetic blockade. We reviewed both pharmacological and non-pharmacological management. Expert commentary: Chronic sympathetic nervous system activation is related to several cardiovascular diseases mediated by various pathways. Advancement in measuring sympathetic activity makes visualizing noninvasively and evaluating the activation level even in single fibers possible. Evidence suggests that sympathetic blockade still has a role in managing hypertension and controlling the heart rate in atrial fibrillation. For ischemic heart disease, beta-adrenergic receptor antagonists have been considered a milestone drug to control symptoms and prevent long-term adverse effects, although its clinical implication has become less potent in the era of successful revascularization. Owing to pathologic involvement of sympathetic nervous system activation in heart failure progression, sympathetic blockade has proved its value in improving the clinical course of patients with heart failure.

  13. Carotid baroreceptor-muscle sympathetic relation in humans.

    Science.gov (United States)

    Rea, R F; Eckberg, D L

    1987-12-01

    The purpose of this study was to define the relation between carotid distending pressure and muscle sympathetic activity in humans. Carotid baroreceptors of nine healthy subjects were compressed or stretched for 5 s with graded neck pressure or suction (+40 to -65 mmHg), and muscle sympathetic nerve activity was recorded. The results delineate several features of human baroreflex function. First, the carotid-muscle sympathetic relation is well described by an inverse sigmoid function. Second, a linear relation exists between carotid distending pressure and sympathetic outflow over a range of approximately 25 mmHg. Third, sympathetic responses to changes of carotid pressures are asymmetric; increases of sympathetic activity during carotid compression are much greater than reductions of sympathetic activity during carotid stretch. Fourth, at rest, normal subjects operate near the threshold level for sympathetic excitation. Thus the carotid-muscle sympathetic baroreflex is poised to oppose reductions more effectively than elevations of arterial pressure, and the range of pressures over which the reflex is active is wider than thought hitherto.

  14. Gender differences in sympathetic nervous system regulation.

    Science.gov (United States)

    Hinojosa-Laborde, C; Chapa, I; Lange, D; Haywood, J R

    1999-02-01

    1. Females are protected against the development of hypertension. The purpose of the current review is to present the evidence for gender differences in the regulation of the sympatho-adrenal nervous system and to determine if these differences support the hypothesis that, in females, the regulation of the sympathetic nervous system (SNS) is altered such that sympatho-adrenal activation is attenuated or sympatho-adrenal inhibition is augmented. 2. The central control of sympatho-adrenal function is different in females and responses vary during the oestral and menstrual cycles. Pathways regulating the SNS appear to be less sensitive to excitatory stimuli and more sensitive to inhibitory stimuli in females compared with males. 3. Gender differences in arterial baroreflex sensitivity suggest that females may have a greater baroreflex sensitivity, such that alterations in blood pressure are more efficiently controlled than in males. Cardiopulmonary reflex inhibition of sympathetic nerve activity is greater in females, possibly resulting in a greater renal excretory function. 4. An attenuated sensitivity to adrenergic nerve stimulation, but not to noradrenaline (NA), suggests that gender differences in noradrenergic neurotransmission may protect females against sympathetic hyperactivity. Gender differences in the regulation of NA release via presynaptic alpha 2-adrenoceptors, the vasoconstrictor response to the cotransmitter neuropeptide Y and the clearance of catecholamines are consistent with this hypothesis. 5. Similarly, attenuated stress-induced increases in plasma catecholamines in women suggest that females are less sensitive and/or less responsive to adrenal medullary activation. This is supported by findings of gender differences in adrenal medullary catecholamine content, release and degradation. 6. We conclude that there is strong evidence that supports the hypothesis that, in females, the regulation of the SNS is altered such that sympatho

  15. Literary ethnographic writing as sympathetic experiment

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Line

    perhaps only implicitly) of research. But we have no direct access to the subjective world of others and can only inhabit their point of view by way of imagination. Writing literary ethnographic text is one way, I will argue, of experimenting with such sympathetic imagination. By putting together observed...... not propose a radical turn towards literary writing in anthropology. Rather, I suggest that we include the courage of imagination inherent to literature and the accompanying doubt into our existing endeavor, if not for anything else, then for the sake of a more human relationship with our so-called informants....

  16. Interaction of Xylamine with peripheral sympathetic neurons

    Energy Technology Data Exchange (ETDEWEB)

    Ransom, R.W.; Waggaman, L.A.; Cho, A.K.

    1985-09-30

    Xylamine (XYL) administered to intact rats caused a 70-80% reduction in norepinephrine (NE) uptake by the vas deferens but had little or no effect on NE content in that tissue. The vas deferens accumulates /sup 3/H-XYL in vitro by a desmethylimipramine (DMI)-sensitive mechanism. Vasa deferentia from 6-hydroxydopamine (60HDA) pretreated animals exhibited a 80% reduction in both NE content and XYL uptake activity. These results indicate that XYL is taken up by sympathetic nerve terminals and can reduce NE uptake activity without depleting terminals of neurotransmitter. 9 references, 4 tables.

  17. Cervical sympathetic chain schwannoma: A case report

    Directory of Open Access Journals (Sweden)

    Inès Nacef

    2014-07-01

    Full Text Available Nerve tumors arising from the sympathetic chain are uncommon slow-growing tumors and represent a diagnosis challenge. Their malignant degeneration is rare. Definitive pre-operative diagnosis may be difficult as investigations are not usually helpful. We report the case of a 23-year old woman who presented with an asymptomatic solitary left cervical swelling. She was evaluated with sonography and computed tomography. Complete surgical excision of the lesion was carried out and histologic examination revealed a schwannoma. Post-operatively, the patient showed clinical findings of Horner’s syndrome. Pathologic and radiological evaluation, differential diagnosis of this neoplasm and its management are discussed.

  18. The oestrogenized rat myometrium inhibits organotypic sympathetic reinnervation.

    Science.gov (United States)

    Brauer, M M; Chávez-Genaro, R; Richeri, A; Viettro, L; Frias, A I; Burnstock, G; Cowen, T

    2002-10-31

    Chronic administration of oestrogen to rats during the infantile/prepubertal period provokes, at 28 days of age, complete loss of noradrenaline-labelled intrauterine sympathetic nerves. It is not known whether oestrogen inhibits the growth or causes the degeneration of developing uterine sympathetic nerves, or whether the uterus recovers its innervation following cessation of infantile/prepubertal oestrogen treatment. In the present study, we analysed the time-course of the effects of oestrogen on the development of uterine sympathetic nerves in the rat, using histochemical methods. In addition, the pattern of sympathetic reinnervation of the uterus of intact and ovariectomised females was assessed 3 and 6 months after cessation of chronic oestrogen treatment. The ability of sympathetic nerves to reinnervate the oestrogenized uterine tissue was assessed in intraocular transplants of uterine myometrium into ovariectomised host rats. Early exposure to oestrogen did not inhibit the approach of sympathetic nerves to the uterus, but prevented the normal growth and maturation of intrauterine sympathetic fibres and abolished the innervation that reached the organ before initiation of treatment. Three or six months following cessation of oestrogen treatment, most of the sympathetic nerves were restricted to the mesometrium and mesometrial entrance, whereas intrauterine innervation remained persistently depressed as a consequence of a sustained oestrous-like state provoked by ovarian dysfunction (polycystic ovary). An organotypic regrowth of uterine sympathetic nerves was observed in ovariectomised infantile/prepubertal oestrogen-treated animals. After 5 weeks in oculo, the innervation of oestrogenized myometrial transplants was reduced by 50%, and substantial changes in the pattern of reinnervation were observed. In control transplants, 86% of the nerves were terminal varicose myometrial and perivascular nerve fibres, whereas 14% were preterminal nerve bundles. In

  19. The Human Sympathetic Nervous System Response to Spaceflight

    Science.gov (United States)

    Ertl, Andrew C.; Diedrich, Andre; Paranjape, Sachin Y.; Biaggioni, Italo; Robertson, Rose Marie; Lane, Lynda D.; Shiavi, Richard; Robertson, David

    2003-01-01

    The sympathetic nervous system is an important part of the autonomic (or automatic) nervous system. When an individual stands up, the sympathetic nervous system speeds the heart and constricts blood vessels to prevent a drop in blood pressure. A significant number of astronauts experience a drop in blood pressure when standing for prolonged periods after they return from spaceflight. Difficulty maintaining blood pressure with standing is also a daily problem for many patients. Indirect evidence available before the Neurolab mission suggested the problem in astronauts while in space might be due partially to reduced sympathetic nervous system activity. The purpose of this experiment was to identify whether sympathetic activity was reduced during spaceflight. Sympathetic nervous system activity can be determined in part by measuring heart rate, nerve activity going to blood vessels, and the release of the hormone norepinephrine into the blood. Norepinephrine is a neurotransmitter discharged from active sympathetic nerve terminals, so its rate of release can serve as a marker of sympathetic nervous system action. In addition to standard cardiovascular measurements (heart rate, blood pressure), we determined sympathetic nerve activity as well as norepinephrine release and clearance on four crewmembers on the Neurolab mission. Contrary to our expectation, the results demonstrated that the astronauts had mildly elevated resting sympathetic nervous system activity in space. Sympathetic nervous system responses to stresses that simulated the cardiovascular effects of standing (lower body negative pressure) were brisk both during and after spaceflight. We concluded that, in the astronauts tested, the activity and response of the sympathetic nervous system to cardiovascular stresses appeared intact and mildly elevated both during and after spaceflight. These changes returned to normal within a few days.

  20. Chain Reconnections observed in Sympathetic Eruptions

    CERN Document Server

    Joshi, Navin Chandra; Magara, Tetsuya; Guo, Yang; Aulanier, Guillaume

    2016-01-01

    The nature of various plausible causal links between sympathetic events is still a controversial issue. In this work, we present multi-wavelength observations of sympathetic eruptions, associated flares and coronal mass ejections (CMEs) occurring on 2013 November 17 in two close-by active regions. Two filaments i.e., F1 and F2 are observed in between the active regions. Successive magnetic reconnections, caused by different reasons (flux cancellation, shear and expansion) have been identified during the whole event. The first reconnection occurred during the first eruption via flux cancellation between the sheared arcades overlying filament F2, creating a flux rope and leading to the first double ribbon solar flare. During this phase we observed the eruption of overlaying arcades and coronal loops, which leads to the first CME. The second reconnection is believed to occur between the expanding flux rope of F2 and the overlying arcades of the filament F1. We suggest that this reconnection destabilized the equi...

  1. Sympathetic adaptations to one-legged training

    Science.gov (United States)

    Ray, C. A.

    1999-01-01

    The purpose of the present study was to determine the effect of leg exercise training on sympathetic nerve responses at rest and during dynamic exercise. Six men were trained by using high-intensity interval and prolonged continuous one-legged cycling 4 day/wk, 40 min/day, for 6 wk. Heart rate, mean arterial pressure (MAP), and muscle sympathetic nerve activity (MSNA; peroneal nerve) were measured during 3 min of upright dynamic one-legged knee extensions at 40 W before and after training. After training, peak oxygen uptake in the trained leg increased 19 +/- 2% (P training (108 +/- 5 to 96 +/- 5 beats/min and 132 +/- 8 to 119 +/- 4 mmHg, respectively, during the third minute of exercise; P training. However, MSNA was significantly less during the third minute of exercise after training (32 +/- 2 to 22 +/- 3 bursts/min; P training effect on MSNA remained when MSNA was expressed as bursts per 100 heartbeats. Responses to exercise in five untrained control subjects were not different at 0 and 6 wk. These results demonstrate that exercise training prolongs the decrease in MSNA during upright leg exercise and indicates that attenuation of MSNA to exercise reported with forearm training also occurs with leg training.

  2. Sympathetic hyperactivity - A hidden enemy in chronic kidney disease patients

    NARCIS (Netherlands)

    Blankestijn, Peter J.

    2007-01-01

    Chronic kidney disease is often characterized by the presence of sympathetic hyperactivity. The aim of this brief review is to summarize available knowledge on the pathogenesis of sympathetic hyperactivity and to discuss its clinical relevance, the consequences of this knowledge for the choice of tr

  3. Sympathetic hyperactivity - A hidden enemy in chronic kidney disease patients

    NARCIS (Netherlands)

    Blankestijn, Peter J.

    2007-01-01

    Chronic kidney disease is often characterized by the presence of sympathetic hyperactivity. The aim of this brief review is to summarize available knowledge on the pathogenesis of sympathetic hyperactivity and to discuss its clinical relevance, the consequences of this knowledge for the choice of tr

  4. Lower limb pain in sympathetic-sensory coupling

    Institute of Scientific and Technical Information of China (English)

    Hongjun Yang; Kairun Peng; Sanjue Hu; Li Xuan

    2011-01-01

    Previous studies have shown that sympathetic nerves are related to certain types of pain, and this phenomenon is referred to as sympathetic-sensory coupling. Chronic pain resulting from nerve injury can be exacerbated by sympathetic stimulation or relieved by sympathetic inhibition. In the present study, the correlation between pain and sympathetic nerves was analyzed in patients with severe pain in lower limbs, as well as in a chronically compressed dorsal root ganglion (CCD) rat model (model of low back pain and sciatica). Patients with severe pain in the lower limbs underwent chemical lumbar sympathectomy (CLS), and the analgesic effects of CLS were compared with painkillers. Results demonstrated significantly relieved lower limb pain following CLS, and the analgesic effects of CLS were superior to those seen with painkillers. In the CCD rat model, dorsal root ganglion neuronal activity significantly increased as a result of electrical stimulation to the sympathetic nerves. These results suggest that sympathetic nerves are closely associated with pain and sympathetic-sensory coupling is likely in lower limb pain in both patients and rat models of CCD.

  5. Renal sympathetic denervation: MDCT evaluation of the renal arteries.

    LENUS (Irish Health Repository)

    Hutchinson, Barry D

    2013-08-01

    Percutaneous transluminal renal sympathetic denervation is a new treatment of refractory systemic hypertension. The purpose of this study was to assess the clinical utility of MDCT to evaluate the anatomic configuration of the renal arteries in the context of renal sympathetic denervation.

  6. Reflex sympathetic dystrophy: Early treatment and psychological aspects

    NARCIS (Netherlands)

    Geertzen, J.H.B.; De Bruijn, H.; De Bruijn-Kofman, A.T.; Arendzen, J.H.

    1994-01-01

    We report the results of two prospective studies of early treatment and psychological aspects in a series of 26 patients with sympathetic reflex dystrophy of the hand in which treatment was started within 3 months after diagnosis. Ismelin blocks is an often used therapy in sympathetic reflex dystrop

  7. Differential Toxicities of Intraneurally Injected Mercuric Chloride for Sympathetic and Somatic Motor Fibers: An Ultrastructural Study

    Directory of Open Access Journals (Sweden)

    Shih-Jung Cheng

    2011-02-01

    Conclusion: This study demonstrated an undue susceptibility of sympathetic fibers to mercury intoxication. The mechanisms that underlie the selective reaction of sympathetic fibers to mercury warrant further investigation.

  8. Dynamic Radiographic Analysis of Sympathetic Cervical Spondylosis Instability

    Institute of Scientific and Technical Information of China (English)

    Jun Qian; Ye Tian; Gui-xing Qiu; Jian-hua Hu

    2009-01-01

    Objective To investigate the correlation between subaxial cervical spine instability and cervical spondylotic sympathetic symptoms as well as the difference of cervical spondylotic subaxial instability between male and female patients. Methods We analyzed retrospectively 318 surgical cases of cervical spondylosis treated at Department of Orthopedic Surgery of Peking Union Medical College Hospital between July 2003 and December 2007. All cases were divided into group A without sympathetic symptoms (n=284) and group B with sympathetic symptoms (n=34). Angular and horizontal translation values between two adjacent vertebral bodies from C2 to C7 were measured separately on hyperflexion and hyperextension lateral cervical spine radiographs. Fisher's exact test was used to evaluate the correlation between subaxial cervical instability and sympathetic symptoms. Intragroup correlation between patient gender and subaxial cervical instability was also evaluated. Results Subaxial instability incidences in groups A and B were 21.8% (62/284) and 55.9% (19/34), respectively. Statistical analysis indicated a definite correlation between subaxial cervical instability and sympathetic symptoms (P=0.000). Among patients without sympathetic symptoms, subaxial instability incidences were 21.4% (37/173) in males and 22.5% (25/111) in females, respectively (P=0.883). While among patients with sympathetic symptoms, subaxial instability incidences were 27.3% (3/11) in males and 69.6% (16/23) in females, respectively, indicating significant difference (P=0.030). Subaxial instability was most commonly seen at C4-C5 intervertebral space in sympathetic cervical spondylosis patients. Conclusions High correlation exists between subaxial cervical spine instability and cervical spondylotic sympathetic symptoms, especially in female patients. Hyperextension and hyperflexion radiographs of cervical spine are important to assess sympathetic cervical spondylotic subaxial instability.

  9. Literary ethnographic writing as sympathetic experiment

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Line

    perhaps only implicitly) of research. But we have no direct access to the subjective world of others and can only inhabit their point of view by way of imagination. Writing literary ethnographic text is one way, I will argue, of experimenting with such sympathetic imagination. By putting together observed...... utterances, acts and hesitations in an overtly fictive experiential whole (fictive because I can only guess it), I not only try out a qualified guess on what takes place in another person; I also make my own assumptions about the existence of such a whole explicit and hence material for reflection. I do...... not propose a radical turn towards literary writing in anthropology. Rather, I suggest that we include the courage of imagination inherent to literature and the accompanying doubt into our existing endeavor, if not for anything else, then for the sake of a more human relationship with our so-called informants....

  10. Sympathetic cooling of nanospheres with cold atoms

    Science.gov (United States)

    Montoya, Cris; Witherspoon, Apryl; Ranjit, Gambhir; Casey, Kirsten; Kitching, John; Geraci, Andrew

    2016-05-01

    Ground state cooling of mesoscopic mechanical structures could enable new hybrid quantum systems where mechanical oscillators act as transducers. Such systems could provide coupling between photons, spins and charges via phonons. It has recently been shown theoretically that optically trapped dielectric nanospheres could reach the ground state via sympathetic cooling with trapped cold atoms. This technique can be beneficial in cases where cryogenic operation of the oscillator is not practical. We describe experimental advances towards coupling an optically levitated dielectric nanosphere to a gas of cold Rubidium atoms. The sphere and the cold atoms are in separate vacuum chambers and are coupled using a one-dimensional optical lattice. This work is partially supported by NSF, Grant Nos. PHY-1205994,PHY-1506431.

  11. Do sympathetic nerves release noradrenaline in "quanta"?

    Science.gov (United States)

    Stjärne, L

    2000-07-01

    The discovery of excitatory junction potentials (EJPs) in guinea-pig vas deferens by Burnstock and Holman (1960) showed for the first time that a sympathetic transmitter, now known to be ATP, is secreted in "quanta". As it was assumed at the time that EJPS are triggered by noradrenaline, this discovery led to attempts to use the fractional overflow of noradrenaline from sympathetically innervated tissues to assess, indirectly, the number of noradrenaline molecules in the average "quantum". The basic finding was that each pulse released 1/50000 of the tissue content of noradrenaline, when reuptake was blocked and prejunctional alpha(2)-adrenoceptors were intact. This provided the constraints, two extreme alternatives: (i) each pulse releases 0.2-3% of the content of a vesicle from all varicosities, or (ii) each pulse releases the whole content of a vesicle from 0.2 to 3% of the varicosities. New techniques have made it possible to address questions about the release probability in individual sites, or the "quantal" size, more directly. Results by optical (comparison of the labelling of SV2 and synaptotagmin, proteins in the membrane of transmitter vesicles), electrophysiological (excitatory junction currents, EJCs, at single visualized varicosities) and amperometric (the noradrenaline oxidation current at a carbon fibre electrode) methods reveal that transmitter exocytosis in varicosities is intermittent. The EJC and noradrenaline oxidation current responses (in rat arteries) to a train of single pulses were observed to be similar in intermittency and amplitude fluctuation. This suggests that they are caused by exocytosis of single or very few "quanta" of ATP and noradrenaline, respectively, equal to the contents of single vesicles, from a small population of release sites. These findings support, but do not conclusively prove the validity of the "intermittent" model of noradrenaline release. The question if noradrenaline is always secreted in packets of preset size

  12. CHAIN RECONNECTIONS OBSERVED IN SYMPATHETIC ERUPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Navin Chandra; Magara, Tetsuya [School of Space Research, Kyung Hee University, Yongin, Gyeonggi-Do, 446-701 (Korea, Republic of); Schmieder, Brigitte; Aulanier, Guillaume [LESIA, Observatoire de Paris, PSL Research University, CNRS Sarbonne Universités, Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Jansson, F-92195 Meudon (France); Guo, Yang, E-mail: navin@khu.ac.kr, E-mail: njoshi98@gmail.com [School of Astronomy and Space Science, Nanjing University, 210023 Nanjing (China)

    2016-04-01

    The nature of various plausible causal links between sympathetic events is still a controversial issue. In this work, we present multiwavelength observations of sympathetic eruptions, associated flares, and coronal mass ejections (CMEs) occurring on 2013 November 17 in two close active regions. Two filaments, i.e., F1 and F2, are observed in between the active regions. Successive magnetic reconnections, caused for different reasons (flux cancellation, shear, and expansion) have been identified during the whole event. The first reconnection occurred during the first eruption via flux cancellation between the sheared arcades overlying filament F2, creating a flux rope and leading to the first double-ribbon solar flare. During this phase, we observed the eruption of overlying arcades and coronal loops, which leads to the first CME. The second reconnection is believed to occur between the expanding flux rope of F2 and the overlying arcades of filament F1. We suggest that this reconnection destabilized the equilibrium of filament F1, which further facilitated its eruption. The third stage of reconnection occurred in the wake of the erupting filament F1 between the legs of the overlying arcades. This may create a flux rope and the second double-ribbon flare and a second CME. The fourth reconnection was between the expanding arcades of the erupting filament F1 and the nearby ambient field, which produced the bi-directional plasma flows both upward and downward. Observations and a nonlinear force-free field extrapolation confirm the possibility of reconnection and the causal link between the magnetic systems.

  13. Glutamate and GABA in vestibulo-sympathetic pathway neurons

    Directory of Open Access Journals (Sweden)

    Gay R Holstein

    2016-02-01

    Full Text Available The vestibulo-sympathetic reflex actively modulates blood pressure during changes in posture. This reflex allows humans to stand up and quadrupeds to rear or climb without a precipitous decline in cerebral perfusion. The vestibulo-sympathetic reflex pathway conveys signals from the vestibular end organs to the caudal vestibular nuclei. These cells, in turn, project to pre-sympathetic neurons in the rostral and caudal ventrolateral medulla (RVLM and CVLM, respectively. The present study assessed glutamate- and GABA-related immunofluorescence associated with central vestibular neurons of the vestibulo-sympathetic reflex pathway in rats. Retrograde FluoroGold tract tracing was used to label vestibular neurons with projections to RVLM or CVLM, and sinusoidal galvanic vestibular stimulation was employed to activate these pathways. Central vestibular neurons of the vestibulo-sympathetic reflex were identified by co-localization of FluoroGold and cFos protein, which accumulates in some vestibular neurons following galvanic stimulation. Triple-label immunofluorescence was used to co-localize glutamate- or GABA- labeling in the identified vestibulo-sympathetic reflex pathway neurons. Most activated projection neurons displayed intense glutamate immunofluorescence, suggestive of glutamatergic neurotransmission. To support this, anterograde tracer was injected into the caudal vestibular nuclei. Vestibular axons and terminals in RVLM and CVLM co-localized the anterograde tracer and vesicular glutamate transporter-2 signals. Other retrogradely-labeled cFos-positive neurons displayed intense GABA immunofluorescence. Vestibulo-sympathetic reflex pathway neurons of both phenotypes were present in the caudal medial and spinal vestibular nuclei, and projected to both RVLM and CVLM. As a group, however, triple-labeled vestibular cells with intense glutamate immunofluorescence were located more rostrally in the vestibular nuclei than the GABAergic neurons. Only the

  14. Sympathetic skin response test in essential hypertensive patients

    Directory of Open Access Journals (Sweden)

    Ann Abdel Kader

    2012-01-01

    Conclusion Although SSR has a low diagnostic value in patients with essential hypertension, it might be a good diagnostic test particularly in the presence of signs and symptoms of sympathetic overactivity such as tachycardia and sweating.

  15. Obesity-Related Metabolic Syndrome: Mechanisms of Sympathetic Overactivity

    Directory of Open Access Journals (Sweden)

    Maria Paola Canale

    2013-01-01

    Full Text Available The prevalence of the metabolic syndrome has increased worldwide over the past few years. Sympathetic nervous system overactivity is a key mechanism leading to hypertension in patients with the metabolic syndrome. Sympathetic activation can be triggered by reflex mechanisms as arterial baroreceptor impairment, by metabolic factors as insulin resistance, and by dysregulated adipokine production and secretion from visceral fat with a mainly permissive role of leptin and antagonist role of adiponectin. Chronic sympathetic nervous system overactivity contributes to a further decline of insulin sensitivity and creates a vicious circle that may contribute to the development of hypertension and of the metabolic syndrome and favor cardiovascular and kidney disease. Selective renal denervation is an emerging area of interest in the clinical management of obesity-related hypertension. This review focuses on current understanding of some mechanisms through which sympathetic overactivity may be interlaced to the metabolic syndrome, with particular regard to the role of insulin resistance and of some adipokines.

  16. Adipose afferent reflex: sympathetic activation and obesity hypertension.

    Science.gov (United States)

    Xiong, X-Q; Chen, W-W; Zhu, G-Q

    2014-03-01

    Excessive sympathetic activity contributes to the pathogenesis of hypertension and the progression of the related organ damage. Adipose afferent reflex (AAR) is a sympatho-excitatory reflex that the afferent activity from white adipose tissue (WAT) increases sympathetic outflow and blood pressure. Hypothalamic paraventricular nucleus (PVN or PVH) is one of the central sites in the control of the AAR, and ionotropic glutamate receptors in the nucleus mediate the AAR. The AAR is enhanced in obesity and obesity hypertension. Enhanced WAT afferent activity and AAR contribute to the excessive sympathetic activation and hypertension in obesity. Blockage of the AAR attenuates the excessive sympathetic activity and hypertension. Leptin may be one of sensors in the WAT for the AAR, and is involved in the enhanced AAR in obesity and hypertension. This review focuses on the neuroanatomical basis and physiological functions of the AAR, and the important role of the enhanced AAR in the pathogenesis of obesity hypertension.

  17. The clinical value of cardiac sympathetic imaging in heart failure

    DEFF Research Database (Denmark)

    Christensen, Thomas Emil; Kjaer, Andreas; Hasbak, Philip

    2014-01-01

    The autonomic nervous system plays an important role in the pathology of heart failure. The single-photon emission computed tomography tracer iodine-123-metaiodobenzylguanidine ((123) I-MIBG) can be used to investigate the activity of the predominant neurotransmitter of the sympathetic nervous...... system, norepinephrine. Also, positron emission tomography tracers are being developed for the same purpose. With (123) I-MIBG as a starting point, this brief review introduces the modalities used for cardiac sympathetic imaging....

  18. Remodelling sympathetic innervation in rat pancreatic islets ontogeny

    Directory of Open Access Journals (Sweden)

    Hiriart Marcia

    2009-06-01

    Full Text Available Abstract Background Pancreatic islets are not fully developed at birth and it is not clear how they are vascularised and innervated. Nerve Growth Factor (NGF is required to guide sympathetic neurons that innervate peripheral organs and also in cardiovascular system and ovary angiogenesis. Pancreatic beta cells of a transgenic mouse that over-expressed NGF in attracts sympathetic hyper-innervation towards them. Moreover, we have previously demonstrated that adult beta cells synthesize and secrete NGF; however, we do not know how is NGF secreted during development, nor if it might be trophic for sympathetic innervation and survival in the pancreas. We analyzed sympathetic innervation and vasculature development in rat pancreatic islets at different developmental stages; foetal (F19, early postnatal (P1, weaning period (P20 and adults. We temporarily correlated these events to NGF secretion by islet cells. Results Sympathetic fibres reached pancreatic islets in the early postnatal period, apparently following blood vessels. The maximal number of sympathetic fibres (TH immunopositive in the periphery of the islets was observed at P20, and then fibres entered the islets and reached the core where beta cells are mainly located. The number of fibres decreased from that stage to adulthood. At all stages studied, islet cells secreted NGF and also expressed the high affinity receptor TrkA. Foetal and neonatal isolated islet cells secreted more NGF than adults. TrkA receptors were expressed at all stages in pancreatic sympathetic fibres and blood vessels. These last structures were NGF–immunoreactive only at early stages (foetal and P0. Conclusion The results suggest that NGF signalling play an important role in the guidance of blood vessels and sympathetic fibres toward the islets during foetal and neonatal stages and could also preserve innervation at later stages of life.

  19. Assessment of cardiac sympathetic nerve integrity with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Raffel, David M. E-mail: raffel@umich.edu; Wieland, Donald M

    2001-07-01

    The autonomic nervous system plays a critical role in the regulation of cardiac function. Abnormalities of cardiac innervation have been implicated in the pathophysiology of many heart diseases, including sudden cardiac death and congestive heart failure. In an effort to provide clinicians with the ability to regionally map cardiac innervation, several radiotracers for imaging cardiac sympathetic neurons have been developed. This paper reviews the development of neuronal imaging agents and discusses their emerging role in the noninvasive assessment of cardiac sympathetic innervation.

  20. Schwanomma From Cervical Sympathetic Chain Ganglion - A Rare Presentation.

    Science.gov (United States)

    Asma, A Affee; Kannah, E

    2015-10-01

    Schwanommas arising from cervical sympathetic chain are tumours that are rare in occurrence. These lesions are usually difficult to differentiate from a vagal schwanomma and a carotid body tumour during the initial workup. In this report, a rarely seen huge cervical sympathetic chain schwanomma case with partial Horner's syndrome is being presented in detail, which to our known knowledge, is one of the few cases reported in literature.

  1. Cardiac fibroblasts regulate sympathetic nerve sprouting and neurocardiac synapse stability.

    Directory of Open Access Journals (Sweden)

    Céline Mias

    Full Text Available Sympathetic nervous system (SNS plays a key role in cardiac homeostasis and its deregulations always associate with bad clinical outcomes. To date, little is known about molecular mechanisms regulating cardiac sympathetic innervation. The aim of the study was to determine the role of fibroblasts in heart sympathetic innervation. RT-qPCR and western-blots analysis performed in cardiomyocytes and fibroblasts isolated from healthy adult rat hearts revealed that Pro-Nerve growth factor (NGF and pro-differentiating mature NGF were the most abundant neurotrophins expressed in cardiac fibroblasts while barely detectable in cardiomyocytes. When cultured with cardiac fibroblasts or fibroblast-conditioned medium, PC12 cells differentiated into/sympathetic-like neurons expressing axonal marker Tau-1 at neurites in contact with cardiomyocytes. This was prevented by anti-NGF blocking antibodies suggesting a paracrine action of NGF secreted by fibroblasts. When co-cultured with cardiomyocytes to mimic neurocardiac synapse, differentiated PC12 cells exhibited enhanced norepinephrine secretion as quantified by HPLC compared to PC12 cultured alone while co-culture with fibroblasts had no effect. However, when supplemented to PC12-cardiomyocytes co-culture, fibroblasts allowed long-term survival of the neurocardiac synapse. Activated fibroblasts (myofibroblasts isolated from myocardial infarction rat hearts exhibited significantly higher mature NGF expression than normal fibroblasts and also promoted PC12 cells differentiation. Within the ischemic area lacking cardiomyocytes and neurocardiac synapses, tyrosine hydroxylase immunoreactivity was increased and associated with local anarchical and immature sympathetic hyperinnervation but tissue norepinephrine content was similar to that of normal cardiac tissue, suggesting depressed sympathetic function. Collectively, these findings demonstrate for the first time that fibroblasts are essential for the setting of

  2. Cardiac Fibroblasts Regulate Sympathetic Nerve Sprouting and Neurocardiac Synapse Stability

    Science.gov (United States)

    Mias, Céline; Coatrieux, Christelle; Denis, Colette; Genet, Gaël; Seguelas, Marie-Hélène; Laplace, Nathalie; Rouzaud-Laborde, Charlotte; Calise, Denis; Parini, Angelo; Cussac, Daniel; Pathak, Atul; Sénard, Jean-Michel; Galés, Céline

    2013-01-01

    Sympathetic nervous system (SNS) plays a key role in cardiac homeostasis and its deregulations always associate with bad clinical outcomes. To date, little is known about molecular mechanisms regulating cardiac sympathetic innervation. The aim of the study was to determine the role of fibroblasts in heart sympathetic innervation. RT-qPCR and western-blots analysis performed in cardiomyocytes and fibroblasts isolated from healthy adult rat hearts revealed that Pro-Nerve growth factor (NGF) and pro-differentiating mature NGF were the most abundant neurotrophins expressed in cardiac fibroblasts while barely detectable in cardiomyocytes. When cultured with cardiac fibroblasts or fibroblast-conditioned medium, PC12 cells differentiated into/sympathetic-like neurons expressing axonal marker Tau-1 at neurites in contact with cardiomyocytes. This was prevented by anti-NGF blocking antibodies suggesting a paracrine action of NGF secreted by fibroblasts. When co-cultured with cardiomyocytes to mimic neurocardiac synapse, differentiated PC12 cells exhibited enhanced norepinephrine secretion as quantified by HPLC compared to PC12 cultured alone while co-culture with fibroblasts had no effect. However, when supplemented to PC12-cardiomyocytes co-culture, fibroblasts allowed long-term survival of the neurocardiac synapse. Activated fibroblasts (myofibroblasts) isolated from myocardial infarction rat hearts exhibited significantly higher mature NGF expression than normal fibroblasts and also promoted PC12 cells differentiation. Within the ischemic area lacking cardiomyocytes and neurocardiac synapses, tyrosine hydroxylase immunoreactivity was increased and associated with local anarchical and immature sympathetic hyperinnervation but tissue norepinephrine content was similar to that of normal cardiac tissue, suggesting depressed sympathetic function. Collectively, these findings demonstrate for the first time that fibroblasts are essential for the setting of cardiac sympathetic

  3. Sympathetic Nervous System, Hypertension, Obesity and Metabolic Syndrome.

    Science.gov (United States)

    Seravalle, Gino; Grassi, Guido

    2016-09-01

    Experimental and clinical studies have clearly shown the role of the sympathetic nervous system in the pathophysiology of several cardiovascular and non-cardiovascular diseases. This short review will be aimed at focusing and discussing the new information collected on two specific clinical conditions such as obesity and metabolic syndrome. The paper will briefly describe the four main mechanisms that represent the common link between these two pathophysiological conditions and that through the sympathetic nervous system contribute to increase the cardiovascular risk.

  4. Sympathetic radiofrequency neurolysis for unilateral lumbar hyperhidrosis: a case report.

    Science.gov (United States)

    Aşik, Züleyha Soytürk; Orbey, Başak Ceyda; Aşik, Ibrahim

    2008-07-01

    Patients with hyperhidrosis suffer from physical, social and mental discomfort which often cannot be treated sufficiently using conservative measures. A new percutaneous approach to sympathectomy using radiofrequency denervation has seemed to offer longer duration of action and less incidence of post sympathetic neuralgia. This article reports the authors' experience with sympathetic RF neurolysis in a 35 year old male with right unilateral lumbar hyperhidrosis. Under scopy guided localization of the lumbar spine sympathetic blockade with local anesthetics to L2-5 vertebral levels were performed as a diagnostic block. Lesion effectiveness is monitored by bilateral feet skin temperature measurement. Clinical effects produced by the first sympathetic ganglion block were sustained for 1 week and then RF neurolysis of lumbar sympathetic ganglion was performed to the same levels for a longer effect. The procedure was accomplished within 30 minutes and the patient was discharged within 2 hours after the procedure. Hyperhidrosis was relieved after the procedure and there were no postsympathectomy neuralgia and sexual dysfunction. The patient obtained improvement of lumbar hyperhidrosis at his first month of follow- up and was satisfied with the outcome. In conclusion, RF neurolysis of lumbar sympathetic ganglions is a safe and effective palliative procedure with minimal invasiveness for relieving excessive sweat secretion in patients with localized hyperhidrosis.

  5. THE SYMPATHETIC NERVOUS SYSTEM ALTERATIONS IN HUMAN HYPERTENSION

    Science.gov (United States)

    Grassi, Guido; Mark, Allyn; Esler, Murray

    2015-01-01

    A number of articles have dealt with the importance and mechanisms of the sympathetic nervous system alterations in experimental animal models of hypertension. This review addresses the role of the sympathetic nervous system in the pathophysiology and therapy of human hypertension. We first discuss the strengths and limitations of various techniques for assessing the sympathetic nervous system in humans, with a focus on heart rate, plasma norepinephrine, microneurographic recording of sympathetic nerve traffic, and measurements of radiolabeled norepinephrine spillover. We then examine the evidence supporting the importance of neuroadrenergic factors as “promoters” and “amplifiers” of human hypertension. We expand on the role of the sympathetic nervous system in two increasingly common forms of secondary hypertension, namely hypertension associated with obesity and with renal disease. With this background, we examine interventions of sympathetic deactivation as a mode of antihypertensive treatment. Particular emphasis is given to the background and results of recent therapeutic approaches based on carotid baroreceptor stimulation and radiofrequency ablation of the renal nerves. PMID:25767284

  6. Angiotensin II, sympathetic nerve activity and chronic heart failure.

    Science.gov (United States)

    Wang, Yutang; Seto, Sai-Wang; Golledge, Jonathan

    2014-03-01

    Sympathetic nerve activity has been reported to be increased in both humans and animals with chronic heart failure. One of the mechanisms believed to be responsible for this phenomenon is increased systemic and cerebral angiotensin II signaling. Plasma angiotensin II is increased in humans and animals with chronic heart failure. The increase in angiotensin II signaling enhances sympathetic nerve activity through actions on both central and peripheral sites during chronic heart failure. Angiotensin II signaling is enhanced in different brain sites such as the paraventricular nucleus, the rostral ventrolateral medulla and the area postrema. Blocking angiotensin II type 1 receptors decreases sympathetic nerve activity and cardiac sympathetic afferent reflex when therapy is administered to the paraventricular nucleus. Injection of an angiotensin receptor blocker into the area postrema activates the sympathoinhibitory baroreflex. In peripheral regions, angiotensin II elevates both norepinephrine release and synthesis and inhibits norepinephrine uptake at nerve endings, which may contribute to the increase in sympathetic nerve activity seen in chronic heart failure. Increased circulating angiotensin II during chronic heart failure may enhance the sympathoexcitatory chemoreflex and inhibit the sympathoinhibitory baroreflex. In addition, increased circulating angiotensin II can directly act on the central nervous system via the subfornical organ and the area postrema to increase sympathetic outflow. Inhibition of angiotensin II formation and its type 1 receptor has been shown to have beneficial effects in chronic heart failure patients.

  7. Role of sympathetic nerve activity in the process of fainting

    Directory of Open Access Journals (Sweden)

    Satoshi eIwase

    2014-09-01

    Full Text Available Syncope is defined as a transient loss of consciousness and postural tone, characterized by rapid onset, short duration, and spontaneous recovery, and the process of syncope progression will be described with two types of sympathetic change. Simultaneous recordings of microneurographically recorded MSNA and continuous and noninvasive blood pressure measurement have disclose what is going on in the course of progression of the syncope. Vasovagal or neurally mediated syncope, three stages are identified in the course of syncope onset, oscillation, imbalance, and catastrophe phases. The vasovagal syncope is characterized by the sympathoexcitation, followed by vagal overcome via the Bezold-Jarisch reflex. Orthostatic syncope is caused by the response failure or lack of sympathetic nerve activity toward the orthostatic challenge followed by the fluid shift, and subsequent cerebral low perfusion. Four causes are considered for the compensatory failure, which triggers the orthostatic syncope; hypovolemia, increased pooling in the lower body, failure to activate the sympathetic activity, and failure of vasoconstriction against sympathetic vasoconstrictive stimulation. Many pathophysiological conditions were described in the viewpoint of 1 exaggerated sympathoexcitation and 2 failure to activate the sympathetic nerve. We conclude that the sympathetic nervous system can control the cardiovascular function, and its failure resulted syncope, however, responses of the system by microneurographically recorded MSNA would determine the pathophysiology of the onset and progression of syncope, explaining the treatment effect that could be achieved by the analysis of this mechanism.

  8. Paroxysmal sympathetic hyperactivity in neurological critical care

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    Rajesh Verma

    2015-01-01

    Full Text Available Introduction: Paroxysmal sympathetic hyperactivity (PSH is a clinical disorder mainly caused by traumatic brain injury, stroke, encephalitis and other types of brain injury. The clinical features are episodes of hypertension, tachycardia, tachypnea, fever and dystonic postures. In this study, we described clinical profile and outcome of six patients of PSH admitted in neurocritical care unit. Materials and Methods: This was a prospective observational study conducted at neurology critical care unit of a tertiary care center. All patients admitted at neurology critical unit during 6-month period from August 2013 to January 2014 were screened for the occurrence of PSH. The clinical details and outcome was documented. Results: PSH was observed in 6 patients. Male to female ratio was 5:1. Mean age ± SD was 36.67 ± 15.19 years. The leading causes were traumatic brain injury (two patients, stroke (two patients and Japanese encephalitis (JE (one patient and tuberculous meningitis (one patient. Conclusion: PSH is an unusual complication in neurocritical care. It prolonged the hospitalization and hampers recovery. The other life-threatening conditions that mimic PSH should be excluded. The association with JE and tuberculous meningitis was not previously described in literature.

  9. Sympathetic nervous system behavior in human obesity.

    Science.gov (United States)

    Davy, Kevin P; Orr, Jeb S

    2009-02-01

    The sympathetic nervous system (SNS) plays an essential role in the regulation of metabolic and cardiovascular homeostasis. Low SNS activity has been suggested to be a risk factor for weight gain and obesity development. In contrast, SNS activation is characteristic of a number of metabolic and cardiovascular diseases that occur more frequently in obese individuals. Until recently, the relation between obesity and SNS behavior has been controversial because previous approaches for assessing SNS activity in humans have produced inconsistent findings. Beginning in the early 1990s, many studies using state of the art neurochemical and neurophysiological techniques have provided important insight. The purpose of the present review is to provide an overview of our current understanding of the region specific alterations in SNS behavior in human obesity. We will discuss findings from our own laboratory which implicate visceral fat as an important depot linking obesity with skeletal muscle SNS activation. The influence of weight change on SNS behavior and the potential mechanisms and consequences of region specific SNS activation in obesity will also be considered.

  10. Thoracic sympathetic block reduces respiratory system compliance

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    Fábio Ely Martins Benseñor

    Full Text Available CONTEXT AND OBJECTIVE: Thoracic epidural anesthesia (TEA following thoracic surgery presents known analgesic and respiratory benefits. However, intraoperative thoracic sympathetic block may trigger airway hyperreactivity. This study weighed up these beneficial and undesirable effects on intraoperative respiratory mechanics. DESIGN AND SETTING: Randomized, double-blind clinical study at a tertiary public hospital. METHODS: Nineteen patients scheduled for partial lung resection were distributed using a random number table into groups receiving active TEA (15 ml 0.5% bupivacaine, n = 9 or placebo (15 ml 0.9% saline, n = 10 solutions that also contained 1:200,000 epinephrine and 2 mg morphine. Under general anesthesia, flows and airway and esophageal pressures were recorded. Pressure-volume curves, lower inflection points (LIP, resistance and compliance at 10 ml/kg tidal volume were established for respiratory system, chest wall and lungs. Student’s t test was performed, including confidence intervals (CI. RESULTS: Bupivacaine rose 5 ± 1 dermatomes upwards and 6 ± 1 downwards. LIP was higher in the bupivacaine group (6.2 ± 2.3 versus 3.6 ± 0.6 cmH2O, p = 0.016, CI = -3.4 to -1.8. Respiratory system and lung compliance were higher in the placebo group (respectively 73.3 ± 10.6 versus 51.9 ± 15.5, p = 0.003, CI = 19.1 to 23.7; 127.2 ± 31.7 versus 70.2 ± 23.1 ml/cmH2O, p < 0.001, CI = 61 to 53. Resistance and chest wall compliance showed no difference. CONCLUSION: TEA decreased respiratory system compliance by reducing its lung component. Resistance was unaffected. Under TEA, positive end-expiratory pressure and recruitment maneuvers are advisable.

  11. Effects of renal sympathetic nerve radiofrequency ablation on norepinephrine spillover rate and sympathetic nerve activity in dogs with hypertension

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    Hang YU

    2012-11-01

    Full Text Available Objective  To evaluate the validity and explore the mechanism of renal sympathetic denervation (RSD in the treatment of dogs with hypertension reproduced by constriction of abdominal aorta. Methods  The hypertension model was reproduced by constriction of abdominal aorta in 20 adult healthy dogs. These dogs were then randomly divided into the treatment group and control group (10 each. Renal sympathetic nerve radiofrequency ablation was done in treatment group 1 month after modeling. The foreleg blood pressure, sympathetic activity and norepinephrine overflow rate of dogs in two groups were detected before modeling, and 1, 2 and 3 months after modeling, and the trend of the change was also observed. Results  One month after modeling, the systolic blood pressure (SBP, diastolic blood pressure (DBP and mean arterial blood pressure (MAP were elevated significantly in control group (146.7±21.0, 89.0±12.7 and 108.3±14.9mmHg compared with those before modeling (119.5±13.2, 76.5±7.8 and 90.9±8mmHg, P < 0.05. The renal sympathetic activity impulse and norepinephrine spillover rate were also enhanced significantly (P < 0.05. The renal sympathetic nerve activity obviously decreased in the treatment group after the operation, and then increased 2 months after the ablation. The norepinephrine spillover rate in treatment group increased significantly 1 month after modeling (P < 0.05, and decreased after ablation, and it lasted to the end of the experiment (P < 0.05. One and two months after ablation, the norepinephrine spillover rate was lower in treatment group than in control group (P < 0.05. Conclusion  Renal sympathetic nerve radiofrequency ablation significantly inhibits the elevation of norepinephrine spillover rate and sympathetic nerve activity in dogs with hypertension.

  12. Cardiovascular indices of peripheral and central sympathetic activation.

    Science.gov (United States)

    Schächinger, H; Weinbacher, M; Kiss, A; Ritz, R; Langewitz, W

    2001-01-01

    A number of sympathetic nervous system (SNS) parameters have been used in cardiovascular psychophysiology. This study aimed to describe the pattern and redundancy of a set of SNS parameters during peripherally induced changes of cardiac sympathetic activation and reflex modulation of central SNS control. Preejection period (PEP) was assessed as a marker of peripheral sympathetic activation. Low-frequency blood pressure variability (BPV) was assessed as an estimate of central SNS control. Peripheral beta-sympathetic stimulation and blockade were achieved with epinephrine and esmolol hydrochloride (beta1-blockade), respectively. Changes in central SNS output were induced by loading and unloading arterial baroreceptors with norepinephrine and nitroprusside sodium, respectively. This single-blinded, crossover study in 24 healthy men also included two placebo control periods. PEP was derived from impedance cardiography and adjusted individually for heart rate. BPV was calculated by power spectral analyses of beat-to-beat heart rate and systolic blood pressure (Finapres system) data. PEP decreased during epinephrine infusion (-40.1 +/- 3.8 ms, p SNS activation by nitroprusside (-16.8 +/- 2.9 ms, p information on both central SNS control and the level of sympathetic cardiac activation achieved.

  13. The articulo-cardiac sympathetic reflex in spinalized, anesthetized rats.

    Science.gov (United States)

    Nakayama, Tomohiro; Suzuki, Atsuko; Ito, Ryuzo

    2006-04-01

    Somatic afferent regulation of heart rate by noxious knee joint stimulation has been proven in anesthetized cats to be a reflex response whose reflex center is in the brain and whose efferent arc is a cardiac sympathetic nerve. In the present study we examined whether articular stimulation could influence heart rate by this efferent sympathetic pathway in spinalized rats. In central nervous system (CNS)-intact rats, noxious articular movement of either the knee or elbow joint resulted in an increase in cardiac sympathetic nerve activity and heart rate. However, although in acutely spinalized rats a noxious movement of the elbow joint resulted in a significant increase in cardiac sympathetic nerve activity and heart rate, a noxious movement of the knee joint had no such effect and resulted in only a marginal increase in heart rate. Because this marginal increase was abolished by adrenalectomy suggests that it was due to the release of adrenal catecholamines. In conclusion, the spinal cord appears to be capable of mediating, by way of cardiac sympathetic nerves, the propriospinally induced reflex increase in heart rate that follows noxious stimulation of the elbow joint, but not the knee joint.

  14. GENDER-SELECTIVE INTERACTION BETWEEN AGING AND CARDIOVASCULAR SYMPATHETIC ACTIVITY

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    Thorat D Kiran

    2010-06-01

    Full Text Available Physiologically aging refers to the impaired ability to maintain homeostasis during external as wellas internal stresses. The sympathetic nervous system becomes tonically, progressively and markedlyactivated with aging in humans. Study is done to measure the cardiovascular sympatheticdysfunctions in the males and females of the different age groups. Total 80, healthy subjects nothaving any major illness and any chronic addiction, were selected for the study. All the subjects wereevaluated by using “CANWIN cardiac autonomic neuropathy analyzer” using the tests like Pulse rateby Palpatory method, Blood Pressure response to sudden standing and Sustained Handgrip test. In all the elderly subjects the sympathetic system was over activated and this over activation of the sympathetic system became more severe as the age advanced. Aging is accompanied by a greater increase in sympathetic activity in women than in men, independent of menopausal status. The study concludes that there is more marked influence of age on sympathetic nervous system activation and impaired sensitivity of baroreceptors in women than men.

  15. Sympathetic neuro-adipose connections mediate leptin-driven lipolysis.

    Science.gov (United States)

    Zeng, Wenwen; Pirzgalska, Roksana M; Pereira, Mafalda M A; Kubasova, Nadiya; Barateiro, Andreia; Seixas, Elsa; Lu, Yi-Hsueh; Kozlova, Albina; Voss, Henning; Martins, Gabriel G; Friedman, Jeffrey M; Domingos, Ana I

    2015-09-24

    Leptin is a hormone produced by the adipose tissue that acts in the brain, stimulating white fat breakdown. We find that the lipolytic effect of leptin is mediated through the action of sympathetic nerve fibers that innervate the adipose tissue. Using intravital two-photon microscopy, we observe that sympathetic nerve fibers establish neuro-adipose junctions, directly "enveloping" adipocytes. Local optogenetic stimulation of sympathetic inputs induces a local lipolytic response and depletion of white adipose mass. Conversely, genetic ablation of sympathetic inputs onto fat pads blocks leptin-stimulated phosphorylation of hormone-sensitive lipase and consequent lipolysis, as do knockouts of dopamine β-hydroxylase, an enzyme required for catecholamine synthesis. Thus, neuro-adipose junctions are necessary and sufficient for the induction of lipolysis in white adipose tissue and are an efferent effector of leptin action. Direct activation of sympathetic inputs to adipose tissues may represent an alternative approach to induce fat loss, circumventing central leptin resistance. PAPERCLIP. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. 宠物龟眼炎的病原鉴定及临床药物治疗的研究%Identification of pathogen from pet chelonian with ophthalmia and the clinic therapy

    Institute of Scientific and Technical Information of China (English)

    陈晨; 潘连德

    2011-01-01

    Symptoms of ophthalmia of pet chelonian included eye closed, eyelid got red and membranae nictitans moved.It is a common disease on pet chelonian.A dominant bacterial strain isolated from the sick chelonian' s eye is assigned as the strain A5.The artificial infection test proved that the isolated A5 was the pathogenic bacterium that caused the disease.Synthesizing the morphology, physiological and biochemical characterization, and 16S rDNA of A5 was sequenced, the results showed that strain A5 exhibited the highest levels of similarity to the Pseudomonas fluorescens bv.C.The drug sensitivity test of strain A5 revealed that the pathogen was sensitive to drugs such as ofloxacin, gentamicin, tenebrimycin and piperacillin.The forty ophthalmic pet chelonians were divided into 8 groups to be treated and the efficacy analyzed in different treatments.The results showed that the drug effect of ofloxacin was better than sulfacetamide sodium and chloramphenicol.The curative effect of sick chelonian treated at 25 ℃ was better than at 5 ℃, and doing surgery was good for the cure of ophthalmia.Adding the dose of drug and intramuscular injection had no significant difference.The study could be helpful for clinic diagnosis in pet chelonian disease.%眼炎是宠物龟疾病中一种常见的疾病,具有闭眼、眼睑红肿、瞬膜异位等症状.从患有眼炎的宠物龟眼部分离出菌株A5,经人工回归感染试验确定其为眼炎的痫原菌.综合该菌在形态、生理生化特征及16S rDNA测序分析等检验结果,确定A5菌株为荧光假单胞菌(Pseudomonas fluorescens bv.C).药敏试验证实,该菌对氧氟沙星、庆大霉素、妥布霉素、氧哌嗪青霉素等抗生素敏感.对40个眼炎病例进行分组药物治疗,比较治疗方案,结果显示:氧氟沙星药效优于氯霉素与磺胺醋酰钠,养殖水温25℃治疗效果优于5 ℃,眼科手术剔除分泌物可缩短治疗时间.增加给药次数至6次/d、增加肌肉注射,疗效

  17. Vascular Mural Cells Promote Noradrenergic Differentiation of Embryonic Sympathetic Neurons.

    Science.gov (United States)

    Fortuna, Vitor; Pardanaud, Luc; Brunet, Isabelle; Ola, Roxana; Ristori, Emma; Santoro, Massimo M; Nicoli, Stefania; Eichmann, Anne

    2015-06-23

    The sympathetic nervous system controls smooth muscle tone and heart rate in the cardiovascular system. Postganglionic sympathetic neurons (SNs) develop in close proximity to the dorsal aorta (DA) and innervate visceral smooth muscle targets. Here, we use the zebrafish embryo to ask whether the DA is required for SN development. We show that noradrenergic (NA) differentiation of SN precursors temporally coincides with vascular mural cell (VMC) recruitment to the DA and vascular maturation. Blocking vascular maturation inhibits VMC recruitment and blocks NA differentiation of SN precursors. Inhibition of platelet-derived growth factor receptor (PDGFR) signaling prevents VMC differentiation and also blocks NA differentiation of SN precursors. NA differentiation is normal in cloche mutants that are devoid of endothelial cells but have VMCs. Thus, PDGFR-mediated mural cell recruitment mediates neurovascular interactions between the aorta and sympathetic precursors and promotes their noradrenergic differentiation.

  18. Propranolol for Paroxysmal Sympathetic Hyperactivity with Lateralizing Hyperhidrosis after Stroke

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    Jason W. Siefferman

    2015-01-01

    Full Text Available Brain injury can lead to impaired cortical inhibition of the hypothalamus, resulting in increased sympathetic nervous system activation. Symptoms of paroxysmal sympathetic hyperactivity may include hyperthermia, tachycardia, tachypnea, vasodilation, and hyperhidrosis. We report the case of a 41-year-old man who suffered from a left middle cerebral artery stroke and subsequently developed central fever, contralateral temperature change, and hyperhidrosis. His symptoms abated with low-dose propranolol and then returned upon discontinuation. Restarting propranolol again stopped his symptoms. This represents the first report of propranolol being used for unilateral dysautonomia after stroke. Propranolol is a lipophilic nonselective beta-blocker which easily crosses the blood-brain barrier and may be used to treat paroxysmal sympathetic hyperactivity.

  19. Role of sympathetic nervous system and neuropeptides in obesity hypertension

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    J.E. Hall

    2000-06-01

    Full Text Available Obesity is the most common cause of human essential hypertension in most industrialized countries. Although the precise mechanisms of obesity hypertension are not fully understood, considerable evidence suggests that excess renal sodium reabsorption and a hypertensive shift of pressure natriuresis play a major role. Sympathetic activation appears to mediate at least part of the obesity-induced sodium retention and hypertension since adrenergic blockade or renal denervation markedly attenuates these changes. Recent observations suggest that leptin and its multiple interactions with neuropeptides in the hypothalamus may link excess weight gain with increased sympathetic activity. Leptin is produced mainly in adipocytes and is believed to regulate energy balance by acting on the hypothalamus to reduce food intake and to increase energy expenditure via sympathetic activation. Short-term administration of leptin into the cerebral ventricles increases renal sympathetic activity, and long-term leptin infusion at rates that mimic plasma concentrations found in obesity raises arterial pressure and heart rate via adrenergic activation in non-obese rodents. Transgenic mice overexpressing leptin also develop hypertension. Acute studies suggest that the renal sympathetic effects of leptin may depend on interactions with other neurochemical pathways in the hypothalamus, including the melanocortin-4 receptor (MC4-R. However, the role of this pathway in mediating the long-term effects of leptin on blood pressure is unclear. Also, it is uncertain whether there is resistance to the chronic renal sympathetic and blood pressure effects of leptin in obese subjects. In addition, leptin also has other cardiovascular and renal actions, such as stimulation of nitric oxide formation and improvement of insulin sensitivity, which may tend to reduce blood pressure in some conditions. Although the role of these mechanisms in human obesity has not been elucidated, this

  20. Bursting into space: alterations of sympathetic control by space travel

    Science.gov (United States)

    Eckberg, D. L.

    2003-01-01

    AIM: Astronauts return to Earth with reduced red cell masses and hypovolaemia. Not surprisingly, when they stand, their heart rates may speed inordinately, their blood pressures may fall, and some may experience frank syncope. We studied autonomic function in six male astronauts (average +/- SEM age: 40 +/- 2 years) before, during, and after the 16-day Neurolab space shuttle mission. METHOD: We recorded electrocardiograms, finger photoplethysmographic arterial pressures, respiration, peroneal nerve muscle sympathetic activity, plasma noradrenaline and noradrenaline kinetics, and cardiac output, and we calculated stroke volume and total peripheral resistance. We perturbed autonomic function before and during spaceflight with graded Valsalva manoeuvres and lower body suction, and before and after the mission with passive upright tilt. RESULTS: In-flight baseline sympathetic nerve activity was increased above pre-flight levels (by 10-33%) in three subjects, in whom noradrenaline spillover and clearance also were increased. Valsalva straining provoked greater reductions of arterial pressure, and proportionally greater sympathetic responses in space than on Earth. Lower body suction elicited greater increases of sympathetic nerve activity, plasma noradrenaline, and noradrenaline spillover in space than on Earth. After the Neurolab mission, left ventricular stroke volume was lower and heart rate was higher during tilt, than before spaceflight. No astronaut experienced orthostatic hypotension or pre-syncope during 10 min of post-flight tilting. CONCLUSION: We conclude that baseline sympathetic outflow, however measured, is higher in space than on earth, and that augmented sympathetic nerve responses to Valsalva straining, lower body suction, and post-flight upright tilt represent normal adjustments to greater haemodynamic stresses associated with hypovolaemia.

  1. The Sympathetic Nervous System in the Pathogenesis of Takotsubo Syndrome.

    Science.gov (United States)

    Wittstein, Ilan S

    2016-10-01

    Takotsubo syndrome is a unique clinical condition of acute heart failure and reversible left ventricular dysfunction frequently precipitated by sudden emotional or physical stress. There is growing evidence that exaggerated sympathetic stimulation is central to the pathogenesis of this syndrome. Precisely how catecholamines mediate myocardial stunning in takotsubo syndrome remains incompletely understood; but possible mechanisms include epicardial spasm, microvascular dysfunction, direct adrenergic-receptor-mediated myocyte injury, and systemic vascular effects that alter ventricular-arterial coupling. Risk factors that increase sympathetic tone and/or catecholamine sensitivity may render individuals particularly susceptible to takotsubo syndrome during episodes of acute stress. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Central and cerebrovascular effects of leg crossing in humans with sympathetic failure

    NARCIS (Netherlands)

    M.P. Harms; W. Wieling; W.N. Colier; J.W. Lenders; N.H. Secher; J.J. van Lieshout

    2010-01-01

    Leg crossing increases arterial pressure and combats symptomatic orthostatic hypotension in patients with sympathetic failure This study compared the central and cerebrovascular effects of leg crossing in patients with sympathetic failure and healthy controls. We addressed the relationship between M

  3. Carotid baroreceptor stimulation, sympathetic activity, baroreflex function, and blood pressure in hypertensive patients.

    NARCIS (Netherlands)

    Heusser, K.; Tank, J.; Engeli, S.; Diedrich, A.; Menne, J.; Eckert, S.; Peters, T.; Sweep, F.C.; Haller, H.; Pichlmaier, A.M.; Luft, F.C.; Jordan, J.

    2010-01-01

    In animals, electric field stimulation of carotid baroreceptors elicits a depressor response through sympathetic inhibition. We tested the hypothesis that the stimulation acutely reduces sympathetic vasomotor tone and blood pressure in patients with drug treatment-resistant arterial hypertension.

  4. A comparison of sympathetic and conventional training methods on responses to initial horse training

    NARCIS (Netherlands)

    Visser, E.K.; Dierendonck, van M.; Ellis, A.D.; Rijksen, C.; Reenen, van C.G.

    2009-01-01

    In `sympathetic horsemanship¿ the importance of the natural behaviour of the horse and the use of body language in communication is emphasised. However, it is unclear what effect sympathetic horsemanship has on the welfare of horses. During a 5-week starting period the effect of a sympathetic (ST) v

  5. Effect of sympathetic nerve block on acute inflammatory pain and hyperalgesia

    DEFF Research Database (Denmark)

    Pedersen, J L; Rung, G W; Kehlet, H

    1997-01-01

    BACKGROUND: Sympathetic nerve blocks relieve pain in certain chronic pain states, but the role of the sympathetic pathways in acute pain is unclear. Thus the authors wanted to determine whether a sympathetic block could reduce acute pain and hyperalgesia after a heat injury in healthy volunteers....

  6. Quantitative measurement of sympathetic neuropathy in patients with diabetes mellitus.

    Science.gov (United States)

    Nasimi, S G; Mearns, A J; Harness, J B; Heath, I

    1991-05-01

    Vasoconstriction occurs in the skin capillary blood flow of the healthy subject when posture changes from supine to standing. Using frequency analysis of the optical photoplethysmograph signal, a statistically significant difference (P less than 0.01) may be demonstrated between supine and standing positions in the lower frequency band (0.01-0.5 Hz) in the foot of normal subjects. This allowed us to develop a simple index: sympathetic power band change (SPBC). Patients with diabetes mellitus often suffer from degeneration in the sympathetic nervous system. This impairs the normal vasoconstrictor response to standing. We have applied the SPBC 'blind' to a group of diabetic patients. Such patients may be divided into three groups according to their SPBC indices: normals with SPBC greater than 2.6 (group A), intermediates with 2.6 greater than or equal to SPBC greater than or equal to 0.26 (group B) and poor with SPBC less than 0.26 (group C). All patients with retinopathy were in group C and five out of the six patients with electrophysiologically confirmed peripheral neuropathy were in group C. Frequency analysis of the photoplethysmograph signal has produced an index of sympathetic tone change when subjects move from supine to standing position. The application of this index to patients with diabetes mellitus shows some patients to have sympathetic vascular tone failure.

  7. Morphine-sensitive paroxysmal sympathetic storm in pontine intracerebral hemorrhage.

    Science.gov (United States)

    Ko, Sang-Bae; Kim, Chi Kyung; Lee, Seung-Hoon; Bae, Hee-Joon; Yoon, Byung-Woo

    2010-11-01

    Paroxysmal sympathetic storm (PSS) is a rare complication of severe traumatic brain injury or cerebrovascular disease. Various medications have been tried in patients with PSS, but the clinical responses of the patients were variable. We report a classic case of PSS after spontaneous pontine hemorrhage in which the patient's fluctuating blood pressure and body temperature were dramatically stabilized using morphine.

  8. Dynamic resistance training decreases sympathetic tone in hypertensive ovariectomized rats

    Energy Technology Data Exchange (ETDEWEB)

    Shimojo, G.L.; Palma, R.K.; Brito, J.O.; Sanches, I.C. [Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP (Brazil); Irigoyen, M.C. [Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); De Angelis, K. [Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP (Brazil)

    2015-03-27

    The aim of this study was to investigate the effects of resistance exercise training on hemodynamics and cardiac autonomic control in ovariectomized spontaneously hypertensive rats. Female rats were divided into 4 groups: sedentary control (SC), sedentary hypertensive (SH), sedentary hypertensive ovariectomized (SHO), and resistance-trained hypertensive ovariectomized (RTHO). Resistance exercise training was performed on a vertical ladder (5 days/week, 8 weeks) at 40-60% maximal load. Direct arterial pressure was recorded. Vagal and sympathetic tones were measured by heart rate (HR) responses to methylatropine (3 mg/kg, iv) and propranolol (4 mg/kg, iv). Ovariectomy resulted in additional increases in blood pressure in hypertensive rats and was associated with decreased vagal tone. Resistance exercise trained rats had lower mean arterial pressure than untrained rats (RTHO: 159±2.2 vs SHO: 177±3.4 mmHg), as well as resting bradycardia (RTHO: 332±9.0 vs SHO: 356±5 bpm). Sympathetic tone was also lower in the trained group. Moreover, sympathetic tone was positively correlated with resting HR (r=0.7, P<0.05). The additional arterial pressure increase in hypertensive rats caused by ovarian hormone deprivation was attenuated by moderate-intensity dynamic resistance training. This benefit may be associated with resting bradycardia and reduced cardiac sympathetic tone after training, which suggests potential benefits of resistance exercise for the management of hypertension after ovarian hormone deprivation.

  9. Cardiac sympathetic nerve terminal function in congestive heart failure

    Institute of Scientific and Technical Information of China (English)

    Chang-seng LIANG

    2007-01-01

    Increased cardiac release of norepinephrine (NE) and depleted cardiac stores of NE are two salient features of the human failing heart. Researches from my labo-ratory have shown that these changes are accompanied by a functional defect of NE uptake in the cardiac sympathetic nerve terminals. Our studies have shown that the decrease of NE uptake is caused by reduction of NE transporter density in the sympathetic nerve endings, and this change is responsible, at least in part, for the increased myocardial interstitial NE, decreased myocardial adrenoceptor density, and increased myocyte apoptosis in experimental cardiomyopathies. We have also provided evidence in both intact animals and cultured PC12 cells that the decrease of NE transporter is induced by the actions of oxidative metabolites of exogenous NE, involving endoplasmic reticulum stress and impaired N-glycosylation of the NE transporter. This change in the cardiac sympathetic NE uptake function, as demonstrated by [123I] metaiodobenzylguanidine in human studies, may not only serve as an important prognostic variable in patients with congestive heart failure, but also be used as a surrogate for the efficacies of various therapeutic interventions for heart failure. Finally, increasing evidence suggests and further studies are needed to show that the cardiac sympathetic nerve terminal function may be a direct target for pharmacologic treatment of congestive heart failure.

  10. Prolonged Paroxysmal Sympathetic Storming Associated with Spontaneous Subarachnoid Hemorrhage

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2013-01-01

    Full Text Available Paroxysmal sympathetic storming (PSS is a rare disorder characterized by acute onset of nonstimulated tachycardia, hypertension, tachypnea, hyperthermia, external posturing, and diaphoresis. It is most frequently associated with severe traumatic brain injuries and has been reported in intracranial tumors, hydrocephalous, severe hypoxic brain injury, and intracerebral hemorrhage. Although excessive release of catecholamine and therefore increased sympathetic activities have been reported in subarachnoid hemorrhage (SAH, there is no descriptive report of PSS primarily caused by spontaneous SAH up to date. Here, we report a case of prolonged PSS in a patient with spontaneous subarachnoid hemorrhage and consequent vasospasm. The sympathetic storming started shortly after patient was rewarmed from hypothermia protocol and symptoms responded to Labetalol, but intermittent recurrence did not resolve until 3 weeks later with treatment involving Midazolam, Fentanyl, Dexmedetomidine, Propofol, Bromocriptine, and minimizing frequency of neurological and vital checks. In conclusion, prolonged sympathetic storming can also be caused by spontaneous SAH. In this case, vasospasm might be a precipitating factor. Paralytics and hypothermia could mask the manifestations of PSS. The treatment of the refractory case will need both timely adjustment of medications and minimization of exogenous stressors or stimuli.

  11. Sympathetic neuroaxonal dystrophy in the aged rat pineal gland.

    Science.gov (United States)

    Schmidt, Robert E; Dorsey, Denise A; Parvin, Curtis A; Beaudet, Lucie N

    2006-10-01

    Dysfunction of circadian melatonin production by the pineal gland in aged humans and rats is thought to reflect the functional loss of its sympathetic innervation. Our ultrastructural neuropathologic studies of the sympathetic innervation of the pineal gland of aged (24 months old) Fischer-344 and Sprague-Dawley rats showed loss of nerve terminals as well as the development of neuroaxonal dystrophy (NAD), an ultrastructurally distinctive distal axonopathy, far in excess of that in young control rats. Immunolocalization of tyrosine hydroxylase confirmed the age-related loss of normal noradrenergic innervation and development of NAD. NAD was more frequent in aged female rats compared to males and was particularly severe in aged female Sprague-Dawley rats compared to Fischer-344 rats. Pineal NGF content was significantly increased or unchanged in female and male aged Fischer-344 rats, respectively, compared to young controls. The rat pineal is a sensitive experimental model for the quantitative ultrastructural examination of age-related neuropathological changes in nerve terminals of postganglionic noradrenergic sympathetic axons, changes which may reflect similar changes in the diffusely distributed sympathetic innervation of other targeted endorgans.

  12. Sympathetically evoked Ca2+ signaling in arterial smooth muscle

    Institute of Scientific and Technical Information of China (English)

    Wei-jin ZANG; Joseph ZACHARIA; Christine LAMONT; Withrow Gil WIER

    2006-01-01

    The sympathetic nervous system plays an essential role in the control of total peripheral vascular resistance and blood flow, by controlling the contraction of small arteries. Perivascular sympathetic nerves release ATP, norepinephrine (NE) and neuropeptide Y. This review summarizes our knowledge of the intracellular Ca2+ signals that are activated by ATP and NE, acting respectively on P2X1 and α1 adrenoceptors in arterial smooth muscle. Each neurotransmitter produces a unique type of post-synaptic Ca2+ signal and associated contraction. The neural release of ATP and NE is thought to vary markedly with the pattern of nerve activity, probably reflecting both pre- and post-synaptic mechanisms. Finally, we show that Ca2+ signaling during neurogenic contractions activated by trains of sympathetic nerve fiber action potentials are in fact significantly different from that elicited by simple bath application of exogenous neurotransmitters to isolated arteries (a common experimental technique), and end by identifying important questions remaining in our understanding of sympathetic neurotransmission and the physiological regulation of contraction of small arteries.

  13. Sympathetic Nerves in Breast Cancer: Angiogenesis and Antiangiogenic Therapy

    Science.gov (United States)

    2013-02-01

    decreased TH synthesis or an accelerated rate of NE uptake into sympathetic nerve terminals (6). To confirm that NE in the synapse is increased with DMI...21. Dimitrijevic M, Pilipovic I, Stanojevic S, Mitic K, Radojevic K, Pesic V, et al. Chronic propranolol treatment affects expression of

  14. Menstrual cycle effects on sympathetic neural responses to upright tilt.

    NARCIS (Netherlands)

    Fu, Q.; Okazaki, K.; Shibata, S.; Shook, R.P.; Gunday, T.B. van; Galbreath, M.M.; Reelick, M.F; Levine, B.D.

    2009-01-01

    Young women are more susceptible to orthostatic intolerance than men, though the sex-specific pathophysiology remains unknown. As blood pressure (BP) is regulated through the baroreflex mechanism, we tested the hypothesis that baroreflex control of muscle sympathetic nerve activity (MSNA) during

  15. Causes and consequences of increased sympathetic activity in renal disease

    NARCIS (Netherlands)

    Joles, JA; Koomans, HA

    2004-01-01

    Much evidence indicates increased sympathetic nervous activity (SNA) in renal disease. Renal ischemia is probably a primary event leading to increased SNA. Increased SNA often occurs in association with hypertension. However, the deleterious effect of increased SNA on the diseased kidney is not only

  16. Baroreflex control of sympathetic activity in experimental hypertension

    Directory of Open Access Journals (Sweden)

    M.C.C. Irigoyen

    1998-09-01

    Full Text Available The arterial baroreceptor reflex system is one of the most powerful and rapidly acting mechanisms for controlling arterial pressure. The purpose of the present review is to discuss data relating sympathetic activity to the baroreflex control of arterial pressure in two different experimental models: neurogenic hypertension by sinoaortic denervation (SAD and high-renin hypertension by total aortic ligation between the renal arteries in the rat. SAD depresses baroreflex regulation of renal sympathetic activity in both the acute and chronic phases. However, increased sympathetic activity (100% was found only in the acute phase of sinoaortic denervation. In the chronic phase of SAD average discharge normalized but the pattern of discharges was different from that found in controls. High-renin hypertensive rats showed overactivity of the renin angiotensin system and a great depression of the baroreflexes, comparable to the depression observed in chronic sinoaortic denervated rats. However, there were no differences in the average tonic sympathetic activity or changes in the pattern of discharges in high-renin rats. We suggest that the difference in the pattern of discharges may contribute to the increase in arterial pressure lability observed in chronic sinoaortic denervated rats.

  17. Sympathetic Overactivity in Chronic Kidney Disease: Consequences and Mechanisms

    Directory of Open Access Journals (Sweden)

    Jasdeep Kaur

    2017-08-01

    Full Text Available The incidence of chronic kidney disease (CKD is increasing worldwide, with more than 26 million people suffering from CKD in the United States alone. More patients with CKD die of cardiovascular complications than progress to dialysis. Over 80% of CKD patients have hypertension, which is associated with increased risk of cardiovascular morbidity and mortality. Another common, perhaps underappreciated, feature of CKD is an overactive sympathetic nervous system. This elevation in sympathetic nerve activity (SNA not only contributes to hypertension but also plays a detrimental role in the progression of CKD independent of any increase in blood pressure. Indeed, high SNA is associated with poor prognosis and increased cardiovascular morbidity and mortality independent of its effect on blood pressure. This brief review will discuss some of the consequences of sympathetic overactivity and highlight some of the potential pathways contributing to chronically elevated SNA in CKD. Mechanisms leading to chronic sympathoexcitation in CKD are complex, multifactorial and to date, not completely understood. Identification of the mechanisms and/or signals leading to sympathetic overactivity in CKD are crucial for development of effective therapeutic targets to reduce the increased cardiovascular risk in this patient group.

  18. Partial cardiac sympathetic denervation after bilateral thoracic sympathectomy in humans.

    Science.gov (United States)

    Moak, Jeffrey P; Eldadah, Basil; Holmes, Courtney; Pechnik, Sandra; Goldstein, David S

    2005-06-01

    Upper thoracic sympathectomy is used to treat several disorders. Sympathetic nerve fibers emanating from thoracic ganglia innervate the heart. Whether unilateral or bilateral upper thoracic sympathectomy affects cardiac sympathetic innervation in humans in vivo has been unclear. The purpose of this study was to assess whether thoracic sympathectomy decreases cardiac sympathetic innervation, as indicated by positron emission tomographic scanning after intravenous injection of the sympathoneural imaging agent 6-[18F]fluorodopamine. Nine patients with previous upper thoracic sympathectomies (four right-sided, one left-sided, four bilateral) underwent thoracic 6-[18F]fluorodopamine scanning between 1 and 2 hours after injection of the imaging agent. In each case, a low rate of entry of norepinephrine into the arm venous drainage (norepinephrine spillover) verified upper limb sympathectomy. Data were compared with those from the interventricular septum of patients with cardiac sympathetic denervation associated with pure autonomic failure and from normal volunteers. All four patients with bilateral sympathectomy had low septal myocardial 6-[18F]fluorodopamine-derived radioactivity (2,673 +/- 92 nCi-kg/cc-mCi at an average of 89 minutes after injection) compared with normal volunteers (3,634 +/- 311 nCi-kg/cc-mCi at 83 minutes, N = 22, P = .007) and higher radioactivity than in patients with pure autonomic failure (1,320 +/- 300 nCi-kg/cc-mCi at 83 minutes, N = 7, P = .003). Patients with unilateral sympathectomy had normal 6-[18F]fluorodopamine-derived radioactivity (3,971 +/- 337 nCi-kg/cc-mCi at 87 minutes). Bilateral upper thoracic sympathectomy partly decreases cardiac sympathetic innervation density.

  19. Relationship between three phase bone scintigram and prognosis after sympathetic blockade in reflex sympathetic dystrophy of the hand

    Energy Technology Data Exchange (ETDEWEB)

    Yokono, Atsuko; Yokono, Satoshi; Oguri, Kenji (Kagawa Medical School, Miki (Japan))

    1990-11-01

    The authors attempted to correlate the changes in three phase bone scintigram (TPBS) with prognosis after sympathetic blockade in reflex sympathetic dystrophy (RSD) of the hand. Subjects were 12 patients of RSD in acute or dystrophic stage, who all had increased images on TPBS. Either intravenous regional sympathectomy with guanethidine or stellate ganglion block was performed repeatedly. We compared TPBS obtained just before and after this series of sympathetic blocks and evaluated the eventual recovery of function of the hand. In 8 patients, blood flow (phase 1) image of TPBS decreased after the blockade. Of these patients, those who showed almost normalized tracer activity not only on flow image but on blood pool (phase 2) and delayed (phase 3) image, returned to normal. But others with normalized blood flow and still increased activity in blood pool and delayed image, remained with mild contracture of the hand. These results suggest that normalization of blood pool and delayed image on TPBS is a predictor of subsequent recovery after sympathetic blockade in RSD. (author).

  20. P2 receptors in the central and peripheral nervous systems modulating sympathetic vasomotor tone.

    Science.gov (United States)

    Ralevic, V

    2000-07-01

    Arterial pressure depends on the level of activity of sympathetic vasoconstrictor outflow to blood vessels. This activity is generated in the central nervous system, and involves inputs from a variety of brain regions projecting to sympathetic preganglionic neurones. Of especial interest are a group of neurones in the rostral ventrolateral medulla (RVLM), as they have been demonstrated to have a fundamental role in reflex regulation of the cardiovascular system, and in generation of tonic drive to sympathetic outflow. Sympathetic outflow to blood vessels is additionally modulated at sympathetic ganglia, and at the peripheral terminals of sympathetic nerves. This review considers the role of P2 purine receptors in this neural pathway. Ionotropic P2X receptors are expressed in the RVLM, in sympathetic ganglia, and at the sympathetic neuromuscular junction, and mediate fast excitatory neurotransmission, indicating a general role for ATP as a regulator of sympathetic vasomotor tone. P2Y receptors couple to G proteins and mediate slower signalling to ATP; they have been reported to inhibit prejunctionally neurotransmission at the peripheral terminals of sympathetic nerves, but little is known about their possible role in the central nervous system and in sympathetic ganglia.

  1. Regulation of the renal sympathetic nerves in heart failure

    Directory of Open Access Journals (Sweden)

    Rohit eRamchandra

    2015-08-01

    Full Text Available Heart failure (HF is a serious debilitating condition with poor survival rates and an increasing level of prevalence. Heart failure is associated with an increase in renal norepinephrine spillover, which is an independent predictor of mortality in HF patients. The excessive sympatho-excitation that is a hallmark of heart failure has long-term effects that contribute to disease progression. An increase in directly recorded renal sympathetic nerve activity has also been recorded in animal models of heart failure. This review will focus on the mechanisms controlling sympathetic nerve activity to the kidney during normal conditions and alterations in these mechanisms during heart failure. In particular the roles of afferent reflexes and central mechanisms will be discussed.

  2. Orexin-A controls sympathetic activity and eating behavior.

    Science.gov (United States)

    Messina, Giovanni; Dalia, Carmine; Tafuri, Domenico; Monda, Vincenzo; Palmieri, Filomena; Dato, Amelia; Russo, Angelo; De Blasio, Saverio; Messina, Antonietta; De Luca, Vincenzo; Chieffi, Sergio; Monda, Marcellino

    2014-01-01

    It is extremely important for the health to understand the regulatory mechanisms of energy expenditure. These regulatory mechanisms play a central role in the pathogenesis of body weight alteration. The hypothalamus integrates nutritional information derived from all peripheral organs. This region of the brain controls hormonal secretions and neural pathways of the brainstem. Orexin-A is a hypothalamic neuropeptide involved in the regulation of feeding behavior, sleep-wakefulness rhythm, and neuroendocrine homeostasis. This neuropeptide is involved in the control of the sympathetic activation, blood pressure, metabolic status, and blood glucose level. This minireview focuses on relationship between the sympathetic nervous system and orexin-A in the control of eating behavior and energy expenditure. The "thermoregulatory hypothesis" of food intake is analyzed, underlining the role played by orexin-A in the control of food intake related to body temperature. Furthermore, the paradoxical eating behavior induced orexin-A is illustrated in this minireview.

  3. Simulating sympathetic detonation using the hydrodynamic models and constitutive equations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo Hoon; Kim, Min Sung; Yoh, Jack J. [Dept. of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Sun, Tae Boo [Hanwha Corporation Defense Rand D Center, Daejeon (Korea, Republic of)

    2016-12-15

    A Sympathetic detonation (SD) is a detonation of an explosive charge by a nearby explosion. Most of times it is unintended while the impact of blast fragments or strong shock waves from the initiating donor explosive is the cause of SD. We investigate the SD of a cylindrical explosive charge (64 % RDX, 20 % Al, 16 % HTPB) contained in a steel casing. The constitutive relations for high explosive are obtained from a thermo-chemical code that provides the size effect data without the rate stick data typically used for building the rate law and equation of state. A full size SD test of eight pallet-packaged artillery shells is performed that provides the pressure data while the hydrodynamic model with proper constitutive relations for reactive materials and the fragmentation model for steel casing is conducted to replicate the experimental findings. The work presents a novel effort to accurately model and reproduce the sympathetic detonation event with a reduced experimental effort.

  4. Orexin-A controls sympathetic activity and eating behavior

    Directory of Open Access Journals (Sweden)

    Giovanni eMessina

    2014-09-01

    Full Text Available It is extremely important for the health to understand the regulatory mechanisms of energy expenditure. These regulatory mechanisms play a central role in the pathogenesis of body weight alteration. The hypothalamus integrates nutritional information derived from all peripheral organs. This region of the brain controls hormonal secretions and neural pathways of the brainstem. Orexin-A is a hypothalamic neuropeptide involved in the regulation of feeding behavior, sleep-wakefulness rhythm, and neuroendocrine homeostasis. This neuropeptide is involved in the control of the sympathetic activation, blood pressure, metabolic status, and blood glucose level. This minireview focuses on relationship between the sympathetic nervous system and orexin-A in the control of eating behavior and energy expenditure. The thermoregulatory hypothesis of food intake is analyzed, underlining the role played by orexin-A in the control of food intake related to body temperature. Furthermore, the paradoxical eating behavior induced orexin-A is illustrated in this minireview.

  5. A Rare Tumor in the Cervical Sympathetic Trunk: Ganglioneuroblastoma

    Directory of Open Access Journals (Sweden)

    Ozan Erol

    2016-01-01

    Full Text Available Ganglioneuroblastoma is a rare tumor with moderate malignancy, which is composed of mature ganglion cells and seen in sympathetic ganglia and adrenal medulla. The diagnosis is possible after cytological and immunohistochemical studies following a needle biopsy or surgical excision. There is no consensus regarding the need for chemo- or radiotherapy after surgery. In this case report, clinical behavior and diagnosis and treatment of the rare tumor cervical ganglioneuroblastoma were discussed.

  6. Sympathetic cooling of $^4$He$^+$ ions in a radiofrequency trap

    CERN Document Server

    Roth, B; Schiller, S

    2004-01-01

    We have generated Coulomb crystals of ultracold $^4$He$^+$ ions in a linear radiofrequency trap, by sympathetic cooling via laser--cooled $^9$Be$^+$. Stable crystals containing up to 150 localized He$^+$ ions at $\\sim$20 mK were obtained. Ensembles or single ultracold He$^+$ ions open up interesting perspectives for performing precision tests of QED and measurements of nuclear radii. The present work also indicates the feasibility of cooling and crystallizing highly charged atomic ions using $^9$Be$^+$ as coolant.

  7. Effects of leptin on sympathetic nerve activity in conscious mice.

    Science.gov (United States)

    Morgan, Donald A; Despas, Fabien; Rahmouni, Kamal

    2015-09-01

    The adipocyte-derived hormone, leptin, has emerged as an important regulator of regional sympathetic nerve activity (SNA) with pathophysiological implications in obesity. Genetically engineered mice are useful to understand the molecular pathways underlying the SNA responses evoked by leptin. However, so far the effect of leptin on direct SNA in mice has been studied under general anesthesia. Here, we examined the sympathetic responses evoked by leptin in conscious mice. Mice were instrumented, under ketamine/xylazine anesthesia, with renal or lumbar SNA recordings using a thin (40 gauge) bipolar platinum-iridium wire. The electrodes were exteriorized at the nape of the neck and mice were allowed (5 h) to recover from anesthesia. Interestingly, the reflex increases in renal and lumbar SNA caused by sodium nitroprusside (SNP)-induced hypotension was higher in the conscious phase versus the anesthetized state, whereas the increase in both renal and lumbar SNA evoked by leptin did not differ between anesthetized or conscious mice. Next, we assessed whether isoflurane anesthesia would yield a better outcome. Again, the SNP-induced increase in renal SNA and baroreceptor-renal SNA reflex were significantly elevated in the conscious states relative to isoflurane-anesthetized phase, but the renal SNA response induced by leptin in the conscious states were qualitatively comparable to those evoked above. Thus, despite improvement in sympathetic reflexes in conscious mice the sympathetic responses evoked by leptin mimic those induced during anesthesia. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  8. [The somato-sympathetic and somato-somatic reflexes in the spontaneous hypertensive rats].

    Science.gov (United States)

    Shcherbin, Iu I; Tsyrlin, V A

    2014-01-01

    In anaesthetized normotensive (Wistar) and hypertensive (SHR) rats, sympathetic and somatic reflexes were studied before and after cervical spinal cord transection. Single shock stimulation of a peripheral afferent nerve of brachial plexus produced reflex discharges in the cervical sympathetic trunk and the radial nerve. In rats with intact brain stem, evoked response in the cervical sympathetic trunk was composed of three components, but evoked response in radial nerve consisted of two components. The total somato-sympathetic reflex in hypertensive rats was more on 54 % than the somato-sympathetic reflex in normotensive rats. The total somato-somatic reflex in hypertensive rats was more on 70 % than the somato-somatic reflex in normotensive rats. In rats with transected brain stem, evoked response in the cervical sympathetic trunk was composed of two components, but evoked response in radial nerve consisted of one component. After neuraxis transection the total sympathetic and somatic reflexes in normotensive rats decreased by 85 and 83 %, respectively. The total sympathetic and somatic reflexes in hypertensive rats decreased by 88 and 84 %, respectively. However, the peak value of evoked discharges in sympathetic and somatic nerves were more in hypertensive rats than in normotensive rats. Suprasegmental and spinal mechanisms responsible for the augmentation of both sympathetic and somatic reflexes are discussed.

  9. Sympathetic Responses to Noxious Stimulation of Muscle and Skin.

    Science.gov (United States)

    Burton, Alexander R; Fazalbhoy, Azharuddin; Macefield, Vaughan G

    2016-01-01

    Acute pain triggers adaptive physiological responses that serve as protective mechanisms that prevent continuing damage to tissues and cause the individual to react to remove or escape the painful stimulus. However, an extension of the pain response beyond signaling tissue damage and healing, such as in chronic pain states, serves no particular biological function; it is maladaptive. The increasing number of chronic pain sufferers is concerning, and the associated disease burden is putting healthcare systems around the world under significant pressure. The incapacitating effects of long-lasting pain are not just psychological - reflexes driven by nociceptors during the establishment of chronic pain may cause serious physiological consequences on regulation of other body systems. The sympathetic nervous system is inherently involved in a host of physiological responses evoked by noxious stimulation. Experimental animal and human models demonstrate a diverse array of heterogeneous reactions to nociception. The purpose of this review is to understand how pain affects the sympathetic nervous system by investigating the reflex cardiovascular and neural responses to acute pain and the long-lasting physiological responses to prolonged (tonic) pain. By observing the sympathetic responses to long-lasting pain, we can begin to understand the physiological consequences of long-term pain on cardiovascular regulation.

  10. Sympathetic nerves bridge the cross-transmission in hemifacial spasm.

    Science.gov (United States)

    Zheng, Xuesheng; Hong, Wenyao; Tang, Yinda; Wu, Zhenghai; Shang, Ming; Zhang, Wenchuan; Zhong, Jun; Li, Shiting

    2012-05-23

    The pathophysiologic basis of hemifacial spasm is abnormal cross-transmission between facial nerve fibers. The author hypothesized that the demyelinated facial nerve fibers were connected with the sympathetic nerve fibers on the offending artery wall, and thus the latter function as a bridge in the cross-transmission circuit. This hypothesis was tested using a rat model of hemifacial spasm. A facial muscle response was recorded while the offending artery wall was electrically stimulated. The nerve fibers on the offending artery wall were blocked with lidocaine, or the superior cervical ganglion, which innervates the offending artery, was resected, and meanwhile the abnormal muscle response was monitored and analyzed. A waveform was recorded from the facial muscle when the offending artery wall was stimulated, named as "Z-L response". The latency of Z-L response was different from that of abnormal muscle response. When the nerve fibers on the offending artery wall were blocked by lidocaine, the abnormal muscle response disappeared gradually and recovered in 2h. The abnormal muscle response disappeared permanently after the sympathetic ganglion was resected. Our findings indicate that cross-transmission between the facial nerve fibers is bridged by the nerve fibers on the offending artery wall, probably sympathetic nerve fibers.

  11. Desflurane increases heart rate independent of sympathetic activity in dogs.

    Science.gov (United States)

    Picker, O; Schwarte, L A; Schindler, A W; Scheeren, T W L

    2003-12-01

    Desflurane has been shown to increase sympathetic activity and heart rate (HR) in a concentration-dependent manner. Nevertheless, desflurane, like all other volatile anaesthetics, increased HR in parallel to vagal inhibition in a previous study. Therefore, our hypothesis is that desflurane elicits tachycardia by vagal inhibition rather than by activation of the sympathetic nervous system. Six dogs were studied awake and during desflurane anaesthesia (1 and 2 MAC) alone, after pretreatment with propranolol (2 mg kg(-1) followed by 1 mg kg(-1) h(-1)), or after pre-treatment with atropine (0.1 mg kg(-1) followed by 0.05 mg kg(-1) h(-1)). The effects on HR and HR variability were compared by an analysis of variance (P MAC of desflurane from about 60 (awake) to 118 +/- 2 beats min(-1) (mean +/- SEM) in controls and to 106 +/- 3 beats min(-1) in dogs pre-treated with propranolol. In contrast, pretreatment with atropine increased HR from 64 +/- 2 to 147 +/- 5 beats min(-1) (awake) and HR decreased to 120 +/- 5 beats min(-1) after adding desflurane. High-frequency power correlated inversely with HR (r2 = 0.95/0.93) during desflurane alone and in the presence of beta-adrenoceptor blockade, with no significant difference between regression lines. There was no correlation between these variables during atropine/desflurane. The increase in HR elicited by desflurane mainly results from vagal inhibition and not from sympathetic activation.

  12. Understanding paroxysmal sympathetic hyperactivity after traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Kimberly S Meyer

    2014-01-01

    Full Text Available Background: Paroxysmal sympathetic hyperactivity (PSH is a condition occurring in a small percentage of patients with severe traumatic brain injury (TBI. It is characterized by a constellation of symptoms associated with excessive adrenergic output, including tachycardia, hypertension, tachypnea, and diaphoresis. Diagnosis is one of exclusion and, therefore, is often delayed. Treatment is aimed at minimizing triggers and pharmacologic management of symptoms. Methods: A literature review using medline and cinahl was conducted to identify articles related to PSH. Search terms included paroxysmal sympathetic hyperactivity, autonomic storming, diencephalic seizures, and sympathetic storming. Reference lists of pertinent articles were also reviewed and these additional papers were included. Results: The literature indicates that the understanding of PSH following TBI is in its infancy. The majority of information is based on small case series. The review revealed treatments that may be useful in treating PSH. Conclusions: Nurses play a critical role in the identification of at-risk patients, symptom complexes, and in the education of family. Early detection and treatment is likely to decrease overall morbidity and facilitate recovery. Further research is needed to establish screening tools and treatment algorithms for PSH.

  13. Sympathetic nerve activity and simulated diving in healthy humans.

    Science.gov (United States)

    Shamsuzzaman, Abu; Ackerman, Michael J; Kuniyoshi, Fatima Sert; Accurso, Valentina; Davison, Diane; Amin, Raouf S; Somers, Virend K

    2014-04-01

    The goal of our study was to develop a simple and practical method for simulating diving in humans using facial cold exposure and apnea stimuli to measure neural and circulatory responses during the stimulated diving reflex. We hypothesized that responses to simultaneous facial cold exposure and apnea (simulated diving) would be synergistic, exceeding the sum of responses to individual stimuli. We studied 56 volunteers (24 female and 32 male), average age of 39 years. All subjects were healthy, free of cardiovascular and other diseases, and on no medications. Although muscle sympathetic nerve activity (MSNA), blood pressure, and vascular resistance increased markedly during both early and late phases of simulated diving, significant reductions in heart rate were observed only during the late phase. Total MSNA during simulated diving was greater than combined MSNA responses to the individual stimuli. We found that simulated diving is a powerful stimulus to sympathetic nerve traffic with significant bradycardia evident in the late phase of diving and eliciting synergistic sympathetic and parasympathetic responses. Our data provide insight into autonomic triggers that could help explain catastrophic cardiovascular events that may occur during asphyxia or swimming, such as in patients with obstructive sleep apnea or congenital long QT syndrome.

  14. Neuronal morphology and the synaptic organisation of sympathetic ganglia.

    Science.gov (United States)

    Gibbins, I L; Jobling, P; Messenger, J P; Teo, E H; Morris, J L

    2000-07-01

    In this article, we provide a short review of the structure and synaptic organisation of the final motor neurons in the sympathetic ganglia of mammals. Combinations of pathway tracing, multiple-labelling immunofluorescence and intracellular dye injection have shown that neurons in different functional pathways differ not only in their patterns of neuropeptide expression, but also in the size of their cell bodies and dendritic fields. Thus, vasoconstrictor neurons consistently are smaller than any other major functional class of neurons. Serial section ultrastructural analysis of dye filled neurons, together with electron microscopic and confocal microscopic analysis of immunolabelled synaptic inputs to sympathetic final motor neurons indicate that synapses are rare and randomly distributed over the surface of the neurons. The total number of synapses is simply proportional to the total surface area of the neurons. Many terminal boutons of peptide-containing preganglionic neurons do not make conventional synapses with target neurons. Furthermore, there is a spatial mismatch in the distribution of peptide-containing terminals and neurons expressing receptors for the corresponding peptides. Together, these results suggest that there are likely to be significant differences in the ways that the final sympathetic motor neurons in distinct functional pathways integrate their synaptic inputs. In at least some pathways, heterosynaptic actions of neuropeptides probably contribute to subtle modulation of ganglionic transmission.

  15. Local Sympathetic Denervation of Femoral Artery in a Rabbit Model by Using 6-Hydroxydopamine In Situ

    Directory of Open Access Journals (Sweden)

    Yufei Jin

    2014-01-01

    Full Text Available Both artery bundle and sympathetic nerve were involved with the metabolism of bone tissues. Whether the enhancing effects of artery bundle result from its accompanying sympathetic nerve or blood supply is still unknown. There is no ideal sympathetic nerve-inhibited method for the in situ denervation of artery bundle. Therefore, we dipped the femoral artery in the 6-hydroxydopamine (6-OHDA locally and observed its effect. Compared with control group, the in situ treatment of 6-OHDA did not damage the normal structure of vascular bundle indicated by hematoxylin-eosin (HE staining. However, the functions of sympathetic nerve was completely inhibited for more than 2 weeks, and only a few function of sympathetic nerve resumed 4 weeks later, evidenced by glyoxylic acid staining and the expression of tyrosine hydroxylase (TH and nerve peptide Y (NPY. Thus, 6-OHDA is promising as an ideal reagent for the local denervation of sympathetic nerve from artery system.

  16. Neural regulation of gastrointestinal inflammation: role of the sympathetic nervous system.

    Science.gov (United States)

    Cervi, Andrea L; Lukewich, Mark K; Lomax, Alan E

    2014-05-01

    The sympathetic innervation of the gastrointestinal (GI) tract regulates motility, secretion and blood flow by inhibiting the activity of the enteric nervous system (ENS) and direct vasoconstrictor innervation of the gut microvasculature. In addition to these well-established roles, there is evidence that the sympathetic nervous system (SNS) can modulate GI inflammation. Postganglionic sympathetic neurons innervate lymphoid tissues and immune cells within the GI tract. Furthermore, innate and adaptive immune cells express receptors for sympathetic neurotransmitters. Activation of these receptors can affect a variety of important immune cell functions, including cytokine release and differentiation of helper T lymphocyte subsets. This review will consider the neuroanatomical evidence of GI immune cell innervation by sympathetic axons, the effects of blocking or enhancing SNS activity on GI inflammation, and the converse modulation of sympathetic neuroanatomy and function by GI inflammation.

  17. The effect of the transplanted pineal gland on the sympathetic innervation of the rat sublingual gland.

    Science.gov (United States)

    Chanthaphavong, R S; Murphy, S M; Anderson, C R

    2004-08-01

    We investigated the effect of the pineal on sympathetic neurons that normally innervate the sublingual gland of the rat. When the pineal gland was transplanted into the sublingual gland, it remained as a distinct mass that was innervated by sympathetic axons. Injection of the retrograde tracer, Fast Blue, into the sublingual gland labelled sympathetic neurons in the ipsilateral superior cervical ganglion (SCG). Thirty per cent of all neurons labelled retrogradely by Fast Blue injection into transplanted pineal glands were immunoreactive for both neuropeptide Y (NPY) and calbindin. This combination is characteristic of sympathetic neurons innervating the pineal gland in its normal location, but not the sympathetic vasoconstrictor neurons normally innervating the sublingual gland. This, and our previous study in which the pineal gland was shown to similarly influence the phenotype of salivary secretomotor neurons, suggests that a range of different functional classes of sympathetic neuron are able to change their phenotype in response to signals released by the pineal gland.

  18. [Sympathetic nerve activity in chronic renal failure - what are the therapeutic options?].

    Science.gov (United States)

    Hausberg, M; Tokmak, F

    2013-11-01

    Patients with chronic renal failure are characterized by a tonic elevation of sympathetic tone. This factor largely contributes to their increased cardiovascular risk. The increased sympathetic drive is caused by activiation of renal afferent fibers in the diseased kidneys. Therapeutic options for hypertensive patients with chronic renal failure with respect to their sympathetic overactivity are inhibitors of the renin-angiotensin-system and central sympatholytic drugs. The role of catheter-based renal denervation in these patients is currently under investigation.

  19. Sympathetic Blocks Provided Sustained Pain Relief in a Patient with Refractory Painful Diabetic Neuropathy

    OpenAIRE

    2012-01-01

    The sympathetic nervous system has been implicated in pain associated with painful diabetic neuropathy. However, therapeutic intervention targeted at the sympathetic nervous system has not been established. We thus tested the hypothesis that sympathetic nerve blocks significantly reduce pain in a patient with painful diabetic neuropathy who has failed multiple pharmacological treatments. The diagnosis of small fiber sensory neuropathy was based on clinical presentations and confirmed by skin ...

  20. Statins decrease dendritic arborization in rat sympathetic neurons by blocking RhoA activation

    OpenAIRE

    Kim, Woo-Yang; Gonsiorek, Eugene A.; Barnhart, Chris; Davare, Monika A.; Engebose, Abby J.; Lauridsen, Holly; Bruun, Donald; Lesiak, Adam; Wayman, Gary; Bucelli, Robert; Higgins, Dennis; Lein, Pamela J.

    2009-01-01

    Clinical and experimental evidence suggest that statins decrease sympathetic activity, but whether peripheral mechanisms involving direct actions on post-ganglionic sympathetic neurons contribute to this effect is not known. Because tonic activity of these neurons is directly correlated with the size of their dendritic arbor, we tested the hypothesis that statins decrease dendritic arborization in sympathetic neurons. Oral administration of atorvastatin (20 mg/kg/day for 7 days) significantly...

  1. Cardiorenal axis and arrhythmias: Will renal sympathetic denervation provide additive value to the therapeutic arsenal?

    Science.gov (United States)

    van Brussel, Peter M; Lieve, Krystien V V; de Winter, Robbert J; Wilde, Arthur A M

    2015-05-01

    Disruption of sympathetic tone may result in the occurrence or maintenance of cardiac arrhythmias. Multiple arrhythmic therapies that intervene by influencing cardiac sympathetic tone are common in clinical practice. These vary from pharmaceutical (β-blockers, angiotensin-converting enzyme inhibitors, and calcium antagonists) to percutaneous/surgical (cardiac sympathetic denervation) interventions. In some patients, however, these therapies have insufficient prophylactic and therapeutic capabilities. A safe and effective additional therapy wherein sympathetic drive is further attenuated would be expedient. Recently, renal sympathetic denervation (RSD) has been subject of research for various sympathetic nervous system-related diseases. By its presumed afferent and efferent sympatholytic effects, RSD might indirectly attenuate sympathetic outflow via the brain to the heart but might also reduce systemic catecholamine excretion and might therefore reduce catecholamine-sensitive arrhythmias. RSD is subject of research for various sympathetically driven arrhythmias, both supraventricular and ventricular. In this review, we give an overview of the rationale behind RSD as potential therapy in mediating arrhythmias that are triggered by a disrupted sympathetic nervous system and discuss the presently available results from animal and human studies.

  2. Renal sympathetic nerve activity during asphyxia in fetal sheep.

    Science.gov (United States)

    Booth, Lindsea C; Malpas, Simon C; Barrett, Carolyn J; Guild, Sarah-Jane; Gunn, Alistair J; Bennet, Laura

    2012-07-01

    The sympathetic nervous system (SNS) is an important mediator of fetal adaptation to life-threatening in utero challenges, such as asphyxia. Although the SNS is active well before term, SNS responses mature significantly over the last third of gestation, and its functional contribution to adaptation to asphyxia over this critical period of life remains unclear. Therefore, we examined the hypotheses that increased renal sympathetic nerve activity (RSNA) is the primary mediator of decreased renal vascular conductance (RVC) during complete umbilical cord occlusion in preterm fetal sheep (101 ± 1 days; term 147 days) and that near-term fetuses (119 ± 0 days) would have a more rapid initial vasomotor response, with a greater increase in RSNA. Causality of the relationship of RSNA and RVC was investigated using surgical (preterm) and chemical (near-term) denervation. All fetal sheep showed a significant increase in RSNA with occlusion, which was more sustained but not significantly greater near-term. The initial fall in RVC was more rapid in near-term than preterm fetal sheep and preceded the large increase in RSNA. These data suggest that although RSNA can increase as early as 0.7 gestation, it is not the primary determinant of RVC. This finding was supported by denervation studies. Interestingly, chemical denervation in near-term fetal sheep was associated with an initial fall in blood pressure, suggesting that by 0.8 gestation sympathetic innervation of nonrenal vascular beds is critical to maintain arterial blood pressure during the rapid initial adaptation to asphyxia.

  3. Projection neurons of the vestibulo-sympathetic reflex pathway.

    Science.gov (United States)

    Holstein, Gay R; Friedrich, Victor L; Martinelli, Giorgio P

    2014-06-15

    Changes in head position and posture are detected by the vestibular system and are normally followed by rapid modifications in blood pressure. These compensatory adjustments, which allow humans to stand up without fainting, are mediated by integration of vestibular system pathways with blood pressure control centers in the ventrolateral medulla. Orthostatic hypotension can reflect altered activity of this neural circuitry. Vestibular sensory input to the vestibulo-sympathetic pathway terminates on cells in the vestibular nuclear complex, which in turn project to brainstem sites involved in the regulation of cardiovascular activity, including the rostral and caudal ventrolateral medullary regions (RVLM and CVLM, respectively). In the present study, sinusoidal galvanic vestibular stimulation was used to activate this pathway, and activated neurons were identified through detection of c-Fos protein. The retrograde tracer Fluoro-Gold was injected into the RVLM or CVLM of these animals, and immunofluorescence studies of vestibular neurons were conducted to visualize c-Fos protein and Fluoro-Gold concomitantly. We observed activated projection neurons of the vestibulo-sympathetic reflex pathway in the caudal half of the spinal, medial, and parvocellular medial vestibular nuclei. Approximately two-thirds of the cells were ipsilateral to Fluoro-Gold injection sites in both the RVLM and CVLM, and the remainder were contralateral. As a group, cells projecting to the RVLM were located slightly rostral to those with terminals in the CVLM. Individual activated projection neurons were multipolar, globular, or fusiform in shape. This study provides the first direct demonstration of the central vestibular neurons that mediate the vestibulo-sympathetic reflex.

  4. Microvascular reactivity during sympathetic stimulations in Raynaud's phenomenon.

    Science.gov (United States)

    Stoyneva, Zlatka B; Dermendjiev, Svetlan M; Medjidieva, Daniela G; Vodenicharov, Vlayko E

    2016-12-01

    The objective of the study was to assess skin autonomic microvascular reactivity to sympathetic stimulations and its association with primary and secondary Raynaud's phenomenon (RP). Laser-Doppler recorded finger pulp skin blood flow was monitored during orthostatic and deep breathing tests of 4 subjects groups, each of them composed of 20 subjects: group 1, healthy controls; group 2, vibration-induced secondary RP (vRP); group 3, primary RP (pRP); group 4, systemic sclerosis-related secondary RP (sclRP). Within groups comparisons by Wilcoxon matched pairs rank test and between groups by Bonferroni's multiple test for unpaired data were done using SPSS Statistics software. Reliably lower initial perfusion values were established in all the RP patients. The local sympathetic axon-reflex mediated responses to orthostasis were reduced in all RP groups with increased perfusions in upright posture instead of decreased. The vasoconstrictor responses to deep breathing tended to increase instead of decreasing in the vRP and pRP groups, while in the sclRP group the perfusions decreased. Strong correlations between the initial finger pulp perfusions and the orthostatic and deep breathing perfusion responses were found in the control, pRP and vRP groups (P<0.0001) and a modest correlation between the initial perfusions and the deep breathing perfusion responses in the sclRP group. Abnormal cutaneous microvascular reactivity to central and local axon-reflex sympathetic stimulations was established in RP patients reflecting self-regulatory dysfunctions which might contribute to the manifestations of the ischemic microcirculatory paroxysms. Laser Doppler flowmetry with functional orthostatic and deep breathing tests contribute to the diagnosis of RP.

  5. Sensory and sympathetic innervation of cervical facet joint in rats

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hai-yu; CHEN An-min; GUO Feng-jing; LIAO Guang-jun; XIAO Wei-dong

    2006-01-01

    Objective: To explore the patterns of innervation of cervical facet joints and determine the pathways from facet joints to dorsal root ganglions (DRGs) in order to clarify the causes of diffuse neck pain, headache, and shoulder pain.Methods: Forty-two male Sprague-Dawley rats,weighing 250-300 g, were randomly divided into three groups: Group A ( n = 18), Group B ( n = 18), and Group C (n = 6 ). Under anesthesia with intraperitoneal pentobarbital sodium (45 mg/kg body weight), a midline dorsal longitudinal incision was made over the cervical spine to expose the left cervical facet joint capsule of all the rats under a microscope. The rats in Group A underwent sympathectomy, but the rats in Group B and Group C did not undergo sympathectomy. Then 0.6 μl 5 % bisbenzimide (Bb) were injected into the C1-2, C3-4 and C5-6 facet joints of 6 rats respectively in Group A and Group B. The holes were immediately sealed with mineral wax to prevent leakage of Bb and the fascia and skin were closed. But in Group C, 0.9% normal saline was injected into the corresponding joint capsules. Then under deep reanesthesia with intraperitoneal pentobarbital sodium (45 mg/kg body weight), C1-C8 left DRGs in all rats and the sympathetic ganglions in Group B were obtained and the number of the labeled neurons was determined.Results: Neurons labeled with Bb were present in C1-C8 DRGs in both Group A and Group B, and sympathetic ganglions in Group B. In the C1-2 and C3-4 subgroups,labeled neurons were present from C1 to C8 DRGs, while in C5-6 subgroups they were from C, to C8. The number of Bb ( + ) neurons after sympathectomy was not significantly different in the injected level from that without sympathectomy. But in the other levels, the number of Bb ( + ) neurons after sympathectomy was significantly less than that without sympathectomy.Conclusions: The innervation of the cervical facet joints is derived from both sensory and sympathetic nervous system, and DRGs are associated with

  6. Further evidence for peptidergic transmission in sympathetic ganglia.

    OpenAIRE

    Jan, Y N; Jan, L Y; Kuffler, S W

    1980-01-01

    We previously proposed that, in sympathetic ganglia of the bullfrog, a peptide which resembles luteinizing hormone-releasing factor (LH-RF, luliberin) functions as the transmitter for the late slow excitatory postsynaptic potential (epsp), a signal that may last 5-10 min. To test this hypothesis further, we have compared the physiological andpharmacological effects of LH-RF with those of the natural transmitter and have found a close parallel. (i) LH-RF, when ejected with a brief pulse of pre...

  7. Sympathetic Wigner-function tomography of a dark trapped ion

    DEFF Research Database (Denmark)

    Mirkhalaf, Safoura; Mølmer, Klaus

    2012-01-01

    A protocol is provided to reconstruct the Wigner function for the motional state of a trapped ion via fluorescence detection on another ion in the same trap. This “sympathetic tomography” of a dark ion without optical transitions suitable for state measurements is based on the mapping of its...... motional state onto one of the collective modes of the ion pair. The quantum state of this vibrational eigenmode is subsequently measured through sideband excitation of the bright ion. Physical processes to implement the desired state transfer are derived and the accomplishment of the scheme is evaluated...

  8. Differential activation of sympathetic discharge to skin and skeletal muscle in humans.

    Science.gov (United States)

    Vissing, S F

    1997-01-01

    The present work provides insight into the relative contribution of different mechanisms in regulating sympathetic discharge to skin and skeletal muscle in humans. Activation of sympathetic nerve activity during common behaviours such as orthostasis and exercise was shown to be highly selective, depending on the specific sympathetic outflow under study. Regarding orthostasis, data from experiments in this thesis revoked the concept that cardiopulmonary afferents only regulate muscle vascular resistance in the forearm, not in the leg. Also the concept that the cutaneous circulation is under baroreceptor control has been challenged. Unloading cardiopulmonary afferents with lower body negative pressure elicited intensity dependent increases in peroneal sympathetic discharge to skeletal muscle, and increases in forearm and calf vascular resistances. Therefore, it was concluded that cardiopulmonary afferents regulate vascular resistance in skeletal muscle of both forearm and calf, suggesting an important role for these afferents in the reflex adjustments to upright posture. In contrast to muscle sympathetic nerve activity, baroreceptor deactivation with lower body negative pressure had no effect on skin sympathetic nerve activity or skin vascular resistance. However, assumption of upright posture increased skin vascular resistance, this increase was abolished when increased vascular transmural pressure was avoided by elevating the arm. Local cutaneous nerve blockade, but not blockade of efferent sympathetic nerve traffic, abolished the vasoconstrictor response to upright posture. Based on these experiments, it was concluded that baroreceptor afferents do not regulate sympathetic vasoconstrictor outflow to the cutaneous circulation. During upright posture at normothermia cutaneous vasoconstriction is mainly driven by a local reflex. To explain activation of sympathetic outflow during exercise two theories have been proposed. One is that a "central motor command" signal

  9. Hydralazine tachycardia and sympathetic cardiovascular reactivity in normal subjects.

    Science.gov (United States)

    Vidrio, H; Tena, I

    1980-11-01

    The correlation between hydralazine-induced tachycardia and overall cardiovascular reactivity to sympathetic stimulation was explored in 50 normal subjects. Blood pressure and heart rate changes after standing, immersion of a hand in cold water, the Valsalva maneuver, and moderate exercise were compared with pressure and rate responses to 20 mg oral hydralazine. The drug did not modify blood pressure but increased heart rate, mainly in the standing position. Because plotting the magnitude of this response suggested a two-population distribution, subjects were divided into hyporeactor and hyperreactor groups. Reactivity did not appear to be related to acetylator phenotype. The magnitude of the cardiac response correlated with heart rate responses to standing and to the Valsalva maneuver; when analyzed separately from hyporeactors, correlation was greater among hyperreactors. Because the orthostatic and Valsalva responses are reflex in nature, these results suggest that hydralazine tachycardia is also reflexly induced, that its magnitude depends on individual baroreceptor sensitivity, which is distributed nonnormally, and that it can be predicted by suitable tests of sympathetic responsiveness.

  10. Gudmundur Finnbogason, "sympathetic understanding," and early Icelandic psychology.

    Science.gov (United States)

    Pind, Jörgen L

    2008-05-01

    Gudmundur Finnbogason (1873-1944) was a pioneer of Icelandic psychology. He was educated at the University of Copenhagen where he finished his M.A. in 1901 in philosophy, specializing in psychology. During the years 1901-1905, Finnbogason played a major role in establishing and shaping the future of primary education in Iceland. He defended his doctoral thesis on "sympathetic understanding" at the University of Copenhagen in 1911. This work deals with the psychology of imitation. In it Finnbogason defends the view that imitation is basically perception so that there is a direct link from perception to motor behavior. Through imitation people tend to assume the countenance and demeanor of other people, thus showing, in Finnbogason's terminology, "sympathetic understanding." Finnbogason's theory of imitation in many respects anticipates contemporary approaches to the psychology of imitation. In 1918 Finnbogason became professor of applied psychology at the recently founded University of Iceland. Here he attempted to establish psychology as an independent discipline. In this he was unsuccessful; his chair was abolished in 1924.

  11. Effects of Antidepressants, but not Psychopathology, on Cardiac Sympathetic Control : A Longitudinal Study

    NARCIS (Netherlands)

    Licht, Carmilla M. M.; Penninx, Brenda W. J. H.; de Geus, Eco J. C.

    2012-01-01

    Increased sympathetic activity has been hypothesized to have a role in the elevated somatic disease risk in persons with depressive or anxiety disorders. However, it remains unclear whether increased sympathetic activity reflects a direct effect of anxiety or depression or an indirect effect of anti

  12. Developmental gene expression of sympathetic nervous system tumors reflects their histogenesis.

    Science.gov (United States)

    Hoehner, J C; Hedborg, F; Eriksson, L; Sandstedt, B; Grimelius, L; Olsen, L; Påhlman, S

    1998-01-01

    Comparisons of the developing human sympathetic nervous system (SNS) to tumors presumed to derive from these cells may suggest tumor progenitors and predict tumor biologic behavior. Classic neuroblastoma (NB) and its more highly differentiated stroma-rich subtypes, extra-adrenal sympathetic paraganglioma, and pheochromocytoma were examined for the presence of the developmentally characterized gene products NSE, S-100, CD44, Bcl-2, HNK-1, PNMT, TrkA, IGF2, and tyrosine hydroxylase. The marker gene expression profiles of these tumors were compared with those similarly determined for a number of normal prenatal and postnatal human SNS cell types. Sympathetic paraganglioma, pheochromocytoma, and stroma-rich NB display marker expression profiles mimicking those of childhood sympathetic paraganglia, adrenal chromaffin cells, and sympathetic neurons, respectively. A selection of differentiating, extra-adrenal NB tumors with prognostically favorable features possess marker gene expression profiles paralleling that observed for fetal extra-adrenal sympathetic paraganglia/small intensely fluorescent cells. In contrast, undifferentiated, clinically aggressive NB tumors manifest characteristics mirroring that of embryonic/early fetal sympathetic neuroblasts of sympathetic ganglia and of the adrenal gland. These findings suggest that clinical features, such as primary tumor location and age at diagnosis, provide prognostic information for NB patients by virtue of the existence and biology of the presumed tumor progenitor cell type.

  13. The Sympathetic Release Test: A Test Used to Assess Thermoregulation and Autonomic Control of Blood Flow

    Science.gov (United States)

    Tansey, E. A.; Roe, S. M.; Johnson, C. J.

    2014-01-01

    When a subject is heated, the stimulation of temperature-sensitive nerve endings in the skin, and the raising of the central body temperature, results in the reflex release of sympathetic vasoconstrictor tone in the skin of the extremities, causing a measurable temperature increase at the site of release. In the sympathetic release test, the…

  14. Sympathetic nervous activity in cirrhosis. A survey of plasma catecholamine studies

    DEFF Research Database (Denmark)

    Henriksen, J H; Ring-Larsen, H; Christensen, N J

    1985-01-01

    in this condition. This may especially apply to the sympathetic tone in the kidney, as evaluated by regional measurements of noradrenaline overflow. Hepatic elimination of catecholamines is only slightly reduced. Activation of the sympathetic nervous system seems to play an important role in the avid sodium...

  15. Origins of the sympathetic innervation of the cervical end of the uterus in the rat.

    Science.gov (United States)

    Vera, P L; Haase, E B; Schramm, L P

    1997-01-30

    A retrograde neuronal tracer (Fast Blue) was injected in the cervical end of the uterine horn of virgin rats. The majority of the retrogradely labeled post-ganglionic sympathetic neurons were found in the sympathetic chain (74%). The superior mesenteric ganglia, inferior mesenteric ganglia and suprarenal ganglia accounted for 22, 3 and uterus resembles that described for other pelvic organs.

  16. Sympathetic skin response: simple test for evaluation of autonomic function in patients with diabetes mellitus?

    Institute of Scientific and Technical Information of China (English)

    Srinivasa Jayachandra; Maxim Pinto; Urban J. A. D'Souza

    2005-01-01

    @@ To the Editor: We read with interest the excellent article by Huang YN et al.1 This important and carefully conducted study illustrates the sympathetic skin response (SSR) test can detect early dysfunction of the small sympathetic fibers in people affected by diabetes mellitus.

  17. Sympathetic activity is increased in polycystic kidney disease and is associated with hypertension

    NARCIS (Netherlands)

    Klein, IHHT; Ligtenberg, G; Oey, PL; Koomans, HA; Blankestijn, PJ

    2001-01-01

    Hypertension is common in patients with polycystic kidney disease (PKD). This study addresses the hypothesis that sympathetic activity is enhanced in hypertensive PKD patients, not only when renal function is impaired but also when renal function is still normal. Muscle sympathetic nerve activity (M

  18. Effects of Antidepressants, but not Psychopathology, on Cardiac Sympathetic Control : A Longitudinal Study

    NARCIS (Netherlands)

    Licht, Carmilla M. M.; Penninx, Brenda W. J. H.; de Geus, Eco J. C.

    2012-01-01

    Increased sympathetic activity has been hypothesized to have a role in the elevated somatic disease risk in persons with depressive or anxiety disorders. However, it remains unclear whether increased sympathetic activity reflects a direct effect of anxiety or depression or an indirect effect of anti

  19. Regional sympathetic denervation after myocardial infarction in humans detected noninvasively using I-123-metaiodobenzylguanidine

    Energy Technology Data Exchange (ETDEWEB)

    Stanton, M.S.; Tuli, M.M.; Radtke, N.L.; Heger, J.J.; Miles, W.M.; Mock, B.H.; Burt, R.W.; Wellman, H.N.; Zipes, D.P. (Indiana Univ. School of Medicine, IN (USA))

    1989-11-15

    Transmural myocardial infarction in dogs produces denervation of sympathetic nerves in viable myocardium apical to the infarct that may be arrhythmogenic. It is unknown whether sympathetic denervation occurs in humans. The purpose of this study was to use iodine-123-metaiodobenzylguanidine (MIBG), a radiolabeled guanethidine analog that is actively taken up by sympathetic nerve terminals, to image noninvasively the cardiac sympathetic nerves in patients with and without ventricular arrhythmias after myocardial infarction. Results showed that 10 of 12 patients with spontaneous ventricular tachyarrhythmias after myocardial infarction exhibited regions of thallium-201 uptake indicating viable perfused myocardium, with no MIBG uptake. Such a finding is consistent with sympathetic denervation. One patient had frequent episodes of nonsustained ventricular tachycardia induced at exercise testing that was eliminated by beta-adrenoceptor blockade. Eleven of the 12 patients had ventricular tachycardia induced at electrophysiologic study and metoprolol never prevented induction. Sympathetic denervation was also detected in two of seven postinfarction patients without ventricular arrhythmias. Normal control subjects had no regions lacking MIBG uptake. This study provides evidence that regional sympathetic denervation occurs in humans after myocardial infarction and can be detected noninvasively by comparing MIBG and thallium-201 images. Although the presence of sympathetic denervation may be related to the onset of spontaneous ventricular tachyarrhythmias in some patients, it does not appear to be related to sustained ventricular tachycardia induced at electrophysiologic study.

  20. The Sympathetic Release Test: A Test Used to Assess Thermoregulation and Autonomic Control of Blood Flow

    Science.gov (United States)

    Tansey, E. A.; Roe, S. M.; Johnson, C. J.

    2014-01-01

    When a subject is heated, the stimulation of temperature-sensitive nerve endings in the skin, and the raising of the central body temperature, results in the reflex release of sympathetic vasoconstrictor tone in the skin of the extremities, causing a measurable temperature increase at the site of release. In the sympathetic release test, the…

  1. Effects of Antidepressants, but not Psychopathology, on Cardiac Sympathetic Control : A Longitudinal Study

    NARCIS (Netherlands)

    Licht, Carmilla M. M.; Penninx, Brenda W. J. H.; de Geus, Eco J. C.

    2012-01-01

    Increased sympathetic activity has been hypothesized to have a role in the elevated somatic disease risk in persons with depressive or anxiety disorders. However, it remains unclear whether increased sympathetic activity reflects a direct effect of anxiety or depression or an indirect effect of

  2. Sympathetic mediated vasomotion and skin capillary permeability in diabetic patients with peripheral neuropathy

    NARCIS (Netherlands)

    Lefrandt, JD; Hoeven, JH; Roon, AM; Smit, AJ; Hoogenberg, K

    2003-01-01

    Aims/hypothesis. A loss of sympathetic function could lead to changes in capillary fluid filtration in diabetic patients. We investigated whether a decreased sympathetically mediated vasomotion in the skin in diabetic patients with peripheral neuropathy is associated with an abnormal capillary leaka

  3. Relevance of Sympathetic Nervous System Activation in Obesity and Metabolic Syndrome.

    Science.gov (United States)

    Thorp, Alicia A; Schlaich, Markus P

    2015-01-01

    Sympathetic tone is well recognised as being implicit in cardiovascular control. It is less readily acknowledged that activation of the sympathetic nervous system is integral in energy homeostasis and can exert profound metabolic effects. Accumulating data from animal and human studies suggest that central sympathetic overactivity plays a pivotal role in the aetiology and complications of several metabolic conditions that can cluster to form the Metabolic Syndrome (MetS). Given the known augmented risk for type 2 diabetes, cardiovascular disease, and premature mortality associated with the MetS understanding the complex pathways underlying the metabolic derangements involved has become a priority. Many factors have been proposed to contribute to increased sympathetic nerve activity in metabolic abnormalities including obesity, impaired baroreflex sensitivity, hyperinsulinemia, and elevated adipokine levels. Furthermore there is mounting evidence to suggest that chronic sympathetic overactivity can potentiate two of the key metabolic alterations of the MetS, central obesity and insulin resistance. This review will discuss the regulatory role of the sympathetic nervous system in metabolic control and the proposed pathophysiology linking sympathetic overactivity to metabolic abnormalities. Pharmacological and device-based approaches that target central sympathetic drive will also be discussed as possible therapeutic options to improve metabolic control in at-risk patient cohorts.

  4. Insulin acts in the arcuate nucleus to increase lumbar sympathetic nerve activity and baroreflex function in rats

    National Research Council Canada - National Science Library

    Cassaglia, Priscila A; Hermes, Sam M; Aicher, Sue A; Brooks, Virginia L

    2011-01-01

    Non‐technical summary  Though the pancreatic hormone insulin is known to act in the brain to increase sympathetic nerve activity and baroreflex control of sympathetic nerve activity, its specific site of action had yet to be identified...

  5. Activation of histamine H3 receptors in human nasal mucosa inhibits sympathetic vasoconstriction.

    Science.gov (United States)

    Varty, LoriAnn M; Gustafson, Eric; Laverty, Maureen; Hey, John A

    2004-01-19

    The peripheral histamine H3 receptor is a presynaptic heterologous receptor located on postganglionic sympathetic nerve fibers innervating sympathetic effector systems such as blood vessels and the heart. An extensive body of evidence shows that activation of the histamine H3 receptor attenuates sympathetic tone by presynaptic inhibition of noradrenaline release. It is proposed that this sympathoinhibitory action, in vivo, leads to reduced vasoconstriction, thereby eliciting a vasodilatory effect. In humans, the peripheral histamine H3 receptor has also been shown to exert a sympathoinhibitory function on specific peripheral autonomic effector systems. For example, human saphenous vein and heart possess functional presynaptic histamine H3 receptors on the sympathetic nerve terminals that upon activation decrease the sympathetic tone to these respective organs. The present studies were conducted to define the role of histamine H3 receptors on neurogenic sympathetic vasoconstrictor responses in human nasal turbinate mucosa. Contractility studies were conducted to evaluate the effect of histamine H3 receptor activation on sympathetic vasoconstriction in surgically isolated human nasal turbinate mucosa. We found that the histamine H3 receptor agonist, (R)-alpha-methylhistamine (30 and 300 nM), inhibited electrical field stimulation-induced (neurogenic) sympathetic vasoconstriction in a concentration-dependent fashion. Pretreatment with the selective histamine H3 receptor antagonist, clobenpropit (100 nM), blocked the sympathoinhibitory effect of (R)-alpha-methylhistamine on the neurogenic sympathetic vasoconstriction. In addition, analysis of Taqman mRNA expression studies showed a specific, high level of distribution of the histamine H3 receptor localized in the human nasal mucosa. Taken together, these studies indicate that histamine H3 receptors modulate vascular contractile responses in human nasal mucosa most likely by inhibiting noradrenaline release from

  6. Egr3 dependent sympathetic target tissue innervation in the absence of neuron death.

    Directory of Open Access Journals (Sweden)

    Lin Li

    Full Text Available Nerve Growth Factor (NGF is a target tissue derived neurotrophin required for normal sympathetic neuron survival and target tissue innervation. NGF signaling regulates gene expression in sympathetic neurons, which in turn mediates critical aspects of neuron survival, axon extension and terminal axon branching during sympathetic nervous system (SNS development. Egr3 is a transcription factor regulated by NGF signaling in sympathetic neurons that is essential for normal SNS development. Germline Egr3-deficient mice have physiologic dysautonomia characterized by apoptotic sympathetic neuron death and abnormal innervation to many target tissues. The extent to which sympathetic innervation abnormalities in the absence of Egr3 is caused by altered innervation or by neuron death during development is unknown. Using Bax-deficient mice to abrogate apoptotic sympathetic neuron death in vivo, we show that Egr3 has an essential role in target tissue innervation in the absence of neuron death. Sympathetic target tissue innervation is abnormal in many target tissues in the absence of neuron death, and like NGF, Egr3 also appears to effect target tissue innervation heterogeneously. In some tissues, such as heart, spleen, bowel, kidney, pineal gland and the eye, Egr3 is essential for normal innervation, whereas in other tissues such as lung, stomach, pancreas and liver, Egr3 appears to have little role in innervation. Moreover, in salivary glands and heart, two tissues where Egr3 has an essential role in sympathetic innervation, NGF and NT-3 are expressed normally in the absence of Egr3 indicating that abnormal target tissue innervation is not due to deregulation of these neurotrophins in target tissues. Taken together, these results clearly demonstrate a role for Egr3 in mediating sympathetic target tissue innervation that is independent of neuron survival or neurotrophin deregulation.

  7. Glial cell line-derived neurotrophic factor (GDNF) enhances sympathetic neurite growth in rat hearts at early developmental stages

    NARCIS (Netherlands)

    K. Miwa; J.K. Lee; Y. Takagishi; T. Opthof; X. Fu; I. Kodama

    2010-01-01

    Molecular signaling of sympathetic innervation of myocardium is an unresolved issue. The purpose of this study was to investigate the effect of neurotrophic factors on sympathetic neurite growth towards cardiomyocytes. Cardiomyocytes (CMs) and sympathetic neurons (SNs) were isolated from neonatal ra

  8. Marked sympathetic activation and baroreflex dysfunction in true resistant hypertension.

    Science.gov (United States)

    Grassi, Guido; Seravalle, Gino; Brambilla, Gianmaria; Pini, Claudio; Alimento, Marina; Facchetti, Rita; Spaziani, Domenico; Cuspidi, Cesare; Mancia, Giuseppe

    2014-12-20

    An increase in sympathetic drive to the heart and the peripheral circulation characterizes mild and severe essential hypertension. However, it remains unsettled whether sympathetic cardiovascular influences are potentiated in true resistant hypertension (RHT). In 32 RHT patients treated with 4.6 ± 0.3 drugs (mean ± SEM) and aged 58.6 ± 2.1 years, 35 non-resistant treated hypertensives (HT) and 19 normotensive controls (NT), all age-matched with RHT, we measured clinic, 24-hour ambulatory and beat-to-beat blood pressures (BP), heart rate (HR, EKG), muscle sympathetic nerve traffic (MSNA, microneurography) and spontaneous baroreflex MSNA-sensitivity. BP values were markedly greater in RHT patients than in NT and HT (172.2 ± 1.7/100.7 ± 1.2 vs 132.1 ± 1.3/82.1 ± 0.9 and 135.5 ± 1.2/83.6 ± 0.9 mmHg, P < 0.01). This was paralleled by a significant and marked increase in MSNA (87.8 ± 2.0 vs 46.8 ± 2.6 and 59.3 ± 1.7 and bursts/100 heartbeats, P < 0.01). In multiple regression analysis the MSNA increase observed in RHT was significantly related to hemodynamic, hormonal and metabolic variables. It was also significantly related to plasma aldosterone values as well as spontaneous baroreflex MSNA-sensitivity, which were the variables that at the multivariate analysis were more closely related to the adrenergic activation of RHT after adjustment for confounders, including antihypertensive treatment (r(2)partial=0.04405 and r(2)partial=0.00878, P<0.05 for both). These data represent the first evidence that RHT is a state of marked adrenergic overdrive, greater for magnitude than that detectable in HT. They also suggest that impaired baroreflex mechanisms, along with hemodynamic and neurohumoral factors, may be responsible for the phenomenon. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Production and sympathetic cooling of complex molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chaobo

    2008-06-24

    This thesis reports on experimental and theoretical studies of the sympathetic cooling of complex molecular ions demonstrating that this general method for cooling atomic and molecular ions is reliable and efficient. For this purpose, complex molecular ions and barium ions have been confined simultaneously in a linear Paul trap. The complex molecular ions are generated in an electrospray ionization system and transferred to the trap via a 2 m long octopole ion guide. These molecular ions are pre-cooled by room temperature helium buffer gas so that they can be captured by the trap. The atomic barium ions are loaded from a barium evaporator oven and are laser-cooled by a 493 nm cooling laser and a 650 nm repumping laser. Due to the mutual Coulomb interaction among these charged particles, the kinetic energy of the complex molecular ions can be reduced significantly. In our experiments we have demonstrated the sympathetic cooling of various molecules (CO{sub 2}, Alexa Fluor 350, glycyrrhetinic acid, cytochrome c) covering a wide mass range from a few tens to 13000 amu. In every case the molecular ions could be cooled down to millikelvin temperatures. Photo-chemical reactions of the {sup 138}Ba{sup +} ions in the ({sup 2}P{sub 1/2}) excited state with gases such as O{sub 2}, CO{sub 2}, or N{sub 2}O, could be observed. If the initial {sup 138}Ba{sup +} ion ensemble is cold, the produced {sup 138}BaO{sup +} ions are cold as well, with a similar temperature as the laser-cooled barium ions (a few tens of millikelvin). The back-reaction of {sup 138}BaO{sup +} ions with neutral CO to {sup 138}Ba{sup +} is possible and was observed in our experiments as well. A powerful molecular dynamics (MD) simulation program has been developed. With this program dynamic properties of ion ensembles, such as sympathetic interactions or heating effects, have been investigated and experimental results have been analyzed to obtain, for example, ion numbers and temperatures. Additionally, the

  10. Highly sensitive index of sympathetic activity based on time-frequency spectral analysis of electrodermal activity.

    Science.gov (United States)

    Posada-Quintero, Hugo F; Florian, John P; Orjuela-Cañón, Álvaro D; Chon, Ki H

    2016-09-01

    Time-domain indices of electrodermal activity (EDA) have been used as a marker of sympathetic tone. However, they often show high variation between subjects and low consistency, which has precluded their general use as a marker of sympathetic tone. To examine whether power spectral density analysis of EDA can provide more consistent results, we recently performed a variety of sympathetic tone-evoking experiments (43). We found significant increase in the spectral power in the frequency range of 0.045 to 0.25 Hz when sympathetic tone-evoking stimuli were induced. The sympathetic tone assessed by the power spectral density of EDA was found to have lower variation and more sensitivity for certain, but not all, stimuli compared with the time-domain analysis of EDA. We surmise that this lack of sensitivity in certain sympathetic tone-inducing conditions with time-invariant spectral analysis of EDA may lie in its inability to characterize time-varying dynamics of the sympathetic tone. To overcome the disadvantages of time-domain and time-invariant power spectral indices of EDA, we developed a highly sensitive index of sympathetic tone, based on time-frequency analysis of EDA signals. Its efficacy was tested using experiments designed to elicit sympathetic dynamics. Twelve subjects underwent four tests known to elicit sympathetic tone arousal: cold pressor, tilt table, stand test, and the Stroop task. We hypothesize that a more sensitive measure of sympathetic control can be developed using time-varying spectral analysis. Variable frequency complex demodulation, a recently developed technique for time-frequency analysis, was used to obtain spectral amplitudes associated with EDA. We found that the time-varying spectral frequency band 0.08-0.24 Hz was most responsive to stimulation. Spectral power for frequencies higher than 0.24 Hz were determined to be not related to the sympathetic dynamics because they comprised less than 5% of the total power. The mean value of time

  11. Distrofia simpático-reflexa Reflex sympathetic dystrophy

    Directory of Open Access Journals (Sweden)

    Ana P. N. Lotito

    2004-04-01

    Full Text Available OBJETIVO: Descrever as características clínicas, laboratoriais e terapêuticas de oito crianças com distrofia simpático-reflexa. DESCRIÇÃO: Foram analisados retrospectivamente oito casos de distrofia simpático-reflexa. O diagnóstico foi baseado na presença de dor no segmento distal de um membro, edema local, alterações vasomotoras e de sensibilidade. Dentre os oito pacientes com distrofia simpático-reflexa, dois eram portadores de lúpus eritematoso sistêmico, um de artrite idiopática juvenil e um de trombastenia de Glanzmann. Quatro eram meninas, e a média de idade foi de 11,5 anos. Os membros inferiores foram acometidos na maioria dos pacientes (7/8, e as características clínicas mais marcantes foram dor, edema e alterações vasomotoras da extremidade afetada (7/8, incapacitação funcional (7/8 e alterações de sensibilidade (3/8. A velocidade de hemossedimentação esteve alterada em três pacientes, e a cintilografia músculo-esquelética em cinco. Todos os pacientes receberam antiinflamatórios não-hormonais e fisioterapia, com melhora clínica observada em sete pacientes em até 6 meses de tratamento. Três pacientes foram submetidos à acupuntura, com boa resposta. Um paciente teve curso de difícil controle, tendo recebido antidepressivos tricíclicos e apresentando melhora após mais de 1 ano de tratamento. COMENTÁRIOS: A distrofia simpático-reflexa é uma doença que deve ser incluída no diagnóstico diferencial das dores em membros na infância, para que se estabeleça o diagnóstico precocemente, evitando-se, assim, prejuízo funcional a médio e longo prazo.OBJECTIVE: To describe eight patients with reflex sympathetic dystrophy in terms of clinical and laboratory characteristics and treatment. DESCRIPTION: Eight children (four girls with reflex sympathetic dystrophy were retrospectively analyzed. The diagnosis of reflex sympathetic dystrophy was based on the presence of pain in the distal extremities, local

  12. Plasma dihydroxyphenylalanine (DOPA) is independent of sympathetic activity in humans

    DEFF Research Database (Denmark)

    Eldrup, E; Christensen, N J; Andreasen, J;

    1989-01-01

    To clarify the origin of plasma DOPA (3,4-Dihydroxyphenylalanine), the relationship between plasma DOPA and acute or chronic changes in sympathetic activity has been studied. Plasma DOPA and noradrenaline (NA) concentrations were measured by reverse-phase high-performance liquid chromatography...... in diabetic patients with autonomic neuropathy compared to diabetics without neuropathy, whereas baseline plasma DOPA concentrations were similar in the three groups investigated: 6.55 (5.03-7.26, median [interquartile range], n = 8) nmol l-1 in diabetics with neuropathy, 7.41 (5.79-7.97, n = 8) nmol l-1...... in diabetics without neuropathy, and 6.85 (5.58-7.36, n = 8) nmol l-1 in controls. No relationship was obtained between baseline values of plasma NE and plasma DOPA. Plasma DOPA did not change in the upright position, whereas plasma NE increased significantly. Our results indicate that plasma DOPA...

  13. Leptin regulates bone formation via the sympathetic nervous system

    Science.gov (United States)

    Takeda, Shu; Elefteriou, Florent; Levasseur, Regis; Liu, Xiuyun; Zhao, Liping; Parker, Keith L.; Armstrong, Dawna; Ducy, Patricia; Karsenty, Gerard

    2002-01-01

    We previously showed that leptin inhibits bone formation by an undefined mechanism. Here, we show that hypothalamic leptin-dependent antiosteogenic and anorexigenic networks differ, and that the peripheral mediators of leptin antiosteogenic function appear to be neuronal. Neuropeptides mediating leptin anorexigenic function do not affect bone formation. Leptin deficiency results in low sympathetic tone, and genetic or pharmacological ablation of adrenergic signaling leads to a leptin-resistant high bone mass. beta-adrenergic receptors on osteoblasts regulate their proliferation, and a beta-adrenergic agonist decreases bone mass in leptin-deficient and wild-type mice while a beta-adrenergic antagonist increases bone mass in wild-type and ovariectomized mice. None of these manipulations affects body weight. This study demonstrates a leptin-dependent neuronal regulation of bone formation with potential therapeutic implications for osteoporosis.

  14. Production of compartmented cultures of rat sympathetic neurons.

    Science.gov (United States)

    Campenot, Robert B; Lund, Karen; Mok, Sue-Ann

    2009-01-01

    The compartmented culture, in which primary neurons plated in a proximal compartment send their axons under silicone grease barriers and into left and right distal compartments, has enhanced the experimental capabilities of neuronal cultures. Treatments can be applied separately to cell bodies/proximal axons or distal axons, and cell bodies/proximal axons and distal axons can be separately harvested and analyzed. Distal axons can be axotomized, and the neurons can be studied while their axons regenerate. Construction of the culture dishes requires 3 h for 48 cultures, and preparing the neurons also requires 3 h. Compartmented cultures provide enough cellular material for biochemical analyses such as immunoblotting. The uses of compartmented cultures have included studies of neurotrophic factor retrograde signaling, axonal transport, and axonal protein and lipid biosynthesis. Here we focus on sympathetic neurons cultured from neonatal rats and provide protocols for the production and some of the uses of compartmented cultures.

  15. Sympathetic cooling of molecular ion motion to the ground state

    CERN Document Server

    Rugango, Rene; Dixon, Thomas H; Gray, John M; Khanyile, Ncamiso; Shu, Gang; Clark, Robert J; Brown, Kenneth R

    2014-01-01

    We demonstrate sympathetic sideband cooling of a $^{40}$CaH$^{+}$ molecular ion co-trapped with a $^{40}$Ca$^{+}$ atomic ion in a linear Paul trap. Both axial modes of the two-ion chain are simultaneously cooled to near the ground state of motion. The center of mass mode is cooled to an average quanta of harmonic motion $\\overline{n}_{\\mathrm{COM}} = 0.13 \\pm 0.03$, corresponding to a temperature of $12.47 \\pm 0.03 ~\\mu$K. The breathing mode is cooled to $\\overline{n}_{\\mathrm{BM}} = 0.05 \\pm 0.02$, corresponding to a temperature of $15.36 \\pm 0.01~\\mu$K.

  16. Pathophysiology of Resistant Hypertension: The Role of Sympathetic Nervous System

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    Costas Tsioufis

    2011-01-01

    Full Text Available Resistant hypertension (RH is a powerful risk factor for cardiovascular morbidity and mortality. Among the characteristics of patients with RH, obesity, obstructive sleep apnea, and aldosterone excess are covering a great area of the mosaic of RH phenotype. Increased sympathetic nervous system (SNS activity is present in all these underlying conditions, supporting its crucial role in the pathophysiology of antihypertensive treatment resistance. Current clinical and experimental knowledge points towards an impact of several factors on SNS activation, namely, insulin resistance, adipokines, endothelial dysfunction, cyclic intermittent hypoxaemia, aldosterone effects on central nervous system, chemoreceptors, and baroreceptors dysregulation. The further investigation and understanding of the mechanisms leading to SNS activation could reveal novel therapeutic targets and expand our treatment options in the challenging management of RH.

  17. Glutamate and GABA in Vestibulo-Sympathetic Pathway Neurons.

    Science.gov (United States)

    Holstein, Gay R; Friedrich, Victor L; Martinelli, Giorgio P

    2016-01-01

    The vestibulo-sympathetic reflex (VSR) actively modulates blood pressure during changes in posture. This reflex allows humans to stand up and quadrupeds to rear or climb without a precipitous decline in cerebral perfusion. The VSR pathway conveys signals from the vestibular end organs to the caudal vestibular nuclei. These cells, in turn, project to pre-sympathetic neurons in the rostral and caudal ventrolateral medulla (RVLM and CVLM, respectively). The present study assessed glutamate- and GABA-related immunofluorescence associated with central vestibular neurons of the VSR pathway in rats. Retrograde FluoroGold tract tracing was used to label vestibular neurons with projections to RVLM or CVLM, and sinusoidal galvanic vestibular stimulation (GVS) was employed to activate these pathways. Central vestibular neurons of the VSR were identified by co-localization of FluoroGold and cFos protein, which accumulates in some vestibular neurons following galvanic stimulation. Triple-label immunofluorescence was used to co-localize glutamate- or GABA- labeling in the identified VSR pathway neurons. Most activated projection neurons displayed intense glutamate immunofluorescence, suggestive of glutamatergic neurotransmission. To support this, anterograde tracer was injected into the caudal vestibular nuclei. Vestibular axons and terminals in RVLM and CVLM co-localized the anterograde tracer and vesicular glutamate transporter-2 signals. Other retrogradely-labeled cFos-positive neurons displayed intense GABA immunofluorescence. VSR pathway neurons of both phenotypes were present in the caudal medial and spinal vestibular nuclei, and projected to both RVLM and CVLM. As a group, however, triple-labeled vestibular cells with intense glutamate immunofluorescence were located more rostrally in the vestibular nuclei than the GABAergic neurons. Only the GABAergic VSR pathway neurons showed a target preference, projecting predominantly to CVLM. These data provide the first

  18. Sympathetic and parasympathetic pupillary dysfunction in familial dysautonomia.

    Science.gov (United States)

    Dütsch, M; Hilz, M J; Rauhut, U; Solomon, J; Neundörfer, B; Axelrod, F B

    2002-03-15

    Objective assessment of autonomic dysfunction in familial dysautonomia (FD) is largely based on the analysis of cardiovascular responses to challenge maneuvers such as orthostatic stress. Infrared pupillometry (IPM) provides an additional reliable method for cranial autonomic evaluation and has the advantage of requiring minimal cooperation.This study was performed to determine whether IPM contributes to the assessment of autonomic function in FD patients. In 14 FD patients and 14 healthy controls, we studied absolute and relative light reflex amplitude, pupillary constriction velocity (v(constr)), pupillary diameter, early and late pupillary re-dilatation velocity (v(dil 1), v(dil 2)) after dark adaptation. Prior to IPM, all patients had an ophthamological examination to evaluate refraction and corneal integrity. In comparison to controls, patients had a significant reduction of the parameters reflecting parasympathetic pupillary function (absolute light reflex amplitude 1.34 +/- 0.21 vs. l.86 +/- 0.14 mm, relative light reflex amplitude 22.74 +/- 7.11% vs. 30.76 +/- 3.57%, v(constr) 3.75 +/- 1.09 vs. 5.80 +/- 0.59 mm/s) and of the parameters reflecting sympathetic pupillary function (diameter 5.69 +/- 0.66 vs. 6.35 +/- 0.60 mm, v(dil 1) 1.29 +/- 0.23 vs. 1.95 +/- 0.23 mm/s, v(dil 2) 0.64 +/- 0.13 vs. 0.72 +/- 0.l2 mm/s; Mann-Whitney U-test: p<0.05). The non-invasive technique of IPM demonstrates dysfunction not only of the cranial parasympathetic, but also of the cranial sympathetic nervous system and, thus, further characterizes autonomic dysfunction in FD.

  19. Sympathetic activation and baroreflex function during intradialytic hypertensive episodes.

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    Dvora Rubinger

    Full Text Available BACKGROUND: The mechanisms of intradialytic increases in blood pressure are not well defined. The present study was undertaken to assess the role of autonomic nervous system activation during intradialytic hypertensive episodes. METHODOLOGY/PRINCIPAL FINDINGS: Continuous interbeat intervals (IBI and systolic blood pressure (SBP were monitored during hemodialysis in 108 chronic patients. Intradialytic hypertensive episodes defined as a period of at least 10 mmHg increase in SBP between the beginning and the end of a dialysis session or hypertension resistant to ultrafiltration occurring during or immediately after the dialysis procedure, were detected in 62 out of 113 hemodialysis sessions. SBP variability, IBI variability and baroreceptor sensitivity (BRS in the low (LF and high (HF frequency ranges were assessed using the complex demodulation technique (CDM. Intradialytic hypertensive episodes were associated with an increased (n = 45 or decreased (n = 17 heart rate. The maximal blood pressure was similar in both groups. In patients with increased heart rate the increase in blood pressure was associated with marked increases in SBP and IBI variability, with suppressed BRS indices and enhanced sympatho-vagal balance. In contrast, in those with decreased heart rate, there were no significant changes in the above parameters. End-of-dialysis blood pressure in all sessions associated with hypertensive episode was significantly higher than in those without such episodes. In logistic regression analysis, predialysis BRS in the low frequency range was found to be the main predictor of intradialytic hypertension. CONCLUSION/SIGNIFICANCE: Our data point to sympathetic overactivity with feed-forward blood pressure enhancement as an important mechanism of intradialytic hypertension in a significant proportion of patients. The triggers of increased sympathetic activity during hemodialysis remain to be determined. Intradialytic hypertensive episodes

  20. Cardiac Sympathetic Hyperactivity after Chemotherapy: Early Sign of Cardiotoxicity?

    Energy Technology Data Exchange (ETDEWEB)

    Guimarães, Sarita Lígia Pessoa de Melo Machado [Pós-Graduação em Ciências da Saúde da Universidade Federal de Pernambuco (PGCS-UFPE), Recife, PE (Brazil); Hospital Agamenon Magalhães (HAM), Recife, PE (Brazil); Brandão, Simone Cristina Soares, E-mail: simonecordis@yahoo.com.br [Pós-Graduação em Ciências da Saúde da Universidade Federal de Pernambuco (PGCS-UFPE), Recife, PE (Brazil); Andrade, Luciana Raposo [Hospital Santa Joana, Recife, PE (Brazil); Maia, Rafael José Coelho [Pós-Graduação em Ciências da Saúde da Universidade Federal de Pernambuco (PGCS-UFPE), Recife, PE (Brazil); Hospital Agamenon Magalhães (HAM), Recife, PE (Brazil); Markman Filho, Brivaldo [Pós-Graduação em Ciências da Saúde da Universidade Federal de Pernambuco (PGCS-UFPE), Recife, PE (Brazil)

    2015-09-15

    Chemotherapy with anthracyclines and trastuzumab can cause cardiotoxicity. Alteration of cardiac adrenergic function assessed by metaiodobenzylguanidine labeled with iodine-123 ({sup 123}I-mIBG) seems to precede the drop in left ventricular ejection fraction. To evaluate and to compare the presence of cardiovascular abnormalities among patients with breast cancer undergoing chemotherapy with anthracyclines and trastuzumab, and only with anthracycline. Patients with breast cancer were analyzed clinical, laboratory, electrocardiographic and echocardiographic and cardiac sympathetic activity. In scintigraphic images, the ratio of {sup 123}I-mIBG uptake between the heart and mediastinum, and the washout rate were calculated. The variables were compared between patients who received anthracyclines and trastuzumab (Group 1) and only anthracyclines (Group 2). Twenty patients, with mean age 57 ± 14 years, were studied. The mean left ventricular ejection fraction by echocardiography was 67.8 ± 4.0%. Mean washout rate was 28.39 ± 9.23% and the ratio of {sup 123}I-mIBG uptake between the heart and mediastinum was 2.07 ± 0.28. Of the patients, 82% showed an increased in washout rate, and the ratio of {sup 123}I-mIBG uptake between the heart and mediastinum decreased in 25%. Concerning the groups, the mean washout rate of Group 1 was 32.68 ± 9.30% and of Group 2 was 24.56 ± 7.72% (p = 0,06). The ratio of {sup 123}I-mIBG uptake between the heart and mediastinum was normal in all patients in Group 2, however, the Group 1, showed 50% the ratio of {sup 123}I-mIBG uptake between the heart and mediastinum ≤ 1.8 (p = 0.02). In women with breast cancer undergoing chemotherapy, assessment of cardiac sympathetic activity with {sup 123}I-mIBG appears to be an early marker of cardiotoxicity. The combination of chemotherapy showed higher risk of cardiac adrenergic hyperactivity.

  1. Sympathetic system activity in obesity and metabolic syndrome.

    Science.gov (United States)

    Tentolouris, N; Liatis, S; Katsilambros, N

    2006-11-01

    Obesity is a very common disease worldwide, resulting from a disturbance in the energy balance. The metabolic syndrome is also a cluster of abnormalities with basic characteristics being insulin resistance and visceral obesity. The major concerns of obesity and metabolic syndrome are the comorbidities, such as type 2 diabetes, cardiovascular disease, stroke, and certain types of cancers. Sympathetic nervous system (SNS) activity is associated with both energy balance and metabolic syndrome. Sympathomimetic medications decrease food intake, increase resting metabolic rate (RMR), and thermogenic responses, whereas blockage of the SNS exerts opposite effects. The contribution of the SNS to the daily energy expenditure, however, is small ( approximately 5%) in normal subjects consuming a weight maintenance diet. Fasting suppresses, whereas meal ingestion induces SNS activity. Most of the data agree that obesity is characterized by SNS predominance in the basal state and reduced SNS responsiveness after various sympathetic stimuli. Weight loss reduces SNS overactivity in obesity. Metabolic syndrome is characterized by enhanced SNS activity. Most of the indices used for the assessment of its activity are better associated with visceral fat than with total fat mass. Visceral fat is prone to lipolysis: this effect is mediated by catecholamine action on the sensitive beta(3)-adrenoceptors found in the intraabdominal fat. In addition, central fat distribution is associated with disturbances in the hypothalamo-pituitary-adrenal axis, suggesting that a disturbed axis may be implicated in the development of the metabolic syndrome. Furthermore, SNS activity induces a proinflammatory state by IL-6 production, which in turn results in an acute phase response. The increased levels of inflammatory markers seen in the metabolic syndrome may be elicited, at least in part, by SNS overactivity. Intervention studies showed that the disturbances of the autonomic nervous system seen in the

  2. New treatment for old disease: management of resistant hypertension by percutaneous renal sympathetic denervation.

    Science.gov (United States)

    Kanai, Takashi; Krum, Henry

    2013-09-01

    Hypertension is a major contributor to cardiovascular events, such as stroke and myocardial infarction, with accelerated sympathetic nerve activity implicated in its pathogenesis. However, hypertension in many patients is not adequately controlled, despite the availability of numerous medication classes. Novel procedure-as well as device-based strategies, such as percutaneous renal sympathetic nerve denervation therapy-have been developed to improve blood pressure in these refractory patients. Renal sympathetic denervation delivers not only a decrease in blood pressure levels but also renal as well as systemic sympathetic nerve activity. The reduction in blood pressure appears to be sustained over 3 years after the procedure, which implies no counterregulatory mechanism or re-innervation of afferent renal sympathetic nerve so far. Renal sympathetic denervation is expected to be a promising treatment for patients with hypertension, congestive heart failure, chronic kidney disease, and metabolic syndrome implicated in the pathogenesis of potentiated sympathetic nerve activity. This review will focus on the current devices and procedures, their outcomes and prospects in the treatment of hypertension.

  3. Empathic and sympathetic orientations toward patient care: conceptualization, measurement, and psychometrics.

    Science.gov (United States)

    Hojat, Mohammadreza; Spandorfer, John; Louis, Daniel Z; Gonnella, Joseph S

    2011-08-01

    To develop instruments for measuring empathic and sympathetic orientations in patient care and to provide evidence in support of their psychometrics. Third-year medical students at Jefferson Medical College responded to four clinical vignettes in 2010. For each vignette, students indicated the extent of their agreement with an empathic response (conveying their understanding of patients' concerns) and with a sympathetic response (sharing patients' feelings). The authors calculated, based on students' responses to the clinical vignettes, two measures of empathic and sympathetic orientation. Students also completed the Jefferson Scale of Empathy (JSE) and the Interpersonal Reactivity Index (IRI). Of the 258 students in the class, 201 (78%) responded to all four vignettes and completed the JSE and IRI. The authors confirmed construct validity of the measures of empathic and sympathetic orientation through factor analysis. The empathic orientation was significantly associated with the measure of empathy (as measured by the JSE) but not with measures of sympathy (as measured by specific scales of the IRI). Conversely, sympathetic orientation was significantly associated with measures of sympathy. Thus, these results support the validity of the empathic and sympathetic orientation measures as assessed by four clinical vignettes. Coefficient alphas for the two measures were, respectively, 0.79 and 0.84. The validated measures of empathic and sympathetic orientation provide research opportunities to enhance the understanding of the contributions of empathy and sympathy to physicians' competence and patient outcomes.

  4. Respiratory modulation of sympathetic nerve activity is enhanced in male rat offspring following uteroplacental insufficiency.

    Science.gov (United States)

    Menuet, C; Wlodek, M E; Fong, A Y; Allen, A M

    2016-06-01

    Sympathetic nerve activity to the cardiovascular system displays prominent respiratory-related modulation which leads to the generation of rhythmic oscillations in blood pressure called Traube-Hering waves. An amplification of this respiratory modulation of sympathetic activity is observed in hypertension of both genetic, the spontaneously hypertensive rat, and induced, chronic intermittent hypoxia or maternal protein restriction during gestation, origin. Male offspring of mothers with uteroplacental insufficiency, induced by bilateral uterine vessel ligation at 18 days of gestation, are also hypertensive in adulthood. In this study we examined whether these male offspring display altered respiratory modulation of sympathetic activity at pre-hypertensive ages compared to controls. Respiratory, cardiovascular and sympathetic parameters were examined using the working heart-brainstem preparation in 35 day old male rats that had reduced birth weight due to uteroplacental insufficiency. Whilst all respiratory parameters were not different between groups, we observed an enhanced respiratory-related burst of thoracic sympathetic nerve activity and amplified Traube-Hering waves in the growth-restricted group. This group also showed an increased sympathetic and bradycardic response to activation of peripheral chemoreceptors. The observations add support to the view that altered respiratory modulation of sympathetic activity represents a common mechanism involved in the development of several forms of hypertension.

  5. Sympathetic Blocks Provided Sustained Pain Relief in a Patient with Refractory Painful Diabetic Neuropathy

    Directory of Open Access Journals (Sweden)

    Jianguo Cheng

    2012-01-01

    Full Text Available The sympathetic nervous system has been implicated in pain associated with painful diabetic neuropathy. However, therapeutic intervention targeted at the sympathetic nervous system has not been established. We thus tested the hypothesis that sympathetic nerve blocks significantly reduce pain in a patient with painful diabetic neuropathy who has failed multiple pharmacological treatments. The diagnosis of small fiber sensory neuropathy was based on clinical presentations and confirmed by skin biopsies. A series of 9 lumbar sympathetic blocks over a 26-month period provided sustained pain relief in his legs. Additional thoracic paravertebral blocks further provided control of the pain in the trunk which can occasionally be seen in severe diabetic neuropathy cases, consequent to extensive involvement of the intercostal nerves. These blocks provided sustained and significant pain relief and improvement of quality of life over a period of more than two years. We thus provided the first clinical evidence supporting the notion that sympathetic nervous system plays a critical role in painful diabetic neuropathy and sympathetic blocks can be an effective management modality of painful diabetic neuropathy. We concluded that the sympathetic nervous system is a valuable therapeutic target of pharmacological and interventional modalities of treatments in painful diabetic neuropathy patients.

  6. Differential effects of oestrogen on developing and mature uterine sympathetic nerves.

    Science.gov (United States)

    Chávez-Genaro, R; Crutcher, K; Viettro, L; Richeri, A; Coirolo, N; Burnstock, G; Cowen, T; Brauer, M M

    2002-04-01

    Oestrogen is a key factor in the remodelling of uterine sympathetic nerves during puberty and the oestrous cycle; these nerves are influenced by changes in their target uterine tissue. The magnitude of oestrogen-induced responses might however be influenced by the maturation stage of sympathetic nerve fibres, the age of the neurons and/or the developmental state of the uterus. We have therefore compared the sympathetic innervation of the uterus following chronic oestrogen treatment of infantile/prepubertal and young adult intact and ovariectomised rats. Treatment of infantile/prepubertal rats resulted in the complete loss of intrauterine noradrenaline (NA)-labelled sympathetic nerves and a marked reduction in the total NA content in the uterine horn. Chronic treatment of young adult rats had little effect. To examine whether the age of the neurons or the degree of development of the uterus determined responsiveness of nerves to oestrogen, we assessed the effects of oestrogen on the sympathetic reinnervation of intraocular transplants of young adult uterine myometrium into ovariectomised adult host rats. Early treatment (10 days post-transplantation) resulted in less sympathetic innervation than late treatment (30 days post-transplantation). Measurements of nerve growth factor (NGF) levels in the uterine horn of control rats before and after puberty and following infantile/prepubertal chronic oestrogen treatment and acute oestrogen treatment of young adult rats revealed a coordinated increase between the growth of the uterus and NGF protein levels. Thus, developing and recently regrown sympathetic nerves are more susceptible to oestrogen-induced changes in the uterus than mature nerves, differential susceptibility is not related to the age of the neurons or the developmental state of the uterus and changes in NGF protein do not account for the differential susceptibility of developing and mature uterine sympathetic nerve fibres to oestrogen. Growing sympathetic

  7. Norepinephrine-induced nerve growth factor depletion causes cardiac sympathetic denervation in severe heart failure.

    Science.gov (United States)

    Kimura, Kensuke; Kanazawa, Hideaki; Ieda, Masaki; Kawaguchi-Manabe, Haruko; Miyake, Yoshiko; Yagi, Takashi; Arai, Takahide; Sano, Motoaki; Fukuda, Keiichi

    2010-08-25

    In severe congestive heart failure (CHF), sympathetic overactivity correlates with the exacerbation of cardiac performance. To test the hypothesis that the cardiac sympathetic nerve density dramatically changes with the acceleration of circulating norepinephrine (NE) concentration, we investigated the temporal association of nerve growth factor (NGF) expression in the heart and cardiac sympathetic nerve density during the development of CHF in the continuous NE-infused rats. The animals were analyzed at 0-, 1-, 3-, 7-, 14-, and 28-day after implantation of osmotic pump at a rate of 0.05 mg/kg/hr. The cardiac performance was temporally facilitated in NE-exposed rats at 3-day in accordance with the sympathetic hyper-innervation induced by the augmentation of NGF mRNA expression in the heart. In NE-treated rats, left ventricular end-diastolic pressure was significantly increased after 7-day and marked left ventricular hypertrophy and systemic fluid retention were observed at 28-day. CHF-induced sympathetic overactivity further increased plasma NE concentration in NE-treated rats and finally reached to 16.1+/-5.6 ng/ml at 28-day (control level was 0.39+/-0.1 ng/ml, pcardiac performance. The cardiac sympathetic fiber loss was also confirmed in NE-exposed DBH (dopamine beta-hydroxylase)-Cre/Floxed-EGFP (enhanced green fluorescent protein) mice with severe CHF, in which sympathetic nerve could be traced by EGFP. Our results suggest that the cardiac sympathetic nerve density is strictly regulated by the NGF expression in the heart and long-exposure of high plasma NE concentration caused myocardial NGF reduction, following sympathetic fiber loss in severe CHF animals.

  8. Physiological and pathophysiological interactions between the respiratory central pattern generator and the sympathetic nervous system.

    Science.gov (United States)

    Molkov, Yaroslav I; Zoccal, Daniel B; Baekey, David M; Abdala, Ana P L; Machado, Benedito H; Dick, Thomas E; Paton, Julian F R; Rybak, Ilya A

    2014-01-01

    Respiratory modulation seen in the sympathetic nerve activity (SNA) implies that the respiratory and sympathetic networks interact. During hypertension elicited by chronic intermittent hypoxia (CIH), the SNA displays an enhanced respiratory modulation reflecting strengthened interactions between the networks. In this chapter, we review a series of experimental and modeling studies that help elucidate possible mechanisms of sympatho-respiratory coupling. We conclude that this coupling significantly contributes to both the sympathetic baroreflex and the augmented sympathetic activity after exposure to CIH. This conclusion is based on the following findings. (1) Baroreceptor activation results in perturbation of the respiratory pattern via transient activation of postinspiratory neurons in the Bötzinger complex (BötC). The same BötC neurons are involved in the respiratory modulation of SNA, and hence provide an additional pathway for the sympathetic baroreflex. (2) Under hypercapnia, phasic activation of abdominal motor nerves (AbN) is accompanied by synchronous discharges in SNA due to the common source of this rhythmic activity in the retrotrapezoid nucleus (RTN). CIH conditioning increases the CO2 sensitivity of central chemoreceptors in the RTN which results in the emergence of AbN and SNA discharges under normocapnic conditions similar to those observed during hypercapnia in naïve animals. Thus, respiratory-sympathetic interactions play an important role in defining sympathetic output and significantly contribute to the sympathetic activity and hypertension under certain physiological or pathophysiological conditions, and the theoretical framework presented may be instrumental in understanding of malfunctioning control of sympathetic activity in a variety of disease states.

  9. Regulation of bile duct motility by vagus and sympathetic nerves in the pigeon.

    Directory of Open Access Journals (Sweden)

    Neya,Toshiaki

    1990-04-01

    Full Text Available Effects of stimulation of the vagus and sympathetic nerves on bile duct peristalses were studied in pigeons anesthetized with urethane. Vagus stimulation increased the frequency of peristalses. Atropine, hexamethonium and tetrodotoxin abolished this excitatory effect. After atropine, inhibition of peristalses sensitive to tetrodotoxin was produced. Stimulation of sympathetic area in the spinal cord inhibited peristalses. Propranolol converted this effect into an excitatory one, which was abolished by phentolamine. The results suggest that vagal and sympathetic innervations of the bile duct in pigeons are similar to those of the sphincter of Oddi in mammalian species.

  10. Quantification of sympathetic hyperinnervation and denervation after myocardial infarction by three-dimensional assessment of the cardiac sympathetic network in cleared transparent murine hearts.

    Science.gov (United States)

    Yokoyama, Teruki; Lee, Jong-Kook; Miwa, Keiko; Opthof, Tobias; Tomoyama, Satoki; Nakanishi, Hiroyuki; Yoshida, Akira; Yasui, Haruyo; Iida, Tadatsune; Miyagawa, Shigeru; Okabe, Shigeo; Sawa, Yoshiki; Sakata, Yasushi; Komuro, Issei

    2017-01-01

    The sympathetic nervous system is critical in maintaining the normal physiological function of the heart. Its dysfunction in pathological states may exacerbate the substrate for arrhythmias. Obviously, knowledge of its three-dimensional (3D) structure is important, however, it has been revealed by conventional methods only to a limited extent. In this study, a new method of tissue clearance in combination with immunostaining unravels the 3D structure of the sympathetic cardiac network as well as its changes after myocardial infarction. Hearts isolated from adult male mice were optically cleared using the CUBIC-perfusion protocol. After making the hearts transparent, sympathetic nerves and coronary vessels were immunofluorescently labeled, and then images were acquired. The spatial distribution of sympathetic nerves was visualized not only along the epicardial surface, but also transmurally. They were distributed over the epicardial surface and penetrated into the myocardium to twist around coronary vessels, but also independent from the coronary vasculature. At 2 weeks after myocardial infarction, we were able to quantify both denervation distal from the site of infarction and nerve sprouting (hyperinnervation) at the ischemic border zone of the hearts in a 3D manner. The nerve density at the ischemic border zone was more than doubled in hearts with myocardial infarction compared to intact mice hearts (3D analyses; n = 5, pmyocardial infarction. Both can be visualized and quantified by a new imaging technique in transparent hearts and thereby become a useful tool in elucidating the role of the sympathetic nervous system in arrhythmias associated with myocardial infarction.

  11. Co-localization of histamine and norepinephrine in sympathetic ganglia and exocytosis of endogenous histamine from cardiac sympathetic nerve endings of macaca mulatto monkey

    Institute of Scientific and Technical Information of China (English)

    Ming-kaiLI; Xiao-xingLUO; Liang-weiCHEN; ZhongCHEN; JiaMENG; JingHU; Yu-meiWU; Jing-ruMENG; ZhengHOU; XueMA

    2005-01-01

    AIM To provide the evidence about localization, biosynthesis, metabolism and release of histamine from the cardiac sympathetic nerve terminals, and endogenous sympathetic histamine could inhibit itsel frelease from the nerve terminal through the presynaptic histamine H3 receptor. METHODS Using double-labeled immunohistochemistry to observe the co-localization of histamine and NE in the superior cer-vical ganglia (SCG) of macaca mulatto monkey; Different-speed centrifugation to obtain the cardiac sympathetic nerve terminal model (the cardiac synaptosomes), spectrofluorometer and ELISA techniques to detect the release of histamine from the cardiacsynaptosomes. RESULTS ( 1 ) The coexistence of histamine and norepinephrine immunoreactivities was identified in the same neuron within SCG of macaca mulatto monkey. (2) Depolarization of macaca mulatto monkey cardiac synaptosomes with 50 mmol/L potassium caused the release of endogenous histamine,

  12. 反射性交感神经营养不良%Reflex sympathetic dystrophy

    Institute of Scientific and Technical Information of China (English)

    马抒音; 张丽苓

    2002-01-01

    @@ Background: Reflex sympathetic dystrophy (RSD),also known as complex regional pain syndrome (CRPS), is a nervous system disorder that often results in severe chronic and burning pain and other symptoms.

  13. Pediatric cervical sympathetic chain schwannoma with Horner syndrome: a rare case presentation.

    Science.gov (United States)

    Bhagat, Sanjeev; Varshney, Saurabh; Bist, Sampan S; Gupta, Nitin

    2014-03-01

    Schwannomas are rare, benign, slowly growing neurogenic tumors that originate in peripheral, spinal, or cranial nerves other than the optic and olfactory nerves. In the head and neck, these tumors usually arise from the vagus nerve and the cervical sympathetic chain in the parapharyngeal space. Cervical sympathetic chain schwannomas represent a rare subgroup of schwannomas; fewer than 60 cases have been reported in the literature. These tumors are rarely seen in children and adolescents. Because patients typically present with an asymptomatic neck mass and vague complaints, clinical suspicion is important in making the diagnosis. Neural deficits at presentation are uncommon. The presence of features of Horner syndrome before excision is very rare, having been previously reported in only 10 cases of cervical sympathetic chain schwannoma. We report an extremely rare case of a cervical sympathetic chain schwannoma in a child who presented with Horner syndrome. The lesion was successfully excised.

  14. The anemia of microgravity and recumbency. Role of sympathetic neural control of erythropoietin production

    Science.gov (United States)

    Robertson, David; Krantz, Sanford B.; Biaggioni, Italo

    We hypothesize that reduced sympathetic stimulation of erythropoietin production may maintain the anemia which develops in virtually all space travellers. We tested this hypothesis in a human model of reduced sympathetic activity. Thirty-three patients with the Bradbury-Eggleston syndrome were divided into three groups according to their hemoglobin (Hgb) level. Patients with low Hgb had lower upright norepinephrine and lower upright renin. Patients with anemia also had inappropriately low plasma erythropoietin levels. We administered recombinant erythropoietin (Epogen) 25-50 units/kg s.c. 3 times per week and found that the anemia seen in autonomic failure could be reversed by this treatment. These results support the hypothesis that erythropoiesis is modulated by the sympathetic nervous system and that such mechanisms may also operate in the microgravity environment where sympathetic activity is reduced.

  15. Expressions of cardiac sympathetic norepinephrine transporter and β1-adrenergic receptor decreased in aged rats

    Institute of Scientific and Technical Information of China (English)

    He LI; Xiao-qing MA; Fan YE; Jing ZHANG; Xin ZHOU; Zhi-hong WANG; Yu-ming LI; Guo-yuan ZHANG

    2009-01-01

    Evidence suggests that the deterioration of communication between the sympathetic nervous system and cardiovas-cular system always accompanies the aging of human and animals. Cardiac sympathetic norepinephrine (NE) transporter (NET) on presynaptic membrane is a predominant component to eliminate released NE in the synaptic cleff and maintains the sensitivity of the β-adrenergic receptor (β-AR). In the present study, we investigated NET and β1-AR mRNA levels and sympathetic nerve density in cardiac sympathetic ganglion and leff ventricular myocardium in 2- and 16-month-old rats with Northern blot analysis and immunohistochemistry. The expression levels of NET mRNA, NET protein and β1-AR mRNA in the ganglia or myocardia of 16-month-old rats were markedly reduced by 67%, 26%, and 43%, respectively, in comparison with those in 2-month-old rats. Our results also show that aging induces a strong decrease of the catecholaminergic nerve fiber density.

  16. Cardiac sympathetic imaging with mIBG in cirrhosis and portal hypertension

    DEFF Research Database (Denmark)

    Møller, Søren; Mortensen, Christian; Bendtsen, Flemming

    2012-01-01

    Autonomic and cardiac dysfunction is frequent in cirrhosis and includes increased sympathetic nervous activity, impaired heart rate variability (HRV), and baroreflex sensitivity (BRS). Quantified (123)I-metaiodobenzylguanidine (mIBG) scintigraphy reflects cardiac noradrenaline uptake, and in pati...

  17. Differential Control of the Sympathetic Nervous System by Leptin: Implications for Obesity

    OpenAIRE

    Rahmouni, Kamal

    2007-01-01

    1. Leptin is a hormone that is secreted by adipocytes and delivered to the brain to regulate appetite and energy expenditure. Other effects of leptin include activation of the sympathetic nervous system and an increase in arterial pressure.

  18. Sympathetic nervous activation in obesity and the metabolic syndrome--causes, consequences and therapeutic implications.

    Science.gov (United States)

    Lambert, Gavin W; Straznicky, Nora E; Lambert, Elisabeth A; Dixon, John B; Schlaich, Markus P

    2010-05-01

    The world wide prevalence of obesity and the metabolic syndrome is escalating. Contrary to earlier experimental evidence, human obesity is characterised by sympathetic nervous activation, with the outflows to both the kidney and skeletal muscle being activated. While the mechanisms responsible for initiating the sympathetic activation remain to be unequivocally elucidated, hyperinsulinemia, obstructive sleep apnoea, increased circulating adipokines, stress and beta adrenergic receptor polymorphisms are implicated. The pattern of sympathetic activation may be the pathophysiological mechanism underpinning much obesity-related illnesses with the consequences including, amongst others, the development of hypertension, insulin resistance, diastolic dysfunction and renal impairment. While diet and exercise are the first line therapy for the treatment of obesity and the metabolic syndrome, pharmacological interventions targeting the sympathetic nervous system, either directly or indirectly are also likely to be of benefit. Importantly, the benefit may not necessarily be weight related but may be associated with a reduction in end organ damage.

  19. Baroreflex gain and vasomotor sympathetic modulation in resistant hypertension.

    Science.gov (United States)

    Freitas, Isabelle Magalhães Guedes; de Almeida, Leonardo Barbosa; Pereira, Natália Portela; Mira, Pedro Augusto de Carvalho; de Paula, Rogério Baumgratz; Martinez, Daniel Godoy; Toschi-Dias, Edgar; Laterza, Mateus Camaroti

    2017-06-01

    The aim of this study was to determine the gain and latency of arterial baroreflex control of heart rate in patients with resistant hypertension compared to patients with essential hypertension and normotensive subjects. Eighteen patients with resistant hypertension (56 ± 10 years, mean of four antihypertensive drugs), 17 patients with essential hypertension (56 ± 11 years, mean of two antihypertensive drugs), and 17 untreated normotensive controls (50 ± 15 years) were evaluated by spectral analysis of the spontaneous fluctuations of arterial pressure (beat-to-beat) and heart rate (ECG). This analysis estimated vasomotor and cardiac autonomic modulations, respectively. The transfer function analysis quantified the gain and latency of the response of output signal (RR interval) per unit of spontaneous change of input signal (systolic arterial pressure). The gain was similarly lower in patients with resistant hypertension and patients with essential hypertension in relation to normotensive subjects (4.67 ± 2.96 vs. 6.60 ± 3.30 vs. 12.56 ± 8.81 ms/mmHg; P resistant hypertension when compared to patients with essential hypertension and normotensive subjects (-4.01 ± 3.19 vs. -2.91 ± 2.10 vs. -1.82 ± 1.09 s; P = 0.04, respectively). In addition, the index of vasomotor sympathetic modulation was significantly increased only in patients with resistant hypertension when compared to patients with essential hypertension and normotensive subjects (4.04 ± 2.86 vs. 2.65 ± 1.88 vs. 2.06 ± 1.70 mmHg(2); P resistant hypertension have reduced gain and increased latency of arterial baroreflex control of heart rate. These patients also have increased vasomotor sympathetic modulation.

  20. Spinal Cord Injury-Induced Dysautonomia via Plasticity in Paravertebral Sympathetic Postganglionic

    Science.gov (United States)

    2015-10-01

    preganglionic divergence and convergence onto thoracic chain SPNs was previously examined in guinea pig 6,7. We began to undertake similar studies in the...autonomic nervous system 18, 195-205 (1987). 6 Blackman, J. G. & Purves, R. D. Intracellular recordings from ganglia of the thoracic sympathetic chain of...the guinea - pig . J Physiol. 203, 173-198. (1969). 7 Lichtman, J. W., Purves, D. & Yip, J. W. Innervation of sympathetic neurones in the guinea - pig

  1. Leptin into the rostral ventral lateral medulla (RVLM augments renal sympathetic nerve activity and blood pressure

    Directory of Open Access Journals (Sweden)

    Maria J Barnes

    2014-08-01

    Full Text Available Leptin is a hormone released from adipose tissue. While this hormone normally acts to reduce feeding behavior and increase energy expenditure, in obesity, resistance to these effects occurs even though the hormone is released in large amounts. Although leptin no longer works to suppress feeding in the obese, leptin retains its potent effects on other autonomic functions such as blood pressure regulation. Leptin has been associated with hypertension and increased sympathetic autonomic activity. Therefore, leptin is emerging as a major contributor to the hypertensive state observed in obesity. Sympathetic control of blood pressure is maintained principally by autonomic reflex control circuits in the caudal brainstem. The rostral ventral-lateral medulla (RVLM is the primary regulator of the sympathetic nervous system, sending excitatory fibers to sympathetic preganglionic neurons to regulate sympathetic control over resistance vessels and blood pressure. Previous studies from our laboratory have shown that neurons in the ventral lateral medulla express leptin receptors (ObRb. Our present study using pseudo-rabies multi-synaptic retrograde tract tracing and immunohistochemical methods revealed that neurons within the RVLM that send sympathetic projections to the kidney express leptin receptors. Acute microinjection of leptin (1 and 3µg; 40nL into the RVLM evoked a significant increase in Mean Arterial Pressure (MAP and renal sympathetic nerve activity (RSNA. When the 3µg dose of leptin was preceded with a leptin antagonist, (SLAN-4; 1ng, it attenuated the cardiovascular response of leptin. Taken together, these data suggest that leptin’s actions within the RVLM may influence blood pressure and renal sympathetic nerve activity.

  2. Reduced sympathetic nervous activity. A potential mechanism predisposing to body weight gain.

    OpenAIRE

    Spraul, M; Ravussin, E; Fontvieille, A M; Rising, R; Larson, D. E.; Anderson, E A

    1993-01-01

    The sympathetic nervous system is recognized to play a role in the etiology of animal and possibly human obesity through its impact on energy expenditure and/or food intake. We, therefore, measured fasting muscle sympathetic nerve activity (MSNA) in the peroneal nerve and its relationship with energy expenditure and body composition in 25 relatively lean Pima Indian males (means +/- SD; 26 +/- 6 yr, 82 +/- 19 kg, 28 +/- 10% body fat) and 19 Caucasian males (29 +/- 5 yr, 81 +/- 13 kg, 24 +/- 9...

  3. Sympathetic neural adaptation to hypocaloric diet with or without exercise training in obese metabolic syndrome subjects

    DEFF Research Database (Denmark)

    Straznicky, Nora E; Lambert, Elisabeth A; Nestel, Paul J

    2010-01-01

    Sympathetic nervous system (SNS) overactivity contributes to the pathogenesis and target organ complications of obesity. This study was conducted to examine the effects of lifestyle interventions (weight loss alone or together with exercise) on SNS function.......Sympathetic nervous system (SNS) overactivity contributes to the pathogenesis and target organ complications of obesity. This study was conducted to examine the effects of lifestyle interventions (weight loss alone or together with exercise) on SNS function....

  4. The human sympathetic nervous system: its relevance in hypertension and heart failure.

    Science.gov (United States)

    Parati, Gianfranco; Esler, Murray

    2012-05-01

    Evidence assembled in this review indicates that sympathetic nervous system dysfunction is crucial in the development of heart failure and essential hypertension. This takes the form of persistent and adverse activation of sympathetic outflows to the heart and kidneys in both conditions. An important goal for clinical scientists is translation of the knowledge of pathophysiology, such as this, into better treatment for patients. The achievement of this 'mechanisms to management' transition is at different stages of development with regard to the two disorders. Clinical translation is mature in cardiac failure, knowledge of cardiac neural pathophysiology having led to the introduction of beta-adrenergic blockers, an effective therapy. With essential hypertension perhaps we are on the cusp of effective translation, with recent successful testing of selective catheter-based renal sympathetic nerve ablation in patients with resistant hypertension, an intervention firmly based on the demonstration of activation of the renal sympathetic outflow. Additional evidence in this regard is provided by the results of pilot studies exploring the possibility to reduce blood pressure in resistant hypertensives through electrical stimulation of the area of carotid baroreceptors. Despite the general importance of the sympathetic nervous system in blood pressure regulation, and the specific demonstration that the blood pressure elevation in essential hypertension is commonly initiated and sustained by sympathetic nervous activation, drugs antagonizing this system are currently underutilized in the care of patients with hypertension. Use of beta-adrenergic blocking drugs is waning, given the propensity of this drug class to have adverse metabolic effects, including predisposition to diabetes development. The blood pressure lowering achieved with carotid baroreceptor stimulation and with the renal denervation device affirms the importance of the sympathetic nervous system in

  5. Quantifying cardiac sympathetic and parasympathetic nervous activities using principal dynamic modes analysis of heart rate variability.

    Science.gov (United States)

    Zhong, Yuru; Jan, Kung-Ming; Ju, Ki Hwan; Chon, Ki H

    2006-09-01

    The ratio between low-frequency (LF) and high-frequency (HF) spectral power of heart rate has been used as an approximate index for determining the autonomic nervous system (ANS) balance. An accurate assessment of the ANS balance can only be achieved if clear separation of the dynamics of the sympathetic and parasympathetic nervous activities can be obtained, which is a daunting task because they are nonlinear and have overlapping dynamics. In this study, a promising nonlinear method, termed the principal dynamic mode (PDM) method, is used to separate dynamic components of the sympathetic and parasympathetic nervous activities on the basis of ECG signal, and the results are compared with the power spectral approach to assessing the ANS balance. The PDM analysis based on the 28 subjects consistently resulted in a clear separation of the two nervous systems, which have similar frequency characteristics for parasympathetic and sympathetic activities as those reported in the literature. With the application of atropine, in 13 of 15 supine subjects there was an increase in the sympathetic-to-parasympathetic ratio (SPR) due to a greater decrease of parasympathetic than sympathetic activity (P=0.003), and all 13 subjects in the upright position had a decrease in SPR due to a greater decrease of sympathetic than parasympathetic activity (Pparasympathetic and sympathetic nervous systems. The culprit is equivalent decreases in both the sympathetic and parasympathetic activities irrespective of the pharmacological blockades. These findings suggest that the PDM shows promise as a noninvasive and quantitative marker of ANS imbalance, which has been shown to be a factor in many cardiac and stress-related diseases.

  6. Direct conscious telemetry recordings demonstrate increased renal sympathetic nerve activity in rats with chronic kidney disease

    OpenAIRE

    Ibrahim M. Salman; Divya Sarma Kandukuri; Joanne Lesley Harrison; Cara Margaret Hildreth; Jacqueline Kathleen Phillips

    2015-01-01

    Chronic kidney disease (CKD) is associated with sympathetic hyperactivity and impaired blood pressure control reflex responses, yet direct evidence demonstrating these features of autonomic dysfunction in conscious animals is still lacking. Here we measured renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) using telemetry-based recordings in a rat model of CKD, the Lewis Polycystic Kidney (LPK) rat, and assessed responses to chemoreflex activation and acute stress. Male...

  7. Enhanced adipose afferent reflex contributes to sympathetic activation in diet-induced obesity hypertension.

    Science.gov (United States)

    Xiong, Xiao-Qing; Chen, Wei-Wei; Han, Ying; Zhou, Ye-Bo; Zhang, Feng; Gao, Xing-Ya; Zhu, Guo-Qing

    2012-11-01

    We recently found that adipose afferent reflex (AAR) induced by chemical stimulation of white adipose tissue (WAT) increased sympathetic outflow and blood pressure in normal rats. The study was designed to test the hypothesis that AAR contributes to sympathetic activation in obesity hypertension. Male rats were fed with a control diet (12% kcal as fat) or high-fat diet (42% kcal as fat) for 12 weeks to induce obesity hypertension. Stimulation of WAT with capsaicin increased renal sympathetic nerve activity and mean arterial pressure. Both AAR and WAT afferent activity were enhanced in obesity hypertension (OH) compared with obesity nonhypertension (ON) and in ON compared with obesity-resistant or control diet rats. WAT sensory denervation induced by resiniferatoxin caused greater decreases in renal sympathetic nerve activity and mean arterial pressure in OH than ON and in ON than obesity-resistant or control. The depressor effect of resiniferatoxin lasted ≥ 3 weeks in OH. Leptin antagonist in WAT reduced renal sympathetic nerve activity and mean arterial pressure in OH. WAT injection of capsaicin increased plasma renin, angiotensin II, and norepinephrine levels in OH and caused more c-fos expression in paraventricular nucleus in OH than ON and in ON than obesity-resistant or control rats. Inhibiting paraventricular nucleus neurons with lidocaine attenuated renal sympathetic nerve activity in OH and ON, decreased mean arterial pressure in OH, and abolished the capsaicin-induced AAR in all groups. The results indicate that enhanced AAR contributes to sympathetic activation in OH, and paraventricular nucleus plays an important role in the enhanced AAR and sympathetic activation in OH.

  8. Mineralocorticoid receptors, inflammation and sympathetic drive in a rat model of systolic heart failure.

    Science.gov (United States)

    Felder, Robert B

    2010-01-01

    Appreciation for the role of aldosterone and mineralocorticoid receptors in cardiovascular disease is accelerating rapidly. Recent experimental work has unveiled a strong relationship between brain mineralocorticoid receptors and sympathetic drive, an important determinant of outcome in heart failure and hypertension. Two putative mechanisms are explored in this manuscript. First, brain mineralocorticoid receptors may influence sympathetic discharge by regulating the release of pro-inflammatory cytokines into the circulation. Blood-borne pro-inflammatory cytokines act upon receptors in the microvasculature of the brain to induce cyclooxygenase-2 activity and the production of prostaglandin E(2), which penetrates the blood-brain barrier to activate the sympathetic nervous system. Second, brain mineralocorticoid receptors may influence sympathetic drive by upregulating the activity of the brain renin-angiotensin system, resulting in NAD(P)H oxidase-dependent superoxide production. A potential role for superoxide-dependent mitogen-activated protein kinase signalling pathways in the regulation of sympathetic nerve activity is also considered. Other potential downstream signalling mechanisms contributing to mineralocorticoid receptor-mediated sympathetic excitation are under investigation.

  9. THE CAFETERIA DIET INCREASES FAT MASS AND CHRONICALLY ELEVATES LUMBAR SYMPATHETIC NERVE ACTIVITY IN RATS

    Science.gov (United States)

    Muntzel, Martin S.; Al-Naimi, Omar Ali S.; Barclay, Alicia; Ajasin, David

    2012-01-01

    Obesity causes sympathetic activation that promotes atherosclerosis, end-organ damage, and hypertension. Because high-fat induced weight gain in rats elevates plasma leptin at 1–3 days following onset of calorie dense diets, we hypothesized that diet-induced overfeeding will increase sympathetic activity within one week following onset of the regimen. To test this, we continuously measured sympathetic activity and blood pressure before and during the onset of diet-induced obesity using a high calorie cafeteria-style diet. Female Wistar rats, in which radiotelemeters had been implanted for continuous monitoring of lumbar sympathetic activity, mean arterial pressure, and heart rate, were randomly assigned to groups that received regular chow (control) or a cafeteria diet for a period of 15 days. This short-term cafeteria-feeding regimen caused modest but non-significant increases in body weight (P = 0.07) and a doubling of brown and white adipose tissue (P cafeteria rats compared with controls (P Cafeteria diet-induced weight gain caused increases in lumbar sympathetic nerve activity that became significant by the 12th day of the diet (p cafeteria-style diet stimulates sustained increases in lumbar sympathetic neural drive in rats. PMID:23090774

  10. Cafeteria diet increases fat mass and chronically elevates lumbar sympathetic nerve activity in rats.

    Science.gov (United States)

    Muntzel, Martin S; Al-Naimi, Omar Ali S; Barclay, Alicia; Ajasin, David

    2012-12-01

    Obesity causes sympathetic activation that promotes atherosclerosis, end-organ damage, and hypertension. Because high-fat induced weight gain in rats elevates plasma leptin at 1 to 3 days after the onset of calorie-dense diets, we hypothesized that diet-induced overfeeding will increase sympathetic activity within 1 week after the onset of the regimen. To test this, we continuously measured sympathetic activity and blood pressure before and during the onset of diet-induced obesity using a high-calorie, cafeteria-style diet. Female Wistar rats, in which radiotelemeters had been implanted for continuous monitoring of lumbar sympathetic activity, mean arterial pressure, and heart rate, were randomly assigned to groups that received regular chow (control) or a cafeteria diet for a period of 15 days. This short-term, cafeteria-feeding regimen caused modest but nonsignificant increases in body weight (P=0.07) and a doubling of brown and white adipose tissue (Pcafeteria rats compared with controls (PCafeteria diet-induced weight gain caused increases in lumbar sympathetic nerve activity that became significant by the 12th day of the diet (Pcafeteria-style diet stimulates sustained increases in lumbar sympathetic neural drive in rats.

  11. Aliskiren ameliorates sympathetic nerve sprouting and suppresses the inducibility of ventricular tachyarrhythmia in postinfarcted rat heart

    Institute of Scientific and Technical Information of China (English)

    JIA Yin-yu; BAO Zhi-wei; WEI Mei-fang; ZHU Jian-hua; GUI Le

    2013-01-01

    Background Aliskiren is an oral renin inhibitor,which inhibits the first rate limiting step in the renin angiotensin aldosterone system.In this study,sympathetic nerve sprouting and the inducibility of ventricular fibrillation after aliskiren treatment in myocardial infarction were investigated.Methods Male Sprague Dawley rats after coronary artery ligation were randomly allocated to four groups:angiotensin converting enzyme inhibitor enalapril,angiotensin receptor blocker valsartan,β adrenergic receptor blocker carvedilol and rennin inhibitor aliskiren treatment for six weeks.Electrophysiological study,histological examination and Western blotting were performed.Results The plasma norepinephrine level and sympathetic nerve innervation significantly increased in treated infarcted rats compared to untreated rats.Aliskiren treatment reduced the sympathetic nerve innervations after myocardial infarction.There is no significant difference in sympathetic nerve innervations after myocardial infarction among the enalapril,valsartan,carvediloand or aliskiren treated groups.Programmed electrical stimulation study showed that inducible ventricular arrhythmia was reduced,ventricular fibrillation threshold was increased and ventricular effective refractory period was prolonged in enalapril,valsartan,carvedilol and aliskiren treated infarcted rats compared to untreated infarcted rats.Cardiomyocytic apoptosis in infarcted region was significantly decreased in enalapril,valsartan,carvedilol and aliskiren treated infarcted rats.Conclusions Aliskiren ameliorated cardiomyocytic apoptosis,attenuated the sympathetic nerve innervations and reduced the vulnerability of ventricular arrhythmias after myocardial infarction.Enalapril,valsartan and carvedilol have similar effects as aliskiren on cardiomyocytic apoptosis,sympathetic nerve innervations and vulnerability of ventricular arrhythmias after myocardial infarction.

  12. Reduced sympathetic neurite outgrowth on uterine tissue sections from rats treated with estrogen.

    Science.gov (United States)

    Richeri, Analía; Bianchimano, Paola; Crutcher, Keith A; Brauer, M Mónica

    2010-05-01

    In order to evaluate the contribution of substrate-bound factors to the extent and patterning of the sympathetic innervation of rat uterus following estrogen treatment, superior cervical ganglion explants from neonatal and adult ovariectomized rats were cultured on tissue sections of fresh frozen uterus from adult ovariectomized rats treated with estrogen or a vehicle. The main findings were: (1) neurite growth was greatly influenced by histological features of the underlying section; (2) on myometrial sections, neurites followed the orientation of the main axis of the longitudinally sectioned muscle cells; (3) neurites showed limited growth on transversally sectioned smooth muscle; (4) neuritic patterning was unaffected by a reduction in migrating ganglionic non-neuronal cells; (5) neurite outgrowth, but not non-neural cell migration, was markedly reduced on myometrial sections from rats treated with estrogen. These results suggest that adult myometrium continues to provide signals allowing the organotypic patterning and growth of sympathetic axons, that estrogen treatment modifies myometrial substrate properties so that it is less supportive for sympathetic neurite growth, and that adult sympathetic neurons retain their ability to recognize substrate-bound cues present in the myometrium. On endometrial sections, neurites formed radially symmetric halos, which were reduced in size on estrogen-treated endometrial substrates. Thus, changes in the neuritogenic capacity of the uterus underlie plasticity in uterine sympathetic nerves, and alterations in substrate-bound factors contribute to the diminished receptivity of the estrogenized uterus to its sympathetic innervation.

  13. Renal sympathetic denervation for treatment of patients with heart failure: summary of the available evidence.

    Science.gov (United States)

    Nammas, Wail; Koistinen, Juhani; Paana, Tuomas; Karjalainen, Pasi P

    2017-02-10

    Heart failure syndrome results from compensatory mechanisms that operate to restore - back to normal - the systemic perfusion pressure. Sympathetic overactivity plays a pivotal role in heart failure; norepinephrine contributes to maintenance of the systemic blood pressure and increasing preload. Cardiac norepinephrine spillover increases in patients with heart failure; norepinephrine exerts direct toxicity on cardiac myocytes resulting in a decrease of synthetic activity and/or viability. Importantly, cardiac norepinephrine spillover is a powerful predictor of mortality in patients with moderate to severe HF. This provided the rationale for trials that demonstrated survival benefit associated with the use of beta adrenergic blockers in heart failure with reduced ejection fraction. Nevertheless, the MOXCON trial demonstrated that rapid uptitration of moxonidine (inhibitor of central sympathetic outflow) in patients with heart failure was associated with excess mortality and morbidity, despite reduction of plasma norepinephrine. Interestingly, renal norepinephrine spillover was the only independent predictor of adverse outcome in patients with heart failure, in multivariable analysis. Recently, renal sympathetic denervation has emerged as a novel approach for control of blood pressure in patients with treatment-resistant hypertension. This article summarizes the available evidence for the effect of renal sympathetic denervation in the setting of heart failure. Key messages Experimental studies supported a beneficial effect of renal sympathetic denervation in heart failure with reduced ejection fraction. Clinical studies demonstrated improvement of symptoms, and left ventricular function. In heart failure and preserved ejection fraction, renal sympathetic denervation is associated with improvement of surrogate endpoints.

  14. Central PACAP mediates the sympathetic effects of leptin in a tissue-specific manner.

    Science.gov (United States)

    Tanida, M; Hayata, A; Shintani, N; Yamamoto, N; Kurata, Y; Shibamoto, T; Morgan, D A; Rahmouni, K; Hashimoto, H

    2013-05-15

    We previously demonstrated that the peptidergic neurotransmitter pituitary adenylate cyclase-activating polypeptide (PACAP) affects the autonomic system and contributes to the control of metabolic and cardiovascular functions. Previous studies have demonstrated the importance of centrally-mediated sympathetic effects of leptin for obesity-related hypertension. Here we tested whether PACAP signaling in the brain is implicated in leptin-induced sympathetic excitation and appetite suppression. In anesthetized mice, intracerebroventricular (ICV) pre-treatment with PACAP6-38, an antagonist of the PACAP receptors (PAC1-R and VPAC2), inhibited the increase in white adipose tissue sympathetic nerve activity (WAT-SNA) produced by ICV leptin (2μg). In contrast, leptin-induced stimulation of renal sympathetic nerve activity (RSNA) was not affected by ICV pre-treatment with PACAP6-38. Moreover, in PACAP-deficient (Adcyap1-/-) mice, ICV leptin-induced WAT-SNA increase was impaired, whereas RSNA response was preserved. The reductions in food intake and body weight evoked by ICV leptin were attenuated in Adcyap1-/- mice. Our data suggest that hypothalamic PACAP signaling plays a key role in the control by leptin of feeding behavior and lipocatabolic sympathetic outflow, but spares the renal sympathetic traffic. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. Nerve Growth Factor Decreases in Sympathetic and Sensory Nerves of Rats with Chronic Heart Failure

    Science.gov (United States)

    Lu, Jian

    2014-01-01

    Nerve growth factor (NGF) plays a critical role in the maintenance and survival of both sympathetic and sensory nerves. Also, NGF can regulate receptor expression and neuronal activity in the sympathetic and sensory neurons. Abnormalities in NGF regulation are observed in patients and animals with heart failure (HF). Nevertheless, the effects of chronic HF on the levels of NGF within the sympathetic and sensory nerves are not known. Thus, the ELISA method was used to assess the levels of NGF in the stellate ganglion (SG) and dorsal root ganglion (DRG) neurons of control rats and rats with chronic HF induced by myocardial infarction. Our data show for the first time that the levels of NGF were significantly decreased (P < 0.05) in the SG and DRG neurons 6–20 weeks after ligation of the coronary artery. In addition, a close relation was observed between the NGF levels and the left ventricular function. In conclusion, chronic HF impairs the expression of NGF in the sympathetic and sensory nerves. Given that sensory afferent nerves are engaged in the sympathetic nervous responses to somatic stimulation (i.e. muscle activity during exercise) via a reflex mechanism, our data indicate that NGF is likely responsible for the development of muscle reflex-mediated abnormal sympathetic responsiveness observed in chronic HF. PMID:24913185

  16. Imaging of the autonomic nervous system: focus on cardiac sympathetic innervation.

    Science.gov (United States)

    Goldstein, David S

    2003-12-01

    Symptoms or signs of abnormal autonomic nervous system function occur commonly in several neurological disorders. Clinical evaluations have depended on physiological, pharmacological, and neurochemical approaches. Recently, imaging of sympathetic noradrenergic innervation has been introduced and applied especially in the heart. Most studies have used the radiolabeled sympathomimetic amine, (123)I-metaiodobenzylguanidine. Decreased uptake or increased "washout" of (123)I-metaiodobenzylguanidine-derived radioactivity is associated with worse prognosis or more severe disease in hypertension, congestive heart failure, arrhythmias, and diabetes mellitus. This pattern may reflect a high rate of postganglionic sympathetic nerve traffic to the heart. Many recent studies have agreed on the remarkable finding that all patients with Parkinson's disease and orthostatic hypotension have a loss of cardiac sympathetic innervation, whereas all patients with multiple system atrophy, often difficult to distinguish clinically from Parkinson's disease, have intact cardiac sympathetic innervation. Because Parkinson's disease entails a postganglionic sympathetic noradrenergic lesion, the disease appears to be not only a movement disorder, with dopamine loss in the nigrostriatal system of the brain, but also a dysautonomia, with noradrenaline loss in the sympathetic nervous system of the heart. As new ligands are developed, one may predict further discoveries of involvement of components of the autonomic nervous system in neurological diseases.

  17. [Role of renal sympathetic nerve and oxidative stress in foot shock-induced hypertension in rats].

    Science.gov (United States)

    Jiang, Ren-Di; Zhang, Zhe; Xu, Jian-Bing; Dong, Tao; Zhang, Guo-Xing

    2015-06-25

    The present study was aimed to investigate the roles of renal sympathetic nerve and oxidative stress in the development of foot shock-induced hypertension. Ninety rats were divided into 6 groups (the number of each group was 15): control group, foot shock group, denervation of renal sympathetic nerve group, denervation of renal sympathetic nerve + foot shock group, Tempol treatment + foot shock group, denervation of renal sympathetic nerve + Tempol treatment + foot shock group. Rats were received electrical foot shock for 14 days (2-4 mA, 75 V, shocks of 50-100 ms every 30 s, for 4 h each session through an electrified grid floor every day). Renal sympathetic ablation was used to remove bilateral renal sympathetic nerve in rats (rats were allowed to recover for one week before the beginning of the foot shock procedure). The antioxidant Tempol was injected intraperitoneally at 1 h before foot shock. Systolic blood pressure was measured at 1 h after foot shock on day 0, 3, 7, 10 and 14. Contents of thiobarbituric acid reactive substance (TBARS), renin, angiotensin II (AngII) and glutathione peroxidase (GSH-Px) in plasma were measured by ELISA after 14-day foot shock. The results showed that systolic blood pressure of foot shock group was significantly increased (P indirectly activate renin-angiotensin-aldosterone system, so the foot shock-induced high blood pressure may be maintained and hypertension may therefore be produced.

  18. Recovery of sympathetic nerve function after lumbar sympathectomy is slower in the hind limbs than in the torso.

    Science.gov (United States)

    Zheng, Zhi-Fang; Liu, Yi-Shu; Min, Xuan; Tang, Jian-Bing; Liu, Hong-Wei; Cheng, Biao

    2017-07-01

    Local sympathetic denervation by surgical sympathectomy is used in the treatment of lower limb ulcers and ischemia, but the restoration of cutaneous sympathetic nerve functions is less clear. This study aims to explore the recovery of cutaneous sympathetic functions after bilateral L2-4 sympathectomy. The skin temperature of the left feet, using a point monitoring thermometer, increased intraoperatively after sympathectomy. The cytoplasm of sympathetic neurons contained tyrosine hydroxylase and dopamine β-hydroxylase, visualized by immunofluorescence, indicated the accuracy of sympathectomy. Iodine starch test results suggested that the sweating function of the hind feet plantar skin decreased 2 and 7 weeks after lumbar sympathectomy but had recovered by 3 months. Immunofluorescence and western blot assay results revealed that norepinephrine and dopamine β-hydroxylase expression in the skin from the sacrococcygeal region and hind feet decreased in the sympathectomized group at 2 weeks. Transmission electron microscopy results showed that perinuclear space and axon demyelination in sympathetic cells in the L5 sympathetic trunks were found in the sympathectomized group 3 months after sympathectomy. Although sympathetic denervation occurred in the sacrococcygeal region and hind feet skin 2 weeks after lumbar sympathectomy, the skin functions recovered gradually over 7 weeks to 3 months. In conclusion, sympathetic functional recovery may account for the recurrence of hyperhidrosis after sympathectomy and the normalization of sympathetic nerve trunks after incomplete injury. The recovery of sympathetic nerve function was slower in the limbs than in the torso after bilateral L2-4 sympathectomy.

  19. Eppur Si Muove: The dynamic nature of physiological control of renal blood flow by the renal sympathetic nerves.

    Science.gov (United States)

    Schiller, Alicia M; Pellegrino, Peter Ricci; Zucker, Irving H

    2016-08-03

    Tubuloglomerular feedback and the myogenic response are widely appreciated as important regulators of renal blood flow, but the role of the sympathetic nervous system in physiological renal blood flow control remains controversial. Where classic studies using static measures of renal blood flow failed, dynamic approaches have succeeded in demonstrating sympathetic control of renal blood flow under normal physiological conditions. This review focuses on transfer function analysis of renal pressure-flow, which leverages the physical relationship between blood pressure and flow to assess the underlying vascular control mechanisms. Studies using this approach indicate that the renal nerves are important in the rapid regulation of the renal vasculature. Animals with intact renal innervation show a sympathetic signature in the frequency range associated with sympathetic vasomotion that is eliminated by renal denervation. In conscious rabbits, this sympathetic signature exerts vasoconstrictive, baroreflex control of renal vascular conductance, matching well with the rhythmic, baroreflex-influenced control of renal sympathetic nerve activity and complementing findings from other studies employing dynamic approaches to study renal sympathetic vascular control. In this light, classic studies reporting that nerve stimulation and renal denervation do not affect static measures of renal blood flow provide evidence for the strength of renal autoregulation rather than evidence against physiological renal sympathetic control of renal blood flow. Thus, alongside tubuloglomerular feedback and the myogenic response, renal sympathetic outflow should be considered an important physiological regulator of renal blood flow. Clinically, renal sympathetic vasomotion may be important for solving the problems facing the field of therapeutic renal denervation.

  20. Reflex sympathetic dystrophy/complex regional pain syndrome, type 1

    Directory of Open Access Journals (Sweden)

    S.H. Botha

    2004-02-01

    Full Text Available Complex regional pain syndrome (CPRS, type 1 is a pain disorder that develops unpredictably and can follow a minor injury. A 12-year-old boy presented with severe pain in the feet and could not walk or stand weight bearing. Normal X-rays showed osteopenic changes and radiolucent lines, which appeared to be stress fractures. Three-phase bone scintigraphy showed no uptake in the left lower leg on the blood pool phase or on the immediate or delayed images. This indicated typical CPRS type 1 in children. The uptake in the right foot was increased and the stress fracture and other illness could not be differentiated. Computed tomography was done to exclude stress fractures. Only osteopenic changes in both calcaneus bones were found and there was no evidence of cortical stress fractures. Magnetic resonance images revealed oedema in the calcaneus and talus bones of both feet. The patient received epidural narcotic infusion with sympathetic blockage for 1 week combined with extensive physiotherapy. The blood pool phase of the bone scan became normal within 2 weeks, and increased uptake in both feet was noticed. The patient was followed up with MRI every 3 months and the bone marrow oedema disappeared after 6 months.

  1. Riding out the storm: sympathetic storming after traumatic brain injury.

    Science.gov (United States)

    Lemke, Denise M

    2004-02-01

    Following acute multiple trauma, hypothalamic stimulation of the sympathetic nervous system and adrenal glands causes an increase in circulating corticoids and catecholamines, or a stress response. In individuals with severe traumatic brain injury or a Glasgow Coma Scale score of 3-8, this response can be exaggerated and episodic. A term commonly used by nurses caring for these individuals to describe this phenomenon is storming. Symptoms can include alterations in level of consciousness, increased posturing, dystonia, hypertension, hyperthermia, tachycardia, tachypnea, diaphoresis, and agitation. These individuals generally are at a low level of neurological activity with minimal alertness, minimal awareness, and reflexive motor response to stimulation, and the storming can take a seemingly peaceful individual into a state of chaos. Diagnosis is commonly made solely on clinical assessment, and treatment is aimed at controlling the duration and severity of the symptoms and preventing additional brain injury. Storming can pose a challenge for the nurse, from providing daily care for the individual in the height of the storming episode and treating the symptoms, to educating the family. Careful assessment of the individual leads the nurse to the diagnosis and places the nurse in the role of moderator of the storming episode, including providing treatment and evaluating outcomes.

  2. Modeling sympathetic cooling of molecules by ultracold atoms

    CERN Document Server

    Lim, Jongseok; Hutson, Jeremy M; Tarbutt, M R

    2015-01-01

    We model sympathetic cooling of ground-state CaF molecules by ultracold Li and Rb atoms. The molecules are moving in a microwave trap, while the atoms are trapped magnetically. We calculate the differential elastic cross sections for CaF-Li and CaF-Rb collisions, using model Lennard-Jones potentials adjusted to give typical values for the s-wave scattering length. Together with trajectory calculations, these differential cross sections are used to simulate the cooling of the molecules, the heating of the atoms, and the loss of atoms from the trap. We show that a hard-sphere collision model based on an energy-dependent momentum transport cross section accurately predicts the molecule cooling rate but underestimates the rates of atom heating and loss. Our simulations suggest that Rb is a more effective coolant than Li for ground-state molecules, and that the cooling dynamics are less sensitive to the exact value of the s-wave scattering length when Rb is used. Using realistic experimental parameters, we find th...

  3. Sympathetic Tone Induced by High Acoustic Tempo Requires Fast Respiration.

    Directory of Open Access Journals (Sweden)

    Ken Watanabe

    Full Text Available Many studies have revealed the influences of music, and particularly its tempo, on the autonomic nervous system (ANS and respiration patterns. Since there is the interaction between the ANS and the respiratory system, namely sympatho-respiratory coupling, it is possible that the effect of musical tempo on the ANS is modulated by the respiratory system. Therefore, we investigated the effects of the relationship between musical tempo and respiratory rate on the ANS. Fifty-two healthy people aged 18-35 years participated in this study. Their respiratory rates were controlled by using a silent electronic metronome and they listened to simple drum sounds with a constant tempo. We varied the respiratory rate-acoustic tempo combination. The respiratory rate was controlled at 15 or 20 cycles per minute (CPM and the acoustic tempo was 60 or 80 beats per minute (BPM or the environment was silent. Electrocardiograms and an elastic chest band were used to measure the heart rate and respiratory rate, respectively. The mean heart rate and heart rate variability (HRV were regarded as indices of ANS activity. We observed a significant increase in the mean heart rate and the low (0.04-0.15 Hz to high (0.15-0.40 Hz frequency ratio of HRV, only when the respiratory rate was controlled at 20 CPM and the acoustic tempo was 80 BPM. We suggest that the effect of acoustic tempo on the sympathetic tone is modulated by the respiratory system.

  4. Adrenal GRK2 upregulation mediates sympathetic overdrive in heart failure.

    Science.gov (United States)

    Lymperopoulos, Anastasios; Rengo, Giuseppe; Funakoshi, Hajime; Eckhart, Andrea D; Koch, Walter J

    2007-03-01

    Cardiac overstimulation by the sympathetic nervous system (SNS) is a salient characteristic of heart failure, reflected by elevated circulating levels of catecholamines. The success of beta-adrenergic receptor (betaAR) antagonists in heart failure argues for SNS hyperactivity being pathogenic; however, sympatholytic agents targeting alpha2AR-mediated catecholamine inhibition have been unsuccessful. By investigating adrenal adrenergic receptor signaling in heart failure models, we found molecular mechanisms to explain the failure of sympatholytic agents and discovered a new strategy to lower SNS activity. During heart failure, there is substantial alpha2AR dysregulation in the adrenal gland, triggered by increased expression and activity of G protein-coupled receptor kinase 2 (GRK2). Adrenal gland-specific GRK2 inhibition reversed alpha2AR dysregulation in heart failure, resulting in lowered plasma catecholamine levels, improved cardiac betaAR signaling and function, and increased sympatholytic efficacy of a alpha2AR agonist. This is the first demonstration, to our knowledge, of a molecular mechanism for SNS hyperactivity in heart failure, and our study identifies adrenal GRK2 activity as a new sympatholytic target.

  5. Reflex sympathetic dystrophy--a complex regional pain syndrome.

    Science.gov (United States)

    Turner-Stokes, L

    2002-12-15

    Reflex sympathetic dystrophy (RSD) is a complex and poorly-understood condition characterized by: (a) pain and altered sensation; (b) motor disturbance and soft tissue change; (c) vasomotor and autonomic changes; and (d) psychosocial disturbance. Neurological symptoms typically do not conform to any particular pattern of nerve damage. Many different names have been ascribed to this condition and most recently the term 'complex regional pain syndrome' has been coined to emphasize the complex interaction of somatic, psychological and behavioural factors. Diagnostic criteria have been proposed by the International Association for the Study of Pain, but are still subject to debate. This review article describes the clinical features which may present as part of the condition, and the patho-physiology and pre-disposing factors so far identified. The evidence for effectiveness of different interventions is presented and a treatment approach outlined for inter-disciplinary management. While RSD is traditionally associated with pain in the extremities, the possibility is raised that the same process may underlie chronic pain syndromes affecting more central structures, such as testicular or pelvic pain.

  6. High-resolution Observations of Sympathetic Filament Eruptions by NVST

    Science.gov (United States)

    Su, Yingna; Li, Shangwei; Zhou, Tuanhui; Van Ballegooijen, Adriaan A.; Sun, Xudong; Ji, Haisheng

    2017-08-01

    We investigate two sympathetic filament eruptions observed by the New Vacuum Solar Telescope (NVST) on 2015 October 15. The full picture of the eruptions is obtained from the corresponding SDO/AIA observations. The two filaments start from the east border of active region NOAA 12434 in the north and end in one large quiescent filament channel in the south. The left filament erupts firstly, followed by the right filament eruption about 10 minutes later. Clear twist structure and rotating motion are observed in both filaments during the eruption. Both eruptions are failed, since the filaments firstly rise up, then flow towards the south and merge into the southern large quiescent filament. We also observe repeating activations of mini filaments below the right filament after its eruption. Using magnetic field models constructed based on SDO/HMI magnetograms by flux rope insertion method, we find that the left filament eruption is likely to be triggered by kink instability, while weakening of overlying magnetic fields due to magnetic reconnection at an X-point between the two filament systems might play an important role in the onset of the right filament eruption.

  7. Sympathetic skin response: a new test to diagnose erectile dysfunction

    Institute of Scientific and Technical Information of China (English)

    Guang-You ZHU; Yan SHEN

    2001-01-01

    Electrophysiological monitoring of the activity of the penile sympathetic skin responses (PSSR) in healthy men and patients with erectile dysfunction (ED). Methods: PSSR were recorded from the skin of penis with disk electrodes at the time of electric stimulation of left median nerves. Results: PSSR were recorded from all the healthy men and almost all the patients. In healthy men the latency of P0, the latency of N1, the duration of N1 and the amplitude of N1 were 1249 ± 111 ms, 2239 ± 286 ms, 1832 ± 505 ms and 470 μV (median), respectively. In ED patients the latency of P0, the latency of N1, the duration of N1 and the amplitude of N1 were 1467 ± 183 ms ( P < 0.01), 2561±453 ms (P <0.05), 2560±861 ms (P <0.01) and 91 μV (P <0.01), respectively. The normal latency of P0 was less than 1471 ms. The normal amplitude of N1 was more than 235 μV. According to this normal value, of 20 patients 11 showed longer latency of P0, and 14 showed lower amplitude of N1 as compared with those of normal subjects.Conclusion: PSSR can be used as an electrophysiological method in assisting the diagnosis of ED.

  8. Sympathetic Solar Filament Eruptions on 2015 March 15

    CERN Document Server

    Wang, Rui; Zimovets, Ivan; Hu, Huidong; Dai, Xinghua; Yang, Zhongwei

    2016-01-01

    The 2015 March 15 coronal mass ejection as one of the two that together drove the largest geomagnetic storm of solar cycle 24 so far was associated with sympathetic filament eruptions. We investigate the relations between the different filaments involved in the eruption. A surge-like small-scale filament motion is confirmed as the trigger that initiated the erupting filament with multi-wavelength observations and using a forced magnetic field extrapolation method. When the erupting filament moved to an open magnetic field region, it experienced an obvious acceleration process and was accompanied by a C-class flare and the rise of another larger filament that eventually failed to erupt. We measure the decay index of the background magnetic field, which presents a critical height of 118 Mm. Combining with a potential field source surface extrapolation method, we analyze the distributions of the large-scale magnetic field, which indicates that the open magnetic field region may provide a favorable condition for ...

  9. Cardiac sympathetic dysfunction in anti-NMDA receptor encephalitis.

    Science.gov (United States)

    Byun, Jung-Ick; Lee, Soon-Tae; Moon, Jangsup; Jung, Keun-Hwa; Shin, Jung-Won; Sunwoo, Jun-Sang; Lim, Jung-Ah; Shin, Yong-Won; Kim, Tae-Joon; Lee, Keon-Joo; Park, Kyung-Il; Jung, Ki-Young; Lee, Sang Kun; Chu, Kon

    2015-12-01

    Patients with anti-NMDA receptor (anti-NMDAR) encephalitis frequently suffer from autonomic dysfunctions, which can cause substantial morbidity. This study assessed cardiac autonomic functions in patients with anti-NMDAR encephalitis using heart rate variability (HRV) analysis. This was a retrospective single-center case-control study. Eleven patients with anti-NMDAR encephalitis and 15 age- and sex-matched controls were included in this study. To ensure that autonomic dysfunction does not occur in any encephalitis, we additionally analyzed HRV of 9 patients with herpes encephalitis (HSE) and compared with that of NMDAR encephalitis patients and controls. Five minute resting stationary electrocardiogram was collected from each subject, and HRV was analyzed. Total power and low frequency (LF) power were lower in anti-NMDAR encephalitis patients than those in controls (p=0.005, 0.001 respectively), indicating cardiac autonomic dysfunction especially in sympathetic system. Patients with HSE showed no significant difference in HRV parameters compared with that of controls. Cardiac autonomic dysfunction was associated with 3 month functional outcome in anti-NMDAR encephalitis patients.

  10. Neurophysiological analysis of target-related sympathetic pathways--from animal to human: similarities and differences.

    Science.gov (United States)

    Jänig, W; Häbler, H-J

    2003-03-01

    The sympathetic nervous system regulates many different target tissues in the somatic and visceral domains of the body in a differentiated manner, indicating that there exist separate sympathetic pathways that are functionally defined by their target cells. Signals generated by central integration and channelled through the preganglionic neurons into the final sympathetic pathways are precisely transmitted through the para- and prevertebral ganglia and at the neuroeffector junctions to the effector cells. Neurophysiological recordings of activity in postganglionic neurons in skin and muscle nerves using microneurography in human subjects and in skin, muscle and visceral nerves, using conventional recording techniques in anaesthetized animals, clearly show that each type of sympathetic neuron exhibits a discharge pattern that is characteristic for its target cells and, therefore, its function. These findings justify labelling the neurons as muscle vasoconstrictor, cutaneous vasoconstrictor, sudomotor, lipomotor, cardiomotor, secretomotor neurons, etc. The discharge patterns monitor aspects of the central organization of the respective sympathetic system in the neuraxis and forebrain. They can be dissected into several distinct reflexes (initiated by peripheral and central afferent inputs) and reactions connected to central signals (related to respiration, circadian and other rhythms, command signals generated in the forebrain, etc). They are functional markers for the sympathetic final pathways. These neurophysiological recordings of the discharge patterns from functionally identified neurons of sympathetic pathways in the human and in animals are the ultimate reference for all experimental investigations that aim to unravel the central organization of the sympathetic systems. The similarities of the results obtained in the in vivo studies in the human and in animals justify concluding that the principles of the central organization of sympathetic systems are

  11. What can we learn about neural control of the cardiovascular system by studying rhythms in sympathetic nerve activity?

    Science.gov (United States)

    Barman, Susan M

    2016-05-01

    Since the first recordings of sympathetic nerve activity in the 1930s, it was very clear that the activity was organized into bursts synchronized to the respiratory and cardiac cycles. Since the early studies, evidence has accumulated showing that sympathetic neural networks are quite complex and generate a variety of periodicities that range between ~0.04 and 10Hz, depending on the physiological state, type of nerve being analyzed, age of the subject, and the species. Despite the ubiquity of sympathetic rhythms, many investigators have failed to consider this oscillatory characteristic of sympathetic nerve activity and instead rely on simply quantifying changes in the level of activity to make decisions about the role of the sympathetic nervous system in mediating certain behaviors. This review highlights work that shows the importance of including an assessment of the frequency characteristics of sympathetic nerve activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Evidence of sympathetic fibers in the male rat pelvic nerve by gross anatomy, retrograde labeling and high resolution autoradiographic study.

    Science.gov (United States)

    Giuliano, F; Facchinetti, P; Bernabé, J; Benoit, G; Calas, A; Rampin, O

    1997-12-01

    Several arguments exist in various animal species and man for the presence of a sympathetic component in the pelvic nerve, classically regarded as parasympathetic. We tested this hypothesis in the male rat. Nerve bundles issued from the sacral region of the paravertebral sympathetic chain and reaching the S1 spinal nerve were identified. Neurons in the sacral parasympathetic nucleus of the L6-S1 spinal cord and in the L2-S1 paravertebral sympathetic chain were retrogradely labeled from the pelvic nerve. Radioautography evidenced labeling of unmyelinated fibers in the pelvic nerve following in vitro incubation with 3H-noradrenaline. A population of sympathetic fibers issued from the lumbosacral sympathetic chain exists in the pelvic nerve of the male rat. This qualitative study provides a morphological basis to uncover the role of the sympathetic outflow present in the pelvic nerve.

  13. A Rationalization of Sympathetic Nucleation-Ledgewise Growth Theory of Bainite Transformation in Fe-C Alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the classic diffusion controlled nucleation and growth theory, the sympathetic nucleationledgewise growth mechanism of bainite was studied theoretically for Iow carbon Fe-C alloys. The rationality of the occurrence of sympathetic nucleation on the terraces of ledges competing with lateral ledge growth and other sites nucleation was demonstrated by the present work quantitatively. The calculations indicated that Iow reaction temperatures and high carbon concentrations may favor the sympathetic nucleation, thus accounting for the formation of multilayer structures of bainite.

  14. Interstitial cells of Cajal mediate excitatory sympathetic neurotransmission in guinea pig prostate.

    Science.gov (United States)

    Wang, Jiang-ping; Ding, Guo-fu; Wang, Qin-zhang

    2013-06-01

    Morphological and functional studies have confirmed that interstitial cells of Cajal (ICCs) are involved in many enteric motor neurotransmission pathways. Recent investigations have demonstrated that human and guinea pig prostate glands possess a distinct cell type with morphological and immunological similarities to ICCs. These prostate ICCs have a close relationship with nerve bundles and smooth muscle cells. Prostate smooth muscle tone is largely induced by stimulation from the sympathetic nervous system, which releases excitatory norepinephrine (NE) to act on the α1-adrenoceptor. We have performed morphological and functional experiments to determine the role of ICCs in sympathetic neurotransmission in the guinea pig prostate based on the hypothesis that prostate ICCs act as mediators of sympathetic neurotransmission. Immunohistochemistry revealed many close points of contact between ICCs and sympathetic nerve bundles and smooth muscle cells. Double-labeled sections revealed that α1-adrenoceptor and the gap junction protein connexin 43 were expressed in prostate ICCs. Surprisingly, prostate ICCs co-expressed tyrosine hydroxylase and dopamine β-hydroxylase, two markers of sympathetic neurons. Functionally, the application of NE evoked a large single inward current in isolated prostate ICCs in a dose-dependent manner. The inward current evoked by NE was mediated via the activation of α1-adrenoceptors, because it was abolished by the non-specific α-adrenoceptor antagonist, phentolamine and the specific α1-adrenoceptor antagonist, prazosin. Thus, ICCs in the guinea pig prostate are target cells for prostate sympathetic nerves and possess the morphological and functional characteristics required to mediate sympathetic signals.

  15. Involvement of hypothalamic AMP-activated protein kinase in leptin-induced sympathetic nerve activation.

    Directory of Open Access Journals (Sweden)

    Mamoru Tanida

    Full Text Available In mammals, leptin released from the white adipose tissue acts on the central nervous system to control feeding behavior, cardiovascular function, and energy metabolism. Central leptin activates sympathetic nerves that innervate the kidney, adipose tissue, and some abdominal organs in rats. AMP-activated protein kinase (AMPK is essential in the intracellular signaling pathway involving the activation of leptin receptors (ObRb. We investigated the potential of AMPKα2 in the sympathetic effects of leptin using in vivo siRNA injection to knockdown AMPKα2 in rats, to produce reduced hypothalamic AMPKα2 expression. Leptin effects on body weight, food intake, and blood FFA levels were eliminated in AMPKα2 siRNA-treated rats. Leptin-evoked enhancements of the sympathetic nerve outflows to the kidney, brown and white adipose tissues were attenuated in AMPKα2 siRNA-treated rats. To check whether AMPKα2 was specific to sympathetic changes induced by leptin, we examined the effects of injecting MT-II, a melanocortin-3 and -4 receptor agonist, on the sympathetic nerve outflows to the kidney and adipose tissue. MT-II-induced sympatho-excitation in the kidney was unchanged in AMPKα2 siRNA-treated rats. However, responses of neural activities involving adipose tissue to MT-II were attenuated in AMPKα2 siRNA-treated rats. These results suggest that hypothalamic AMPKα2 is involved not only in appetite and body weight regulation but also in the regulation of sympathetic nerve discharges to the kidney and adipose tissue. Thus, AMPK might function not only as an energy sensor, but as a key molecule in the cardiovascular, thermogenic, and lipolytic effects of leptin through the sympathetic nervous system.

  16. Involvement of hypothalamic AMP-activated protein kinase in leptin-induced sympathetic nerve activation.

    Science.gov (United States)

    Tanida, Mamoru; Yamamoto, Naoki; Shibamoto, Toshishige; Rahmouni, Kamal

    2013-01-01

    In mammals, leptin released from the white adipose tissue acts on the central nervous system to control feeding behavior, cardiovascular function, and energy metabolism. Central leptin activates sympathetic nerves that innervate the kidney, adipose tissue, and some abdominal organs in rats. AMP-activated protein kinase (AMPK) is essential in the intracellular signaling pathway involving the activation of leptin receptors (ObRb). We investigated the potential of AMPKα2 in the sympathetic effects of leptin using in vivo siRNA injection to knockdown AMPKα2 in rats, to produce reduced hypothalamic AMPKα2 expression. Leptin effects on body weight, food intake, and blood FFA levels were eliminated in AMPKα2 siRNA-treated rats. Leptin-evoked enhancements of the sympathetic nerve outflows to the kidney, brown and white adipose tissues were attenuated in AMPKα2 siRNA-treated rats. To check whether AMPKα2 was specific to sympathetic changes induced by leptin, we examined the effects of injecting MT-II, a melanocortin-3 and -4 receptor agonist, on the sympathetic nerve outflows to the kidney and adipose tissue. MT-II-induced sympatho-excitation in the kidney was unchanged in AMPKα2 siRNA-treated rats. However, responses of neural activities involving adipose tissue to MT-II were attenuated in AMPKα2 siRNA-treated rats. These results suggest that hypothalamic AMPKα2 is involved not only in appetite and body weight regulation but also in the regulation of sympathetic nerve discharges to the kidney and adipose tissue. Thus, AMPK might function not only as an energy sensor, but as a key molecule in the cardiovascular, thermogenic, and lipolytic effects of leptin through the sympathetic nervous system.

  17. Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight

    Science.gov (United States)

    Levine, Benjamin D.; Pawelczyk, James A.; Ertl, Andrew C.; Cox, James F.; Zuckerman, Julie H.; Diedrich, Andre; Biaggioni, Italo; Ray, Chester A.; Smith, Michael L.; Iwase, Satoshi; Saito, Mitsuru; Sugiyama, Yoshiki; Mano, Tadaaki; Zhang, Rong; Iwasaki, Kenichi; Lane, Lynda D.; Buckey, Jay C Jr; Cooke, William H.; Baisch, Friedhelm J.; Eckberg, Dwain L.; Blomqvist, C. Gunnar

    2002-01-01

    Orthostatic intolerance is common when astronauts return to Earth: after brief spaceflight, up to two-thirds are unable to remain standing for 10 min. Previous research suggests that susceptible individuals are unable to increase their systemic vascular resistance and plasma noradrenaline concentrations above pre-flight upright levels. In this study, we tested the hypothesis that adaptation to the microgravity of space impairs sympathetic neural responses to upright posture on Earth. We studied six astronauts approximately 72 and 23 days before and on landing day after the 16 day Neurolab space shuttle mission. We measured heart rate, arterial pressure and cardiac output, and calculated stroke volume and total peripheral resistance, during supine rest and 10 min of 60 deg upright tilt. Muscle sympathetic nerve activity was recorded in five subjects, as a direct measure of sympathetic nervous system responses. As in previous studies, mean (+/- S.E.M.) stroke volume was lower (46 +/- 5 vs. 76 +/- 3 ml, P = 0.017) and heart rate was higher (93 +/- 1 vs. 74 +/- 4 beats min(-1), P = 0.002) during tilt after spaceflight than before spaceflight. Total peripheral resistance during tilt post flight was higher in some, but not all astronauts (1674 +/- 256 vs. 1372 +/- 62 dynes s cm(-5), P = 0.32). No crew member exhibited orthostatic hypotension or presyncopal symptoms during the 10 min of postflight tilting. Muscle sympathetic nerve activity was higher post flight in all subjects, in supine (27 +/- 4 vs. 17 +/- 2 bursts min(-1), P = 0.04) and tilted (46 +/- 4 vs. 38 +/- 3 bursts min(-1), P = 0.01) positions. A strong (r(2) = 0.91-1.00) linear correlation between left ventricular stroke volume and muscle sympathetic nerve activity suggested that sympathetic responses were appropriate for the haemodynamic challenge of upright tilt and were unaffected by spaceflight. We conclude that after 16 days of spaceflight, muscle sympathetic nerve responses to upright tilt are normal.

  18. Increased vascular sympathetic modulation in mice with Mas receptor deficiency.

    Science.gov (United States)

    Rabello Casali, Karina; Ravizzoni Dartora, Daniela; Moura, Marina; Bertagnolli, Mariane; Bader, Michael; Haibara, Andrea; Alenina, Natalia; Irigoyen, Maria Claudia; Santos, Robson A

    2016-01-01

    The angiotensin-converting enzyme 2 (ACE2)/angiotensin (Ang)-(1-7)/Mas axis could modulate the heart rate (HR) and blood pressure variabilities (BPV) which are important predictors of cardiovascular risk and provide information about the autonomic modulation of the cardiovascular system. Therefore we investigated the effect of Mas deficiency on autonomic modulation in wild type and Mas-knockout (KO) mice. Blood pressure was recorded at high sample rate (4000 Hz). Stationary sequences of 200-250 beats were randomly chosen. Frequency domain analysis of HR and BPV was performed with an autoregressive algorithm on the pulse interval sequences and on respective systolic sequences. The KO group presented an increase of systolic arterial pressure (SAP; 127.26±11.20 vs 135.07±6.98 mmHg), BPV (3.54±1.54 vs 5.87±2.12 mmHg(2)), and low-frequency component of systolic BPV (0.12±0.11 vs 0.47±0.34 mmHg(2)). The deletion of Mas receptor is associated with an increase of SAP and with an increased BPV, indicating alterations in autonomic control. Increase of sympathetic vascular modulation in absence of Mas evidences the important role of Ang-(1-7)/Mas on cardiovascular regulation. Moreover, the absence of significant changes in HR and HRV can indicate an adaptation of autonomic cardiac balance. Our results suggest that the Ang-(1-7)/Mas axis seems more important in autonomic modulation of arterial pressure than HR. © The Author(s) 2016.

  19. Sympathetic nervous system influence on the innate immune response.

    Science.gov (United States)

    Maestroni, Georges J M

    2006-06-01

    Our studies focused on the sympathetic nervous system (SNS) influence on dendritic cells (DCs), which play a crucial role in the innate immune response. We found that DCs express a variety of adrenergic receptors (ARs) with alpha1-ARs playing a stimulatory and beta2-ARs an inhibitory effect on DCs migration. beta2-ARs in skin and bone marrow-derived DCs when stimulated by bacterial toll-like receptors (TLRs) agonists respond to norepinephrine (NE) by decreased interleukin-12 (IL-12) and increased IL-10 production which in turn downregulates inflammatory cytokine production and CCR7 expression and thus their migration ability leading to reduced T helper-1 (Th1) priming. We also found that contact sensitizers that may induce a predominant Th1 response, do so by inhibiting the local NE turnover in the skin. The SNS seems therefore to contribute in shaping the information conveyed by DCs to T cells and thus in inducing the appropriate adaptive immune response. In this sense, the SNS physiological influence may allow Th2 priming to fight infections sustained by extracellular pathogens and limit the risk for organ-specific autoimmune reactions associated with excessive Th1 priming and inhibition of T regulatory cell functions. More recently, we found that preconditioning of the skin by beta-adrenergic antagonist and the TLR2 agonist S. Aureus peptidoglycan (PGN) may instruct a Th1 adaptive response to a soluble protein antigen. On the contrary, when the TLR4 agonist E. Coli lipopolysaccharide was used, the presence of the beta-adrenergic antagonist was not effective. These effects were consonant with the pattern of TLRs expression shown by epidermal keratinocytes (EKs) but not by skin DCs. As beta-ARs signaling defects together with S. Aureus infections are thought to serve as initiation and/or persistence factors for numerous Th1-sustained autoimmune inflammatory skin diseases, we might have disclosed at least part of the relevant pathogenetic mechanism.

  20. Change in sympathetic nerve firing pattern associated with dietary weight loss in the metabolic syndrome

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    Elisabeth Annie Lambert

    2011-08-01

    Full Text Available Sympathetic activation in subjects with the metabolic syndrome (MS plays a role in the pathogenesis of cardiovascular disease development. Diet-induced weight loss decreases sympathetic outflow. However the mechanisms that account for sympathetic inhibition are not known. We sought to provide a detailed description of the sympathetic response to diet by analyzing the firing behavior of single-unit sympathetic nerve fibres. Fourteen subjects (57±2 years, 9 men, 5 females fulfilling ATP III criteria for the MS underwent a 3-month low calorie diet. Metabolic profile, hemodynamic parameters and multi-unit and single unit muscle sympathetic nerve activity (MSNA, microneurography were assessed prior to and at the end of the diet. Patients’ weight dropped from 96±4 to 88±3 kg (P<0.001. This was associated with a decrease in systolic and diastolic blood pressure (-12 ±3 and -5±2 mmHg, P<0.05, and in heart rate (-7±2 bpm, P<0.01 and an improvement in all metabolic parameters (fasting glucose: -0.302.1±0.118 mmol/l, total cholesterol: -0.564±0.164 mmol/l, triglycerides: -0.414±0.137 mmol/l, P<0.05. Multi-unit MSNA decreased from 68±4 to 59±5 bursts per 100 heartbeats (P<0.05. Single-unit MSNA indicated that the firing rate of individual vasoconstrictor fibres decreased from 59±10 to 32±4 spikes per 100 heart beats (P<0.05. The probability of firing decreased from 34±5 to 23±3 % of heartbeats (P<0.05, and the incidence of multiple firing decreased from 14±4 to 6±1 % of heartbeats (P<0.05. Cardiac and sympathetic baroreflex function were significantly improved (cardiac slope: 6.57±0.69 to 9.57±1.20 msec.mmHg-1; sympathetic slope: -3.86±0.34 to -5.05±0.47 bursts per 100 heartbeats.mmHg-1 P<0.05 for both. Hypocaloric diet decreased sympathetic activity and improved hemodynamic and metabolic parameters. The sympathoinhibition associated with weight loss involves marked changes, not only in the rate but also in the firing pattern of

  1. Prejunctional inhibition of sympathetically evoked pupillary dilation in cats by activation of histamine H3 receptors.

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    Koss, M C; Hey, J A

    1993-08-01

    Frequency-dependent pupillary dilations were evoked by electrical stimulation of the pre- or post-ganglionic cervical sympathetic nerve (sympatho-excitation) or the hypothalamus (parasympatho-inhibition) in sympathectomized anesthetized cats. Systemic administration of the selective histamine H3 receptor agonist (R)-alpha-methylhistamine (R alpha MeHA) produced a dose-dependent depression of mydriasis due to direct neural sympathetic activation but had no effect on responses elicited by parasympathetic withdrawal. The histamine H2 receptor agonist, dimaprit, was inactive. R alpha MeHA was much more effective in depressing sympathetic responses obtained at lower frequencies when compared to higher frequencies of stimulation. Responses evoked both pre- and postganglionically were inhibited by R alpha MeHA. This peripheral sympatho-inhibitory action of R alpha MeHA was antagonized by the histamine H3 receptor blocker thioperamide but not by intravenous pretreatment with the histamine H1 receptor antagonist chlorpheniramine. Histamine H2 receptor blockers cimetidine and ranitidine were also without effect. R alpha MeHA did not depress pupillary responses elicited by i.v. (-)-adrenaline. The results demonstrate that histamine H3 receptors modulate sympathetic activation of the iris at a site proximal to the iris dilator muscle. The predominant mechanism of action appears to the prejunctional inhibition of noradrenaline release from postganglionic sympathetic nerve endings. However, a concomitant ganglionic inhibitory action cannot be excluded.

  2. Electrical storm: Role of stellate ganglion blockade and anesthetic implications of left cardiac sympathetic denervation

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    Shrinivas Gadhinglajkar

    2013-01-01

    Full Text Available An electrical storm is usually associated with catecholaminergic surge following myocardial ischaemia and manifest as recurrent ventricular arrhythmias, requiring frequent DC shocks. Delivering repeated DC shocks induces myocardial damage and further worsens the arrhythmias, which are resistant to the antiarrhythmic drugs. Cardiac sympathetic blockade abates the excessive catecholaminergic drive and help pacifying the malignant ventricular arrhythmias. We treated the electrical storm in a 52-year-old male with ultrasound-guided left sympathetic ganglion block followed by surgical left cardiac sympathetic denervation. The patient remained symptom-free without any incident of ventricular arrhythmias for 8 months after the surgery. The ultrasonography during blockade of the stellate ganglion enhances the success rate of the technique, reduces the quantity of local anaesthetic required to produce desired effects and prevents technical complications. Supraclavicular surgical access to the upper thoracic sympathetic chain obviates the necessity for one lung ventilation and lateral decubitus during surgery, when the patient is in hemodynamically unstable condition. Sympathectomy can be performed under general anaesthesia taking cautions to avoid sympathetic stimulation in intraoperative period.

  3. Degenerative pathological irritations to cervical PLL may play a role in presenting sympathetic symptoms.

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    Wang, Zhanchao; Wang, Xinwei; Yuan, Wen; Jiang, Dongjie

    2011-11-01

    The mechanism of cervical vertigo remains unknown. Stimulation of arterial vertebralis caused by osteophyte of the Luschka joint or segmental instability of the cervical spine was considered to be a potential factor contributing to it. Years of studies found that the ischemia of the vertebral artery is not directly correlated with the clinical symptoms of vertigo, and can not be used to explain cervical vertigo as a sole reason. As proven by clinical practical experience, the routine anterior cervical decompression and fusion (ACDF) procedure, in which the degenerative disc and posterior longitudinal ligament (PLL) were often removed, shows positive results for elimination of the sympathetic symptoms. In this article, we hypothesize that: (1) there are sympathetic nerve postganglionic fibers distributed in the PLL or discs; (2) pathological changes secondary to degeneration of the intervertebral disc may cause irritation of sympathetic nerve fibers in PLL or discs, leading to sympathetic symptoms via certain pathways; (3) removal of the PLL or stabilization of the segment which decreases the irritation to PLL will help to eliminate the sympathetic symptoms. Copyright © 2011. Published by Elsevier Ltd.

  4. Pmch-deficiency in rats is associated with normal adipocyte differentiation and lower sympathetic adipose drive.

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    Mul, Joram D; O'Duibhir, Eoghan; Shrestha, Yogendra B; Koppen, Arjen; Vargoviç, Peter; Toonen, Pim W; Zarebidaki, Eleen; Kvetnansky, Richard; Kalkhoven, Eric; Cuppen, Edwin; Bartness, Timothy J

    2013-01-01

    The orexigenic neuropeptide melanin-concentrating hormone (MCH), a product of Pmch, is an important mediator of energy homeostasis. Pmch-deficient rodents are lean and smaller, characterized by lower food intake, body-, and fat mass. Pmch is expressed in hypothalamic neurons that ultimately are components in the sympathetic nervous system (SNS) drive to white and interscapular brown adipose tissue (WAT, iBAT, respectively). MCH binds to MCH receptor 1 (MCH1R), which is present on adipocytes. Currently it is unknown if Pmch-ablation changes adipocyte differentiation or sympathetic adipose drive. Using Pmch-deficient and wild-type rats on a standard low-fat diet, we analyzed dorsal subcutaneous and perirenal WAT mass and adipocyte morphology (size and number) throughout development, and indices of sympathetic activation in WAT and iBAT during adulthood. Moreover, using an in vitro approach we investigated the ability of MCH to modulate 3T3-L1 adipocyte differentiation. Pmch-deficiency decreased dorsal subcutaneous and perirenal WAT mass by reducing adipocyte size, but not number. In line with this, in vitro 3T3-L1 adipocyte differentiation was unaffected by MCH. Finally, adult Pmch-deficient rats had lower norepinephrine turnover (an index of sympathetic adipose drive) in WAT and iBAT than wild-type rats. Collectively, our data indicate that MCH/MCH1R-pathway does not modify adipocyte differentiation, whereas Pmch-deficiency in laboratory rats lowers adiposity throughout development and sympathetic adipose drive during adulthood.

  5. Multilevel interactions between the sympathetic and parasympathetic nervous systems: a minireview.

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    Ondicova, K; Mravec, B

    2010-04-01

    In order to allow precise regulation of bodily functions, the activity of the autonomic nervous system must be precisely regulated. The traditional model concerning the regulation of norepinephrine and acetylcholine release in target tissues suggests that the activities of the efferent arms of the autonomic nervous system are more or less independent of each other. However, plenty of experimental and clinical studies have demonstrated the presence of multiple interactions between the sympathetic and parasympathetic nervous system that are mediated through several pathways and mechanisms at both central and peripheral levels of the neuraxis. Interactions within the central nervous system are mediated predominantly by neurons within the nucleus of the solitary tract and paraventricular hypothalamic nucleus. Peripheral interactions are based on the morphological-functional organization of the sympathetic and parasympathetic pathways at the levels of the sympathetic prevertebral ganglia or neuroeffector connections. Furthermore, evidence suggests that neuroeffector connections may be realized at the axo-axonal, presynaptic, postsynaptic, and post-receptor levels. Alterations in interactions between the sympathetic and parasympathetic nervous system can lead to unbalanced autonomic activities, which may influence the development of various disorders, including cardiovascular, inflammatory, metabolic, neurological, and psychiatric diseases. The aim of this article is to illustrate the complexity of interaction between the sympathetic and parasympathetic nervous systems and to describe the role of these interactions in the heart, adrenal medulla, and vagal trunk.

  6. EFFECTS OF INTRAVENOUS FENTANYL ON SPONTANEOUS RENAL SYMPATHETIC NERVE ACTIVITY IN NORMAL AND VAGOTOMIZED RABBITS

    Institute of Scientific and Technical Information of China (English)

    Chen Wang; James G.Whitwam

    2004-01-01

    Objective To investigate the roles of sympathetic and vagus nerves in hypotension and bradycardia induced by fentanyl.Methods Fourteen rabbits were divided into 2 groups: normal and vagotomized rabbits. Rabbits were anesthetized,paralyzed, and artificial ventilated. Right renal sympathetic nerve was exposed and prepared for recording electrical activity.Fentanyl was injected intravenously in incremental doses of 1, 4, 15, 30, and 50 μg/kg at 10 minutes intervals.Results Fentanyl significantly reduced the spontaneous activity of renal sympathetic nerve, mean arterial pressure, and heart rate above a total dose of 20 μg/kg in both normal and vagotomized rabbits. However, normal rabbits spontaneous sympathetic nerve activity and mean arterial pressure were more depressed than vagotomized rabbits at total doses of 50 and 100 μg/kg. There were no significant difference in the reduction of heart rate between normal and vagotomized rabbits.Conclusion Fentanyl induction of bradycardia and hypotension in rabbits is mainly due to depression of sympathetic nerve activity.

  7. Sympathetic-leptin relationship in obesity: effect of weight loss.

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    Quilliot, Didier; Böhme, Philip; Zannad, Faiez; Ziegler, Olivier

    2008-04-01

    Obese patients have high plasma leptin concentrations that do not induce the expected responses on weight regulation, suggesting a leptin resistance in obesity. Elevated leptin levels are also thought to be related to a high sympathetic nervous system (SNS) activity. This effect could be preserved, lowered, or even abolished in obesity. We planned to investigate the possible association in a longitudinal study. Ninety-five normotensive healthy women, aged 40.4 +/- 11.4 years and body mass index of 33.2 +/- 2.3 kg/m(2), were studied. Baseline leptin, fat mass, and heart rate variability were measured and included in a 6-month longitudinal study. Body composition was measured by dual-energy x-ray absorption. Time domain heart rate variability, QT dynamicity, and spectral components on ambulatory electrocardiographs were analyzed. Dietary advice was given by a dietitian to the patient (maximum caloric reduction of 30%), and subjects were randomized in 3 treatment groups: sibutramine 10 mg, sibutramine 20 mg, or placebo. At baseline, low frequencies (LF) and the LF-high frequencies (HF) ratio, mainly related to the SNS, were negatively correlated to leptin concentration (r = -0.30, P = .002 and r = -0.36, P < .001) and to the leptin-fat mass ratio (r = -0.28, P = .004 and r = - 0.33, P = .0007), thus explaining 38% of the LF variance and 33% of the LF/HF variance. Diastolic blood pressure was also negatively correlated to leptin concentrations (-0.20, P = .04) and to the leptin-fat mass ratio (-0.22, P = .022). In contrast, no consistent correlations between leptin and the time domain components related to vagal activity were observed. At 6 months, after completion of the weight loss program, LF significantly decreased (-7.7% +/- 7.9%, P < .001), whereas HF was higher than the initial value (+20% +/- 5.2%). The leptin-fat mass ratio remained negatively correlated to the LF (r = -0.34, P = .030) and to LF/HF (r = -0.35, P = .021) values, explaining 21% of the LF

  8. Sympathetic neural control of indoleamine metabolism in the rat pineal gland

    Science.gov (United States)

    Lynch, H. J.; Hsuan, M.; Wurtman, R. J.

    1975-01-01

    The mechanisms responsible for the acceleration in rat pineal biosynthetic activity in response to prolonged exposure to darkness or to immobilization were investigated in animals whose pineals were surgically denervated. Some animals were adrenalectomized to remove one potential source of circulating catecholamines, and some were subjected to a partial chemical sympathectomy accomplished by a series of intravenous injections of 6-hydroxydopamine. Results suggest that N-acetyltransferase (NAT) activity can be enhanced either by release of norepinephrine from sympathetic terminals within the pineal or from sympathetic nerve terminals elsewhere. The stress of immobilization stimulates the pineal by increasing circulating catecholamines. Photic control of pineal function requires intact pineal sympathetic innervation, since the onset of darkness apparently does not cause a sufficient rise in circulating catecholamines to stimulate the pineal. The present studies suggest that nonspecific stress triggers increased biosynthesis and secretion of melatonin; it is possible that this hormone may participate in mechanisms of adaptation.

  9. Olfactory ensheathing cell transplantation improves sympathetic skin responses in chronic spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Zuncheng Zheng; Guifeng Liu; Yuexia Chen; Shugang Wei

    2013-01-01

    Forty-three patients with chronic spinal cord injury for over 6 months were transplanted with bryonic olfactory ensheathing cells, 2-4 × 106, into multiple sites in the injured area under the sur-gical microscope. The sympathetic skin response in patients was measured with an electromyo-graphy/evoked potential instrument 1 day before transplantation and 3-8 weeks after trans-tion. Spinal nerve function of patients was assessed using the American Spinal Injury Association impairment scale. The sympathetic skin response was elicited in 32 cases before olfactory en-sheathing celltransplantation, while it was observed in 34 cases after transplantation. tantly, sympathetic skin response latency decreased significantly and amplitude increased cantly after transplantation. Transplantation of olfactory ensheathing cells also improved American Spinal Injury Association scores for movement, pain and light touch. Our findings indicate that factory ensheathing celltransplantation improves motor, sensory and autonomic nerve functions in patients with chronic spinal cord injury.

  10. Role of the sympathetic nervous system in carbon tetrachloride-induced hepatotoxicity and systemic inflammation.

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    Jung-Chun Lin

    Full Text Available Carbon tetrachloride (CCl4 is widely used as an animal model of hepatotoxicity and the mechanisms have been arduously studied, however, the contribution of the sympathetic nervous system (SNS in CCl4-induced acute hepatotoxicity remains controversial. It is also known that either CCl4 or SNS can affect systemic inflammatory responses. The aim of this study was to establish the effect of chemical sympathectomy with 6-hydroxydopamine (6-OHDA in a mouse model of CCl4-induced acute hepatotoxicity and systemic inflammatory response. Mice exposed to CCl4 or vehicle were pretreated with 6-OHDA or saline. The serum levels of aminotransferases and alkaline phosphatase in the CCl4-poisoning mice with sympathetic denervation were significantly lower than those without sympathetic denervation. With sympathetic denervation, hepatocellular necrosis and fat infiltration induced by CCl4 were greatly decreased. Sympathetic denervation significantly attenuated CCl4-induced lipid peroxidation in liver and serum. Acute CCl4 intoxication showed increased expression of inflammatory cytokines/chemokines [eotaxin-2/CCL24, Fas ligand, interleukin (IL-1α, IL-6, IL-12p40p70, monocyte chemoattractant protein-1 (MCP-1/CCL2, and tumor necrosis factor-α (TNF-α], as well as decreased expression of granulocyte colony-stimulating factor and keratinocyte-derived chemokine. The overexpressed levels of IL-1α, IL-6, IL-12p40p70, MCP-1/CCL2, and TNF-α were attenuated by sympathetic denervation. Pretreatment with dexamethasone significantly reduced CCl4-induced hepatic injury. Collectively, this study demonstrates that the SNS plays an important role in CCl4-induced acute hepatotoxicity and systemic inflammation and the effect may be connected with chemical- or drug-induced hepatotoxicity and circulating immune response.

  11. Moxonidine normalizes sympathetic hyperactivity in patients with eprosartan-treated chronic renal failure.

    Science.gov (United States)

    Neumann, Jutta; Ligtenberg, Gerry; Oey, Liam; Koomans, Hein A; Blankestijn, Peter J

    2004-11-01

    Enalapril and losartan reduce but not normalize sympathetic hyperactivity in patients with hypertensive chronic renal failure (CRF). This study assessed the effect of chronic eprosartan on BP and sympathetic activity, and assessed the effect of moxonidine during chronic eprosartan treatment. In 11 stable patients with CRF (creatinine clearance 47 +/- 10 ml/min), muscle sympathetic nerve activity (MSNA; peroneal nerve), BP, and baroreceptor sensitivity were measured in the absence of antihypertensive drugs (except diuretics) during chronic eprosartan therapy (600 mg for 6 wk) and in 9 patients after moxonidine (0.2 mg for 6 wk) was added. Normovolemia was controlled by diuretics and confirmed by extracellular fluid volume measurements. BP, heart rate, and MSNA were higher in patients than in 22 controls. During eprosartan therapy, mean arterial pressure (111 +/- 9 to 98 +/- 7 mmHg, P < 0.001), heart rate (71 +/- 10 to 65 +/- 8 bpm, P < 0.001), and MSNA (35 +/- 10 to 27 +/- 8 bursts/min, P < 0.001) decreased. After the addition of moxonidine (n = 9), a further reduction of mean arterial pressure to 89 +/- 7 mmHg (P < 0.05) and of MSNA to 20 +/- 10 bursts/min (P < 0.05) occurred. Sympathetic activity in patients with CRF can be normalized, and angiotensin II-independent sympathetic hyperactivity contributes to the pathogenesis of renal hypertension. Sympathetic hyperactivity is associated with poor cardiovascular outcomes, implying that reduction might be beneficial to the patients. The addition of moxonidine to angiotensin II antagonist treatment might be appropriate.

  12. Sympathetic nerve-derived ATP regulates renal medullary blood flow via vasa recta pericytes

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    Scott S Wildman

    2013-10-01

    Full Text Available Pericyte cells are now known to be a novel locus of blood flow control, being able to regulate capillary diameter via their unique morphology and expression of contractile proteins. We have previously shown that exogenous ATP causes constriction of vasa recta via renal pericytes, acting at a variety of membrane bound P2 receptors on descending vasa recta, and therefore may be able to regulate medullary blood flow (MBF. Regulation of MBF is essential for appropriate urine concentration and providing essential oxygen and nutrients to this region of high, and variable, metabolic demand. Various sources of endogenous ATP have been proposed, including from epithelial, endothelial and red blood cells in response to stimuli such as mechanical stimulation, local acidosis, hypoxia, and exposure to various hormones. Extensive sympathetic innervation of the nephron has previously been shown, however the innervation reported has focused around the proximal and distal tubules, and ascending loop of Henle. We hypothesise that sympathetic nerves are an additional source of ATP acting at renal pericytes and therefore regulate MBF. Using a rat live kidney slice model in combination with video imaging and confocal microscopy techniques we firstly show sympathetic nerves in close proximity to vasa recta pericytes in both the outer and inner medulla. Secondly, we demonstrate pharmacological stimulation of sympathetic nerves in situ (by tyramine evokes pericyte-mediated vasoconstriction of vasa recta capillaries; inhibited by the application of the P2 receptor antagonist suramin. Lastly, tyramine-evoked vasoconstriction of vasa recta by pericytes is significantly less than ATP-evoked vasoconstriction. Sympathetic innervation may provide an additional level of functional regulation in the renal medulla that is highly localized. It now needs to be determined under which physiological/pathophysiological circumstances that sympathetic innervation of renal pericytes is

  13. Sympathetic innervation of the spleen in male Brown Norway rats: a longitudinal aging study.

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    Perez, Sam D; Silva, Dorian; Millar, Ashley Brooke; Molinaro, Christine A; Carter, Jeff; Bassett, Katie; Lorton, Dianne; Garcia, Paola; Tan, Laren; Gross, Jonathon; Lubahn, Cheri; Thyagarajan, Srinivasan; Bellinger, Denise L

    2009-12-11

    Aging leads to reduced cellular immunity with consequent increased rates of infectious disease, cancer, and autoimmunity in the elderly. The sympathetic nervous system (SNS) modulates innate and adaptive immunity via innervation of lymphoid organs. In aged Fischer 344 (F344) rats, noradrenergic (NA) nerve density in secondary lymphoid organs declines, which may contribute to immunosenescence with aging. These studies suggest there is SNS involvement in age-induced immune dysregulation. The purpose of this study was to longitudinally characterize age-related change in sympathetic innervation of the spleen and sympathetic activity/tone in male Brown Norway (BN) rats, which live longer and have a strikingly different immune profile than F344 rats, the traditional animal model for aging research. Splenic sympathetic neurotransmission was evaluated between 8 and 32 months of age by assessing (1) NA nerve fiber density, (2) splenic norepinephrine (NE) concentration, and (3) circulating catecholamine levels after decapitation. We report a decline in NA nerve density in splenic white pulp (45%) at 15 months of age compared with 8-month-old (M) rats, which is followed by a much slower rate of decline between 24 and 32 months. Lower splenic NE concentrations between 15 and 32 months of age compared with 8M rats were consistent with morphometric findings. Circulating catecholamine levels after decapitation stress generally dropped with increasing age. These findings suggest there is a sympathetic-to-immune system dysregulation beginning at middle age. Given the unique T-helper-2 bias in BN rats, altered sympathetic-immune communication may be important for understanding the age-related rise in asthma and autoimmunity.

  14. Cold pressor test demonstrates residual sympathetic cardiovascular activation in familial dysautonomia.

    Science.gov (United States)

    Hilz, M J; Axelrod, F B; Braeske, K; Stemper, B

    2002-04-15

    In familial dysautonomia (FD), i.e. Riley-Day-syndrome, sympathetic cardiovascular function, as well as afferent temperature and pain mediating neurons, are significantly reduced. Thus, it was questioned if cold pressor test (CPT), which normally enhances sympathetic outflow and induces peripheral vasoconstriction by the activation of thermo- and nociceptive system activation, could be used to assess sympathetic function in FD. To evaluate whether CPT can be used to assess sympathetic activation in FD, we performed CPT in 15 FD patients and 18 controls. After a 35-min resting period, participants immersed their right hand and arm up to the elbow into 0-1 degrees C cold water while we monitored heart rate (HR), respiration, beat-to-beat radial artery blood pressure (BP), and laser Doppler skin blood flow (SBF) at the right index finger pulp. From these measurements, heart rate variability parameters were calculated: root mean square of successive differences (RMSSD), coefficient of variation (CV), low and high frequency (LF, HF) power spectra of the electrocardiogram (ECG). All participants perceived cold stimulation and indicated discomfort. In controls, SBF decreased and HR and BP increased rapidly upon CPT. After 60 s, SBF indicated secondary vasodilatation in six controls, BP rise attenuated and HR returned to baseline in all controls. In the patients, SBF remained unchanged, HR and BP increased significantly, but after 50-60 s of CPT and changes were lower than in controls (p<0.05). RMSSD and CV decreased and LF increased significantly only in the controls. We conclude that CPT activates sympathetic HR and BP modulation despite impaired pain and temperature perception in FD patients. BP increase in the presence of almost unchanged SBF might be due to HR increase and to nociceptive arousal and emotionally induced catecholamine release as seen in emotional crises of FD patients. CPT assesses sympathetic cardiovascular responses independently from baroreflex

  15. Differential cardiac responses to unilateral sympathetic nerve stimulation in the isolated innervated rabbit heart.

    Science.gov (United States)

    Winter, James; Tanko, Abdul Samed; Brack, Kieran E; Coote, John H; Ng, G André

    2012-01-26

    The heart receives both a left and right sympathetic innervation. Currently there is no description of an in vitro whole heart preparation for comparing the influence of each sympathetic supply on cardiac function. The aim was to establish the viability of using an in vitro model to investigate the effects of left and right sympathetic chain stimulation (LSS/RSS). For this purpose the upper sympathetic chain on each side was isolated and bipolar stimulating electrodes were attached between T2-T3 and electrically insulated from surrounding tissue in a Langendorff innervated rabbit heart preparation (n=8). Heart rate (HR) was investigated during sinus rhythm, whilst dromotropic, inotropic and ventricular electrophysiological effects were measured during constant pacing (250 bpm). All responses exhibited linear increases with increases in stimulation frequency (2-10 Hz). The change in HR was larger during RSS than LSS (P<0.01), increasing by 78±9 bpm and 49±8 bpm respectively (10 Hz, baseline; 145±7 bpm). Left ventricular pressure was increased from a baseline of 50±4 mmHg, by 22±5 mmHg (LSS, 10 Hz) and 4±1 mmHg (RSS, 10 Hz) respectively (P<0.001). LSS, but not RSS, caused a shortening of basal and apical monophasic action potential duration (MAPD90). We demonstrate that RSS exerts a greater effect at the sinoatrial node and LSS at the left ventricle. The study confirms previous experiments on dogs and cats, provides quantitative data on the comparative influence of right and left sympathetic nerves and demonstrates the feasibility of isolating and stimulating the ipsilateral cardiac sympathetic supply in an in vitro innervated rabbit heart preparation.

  16. Raised tone reveals ATP as a sympathetic neurotransmitter in the porcine mesenteric arterial bed.

    Science.gov (United States)

    Shatarat, Amjad; Dunn, William R; Ralevic, Vera

    2014-12-01

    The relative importance of ATP as a functional sympathetic neurotransmitter in blood vessels has been shown to be increased when the level of preexisting vascular tone or pressure is increased, in studies carried out in rat mesenteric arteries. The aim of the present study was to determine whether tone influences the involvement of ATP as a sympathetic cotransmitter with noradrenaline in another species. We used the porcine perfused mesenteric arterial bed and porcine mesenteric large, medium and small arteries mounted for isometric tension recording, because purinergic cotransmission can vary depending on the size of the blood vessel. In the perfused mesenteric bed at basal tone, sympathetic neurogenic vasocontractile responses were abolished by prazosin, an α1-adrenoceptor antagonist, but there was no significant effect of α,β-methylene ATP, a P2X receptor-desensitizing agent. Submaximal precontraction of the mesenteric arterial bed with U46619, a thromboxane A2 mimetic, augmented the sympathetic neurogenic vasocontractile responses; under these conditions, both α,β-methylene ATP and prazosin attenuated the neurogenic responses. In the mesenteric large, medium and small arteries, prazosin attenuated the sympathetic neurogenic contractile responses under conditions of both basal and U46619-raised tone. α,β-Methylene ATP was effective in all of these arteries only under conditions of U46619-induced tone, causing a similar inhibition in all arteries, but had no significant effect on sympathetic neurogenic contractions at basal tone. These data show that ATP is a cotransmitter with noradrenaline in porcine mesenteric arteries; the purinergic component was revealed under conditions of partial precontraction, which is more relevant to physiological conditions.

  17. Chronic orthostatic intolerance: a disorder with discordant cardiac and vascular sympathetic control

    Science.gov (United States)

    Furlan, R.; Jacob, G.; Snell, M.; Robertson, D.; Porta, A.; Harris, P.; Mosqueda-Garcia, R.

    1998-01-01

    BACKGROUND: Chronic orthostatic intolerance (COI) is a debilitating autonomic condition in young adults. Its neurohumoral and hemodynamic profiles suggest possible alterations of postural sympathetic function and of baroreflex control of heart rate (HR). METHODS AND RESULTS: In 16 COI patients and 16 healthy volunteers, intra-arterial blood pressure (BP), ECG, central venous pressure (CVP), and muscle sympathetic nerve activity (MSNA) were recorded at rest and during 75 degrees tilt. Spectral analysis of RR interval and systolic arterial pressure (SAP) variabilities provided indices of sympathovagal modulation of the sinoatrial node (ratio of low-frequency to high-frequency components, LF/HF) and of sympathetic vasomotor control (LFSAP). Baroreflex mechanisms were assessed (1) by the slope of the regression line obtained from changes of RR interval and MSNA evoked by pharmacologically induced alterations in BP and (2) by the index alpha, obtained from cross-spectral analysis of RR and SAP variabilities. At rest, HR, MSNA, LF/HF, and LFSAP were higher in COI patients, whereas BP and CVP were similar in the two groups. During tilt, BP did not change and CVP fell by the same extent in the 2 groups; the increase of HR and LF/HF was more pronounced in COI patients. Conversely, the increase of MSNA was lower in COI than in control subjects. Baroreflex sensitivity was similar in COI and control subjects at rest; tilt reduced alpha similarly in both groups. CONCLUSIONS: COI is characterized by an overall enhancement of noradrenergic tone at rest and by a blunted postganglionic sympathetic response to standing, with a compensatory cardiac sympathetic overactivity. Baroreflex mechanisms maintain their functional responsiveness. These data suggest that in COI, the functional distribution of central sympathetic tone to the heart and vasculature is abnormal.

  18. Effects of antidepressants, but not psychopathology, on cardiac sympathetic control: a longitudinal study.

    Science.gov (United States)

    Licht, Carmilla M M; Penninx, Brenda W J H; de Geus, Eco J C

    2012-10-01

    Increased sympathetic activity has been hypothesized to have a role in the elevated somatic disease risk in persons with depressive or anxiety disorders. However, it remains unclear whether increased sympathetic activity reflects a direct effect of anxiety or depression or an indirect effect of antidepressant medication. The aim of this study was to test longitudinally whether cardiac sympathetic control, measured by pre-ejection period (PEP), was increased by depression/anxiety status and by antidepressant use. Cross-sectional and longitudinal data were from a depression and anxiety cohort: the Netherlands Study of Depression and Anxiety (NESDA). Baseline data of 2838 NESDA subjects (mean age 41.7 years, 66.7% female) and 2-year follow-up data of 2226 subjects were available for analyses. Included were subjects with and without depressive/anxiety disorders, using or not using different antidepressants at baseline or follow-up. The PEP was measured non-invasively by 1.5 h of ambulatory impedance cardiography. Cross-sectional analyses compared PEP across psychopathology and antidepressant groups. Longitudinal analyses compared 2-year changes in PEP in relation to changes in psychopathology and antidepressant use. Cross-sectional analyses showed that antidepressant-naïve depressive/anxious subjects had comparable PEP as controls, whereas subjects using tricyclic (TCA) or combined serotonergic/noradrenergic antidepressants (SNRI) had significantly shorter PEP compared with controls. In contrast, subjects using selective serotonin re-uptake inhibitors (SSRIs) had longer PEP than controls. Longitudinal results confirmed these findings: compared with 2-year change in PEP in continuous non-users (+2 ms), subjects who started TCA or SNRI treatment showed significantly shortened PEP (-11 ms, p=0.005 and pantidepressant use. These findings suggest that depressive and anxiety disorders are not associated with increased cardiac sympathetic control. However, results pose

  19. Chronic orthostatic intolerance: a disorder with discordant cardiac and vascular sympathetic control

    Science.gov (United States)

    Furlan, R.; Jacob, G.; Snell, M.; Robertson, D.; Porta, A.; Harris, P.; Mosqueda-Garcia, R.

    1998-01-01

    BACKGROUND: Chronic orthostatic intolerance (COI) is a debilitating autonomic condition in young adults. Its neurohumoral and hemodynamic profiles suggest possible alterations of postural sympathetic function and of baroreflex control of heart rate (HR). METHODS AND RESULTS: In 16 COI patients and 16 healthy volunteers, intra-arterial blood pressure (BP), ECG, central venous pressure (CVP), and muscle sympathetic nerve activity (MSNA) were recorded at rest and during 75 degrees tilt. Spectral analysis of RR interval and systolic arterial pressure (SAP) variabilities provided indices of sympathovagal modulation of the sinoatrial node (ratio of low-frequency to high-frequency components, LF/HF) and of sympathetic vasomotor control (LFSAP). Baroreflex mechanisms were assessed (1) by the slope of the regression line obtained from changes of RR interval and MSNA evoked by pharmacologically induced alterations in BP and (2) by the index alpha, obtained from cross-spectral analysis of RR and SAP variabilities. At rest, HR, MSNA, LF/HF, and LFSAP were higher in COI patients, whereas BP and CVP were similar in the two groups. During tilt, BP did not change and CVP fell by the same extent in the 2 groups; the increase of HR and LF/HF was more pronounced in COI patients. Conversely, the increase of MSNA was lower in COI than in control subjects. Baroreflex sensitivity was similar in COI and control subjects at rest; tilt reduced alpha similarly in both groups. CONCLUSIONS: COI is characterized by an overall enhancement of noradrenergic tone at rest and by a blunted postganglionic sympathetic response to standing, with a compensatory cardiac sympathetic overactivity. Baroreflex mechanisms maintain their functional responsiveness. These data suggest that in COI, the functional distribution of central sympathetic tone to the heart and vasculature is abnormal.

  20. Sympathetic Vasoconstrictor Responsiveness of the Leg Vasculature During Experimental Endotoxemia and Hypoxia in Humans

    DEFF Research Database (Denmark)

    Brassard, Patrice; Zaar, Morten; Thaning, Pia

    2016-01-01

    : Endotoxemia increased body temperature from 36.9 ± 0.4°C to 38.6 ± 0.5°C (p ...OBJECTIVE: Sympathetic vasoconstriction regulates peripheral circulation and controls blood pressure, but sepsis is associated with hypotension. We evaluated whether apparent loss of sympathetic vasoconstrictor responsiveness relates to distended smooth muscles or to endotoxemia and/or hypoxia....... DESIGN: Prospective descriptive study. SETTING: Hospital research laboratory. SUBJECTS: Ten healthy young men (age [mean ± SD], 31 ± 8 yr; body weight, 83 ± 10 kg) participated in the study. INTERVENTIONS: Leg blood flow and mean arterial pressure were determined, whereas leg vascular conductance...

  1. Vibration sense and sympathetic vasoconstrictor activity in patients with occlusive arterial disease

    DEFF Research Database (Denmark)

    Bjerre-Jepsen, K; Henriksen, O; Parm, Martin Lehnsbo

    1983-01-01

    The function of sympathetic vasoconstrictor fibres was studied in 18 patients with occlusive arterial disease of the legs and somatic neuropathy, as evidenced as an increased vibration perception threshold. Nine patients suffered from long-term diabetes mellitus. Sympathetic vasoconstrictor...... of vibration sense, abnormal vasoconstrictor function was found. In three of these patients, the abnormal response most likely could be ascribed to impaired function of the vascular smooth muscle cells. Neither in diabetics nor in non-diabetics could an abnormal vibration sense be taken as evidence for loss...

  2. Human muscle sympathetic nerve activity and plasma noradrenaline kinetics in space

    Science.gov (United States)

    Ertl, Andrew C.; Diedrich, Andre; Biaggioni, Italo; Levine, Benjamin D.; Robertson, Rose Marie; Cox, James F.; Zuckerman, Julie H.; Pawelczyk, James A.; Ray, Chester A.; Buckey, Jay C Jr; Lane, Lynda D.; Shiavi, Richard; Gaffney, F. Andrew; Costa, Fernando; Holt, Carol; Blomqvist, C. Gunnar; Eckberg, Dwain L.; Baisch, Friedhelm J.; Robertson, David

    2002-01-01

    Astronauts returning from space have reduced red blood cell masses, hypovolaemia and orthostatic intolerance, marked by greater cardio-acceleration during standing than before spaceflight, and in some, orthostatic hypotension and presyncope. Adaptation of the sympathetic nervous system occurring during spaceflight may be responsible for these postflight alterations. We tested the hypotheses that exposure to microgravity reduces sympathetic neural outflow and impairs sympathetic neural responses to orthostatic stress. We measured heart rate, photoplethysmographic finger arterial pressure, peroneal nerve muscle sympathetic activity and plasma noradrenaline spillover and clearance, in male astronauts before, during (flight day 12 or 13) and after the 16 day Neurolab space shuttle mission. Measurements were made during supine rest and orthostatic stress, as simulated on Earth and in space by 7 min periods of 15 and 30 mmHg lower body suction. Mean (+/- S.E.M.) heart rates before lower body suction were similar pre-flight and in flight. Heart rate responses to -30 mmHg were greater in flight (from 56 +/- 4 to 72 +/- 4 beats min(-1)) than pre-flight (from 56 +/- 4 at rest to 62 +/- 4 beats min(-1), P < 0.05). Noradrenaline spillover and clearance were increased from pre-flight levels during baseline periods and during lower body suction, both in flight (n = 3) and on post-flight days 1 or 2 (n = 5, P < 0.05). In-flight baseline sympathetic nerve activity was increased above pre-flight levels (by 10-33 %) in the same three subjects in whom noradrenaline spillover and clearance were increased. The sympathetic response to 30 mmHg lower body suction was at pre-flight levels or higher in each subject (35 pre-flight vs. 40 bursts min(-1) in flight). No astronaut experienced presyncope during lower body suction in space (or during upright tilt following the Neurolab mission). We conclude that in space, baseline sympathetic neural outflow is increased moderately and sympathetic

  3. Psychological aspects of reflex sympathetic dystrophy: a review of the adult and paediatric literature.

    Science.gov (United States)

    Lynch, M E

    1992-06-01

    In 1864, W. Mitchell and colleagues first described the clinical syndrome which came to be known as 'causalgia'. Since that time, the concept of sympathetically related pain has evolved. There is general agreement that profound emotional and behavioural changes can follow these types of pain. Opinions have varied widely on the issue of a psychological etiology. It has often been suggested that certain personality traits predispose one to develop sympathetically related pain syndromes. A review of the literature reveals no valid evidence to substantiate this claim.

  4. Sympathetic cooling in an optically trapped mixture of alkali and spin-singlet atoms.

    Science.gov (United States)

    Ivanov, Vladyslav V; Khramov, Alexander; Hansen, Anders H; Dowd, William H; Münchow, Frank; Jamison, Alan O; Gupta, Subhadeep

    2011-04-15

    We report on the realization of a stable mixture of ultracold lithium and ytterbium atoms confined in a far-off-resonance optical dipole trap. We observe sympathetic cooling of 6Li by 174Yb and extract the s-wave scattering length magnitude |a(6Li-174Yb)|=(13±3)a0 from the rate of interspecies thermalization. Using forced evaporative cooling of 174Yb, we achieve reduction of the 6Li temperature to below the Fermi temperature, purely through interspecies sympathetic cooling.

  5. Sex differences in the modulation of vasomotor sympathetic outflow during static handgrip exercise in healthy young humans

    NARCIS (Netherlands)

    Jarvis, S.S.; Gundy, T.B. Van; Galbreath, M.M.; Shibata, S.; Okazaki, K.; Reelick, M.F; Levine, B.D.; Fu, Q.

    2011-01-01

    Sex differences in sympathetic neural control during static exercise in humans are few and the findings are inconsistent. We hypothesized women would have an attenuated vasomotor sympathetic response to static exercise, which would be further reduced during the high sex hormone [midluteal (ML)] vs.

  6. Agmatine suppresses peripheral sympathetic tone by inhibiting N-type Ca(2+) channel activity via imidazoline I2 receptor activation.

    Science.gov (United States)

    Kim, Young-Hwan; Jeong, Ji-Hyun; Ahn, Duck-Sun; Chung, Seungsoo

    2016-08-26

    Agmatine, a putative endogenous ligand of imidazoline receptors, suppresses cardiovascular function by inhibiting peripheral sympathetic tone. However, the molecular identity of imidazoline receptor subtypes and its cellular mechanism underlying the agmatine-induced sympathetic suppression remains unknown. Meanwhile, N-type Ca(2+) channels are important for the regulation of NA release in the peripheral sympathetic nervous system. Therefore, it is possible that agmatine suppresses NA release in peripheral sympathetic nerve terminals by inhibiting Ca(2+) influx through N-type Ca(2+) channels. We tested this hypothesis by investigating agmatine effect on electrical field stimulation (EFS)-evoked contraction and NA release in endothelium-denuded rat superior mesenteric arterial strips. We also investigated the effect of agmatine on the N-type Ca(2+) current in superior cervical ganglion (SCG) neurons in rats. Our study demonstrates that agmatine suppresses peripheral sympathetic outflow via the imidazoline I2 receptor in rat mesenteric arteries. In addition, the agmatine-induced suppression of peripheral vascular sympathetic tone is mediated by modulating voltage-dependent N-type Ca(2+) channels in sympathetic nerve terminals. These results suggest a potential cellular mechanism for the agmatine-induced suppression of peripheral sympathetic tone. Furthermore, they provide basic and theoretical information regarding the development of new agents to treat hypertension.

  7. Control of pineal indole biosynthesis by changes in sympathetic tone caused by factors other than environmental lighting.

    Science.gov (United States)

    Lynch, H. J.; Eng, J. P.; Wurtman, R. J.

    1973-01-01

    Description of experimental investigations showing that, in addition to environmental lighting, other manipulations known to modify sympathetic tone can also modify pineal indole biosynthesis. Comparable alterations in sympathetic tone that occur in response to activity or feeding cycles may be instrumental in generating the pineal rhythms that persist in the absence of light-dark cycle.

  8. Distinct localization and target specificity of galanin-immunoreactive sympathetic preganglionic neurons of a teleost, the filefish Stephanolepis cirrhifer.

    Science.gov (United States)

    Funakoshi, K; Kadota, T; Atobe, Y; Nakano, M; Hibiya, K; Goris, R C; Kishida, R

    2000-03-15

    Immunoreactivity for galanin was examined in the sympathetic preganglionic neurons in the spinal cord, adrenal glands, sympathetic ganglia, and some sensory ganglia of the filefish Stephanolepis cirrhifer. Galanin-immunoreactive neurons were found only in the rostral part, but not in the caudal part of the central autonomic nucleus (a column of sympathetic preganglionic neurons of teleosts). Many galanin-immunoreactive nerve terminals were found in contact with neurons in the celiac ganglia and the cranial sympathetic ganglia on both sides of the body. Most neurons encircled by galanin-immunoreactive nerve fibers were negative for tyrosine hydroxylase. Galanin-immunoreactive nerve fibers were very sparse in the spinal sympathetic paravertebral ganglia. No galanin-immunoreactive nerve fibers were found in the adrenal glands. No sensory neurons of the trigeminal, vagal, or spinal dorsal root ganglia were positive for galanin-immunoreactivity. These results suggest that galanin-immunoreactive sympathetic preganglionic neurons have distinct segmental localization and might project specifically to a population of non-adrenergic sympathetic postganglionic neurons in the celiac and cranial sympathetic ganglia.

  9. Enlarged superior cervical sympathetic ganglion mimicking a metastatic lymph node in the retropharyngeal space: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Min; Kim, Jin Na; Kim, Se Hoon; Choi, Eun Chang [Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2017-04-15

    The superior cervical sympathetic ganglion, the largest and most cranial of the three cervical sympathetic ganglia, transfers sympathetic signals to specific targets on the head and neck. This ganglion is located just lateral to the retropharyngeal space along the medial margin of the carotid sheath. Located thus, an enlarged superior cervical sympathetic ganglion can mimic a metastatic lymph node in the retropharyngeal space of the suprahyoid neck in head and neck cancer patients. However, this is often disregarded by radiologists due to lack of interest in its anatomic location. We present a case of an enlarged superior cervical sympathetic ganglion mimicking a retropharyngeal metastatic lymph node in a 42-year-old man with oral tongue cancer.

  10. Radionuclide imaging of cardiac sympathetic innervation in heart failure: unlocking untapped potential.

    Science.gov (United States)

    Gupta, Shuchita; Amanullah, Aman

    2015-03-01

    Heart failure (HF) is associated with sympathetic overactivity, which contributes to disease progression and arrhythmia development. Cardiac sympathetic innervation imaging can be performed using radiotracers that are taken up in the presynaptic nerve terminal of sympathetic nerves. The commonly used radiotracers are (123)I-metaiodobenzylguanidine ((123)I-mIBG) for planar and single-photon emission computed tomography imaging, and (11)C-hydroxyephedrine for positron emission tomography imaging. Sympathetic innervation imaging has been used in assessing prognosis, response to treatment, risk of ventricular arrhythmias and sudden death and prediction of response to cardiac resynchronization therapy in patients with HF. Other potential applications of these techniques are in patients with chemotherapy-induced cardiomyopathy, predicting myocardial recovery in patients with left ventricular assist devices, and assessing reinnervation following cardiac transplantation. There is a lack of standardization with respect to technique of (123)I-mIBG imaging that needs to be overcome for the imaging modality to gain popularity in clinical practice.

  11. Antagonistic and Synergistic Activation of Cardiovascular Vagal and Sympathetic Motor Outflows in Trigeminal Reflexes.

    Science.gov (United States)

    Buchholz, Bruno; Kelly, Jazmín; Bernatene, Eduardo A; Méndez Diodati, Nahuel; Gelpi, Ricardo J

    2017-01-01

    The trigeminal nerve and heart are strongly related through somato-autonomic nervous reflexes that induce rapid changes in cardiovascular function. Several trigeminal reflexes have been described, but the diving and trigeminocardiac reflexes are the most studied. The heart is a target organ dually innervated by the sympathetic and parasympathetic systems. Thus, how cardiac function is regulated during the trigeminal reflexes is the result of the combination of an increased parasympathetic response and increased, decreased, or unaltered sympathetic activity. Various hemodynamic changes occur as a consequence of these alterations in autonomic tone. Often in the oxygen-conserving physiological reflexes such as the diving reflex, sympathetic/parasympathetic co-activation reduces the heart rate and either maintains or increases blood pressure. Conversely, in the trigeminocardiac reflex, bradycardia and hypotension due to parasympathetic activation and sympathetic inactivation tend to be observed. These sudden cardiac innervation disturbances may promote the generation of arrhythmias or myocardial ischemia during surgeries in the trigeminal territory. However, the function and mechanisms involved in the trigeminal reflexes remain to be fully elucidated. The current review provides a brief update and analysis of the features of these reflexes, with special focus on how the autonomic nervous system interacts with cardiovascular function.

  12. Paroxysmal sympathetic hyperactivity after acquired brain injury: consensus on conceptual definition, nomenclature, and diagnostic criteria.

    Science.gov (United States)

    Baguley, Ian J; Perkes, Iain E; Fernandez-Ortega, Juan-Francisco; Rabinstein, Alejandro A; Dolce, Giuliano; Hendricks, Henk T

    2014-09-01

    A syndrome of paroxysmal, episodic sympathetic hyperactivity after acquired brain injury has been recognized for almost 60 years. This project sought to simplify the confused nomenclature for the condition (>31 eponyms) and simplify the nine overlapping sets of diagnostic criteria. A consensus-developed questionnaire based on a systematic review of the literature was circulated to a widely representative, international expert group utilizing a Delphi approach. Diagnostic criteria were dropped if group consensus failed to agree on their relative importance, with a goal of reaching a Cronbach α of 0.8 (suitable for research purposes). The resulting criteria were combined into an assessment measure for clinical and research settings. The consensus group recommend that the term "paroxysmal sympathetic hyperactivity" replace previous terms to describe the "syndrome, recognised in a subgroup of survivors of severe acquired brain injury, of simultaneous, paroxysmal transient increases in sympathetic [elevated heart rate, blood pressure, respiratory rate, temperature, sweating] and motor [posturing] activity." An 11 point probabilistic diagnostic scale was developed with reference to published criteria, yielding an acceptable Cronbach α of 0.8. These 11 items were proceduralized and combined with a symptom severity index to produce a diagnostic tool for use with adults (the paroxysmal sympathetic hyperactivity assessment measure [PSH-AM]). Development of a pediatric version of the scale and further research into the validity of the PSH-AM is recommended. The consensus position builds on previous literature to establish diagnostic definitions and criteria, an important move to standardize research and management of this condition.

  13. Marital Conflict and Children's Externalizing Behavior: Interactions between Parasympathetic and Sympathetic Nervous System Activity

    Science.gov (United States)

    El-Sheikh, Mona; Kouros, Chrystyna D.; Erath, Stephen; Cummings, E. Mark; Keller, Peggy; Staton, Lori

    2009-01-01

    Toward greater specificity in the prediction of externalizing problems in the context of interparental conflict, interactions between children's parasympathetic and sympathetic nervous system (PNS and SNS) activity were examined as moderators. PNS activity was indexed by respiratory sinus arrhythmia (RSA) and RSA reactivity (RSA-R) to lab…

  14. Cortisol and Children's Adjustment: The Moderating Role of Sympathetic Nervous System Activity

    Science.gov (United States)

    El-Sheikh, Mona; Erath, Stephen A.; Buckhalt, Joseph A.; Granger, Douglas A.; Mize, Jacquelyn

    2008-01-01

    We examined relations among cortisol, markers of sympathetic nervous system (SNS) activity (including salivary alpha-amylase and skin conductance level), and children's adjustment. We also tested the Bauer et al. ("Journal of Developmental and Behavioral Pediatrics," 23(2), 102-113, 2002) hypothesis that interactions between the SNS and cortisol…

  15. Comparison of sympathetic nerve responses to neck and forearm isometric exercise

    Science.gov (United States)

    Steele, S. L. Jr; Ray, C. A.

    2000-01-01

    PURPOSE: Although the autonomic and cardiovascular responses to arm and leg exercise have been studied, the sympathetic adjustments to exercise of the neck have not. The purpose of the present study was twofold: 1) to determine sympathetic and cardiovascular responses to isometric contractions of the neck extensors and 2) to compare sympathetic and cardiovascular responses to isometric exercise of the neck and forearm. METHODS: Muscle sympathetic nerve activity (MSNA), mean arterial pressure (MAP), and heart rate were measured in nine healthy subjects while performing isometric neck extension (INE) and isometric handgrip (IHG) in the prone position. After a 3-min baseline period, subjects performed three intensities of INE for 2.5 min each: 1) unloaded (supporting head alone), 2) 10% maximal voluntary contraction (MVC), and 3) 30% MVC, then subjects performed two intensities (10% and 30% MVC) of IHG for 2.5 min. RESULTS: Supporting the head by itself did not significantly change any of the variables. During [NE, MAP significantly increased by 10 +/- 2 and 31 +/- 4 mm Hg and MSNA increased by 67 +/- 46 and 168 +/- 36 units/30 s for 10% and 30% MVC, respectively. IHG and INE evoked similar responses at 10% MVC, but IHG elicited higher peak MAP and MSNA at 30% MVC (37 +/- 7 mm Hg (P architecture of the neck and forearm are responsible for these differences in peak responses.

  16. CT-guided thoracic sympathetic blockade for palmar hyperhidrosis: Immediate results and postoperative quality of life.

    Science.gov (United States)

    Guo, Jian-Guo; Fei, Yong; Huang, Bing; Yao, Ming

    2016-12-01

    The purpose of this study was to evaluate the results, complications, and degree of satisfaction among patients who underwent a CT-guided percutaneous puncture thoracic sympathetic blockade. A total of 186 patients underwent CT-guided thoracic sympathetic blockade based on case histories and a prospective pre- and postoperative questionnaire survey. The study sample was composed of 93 patients with an age range from 18 to 34years and a diagnosis with primary palmar hyperhidrosis (severe in some patients). Percutaneous puncture thoracic sympathetic blockade guided by CT was performed under local anesthesia in all patients. Heart rate (HR), non-invasive blood pressure (NIBP), arterial oxygen saturation (SPO2), perfusion index (PI), and palmar temperature (T) were monitored before and after treatment. Follow-up included a questionnaire on life quality and degree of satisfaction. Ten minutes after treatment, the SPO2, PI, and temperature all raised remarkably ([92.75±2.02]% vs. [98.85±1.09]%, [1.55±0.69]% vs. [8.60±0.94]%, [30.95±1.27]°C vs. [35.75±0.55]°C, respectively, Phyperhidrosis, 87.6% reported improvement in their quality of life. CT-guided percutaneous puncture thoracic sympathetic blockade is a safe, effective, and minimally invasive technique for the treatment of palmar hyperhidrosis. Despite the high rate of compensatory hyperhidrosis, it produces a high rate of patient satisfaction.

  17. Comparison of sympathetic nerve responses to neck and forearm isometric exercise

    Science.gov (United States)

    Steele, S. L. Jr; Ray, C. A.

    2000-01-01

    PURPOSE: Although the autonomic and cardiovascular responses to arm and leg exercise have been studied, the sympathetic adjustments to exercise of the neck have not. The purpose of the present study was twofold: 1) to determine sympathetic and cardiovascular responses to isometric contractions of the neck extensors and 2) to compare sympathetic and cardiovascular responses to isometric exercise of the neck and forearm. METHODS: Muscle sympathetic nerve activity (MSNA), mean arterial pressure (MAP), and heart rate were measured in nine healthy subjects while performing isometric neck extension (INE) and isometric handgrip (IHG) in the prone position. After a 3-min baseline period, subjects performed three intensities of INE for 2.5 min each: 1) unloaded (supporting head alone), 2) 10% maximal voluntary contraction (MVC), and 3) 30% MVC, then subjects performed two intensities (10% and 30% MVC) of IHG for 2.5 min. RESULTS: Supporting the head by itself did not significantly change any of the variables. During [NE, MAP significantly increased by 10 +/- 2 and 31 +/- 4 mm Hg and MSNA increased by 67 +/- 46 and 168 +/- 36 units/30 s for 10% and 30% MVC, respectively. IHG and INE evoked similar responses at 10% MVC, but IHG elicited higher peak MAP and MSNA at 30% MVC (37 +/- 7 mm Hg (P type composition, muscle mass, and/or muscle architecture of the neck and forearm are responsible for these differences in peak responses.

  18. Comparison of sympathetic nerve responses to neck and forearm isometric exercise

    Science.gov (United States)

    Steele, S. L. Jr; Ray, C. A.

    2000-01-01

    PURPOSE: Although the autonomic and cardiovascular responses to arm and leg exercise have been studied, the sympathetic adjustments to exercise of the neck have not. The purpose of the present study was twofold: 1) to determine sympathetic and cardiovascular responses to isometric contractions of the neck extensors and 2) to compare sympathetic and cardiovascular responses to isometric exercise of the neck and forearm. METHODS: Muscle sympathetic nerve activity (MSNA), mean arterial pressure (MAP), and heart rate were measured in nine healthy subjects while performing isometric neck extension (INE) and isometric handgrip (IHG) in the prone position. After a 3-min baseline period, subjects performed three intensities of INE for 2.5 min each: 1) unloaded (supporting head alone), 2) 10% maximal voluntary contraction (MVC), and 3) 30% MVC, then subjects performed two intensities (10% and 30% MVC) of IHG for 2.5 min. RESULTS: Supporting the head by itself did not significantly change any of the variables. During [NE, MAP significantly increased by 10 +/- 2 and 31 +/- 4 mm Hg and MSNA increased by 67 +/- 46 and 168 +/- 36 units/30 s for 10% and 30% MVC, respectively. IHG and INE evoked similar responses at 10% MVC, but IHG elicited higher peak MAP and MSNA at 30% MVC (37 +/- 7 mm Hg (P muscle fiber type composition, muscle mass, and/or muscle architecture of the neck and forearm are responsible for these differences in peak responses.

  19. Vav3 proto-oncogene deficiency leads to sympathetic hyperactivity and cardiovascular dysfunction.

    Science.gov (United States)

    Sauzeau, Vincent; Sevilla, María A; Rivas-Elena, Juan V; de Alava, Enrique; Montero, María J; López-Novoa, José M; Bustelo, Xosé R

    2006-07-01

    Although much is known about environmental factors that predispose individuals to hypertension and cardiovascular disease, little information is available regarding the genetic and signaling events involved. Indeed, few genes associated with the progression of these pathologies have been discovered despite intensive research in animal models and human populations. Here we identify Vav3, a GDP-GTP exchange factor that stimulates Rho and Rac GTPases, as an essential factor regulating the homeostasis of the cardiovascular system. Vav3-deficient mice exhibited tachycardia, systemic arterial hypertension and extensive cardiovascular remodeling. These mice also showed hyperactivity of sympathetic neurons from the time of birth. The high catecholamine levels associated with this condition led to the activation of the renin-angiotensin system, increased levels of kidney-related hormones and the progressive loss of cardiovascular and renal homeostasis. Pharmacological studies with drugs targeting sympathetic and renin-angiotensin responses confirmed the causative role and hierarchy of these events in the development of the Vav3-null mouse phenotype. These observations uncover the crucial role of Vav3 in the regulation of the sympathetic nervous system (SNS) and cardiovascular physiology, and reveal a signaling pathway that could be involved in the pathophysiology of human disease states involving tachycardia and sympathetic hyperactivity with unknown etiologies.

  20. Enhanced sympathetic arousal in response to FMRI scanning correlates with task induced activations and deactivations.

    Directory of Open Access Journals (Sweden)

    Markus Muehlhan

    Full Text Available It has been repeatedly shown that functional magnetic resonance imaging (fMRI triggers distress and neuroendocrine response systems. Prior studies have revealed that sympathetic arousal increases, particularly at the beginning of the examination. Against this background it appears likely that those stress reactions during the scanning procedure may influence task performance and neural correlates. However, the question how sympathetic arousal elicited by the scanning procedure itself may act as a potential confounder of fMRI data remains unresolved today. Thirty-seven scanner naive healthy subjects performed a simple cued target detection task. Levels of salivary alpha amylase (sAA, as a biomarker for sympathetic activity, were assessed in samples obtained at several time points during the lab visit. SAA increased two times, immediately prior to scanning and at the end of the scanning procedure. Neural activation related to motor preparation and timing as well as task performance was positively correlated with the first increase. Furthermore, the first sAA increase was associated with task induced deactivation (TID in frontal and parietal regions. However, these effects were restricted to the first part of the experiment. Consequently, this bias of scanner related sympathetic activation should be considered in future fMRI investigations. It is of particular importance for pharmacological investigations studying adrenergic agents and the comparison of groups with different stress vulnerabilities like patients and controls or adolescents and adults.

  1. Thin-fiber mechanoreceptors reflexly increase renal sympathetic nerve activity during static contraction.

    Science.gov (United States)

    Kim, Jong Kyung; Hayes, Shawn G; Kindig, Angela E; Kaufman, Marc P

    2007-02-01

    The renal vasoconstriction induced by the sympathetic outflow during exercise serves to direct blood flow from the kidney toward the exercising muscles. The renal circulation seems to be particularly important in this regard, because it receives a substantial part of the cardiac output, which in resting humans has been estimated to be 20%. The role of group III mechanoreceptors in causing the reflex renal sympathetic response to static contraction remains an open question. To shed some light on this question, we recorded the renal sympathetic nerve responses to static contraction before and after injection of gadolinium into the arterial supply of the statically contracting triceps surae muscles of decerebrate unanesthetized and chloralose-anesthetized cats. Gadolinium has been shown to be a selective blocker of mechanogated channels in thin-fiber muscle afferents, which comprise the afferent arm of the exercise pressor reflex arc. In decerebrate (n = 15) and chloralose-anesthetized (n = 12) cats, we found that gadolinium (10 mM; 1 ml) significantly attenuated the renal sympathetic nerve and pressor responses to static contraction (60 s) after a latent period of 60 min; both responses recovered after a latent period of 120 min. We conclude that thin-fiber mechanoreceptors supplying contracting muscle are involved in some of the renal vasoconstriction evoked by the exercise pressor reflex.

  2. Differential sympathetic activation in muscle and skin neural districts in the metabolic syndrome.

    Science.gov (United States)

    Grassi, Guido; Quarti-Trevano, Fosca; Seravalle, Gino; Dell'Oro, Raffaella; Dubini, Antonella; Mancia, Giuseppe

    2009-10-01

    The present study was designed to determine whether and to what extent the activation of the sympathetic nervous system reported in the metabolic syndrome is generalized to the whole cardiovascular system or if it is rather confined to selected vascular districts. In 16 untreated patients with metabolic syndrome, 12 essential hypertensive subjects, 12 obese subjects, and 14 lean healthy normotensive controls, we measured blood pressure (Finapres, Englewood, CO), heart rate (electrocardiogram), venous plasma norepinephrine (high-performance liquid chromatography), and postganglionic sympathetic nerve traffic in the skeletal muscle and in the skin districts (microneurography). The muscle and skin nerve traffic measurements were obtained in a randomized sequence. Measurements also included skin sympathetic nerve responses to an arousal (acoustic stimulus). The 4 groups of subjects had superimposable ages. Muscle sympathetic nerve traffic values were significantly higher in subjects with hypertension and in those with obesity than in controls (51.2 +/- 2.8 and 52.0 +/- 3.0 vs 37.2 +/- 3.3 bursts per 100 heart beats, respectively; P fashion by the various components of the disease.

  3. Impact of sympathetic nervous system activity on post-exercise flow-mediated dilatation in humans.

    NARCIS (Netherlands)

    Atkinson, C.L.; Lewis, N.C.; Carter, H.H.; Thijssen, D.H.J.; Ainslie, P.N.; Green, D.J.

    2015-01-01

    KEY POINTS: Previous studies indicate a transient reduction in arterial function following large muscle group exercise, but the mechanisms involved are unknown. Sympathetic nervous system activation may contribute to such reductions through direct effects in the artery wall, or because of decreases

  4. Marital Conflict and Children's Externalizing Behavior: Interactions between Parasympathetic and Sympathetic Nervous System Activity

    Science.gov (United States)

    El-Sheikh, Mona; Kouros, Chrystyna D.; Erath, Stephen; Cummings, E. Mark; Keller, Peggy; Staton, Lori

    2009-01-01

    Toward greater specificity in the prediction of externalizing problems in the context of interparental conflict, interactions between children's parasympathetic and sympathetic nervous system (PNS and SNS) activity were examined as moderators. PNS activity was indexed by respiratory sinus arrhythmia (RSA) and RSA reactivity (RSA-R) to lab…

  5. Renal sympathetic nervous system and the effects of denervation on renal arteries

    Institute of Scientific and Technical Information of China (English)

    Arun; Kannan; Raul; Ivan; Medina; Nagapradeep; Nagajothi; Saravanan; Balamuthusamy

    2014-01-01

    Resistant hypertension is associated with chronic activation of the sympathetic nervous system resulting in various comorbidities. The prevalence of resistant hypertension is often under estimated due to various reasons. Activation of sympathetic nervous system at the renal-as well as systemic-level contributes to the increased level of catecholamines and resulting increase in the blood pressure. This increased activity was demonstrated by increased muscle sympathetic nerve activity and renal and total body noradrenaline spillover. Apart from the hypertension, it is hypothesized to be associated with insulin resistance, congestive heart failure and obstructive sleep apnea. Renal denervation is a novel procedure where the sympathetic afferent and efferent activity is reduced by various techniques and has been used successfully to treat drug-resistant hypertension improvement of various metabolic derangements.Renal denervation has the unique advantage of offering the denervation at the renal level, thus mitigating the systemic side effects. Renal denervation can be done by various techniques including radiofrequency ablation, ultrasound guided ablation and chemical ablation. Various trials evaluated the role of renal denervation in the management of resistant hypertension and have found promising results. More studies are underway to evaluate the role of renal denervation in patients presenting with resistant hypertension in different scenarios. Appropriate patient selection might be the key in determining the effectiveness of the procedure.

  6. ALTERED SYMPATHETIC CONTROL OF NUTRIENT MOBILIZATION DURING PHYSICAL EXERCISE AFTER LESIONS IN THE VMH

    NARCIS (Netherlands)

    Balkan, B.; Strubbe, J.H.; Bruggink, J.E.; Steffens, A.B.

    1991-01-01

    To study the impact of obesity on sympathetic nervous regulation of nutrient mobilization, obese rats and lean controls were subjected to physical exercise. Male Wistar rats, rendered obese by bilateral electrolytic lesions of the ventromedial hypothalamus (VMH) were subjected to 15 min swimming. Pe

  7. Heart failure causes cholinergic transdifferentiation of cardiac sympathetic nerves via gp130-signaling cytokines in rodents.

    Science.gov (United States)

    Kanazawa, Hideaki; Ieda, Masaki; Kimura, Kensuke; Arai, Takahide; Kawaguchi-Manabe, Haruko; Matsuhashi, Tomohiro; Endo, Jin; Sano, Motoaki; Kawakami, Takashi; Kimura, Tokuhiro; Monkawa, Toshiaki; Hayashi, Matsuhiko; Iwanami, Akio; Okano, Hideyuki; Okada, Yasunori; Ishibashi-Ueda, Hatsue; Ogawa, Satoshi; Fukuda, Keiichi

    2010-02-01

    Although several cytokines and neurotrophic factors induce sympathetic neurons to transdifferentiate into cholinergic neurons in vitro, the physiological and pathophysiological roles of this remain unknown. During congestive heart failure (CHF), sympathetic neural tone is upregulated, but there is a paradoxical reduction in norepinephrine synthesis and reuptake in the cardiac sympathetic nervous system (SNS). Here we examined whether cholinergic transdifferentiation can occur in the cardiac SNS in rodent models of CHF and investigated the underlying molecular mechanism(s) using genetically modified mice. We used Dahl salt-sensitive rats to model CHF and found that, upon CHF induction, the cardiac SNS clearly acquired cholinergic characteristics. Of the various cholinergic differentiation factors, leukemia inhibitory factor (LIF) and cardiotrophin-1 were strongly upregulated in the ventricles of rats with CHF. Further, LIF and cardiotrophin-1 secreted from cultured failing rat cardiomyocytes induced cholinergic transdifferentiation in cultured sympathetic neurons, and this process was reversed by siRNAs targeting Lif and cardiotrophin-1. Consistent with the data in rats, heart-specific overexpression of LIF in mice caused cholinergic transdifferentiation in the cardiac SNS. Further, SNS-specific targeting of the gene encoding the gp130 subunit of the receptor for LIF and cardiotrophin-1 in mice prevented CHF-induced cholinergic transdifferentiation. Cholinergic transdifferentiation was also observed in the cardiac SNS of autopsied patients with CHF. Thus, CHF causes target-dependent cholinergic transdifferentiation of the cardiac SNS via gp130-signaling cytokines secreted from the failing myocardium.

  8. Bombesin-like receptor 3 regulates blood pressure and heart rate via a central sympathetic mechanism

    OpenAIRE

    Lateef, Dalya M.; Xiao, Cuiying; Brychta, Robert J.; Diedrich, Andr?; Schnermann, Jurgen; Reitman, Marc L.

    2016-01-01

    MK-5046, a bombesin-like receptor 3 (BRS-3) agonist, increases heart rate and blood pressure via increased central sympathetic tone. Brs3 null mice have a reduced resting heart rate that increases disproportionately with physical activity. BRS-3 contributes to the central regulation of heart rate and blood pressure.

  9. Acute electromyostimulation decreases muscle sympathetic nerve activity in patients with advanced chronic heart failure (EMSICA Study.

    Directory of Open Access Journals (Sweden)

    Marc Labrunée

    Full Text Available BACKGROUND: Muscle passive contraction of lower limb by neuromuscular electrostimulation (NMES is frequently used in chronic heart failure (CHF patients but no data are available concerning its action on sympathetic activity. However, Transcutaneous Electrical Nerve Stimulation (TENS is able to improve baroreflex in CHF. The primary aim of the present study was to investigate the acute effect of TENS and NMES compared to Sham stimulation on sympathetic overactivity as assessed by Muscle Sympathetic Nerve Activity (MSNA. METHODS: We performed a serie of two parallel, randomized, double blinded and sham controlled protocols in twenty-two CHF patients in New York Heart Association (NYHA Class III. Half of them performed stimulation by TENS, and the others tested NMES. RESULTS: Compare to Sham stimulation, both TENS and NMES are able to reduce MSNA (63.5 ± 3.5 vs 69.7 ± 3.1 bursts / min, p < 0.01 after TENS and 51.6 ± 3.3 vs 56.7 ± 3.3 bursts / min, p < 0, 01 after NMES. No variation of blood pressure, heart rate or respiratory parameters was observed after stimulation. CONCLUSION: The results suggest that sensory stimulation of lower limbs by electrical device, either TENS or NMES, could inhibit sympathetic outflow directed to legs in CHF patients. These properties could benefits CHF patients and pave the way for a new non-pharmacological approach of CHF.

  10. A unique pattern of intracranial pressure in a patient with traumatic paroxysmal sympathetic storm.

    Science.gov (United States)

    Woo, Hyun Jin; Park, Seong Hyun; Hwang, Sung Kyoo

    2010-01-01

    Paroxysmal sympathetic storm (PSS), or diencephalic seizure, usually appears in patients with severe traumatic brain injury and is characterized by various sympathetic symptoms. The physiological effects of this syndrome are not well studied. The authors monitored intracranial pressure (ICP) in a patient with PSS and reviewed its impact on the physiology and management of the syndrome. A 12-year-old male patient was involved in a traffic accident. Upon arrival at the emergency room, his Glasgow Coma Scale score was 5 and he showed decerebration. A brain CT showed an intracerebral hematoma in the right basal ganglia, at which point craniotomy and removal of the hematoma were performed. Continuous intracranial monitoring was performed using the fiber-optic intraparenchymal method. Beginning the day after the trauma, the patient began exhibiting sympathetic symptoms including intermittent episodes of fever, tachycardia, increased blood pressure, tachypnea, diaphoresis and decerebrate rigidity. These episodes were accompanied by ICP elevation of greater than 20 mm Hg. ICP was decreased during hyperventilation, and the episodic symptoms subsided as ICP normalized. PaCO(2) was periodically altered in association with hyperventilation. Electroencephalogram did not show epileptiform discharges, and the sympathetic spells were aborted by continuous intravenous midazolam infusion. The authors report on a pattern of ICP monitoring in association with PSS. Traumatic PSS should be recognized in the appropriate setting to prevent secondary brain damage.

  11. EXERCISE-INDUCED SYMPATHETIC FFA MOBILIZATION IN VMH-LESIONED RATS IS NORMALIZED BY FASTING

    NARCIS (Netherlands)

    Balkan, B.; Dijk, G. van; Strubbe, J.H.; Bruggink, J.E.; Steffens, A.B.

    This study investigates whether reduced sympathetic responses during physical exercise in ventromedial hypothalamus (VMH)-lesioned obese rats are the direct result of damage to hypothalamic circuits or a secondary effect of the altered metabolism in obesity. Obese, VMH-lesioned rats and lean

  12. Effects of cervical sympathetic nerve stimulation on the cerebral microcirculation: possible clinical implications.

    Science.gov (United States)

    Passatore, M; Deriu, F; Roatta, S; Grassi, C; Micieli, G

    1996-01-01

    The action of bilateral cervical sympathetic nerve (CSN) stimulation on mean cerebral blood flow (CBF) and on its rhythmical fluctuations was studied in normotensive rabbits by using laser-Doppler flowmetry (LDF). A reduction in mean CBF, mediated by alpha-adrenoceptors, was the predominant effect; it was more often present and larger in size in the vascular beds supplied by the carotid than in those supplied by the vertebro-basilar system. This suggests that the sympathetic action facilitates a redistribution of blood flow to the brain stem. The effect induced by CSN stimulation on CBF spontaneous oscillations was a consistent decrease in amplitude and an increase in frequency, irrespective of the changes produced on the mean level of CBF. The possible implications of the sympathetic action on the state of the blood-brain barrier (BBB) are discussed. Experimental and clinical data dealing with the influence of sympathetic activation on the cerebrovascular system have been compared. As a result the possibility of analysing the spontaneous oscillations of CBF for clinical purposes is suggested.

  13. Sympathetic activation by the cold pressor test does not increase the muscle force generation capacity.

    Science.gov (United States)

    Roatta, Silvestro; Farina, Dario

    2011-06-01

    A positive inotropic action by the sympathetic nervous system on skeletal muscles has been observed and investigated in animal and in vitro studies. This action provided a theoretical basis for the putative ergogenic action of catecholamines and adrenergic agonists, although there is no clear evidence of this effect in humans. The aim of this study was to investigate the occurrence of inotropic effects associated to physiological sympathetic activation in healthy subjects. The muscle force capacity was investigated in the tibialis anterior (n = 9 subjects) and in the soleus (n = 9) muscles electrically stimulated with single pulses and double pulses with variable interspike interval (4-1,000 ms) and short pulse trains (frequency: 5-14 Hz) before, during, and after sympathetic activation by the cold pressor test (CPT). CPT significantly decreased by 10.4 ± 7.2 and 10.6 ± 4.4% the force produced by single and double pulse stimulation, respectively, and produced smaller decreases in the force obtained by train stimulation in the tibialis anterior, while no significant changes were observed in either type of contraction in the soleus muscle. CPT failed to induce any increase in the force capacity of the investigated muscles. The prevalent decrease in force evidenced in this study supports the concept that the weakening sympathetic action on type I fiber, already shown to occur in humans, prevails over the putative potentiating action.

  14. Adaptive reaction of boys’ sympathetic-adrenal system to physical activity in puberty.

    Directory of Open Access Journals (Sweden)

    Alekcei Anatolevich Zverev

    2016-04-01

    Full Text Available This paper deals with the study of adaptive reactions of the sympathetic-adrenal system of 11-16-year-old boys to graduated exercise at different pubertal stages. To evaluate the functional state of the cardiovascular system, the heart rate, systolic and cardiac output were determined. The state of the sympathetic-adrenal system was analyzed by the excretion level of catecholamines and DOPA. Cardiac output in response to graduated exercise in boys at pubertal stages 1-2 is substantially ensured by the increased heart rate, and at the other stages of puberty - mainly due to increase in stroke volume, which is estimated as a favorable response to exercise. In mechanisms of urgent adaptation to graduated exercise, the boys of third and fourth pubertal stages show an intensive functioning of the cardiovascular system and a reducing reserve capacity of the sympathetic-adrenal system. The adolescents of fifth pubertal stage show economical response to functional tests, a reduced reactivity of the components of the sympathetic-adrenal system on the background of a significant increase in the excretion of precursors.

  15. Is kidney ischemia the central mechanism in parallel activation of the renin and sympathetic system?

    NARCIS (Netherlands)

    Siddiqi, Laima; Joles, Jaap A.; Grassi, Guido; Blankestijn, Peter J.

    2009-01-01

    In chronic kidney disease simultaneous activation of the renin - angiotensin and sympathetic systems occurs. Kidney ischemia seems to play a key role in the pathogenesis. This review firstly summarizes experimental and clinical evidence in chronic kidney disease supporting this idea and addresses th

  16. Sympathetic skin response in incomplete spinal cord injury with urinary incontinence

    Directory of Open Access Journals (Sweden)

    Reza Emad

    2013-01-01

    Full Text Available Objectives: Sympathetic skin response (SSR is a test for evaluation of the sympathetic sweat gland pathways, and it has been used to study the central sympathetic pathways in spinal cord injury (SCI. This study aimed to assess the autonomic pathways according to normal or abnormal SSR in urinary incontinence patients due to incomplete spinal cord injury. Materials and Methods: Suprapubic, palmar, and plantar SSR to the peripheral nerve electrical stimulation were recorded in 16 urinary incontinence patients with incomplete spinal cord injury at various neurological levels and in 30 healthy control subjects. Results: All the recordings of SSR from the incomplete SCI patients with urinary incontinence as compared with their counterparts in the control group showed significantly reduced amplitudes with more prominent reduction in the suprapubic area recording site (P value < 0.0004. SSR with significantly prolonged latencies were recorded from palm and plantar areas in response to suprapubic area and tibial N stimuli, respectively (P value < 0.02. In this study, a significantly higher stimulus intensity (P value < 0.01 was needed to elicit SSR in the cases compared with the control group. Conclusion: This study showed abnormal SSR in urinary incontinence patients due to incomplete SCI. In addition, for the first time we have described recording of abnormal SSR from the suprapubic area as another way to show bladder sympathetic system involvement.

  17. Evidence for differential sympathetic and parasympathetic reinnervation after heart transplantation in humans

    NARCIS (Netherlands)

    Tio, RA; Reyners, AKL; Van Veldhuisen, DJ; Van den Berg, MP; Brouwer, RMHJ; Haaksma, J; Smit, AJ; Crijns, HJGM

    1997-01-01

    During heart transplantation (HTX) all neural connections are severed, Ln humans, signs of autonomic reinnervation have been found, in this study non-invasive tests were used to compare signs of sympathetic and parasympathetic reinnervation. Non-invasive autonomic function tests and heart rate varia

  18. Sympathetic nonadrenergic transmission contributes to autonomic dysreflexia in spinal cord-injured individuals.

    NARCIS (Netherlands)

    Groothuis, J.T.; Rongen, G.A.P.J.M.; Deinum, J.; Pickkers, P.; Danser, A.H.; Geurts, A.C.H.; Smits, P.; Hopman, M.T.E.

    2010-01-01

    Autonomic dysreflexia is a hypertensive episode in spinal cord-injured individuals induced by exaggerated sympathetic activity and thought to be alpha-adrenergic mediated. alpha-Adrenoceptor antagonists have been a rational first choice; nevertheless, calcium channel blockers are primarily used in a

  19. Central Sympathetic Inhibition: a Neglected Approach for Treatment of Cardiac Arrhythmias?

    Science.gov (United States)

    Cagnoni, Francesca; Destro, Maurizio; Bontempelli, Erika; Locatelli, Giovanni; Hering, Dagmara; Schlaich, Markus P

    2016-02-01

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Overactivation of the sympathetic nervous system (SNS) plays an important role in the pathogenesis of comorbidities related to AF such as hypertension, congestive heart failure, obesity, insulin resistance, and obstructive sleep apnea. Methods that reduce sympathetic drive, such as centrally acting sympatho-inhibitory agents, have been shown to reduce the incidence of spontaneous or induced atrial arrhythmias, suggesting that neuromodulation may be helpful in controlling AF. Moxonidine acts centrally to reduce activity of the SNS, and clinical trials indicate that this is associated with a decreased AF burden in hypertensive patients with paroxysmal AF and reduced post-ablation recurrence of AF in patients with hypertension who underwent pulmonary vein isolation (PVI). Furthermore, device-based approaches to reduce sympathetic drive, such as renal denervation, have yielded promising results in the prevention and treatment of cardiac arrhythmias. In light of these recent findings, targeting elevated sympathetic drive with either pharmacological or device-based approaches has become a focus of clinical research. Here, we review the data currently available to explore the potential utility of sympatho-inhibitory therapies in the prevention and treatment of cardiac arrhythmias.

  20. Inter-individual Relationships between Sympathetic Arterial Baroreflex Function and Cerebral Perfusion Control in Healthy Males

    OpenAIRE

    Trevor Witter; Yu-Chieh Tzeng; Terry O'Donnell; Jessica Kusel; Bridget Walker; Mary Berry; Chloe E. Taylor

    2017-01-01

    Maintenance of adequate cerebral perfusion during normal physiological challenges requires integration between cerebral blood flow (CBF) and systemic blood pressure control mechanisms. Previous studies have shown that cardiac baroreflex sensitivity (BRS) is inversely related to some measures of cerebral autoregulation. However, interactions between the sympathetic arterial baroreflex and cerebral perfusion control mechanisms have not been explored. To determine the nature and magnitude of the...

  1. ACE INHIBITION ATTENUATES SYMPATHETIC CORONARY VASOCONSTRICTION IN PATIENTS WITH CORONARY-ARTERY DISEASE

    NARCIS (Netherlands)

    PERONDI, R; SAINO, A; TIO, RA; POMIDOSSI, G; GREGORINI, L; ALESSIO, P; MORGANTI, A; ZANCHETTI, A; MANCIA, G

    1992-01-01

    Background. In humans, angiotensin converting enzyme (ACE) inhibition attenuates the vasoconstriction induced by sympathetic stimulation in a number of peripheral districts. Whether this is also the case in the coronary circulation is unknown, however. Methods and Results. In nine normotensive patie

  2. Cortisol-induced impairments of working memory require acute sympathetic activation

    NARCIS (Netherlands)

    Elzinga, B.M.; Roelofs, K.

    2005-01-01

    The present study assessed whether the effects of cortisol on working memory depend on the level of adrenergic activity (as measured by sympathetic activation) during memory performance. After exposure to a psychosocial stress task, participants were divided into cortisol responders and nonresponder

  3. Cortisol and Children's Adjustment: The Moderating Role of Sympathetic Nervous System Activity

    Science.gov (United States)

    El-Sheikh, Mona; Erath, Stephen A.; Buckhalt, Joseph A.; Granger, Douglas A.; Mize, Jacquelyn

    2008-01-01

    We examined relations among cortisol, markers of sympathetic nervous system (SNS) activity (including salivary alpha-amylase and skin conductance level), and children's adjustment. We also tested the Bauer et al. ("Journal of Developmental and Behavioral Pediatrics," 23(2), 102-113, 2002) hypothesis that interactions between the SNS and cortisol…

  4. Pacemaker current inhibition in experimental human cardiac sympathetic activation: a double-blind, randomized, crossover study

    NARCIS (Netherlands)

    Schroeder, C.; Heusser, K.; Zoerner, A.A.; Grosshennig, A.; Wenzel, D.; May, M.; Sweep, F.C.; Mehling, H.; Luft, F.C.; Tank, J.; Jordan, J.

    2014-01-01

    Hyperpolarization-activated, cyclic nucleotide-gated 4 (HCN4) channels comprise the final pathway for autonomic heart rate (HR) regulation. We hypothesized that HCN4 inhibition could reverse autonomic imbalance in a human model of cardiac sympathetic activation. Nineteen healthy men ingested oral me

  5. Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans

    NARCIS (Netherlands)

    Kox, M.; Eijk, L.T.G.J. van; Zwaag, J.; Wildenberg, J. van den; Sweep, F.C.; Hoeven, J.G. van der; Pickkers, P.

    2014-01-01

    Excessive or persistent proinflammatory cytokine production plays a central role in autoimmune diseases. Acute activation of the sympathetic nervous system attenuates the innate immune response. However, both the autonomic nervous system and innate immune system are regarded as systems that cannot b

  6. ALTERED SYMPATHETIC CONTROL OF NUTRIENT MOBILIZATION DURING PHYSICAL EXERCISE AFTER LESIONS IN THE VMH

    NARCIS (Netherlands)

    Balkan, B.; Strubbe, J.H.; Bruggink, J.E.; Steffens, A.B.

    1991-01-01

    To study the impact of obesity on sympathetic nervous regulation of nutrient mobilization, obese rats and lean controls were subjected to physical exercise. Male Wistar rats, rendered obese by bilateral electrolytic lesions of the ventromedial hypothalamus (VMH) were subjected to 15 min swimming. Pe

  7. EXERCISE-INDUCED SYMPATHETIC FFA MOBILIZATION IN VMH-LESIONED RATS IS NORMALIZED BY FASTING

    NARCIS (Netherlands)

    Balkan, B.; Dijk, G. van; Strubbe, J.H.; Bruggink, J.E.; Steffens, A.B.

    1992-01-01

    This study investigates whether reduced sympathetic responses during physical exercise in ventromedial hypothalamus (VMH)-lesioned obese rats are the direct result of damage to hypothalamic circuits or a secondary effect of the altered metabolism in obesity. Obese, VMH-lesioned rats and lean control

  8. Histamine H3 receptor activation inhibits neurogenic sympathetic vasoconstriction in porcine nasal mucosa.

    Science.gov (United States)

    Varty, LoriAnn M; Hey, John A

    2002-10-11

    Histamine release from mast cells is a primary mediator of rhinorrhea, nasal mucosal swelling, increased secretion, sneezing, pruritus and congestion that occur in allergic rhinitis. It is well known that histamine H(1) receptor antagonists inhibit the itch and rhinorhea, but do not block the allergic nasal congestion. A growing body of evidence shows that in addition to histamine H(1) receptors, activation of H(3) receptors may contribute to the procongestant nasal actions of histamine. Activation of the prejunctional histamine H(3) receptor modulates sympathetic control of nasal vascular tone and resistance. The present study was conducted to further characterize the role of histamine H(3) receptors on neurogenic sympathetic vascular contractile responses in isolated porcine nasal turbinate mucosa. We presently found that the histamine H(3) receptor agonist, (R)-alpha-methylhistamine (10-1000 nM), inhibited electrical field stimulation-induced sympathetic vasomotor contractions in a concentration-dependent fashion. Pretreatment with either of the selective histamine H(3) receptor antagonists, thioperamide and clobenpropit, blocked the sympathoinhibitory effect of (R)-alpha-methylhistamine in porcine turbinate mucosa. The effect of compound 48/80, an agent that elicits the release of endogenous histamine from mast cells on nasal sympathetic contractile responses, was also tested. The action of compound 48/80 to release mast cell-derived histamine in the nose mimics many of the nasal responses associated with allergic rhinitis, extravascular leakage and decreased nasal patency. We presently found that compound 48/80 also inhibited the electrical field stimulation-induced sympathetic response. Pretreatment with the H(3) receptor antagonist clobenpropit blocked the sympathoinhibitory action of compound 48/80 on sympathetic contractile responses in nasal mucosa. Taken together, these studies indicate that histamine H(3) receptors modulate vascular contractile

  9. Power Spectral Density Analysis of Electrodermal Activity for Sympathetic Function Assessment.

    Science.gov (United States)

    Posada-Quintero, Hugo F; Florian, John P; Orjuela-Cañón, Alvaro D; Aljama-Corrales, Tomas; Charleston-Villalobos, Sonia; Chon, Ki H

    2016-10-01

    Time-domain features of electrodermal activity (EDA), the measurable changes in conductance at the skin surface, are typically used to assess overall activation of the sympathetic system. These time domain features, the skin conductance level (SCL) and the nonspecific skin conductance responses (NS.SCRs), are consistently elevated with sympathetic nervous arousal, but highly variable between subjects. A novel frequency-domain approach to quantify sympathetic function using the power spectral density (PSD) of EDA is proposed. This analysis was used to examine if some of the induced stimuli invoke the sympathetic nervous system's dynamics which can be discernible as a large spectral peak, conjectured to be present in the low frequency band. The resulting indices were compared to the power of low-frequency components of heart rate variability (HRVLF) time series, as well as to time-domain features of EDA. Twelve healthy subjects were subjected to orthostatic, physical and cognitive stress, to test these techniques. We found that the increase in the spectral powers of the EDA was largely confined to 0.045-0.15 Hz, which is in the prescribed band for HRVLF. These low frequency components are known to be, in part, influenced by the sympathetic nervous dynamics. However, we found an additional 5-10% of the spectral power in the frequency range of 0.15-0.25 Hz with all three stimuli. Thus, dynamics of the normalized sympathetic component of the EDA, termed EDASympn, are represented in the frequency band 0.045-0.25 Hz; only a small amount of spectral power is present in frequencies higher than 0.25 Hz. Our results showed that the time-domain indices (the SCL and NS.SCRs), and EDASympn, exhibited significant increases under orthostatic, physical, and cognitive stress. However, EDASympn was more responsive than the SCL and NS.SCRs to the cold pressor stimulus, while the latter two were more sensitive to the postural and Stroop tests. Additionally, EDASympn exhibited an

  10. Sympathetic modulation of muscle spindle afferent sensitivity to stretch in rabbit jaw closing muscles.

    Science.gov (United States)

    Roatta, S; Windhorst, U; Ljubisavljevic, M; Johansson, H; Passatore, M

    2002-04-01

    Previous reports showed that sympathetic stimulation affects the activity of muscle spindle afferents (MSAs). The aim of the present work is to study the characteristics of sympathetic modulation of MSA response to stretch: (i) on the dynamic and static components of the stretch response, and (ii) on group Ia and II MSAs to evaluate potentially different effects. In anaesthetised rabbits, the peripheral stump of the cervical sympathetic nerve (CSN) was stimulated at 10 impulses s(-1) for 45-90 s. The responses of single MSAs to trapezoidal displacement of the mandible were recorded from the mesencephalic trigeminal nucleus. The following characteristic parameters were determined from averaged trapezoidal responses: initial frequency (IF), peak frequency at the end of the ramp (PF), and static index (SI). From these, other parameters were derived: dynamic index (DI = PF - SI), dynamic difference (DD = PF - IF) and static difference (SD = SI - IF). The effects of CSN stimulation were also evaluated during changes in the state of intrafusal muscle fibre contraction induced by succinylcholine and curare. In a population of 124 MSAs, 106 units (85.4 %) were affected by sympathetic stimulation. In general, while changes in resting discharge varied among different units (Ia vs. II) and experimental conditions (curarised vs. non-curarised), ranging from enhancement to strong depression of firing, the amplitude of the response to muscle stretches consistently decreased. This was confirmed and detailed in a quantitative analysis performed on 49 muscle spindle afferents. In both the non-curarised (23 units) and curarised (26 units) condition, stimulation of the CSN reduced the response amplitude in terms of DD and SD, but hardly affected DI. The effects were equally present in both Ia and II units; they were shown to be independent from gamma drive and intrafusal muscle tone and not secondary to muscle hypoxia. Sympathetic action on the resting discharge (IF) was less

  11. Aldosterone-induced brain MAPK signaling and sympathetic excitation are angiotensin II type-1 receptor dependent.

    Science.gov (United States)

    Zhang, Zhi-Hua; Yu, Yang; Wei, Shun-Guang; Felder, Robert B

    2012-02-01

    Angiotensin II (ANG II)-induced mitogen-activated protein kinase (MAPK) signaling upregulates angiotensin II type-1 receptors (AT(1)R) in hypothalamic paraventricular nucleus (PVN) and contributes to AT(1)R-mediated sympathetic excitation in heart failure. Aldosterone has similar effects to increase AT(1)R expression in the PVN and sympathetic drive. The present study was undertaken to determine whether aldosterone also activates the sympathetic nervous system via MAPK signaling and, if so, whether its effect is independent of ANG II and AT(1)R. In anesthetized rats, a 4-h intravenous infusion of aldosterone induced increases (P < 0.05) in phosphorylated (p-) p44/42 MAPK in PVN, PVN neuronal excitation, renal sympathetic nerve activity (RSNA), mean blood pressure (MBP), and heart rate (HR). Intracerebroventricular or bilateral PVN microinjection of the p44/42 MAPK inhibitor PD-98059 reduced the aldosterone-induced RSNA, HR, and MBP responses. Intracerebroventricular pretreatment (5 days earlier) with pooled small interfering RNAs targeting p44/42 MAPK reduced total and p-p44/42 MAPK, aldosterone-induced c-Fos expression in the PVN, and the aldosterone-induced increases in RSNA, HR, and MBP. Intracerebroventricular infusion of either the mineralocorticoid receptor antagonist RU-28318 or the AT(1)R antagonist losartan blocked aldosterone-induced phosphorylation of p44/42 MAPK and prevented the increases in RSNA, HR, and MBP. These data suggest that aldosterone-induced sympathetic excitation depends upon that AT(1)R-induced MAPK signaling in the brain. The short time course of this interaction suggests a nongenomic mechanism, perhaps via an aldosterone-induced transactivation of the AT(1)R as described in peripheral tissues.

  12. Subfornical organ mediates sympathetic and hemodynamic responses to blood-borne proinflammatory cytokines.

    Science.gov (United States)

    Wei, Shun-Guang; Zhang, Zhi-Hua; Beltz, Terry G; Yu, Yang; Johnson, Alan Kim; Felder, Robert B

    2013-07-01

    Proinflammatory cytokines play an important role in regulating autonomic and cardiovascular function in hypertension and heart failure. Peripherally administered proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), act on the brain to increase blood pressure, heart rate, and sympathetic nerve activity. These molecules are too large to penetrate the blood-brain barrier, and so the mechanisms by which they elicit these responses remain unknown. We tested the hypothesis that the subfornical organ (SFO), a forebrain circumventricular organ that lacks a blood-brain barrier, plays a major role in mediating the sympathetic and hemodynamic responses to circulating proinflammatory cytokines. Intracarotid artery injection of TNF-α (200 ng) or IL-1β (200 ng) dramatically increased mean blood pressure, heart rate, and renal sympathetic nerve activity in rats with sham lesions of the SFO (SFO-s). These excitatory responses to intracarotid artery TNF-α and IL-1β were significantly attenuated in SFO-lesioned (SFO-x) rats. Similarly, the increases in mean blood pressure, heart rate, and renal sympathetic nerve activity in response to intravenous injections of TNF-α (500 ng) or IL-1β (500 ng) in SFO-s rats were significantly reduced in the SFO-x rats. Immunofluorescent staining revealed a dense distribution of the p55 TNF-α receptor and the IL-1 receptor accessory protein, a subunit of the IL-1 receptor, in the SFO. These data suggest that SFO is a predominant site in the brain at which circulating proinflammatory cytokines act to elicit cardiovascular and sympathetic responses.

  13. Comparison of two isometric handgrip protocols on sympathetic arousal in women.

    Science.gov (United States)

    Nielsen, Shawn E; Mather, Mara

    2015-04-01

    Isometric handgrip is commonly used in stress research because the task reliably increases sympathetic arousal. Various handgrip protocols have been used; they vary in handgrip strength, duration of grip, and the number of cycles of handgrip and rest. However, most protocols require the calibration of a maximum voluntary contraction (MVC) prior to the handgrip task, which is not always convenient (i.e., in a functional magnetic resonance imaging study). Here, we wanted to test whether two handgrip protocols with different strength, duration and cycle protocols would reliably elicit sympathetic arousal in the absence of calibrating an MVC. Sixty-two healthy naturally cycling women and women on hormonal contraception participated in one of the two isometric handgrip protocols using a hand therapy ball of medium resistance. Women completed one of the following handgrip protocols: 1) 30% of a perceived maximum voluntary contraction for 3 min or 2) 3 cycles of maximum voluntary contraction for 18s with a one minute rest in between. All handgrip blocks were counterbalanced with a control condition. Sympathetic arousal was measured throughout the session via pupil diameter changes and salivary alpha-amylase. Results indicate that in the absence of calibrating an MVC, the handgrip tasks elicited different changes in sympathetic arousal. Pupil dilation responses increased significantly in the handgrip versus control blocks only in participants in the 18-s protocol. Additionally, more participants exhibited a salivary alpha-amylase response to the handgrip block in the 18-s condition compared to the 3-min condition. Thus, these results suggest that neuroimaging and behavioral studies with isometric handgrip should be able to successfully induce sympathetic nervous activity with the 18-s paradigm, regardless of the handgrip device and the ability to calibrate an MVC. Published by Elsevier Inc.

  14. Pmch-deficiency in rats is associated with normal adipocyte differentiation and lower sympathetic adipose drive.

    Directory of Open Access Journals (Sweden)

    Joram D Mul

    Full Text Available The orexigenic neuropeptide melanin-concentrating hormone (MCH, a product of Pmch, is an important mediator of energy homeostasis. Pmch-deficient rodents are lean and smaller, characterized by lower food intake, body-, and fat mass. Pmch is expressed in hypothalamic neurons that ultimately are components in the sympathetic nervous system (SNS drive to white and interscapular brown adipose tissue (WAT, iBAT, respectively. MCH binds to MCH receptor 1 (MCH1R, which is present on adipocytes. Currently it is unknown if Pmch-ablation changes adipocyte differentiation or sympathetic adipose drive. Using Pmch-deficient and wild-type rats on a standard low-fat diet, we analyzed dorsal subcutaneous and perirenal WAT mass and adipocyte morphology (size and number throughout development, and indices of sympathetic activation in WAT and iBAT during adulthood. Moreover, using an in vitro approach we investigated the ability of MCH to modulate 3T3-L1 adipocyte differentiation. Pmch-deficiency decreased dorsal subcutaneous and perirenal WAT mass by reducing adipocyte size, but not number. In line with this, in vitro 3T3-L1 adipocyte differentiation was unaffected by MCH. Finally, adult Pmch-deficient rats had lower norepinephrine turnover (an index of sympathetic adipose drive in WAT and iBAT than wild-type rats. Collectively, our data indicate that MCH/MCH1R-pathway does not modify adipocyte differentiation, whereas Pmch-deficiency in laboratory rats lowers adiposity throughout development and sympathetic adipose drive during adulthood.

  15. Acute and chronic estrogen supplementation decreases uterine sympathetic innervation in ovariectomized adult virgin rats.

    Science.gov (United States)

    Zoubina, E V; Mize, A L; Alper, R H; Smith, P G

    2001-10-01

    Uterine innervation undergoes substantial reorganization associated with changes in reproductive status. Nerves innervating the uterus are decreased in pregnancy and puberty, and even the normal rodent estrous cycle is characterized by fluctuations in numbers of myometrial nerve fibers. During the follicular (proestrus/estrous) phase of the estrous cycle, intact nerves are rapidly depleted and then return over the next 2-3 days in the luteal (metestrus/diestrus) phase. We hypothesize that uterine nerve depletion is initiated by increased circulating estrogen in the follicular phase. However, studies have not shown whether estrogen can reduce uterine innervation and, if so, whether the time course is compatible with the rapid changes observed in the estrous cycle. These questions were addressed in the present study. Mature ovariectomized virgin rats received 17-beta-estradiol as a single injection (10 microg/kg s.c.) or chronically from timed-release pellets (0.1 microg/pellet for 3 weeks sustained release). Total (protein gene-product 9.5-immunoreactive) and sympathetic (dopamine beta-hydroxylase-immunoreactive) uterine innervation was assessed quantitatively. Both total and sympathetic innervation was abundant in uterine longitudinal smooth muscle of ovariectomized rats. However, following acute or chronic estrogen administration, total and sympathetic fiber numbers were markedly decreased. This was not due to altered uterine size, as reductions persisted after correcting for size differences. Our results indicate that sympathetic nerves are lost from uterine smooth muscle after estradiol treatment in a manner similar to that seen in the intact animal during estrus and pregnancy. This suggests that the rise in estradiol prior to estrus is sufficient to deplete uterine sympathetic innervation.

  16. Ghrelin modulates sympathetic nervous system activity and stress response in lean and overweight men.

    Science.gov (United States)

    Lambert, Elisabeth; Lambert, Gavin; Ika-Sari, Carolina; Dawood, Tye; Lee, Katie; Chopra, Reena; Straznicky, Nora; Eikelis, Nina; Drew, Sara; Tilbrook, Alan; Dixon, John; Esler, Murray; Schlaich, Markus P

    2011-07-01

    Ghrelin is a growth hormone-releasing peptide secreted by the stomach with potent effects on appetite. Experimental and clinical studies indicate that ghrelin also influences cardiovascular regulation and metabolic function and mediates behavioral responses to stress. We investigated the effects of ghrelin on blood pressure (BP), sympathetic nervous system activity, and mental stress responses in lean (n=13) and overweight or obese (n=13) individuals. Subjects received an intravenous infusion of human ghrelin (5 pmol/kg per minute for 1 hour) and saline in a randomized fashion. Ghrelin decreased systolic (-6 and -11 mm Hg) and diastolic BP (-8 mm Hg for both), increased muscle sympathetic nervous system activity (18±2 to 28±3 bursts per min, P<0.05 and from 21±2 to 32±3 bursts per min, P<0.001) in lean and overweight or obese subjects, respectively, without a significant change in heart rate, calf blood flow, or vascular resistance. Ghrelin induced a rise in plasma glucose concentration in lean individuals (P<0.05) and increased cortisol levels in both groups (P<0.05). Stress induced a significant change in mean BP (+22 and +27 mm Hg), heart rate (+36 and +29 bpm), and muscle sympathetic nervous system activity (+6.1±1.6 and +6.8±2.7 bursts per min) during saline infusion in lean and overweight or obese subjects, respectively. During ghrelin infusion, the changes in BP and muscle sympathetic nerve activity in response to stress were significantly reduced in both groups (P<0.05). In conclusion, ghrelin exerts unique effects in that it reduces BP and increases muscle sympathetic nervous system activity and blunts cardiovascular responses to mental stress. These responses may represent a combination of peripheral (baroreflex-mediated) and central effects of ghrelin.

  17. Reactive oxygen species are involved in BMP-induced dendritic growth in cultured rat sympathetic neurons.

    Science.gov (United States)

    Chandrasekaran, Vidya; Lea, Charlotte; Sosa, Jose Carlo; Higgins, Dennis; Lein, Pamela J

    2015-07-01

    Previous studies have shown that bone morphogenetic proteins (BMPs) promote dendritic growth in sympathetic neurons; however, the downstream signaling molecules that mediate the dendrite promoting activity of BMPs are not well characterized. Here we test the hypothesis that reactive oxygen species (ROS)-mediated signaling links BMP receptor activation to dendritic growth. In cultured rat sympathetic neurons, exposure to any of the three mechanistically distinct antioxidants, diphenylene iodinium (DPI), nordihydroguaiaretic acid (NGA) or desferroxamine (DFO), blocked de novo BMP-induced dendritic growth. Addition of DPI to cultures previously induced with BMP to extend dendrites caused dendritic retraction while DFO and NGA prevented further growth of dendrites. The inhibition of the dendrite promoting activity of BMPs by antioxidants was concentration-dependent and occurred without altering axonal growth or neuronal cell survival. Antioxidant treatment did not block BMP activation of SMAD 1,5 as determined by nuclear localization of these SMADs. While BMP treatment did not cause a detectable increase in intracellular ROS in cultured sympathetic neurons as assessed using fluorescent indicator dyes, BMP treatment increased the oxygen consumption rate in cultured sympathetic neurons as determined using the Seahorse XF24 Analyzer, suggesting increased mitochondrial activity. In addition, BMPs upregulated expression of NADPH oxidase 2 (NOX2) and either pharmacological inhibition or siRNA knockdown of NOX2 significantly decreased BMP-7 induced dendritic growth. Collectively, these data support the hypothesis that ROS are involved in the downstream signaling events that mediate BMP7-induced dendritic growth in sympathetic neurons, and suggest that ROS-mediated signaling positively modulates dendritic complexity in peripheral neurons.

  18. Nonselective Blocking of the Sympathetic Nervous System Decreases Detrusor Overactivity in Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Chang-Shin Park

    2012-04-01

    Full Text Available The involuntary dual control systems of the autonomic nervous system (ANS in the bladder of awake spontaneously hypertensive rats (SHRs were investigated through simultaneous registrations of intravesical and intraabdominal pressures to observe detrusor overactivity (DO objectively as a core symptom of an overactive bladder. SHRs (n = 6 showed the features of overactive bladder syndrome during urodynamic study, especially DO during the filling phase. After injection of the nonselective sympathetic blocking agent labetalol, DO disappeared in 3 of 6 SHRs (50%. DO frequency decreased from 0.98 ± 0.22 min−1 to 0.28 ± 0.19 min−1 (p < 0.01, and DO pressure decreased from 3.82 ± 0.57 cm H2O to 1.90 ± 0.86 cm H2O (p < 0.05. This suggests that the DO originating from the overactive parasympathetic nervous system is attenuated by the nonselective blocking of the sympathetic nervous system. The detailed mechanism behind this result is still not known, but parasympathetic overactivity seems to require overactive sympathetic nervous system activity in a kind of balance between these two systems. These findings are consistent with recent clinical findings suggesting that patients with idiopathic overactive bladder may have ANS dysfunction, particularly a sympathetic dysfunction. The search for newer and better drugs than the current anticholinergic drugs as the mainstay for overactive bladder will be fueled by our research on these sympathetic mechanisms. Further studies of this principle are required.

  19. Selective quantification of the cardiac sympathetic and parasympathetic nervous systems by multisignal analysis of cardiorespiratory variability.

    Science.gov (United States)

    Chen, Xiaoxiao; Mukkamala, Ramakrishna

    2008-01-01

    Heart rate (HR) power spectral indexes are limited as measures of the cardiac autonomic nervous systems (CANS) in that they neither offer an effective marker of the beta-sympathetic nervous system (SNS) due to its overlap with the parasympathetic nervous system (PNS) in the low-frequency (LF) band nor afford specific measures of the CANS due to input contributions to HR [e.g., arterial blood pressure (ABP) and instantaneous lung volume (ILV)]. We derived new PNS and SNS indexes by multisignal analysis of cardiorespiratory variability. The basic idea was to identify the autonomically mediated transfer functions relating fluctuations in ILV to HR (ILV-->HR) and fluctuations in ABP to HR (ABP-->HR) so as to eliminate the input contributions to HR and then separate each estimated transfer function in the time domain into PNS and SNS indexes using physiological knowledge. We evaluated these indexes with respect to selective pharmacological autonomic nervous blockade in 14 humans. Our results showed that the PNS index derived from the ABP-->HR transfer function was correctly decreased after vagal and double (vagal + beta-sympathetic) blockade (P < 0.01) and did not change after beta-sympathetic blockade, whereas the SNS index derived from the same transfer function was correctly reduced after beta-sympathetic blockade in the standing posture and double blockade (P < 0.05) and remained the same after vagal blockade. However, this SNS index did not significantly decrease after beta-sympathetic blockade in the supine posture. Overall, these predictions were better than those provided by the traditional high-frequency (HF) power, LF-to-HF ratio, and normalized LF power of HR variability.

  20. Decreased adrenergic tone in acromegaly: evidence from direct recording of muscle sympathetic nerve activity.

    Science.gov (United States)

    Seravalle, G; Carzaniga, C; Attanasio, R; Grassi, G; Lonati, L; Facchini, C; Cozzi, R; Fatti, L M; Montini, M; Vitale, G; Sciortino, G; Damanti, S; Brambilla, G; Cavagnini, F; Mancia, G; Scacchi, M

    2012-08-01

    Sympathovagal imbalance has been shown in acromegaly by indirect measurements of adrenergic tone. Data regarding direct measurement of sympathetic activity are lacking as yet. Aim of this study was to assess the adrenergic tone through direct recording of muscle sympathetic nerve activity (MSNA) in acromegalic patients. Fifteen patients (age 26-66 years, eight women) with newly diagnosed active acromegaly without hyperprolactinaemia, pituitary hormone deficiencies, obstructive sleep apnoea and cardiac hypertrophy, and 15 healthy subjects matched for age, sex and body mass index were recruited. After evaluating anthropometric and echocardiographic parameters, anterior pituitary function, glucose and lipid metabolism, and measuring plasma leptin, direct recording of sympathetic outflow via the microneurographic technique was performed. For similar anthropometric and metabolic parameters in patients and controls, HOMA index was significantly increased in the former (4·2 ± 2·39 vs 1·6 ± 0·19, P < 0·001). Surprisingly, this finding of insulin resistance was accompanied by a marked sympathetic inhibition (MSNA 18·3 ± 8·10 vs 37·3 ± 6·48 bursts/min, P < 0·0001, respectively in patients and controls). A reduction in plasma leptin (1·6 ± 1·04 vs 6·5 ± 2·01 μg/l, P < 0·0001) was also recorded in the patients. MSNA was positively correlated with leptin (P < 0·0001). Newly diagnosed acromegalic patients without cardiac hypertrophy display a decreased sympathetic outflow in spite of insulin resistance. This finding might be related to hypoleptinaemia. © 2012 Blackwell Publishing Ltd.

  1. Connections of Barrington's nucleus to the sympathetic nervous system in rats.

    Science.gov (United States)

    Cano, G; Card, J P; Rinaman, L; Sved, A F

    2000-03-15

    Barrington's nucleus (BN) has been considered a pontine center related exclusively to the control of pelvic parasympathetic activity. The present study demonstrates an anatomical linkage between BN and autonomic outflow to visceral targets innervated exclusively by the sympathetic division of the autonomic nervous system. Temporal analysis of infection after injection of pseudorabies virus (PRV), a retrograde transynaptic tracer, into two sympathetically innervated organs, the spleen and the kidney, revealed the presence of infected neurons in BN at early post-inoculation survival intervals. Immunohistochemical localization of PRV after spleen injections showed that a small subpopulation of BN neurons became labeled in a time frame coincident with the appearance of infected neurons in other brain regions known to project to sympathetic preganglionic neurons (SPNs) in the thoracic spinal cord; a larger number of infected neurons appeared in BN at intermediate intervals after PRV injections into the spleen or kidney. Coinjection of the retrograde tracer Fluoro-Gold i.p. and PRV into the spleen demonstrated that parasympathetic preganglionic neurons in the caudal medulla or lumbo-sacral spinal cord were not infected, indicating that infected BN neurons were not infected via a parasympathetic route. Thus, BN neurons become infected after PRV injections into the spleen or kidney either directly through BN projections to SPNs, or secondarily via BN projections to infected pre-preganglionic neurons. These results demonstrate an anatomical linkage, either direct or indirect, between BN and sympathetic activity. Because BN receives numerous inputs from diverse brain regions, the relation of BN with both branches of the autonomic nervous system suggests that this nucleus might play a role in the integration of supraspinal inputs relevant to the central coordination of sympathetic and parasympathetic activity.

  2. Localization of sympathetic postganglionic neurons innervating mesenteric artery and vein in rats.

    Science.gov (United States)

    Hsieh, N K; Liu, J C; Chen, H I

    2000-04-12

    Physiological and histochemical studies have demonstrated the control and innervation of sympathetic nerves to the artery and vein vessels of splanchnic circulation. In our laboratory, we first used the technique of retrograde transport of horseradish peroxidase to identify the origin of sympathetic neurons innervating the mesenteric vein. In this study, double fluorescence staining technique was used for a simultaneous localization of the sympathetic postganglionic neurons supplying the mesenteric artery and vein in rats. First-order branches of mesenteric artery (A) and vein (V) in the vicinity of ileo-cecal junction were isolated for application of fluorescent dyes (Fast Blue, FB and Diamidino Yellow, DY). The application of FB and DY on A and V was alternated in the next animal to minimize the difference in dye uptake. The animal was allowed to recover for 6-7 days assuring a complete uptake of FB and DY into the cytoplasm and nucleus, respectively. The number of FB, DY and double staining neurons in the prevertebral and paravertebral ganglia were counted under a fluorescent microscope after animal fixation and serial frozen section (30 microm) of the sympathetic ganglia. Our study revealed the following findings: (1) Distribution of the fluorescence-staining neurons in the sympathetic ganglia was as follows: right celiac ganglion (39%), superior mesenteric ganglion (30%), left celiac ganglion (26%), inferior mesenteric ganglion (1%) and paravertebral ganglia (4%). (2) Double staining neurons that dually innervate A and V amounted to 54% of total staining neurons. There were 41% neurons singly innervating A and 5% innervating V. (3) The ratio of neurons supplying the A and V ranged from 1.41 to 1.75 (average 1.61). (4) There was no distinct topographical distribution with respect to the neuron location innervating A and V. The distribution of neurons appeared in a scattering pattern.

  3. The interpretation of pain relief and sensory changes following sympathetic blockade.

    Science.gov (United States)

    Dellemijn, P L; Fields, H L; Allen, R R; McKay, W R; Rowbotham, M C

    1994-12-01

    A comparative study of the effects of sympathetic blockade by stellate ganglion block (SGB) and intravenous phentolamine infusion (PhI) was carried out in 24 patients with presumed sympathetically maintained pain of an upper extremity. A total of 15 SGBs and 16 PhIs were performed, with seven patients undergoing both procedures. All patients developed a Horner's syndrome with SGB and nasal stuffiness and cardiovascular changes with PhI. Similar pain relief was obtained with SGB and PhI in six of the seven who underwent both procedures. Pre-procedure patient characteristics including age, sex, duration of pain, historical and physical examination features suggestive of the reflex sympathetic dystrophy syndrome, and sensory disturbances such as allodynia and hyperpathia did not predict pain relief from either procedure. Changes in skin temperature following the sympatholytic procedure did not correlate with pain relief. For PhI, pain relief correlated with the magnitude of decrease in systolic blood pressure. After SGB, changes in quantitative thermal sensory testing (QST) suggestive of a partial deficit in thermal sensation correlated with pain relief. In 20 normal controls, water bath immersion to cool the hand passively by 7 degrees C and warm the hand passively by 4 degrees C had small and selective effects on thermal QST thresholds, but did not produce a general impairment in thermal sensation. In conclusion, the diagnosis of sympathetically maintained pain based on the history and physical examination alone cannot be made with confidence and therefore a sympatholytic procedure is necessary. When SGB produces pain relief but PhI does not, systemic absorption of local anaesthetic and/or sensory blockade by spread to somatic nerves may be the reason. Thus, PhI appears to be a less sensitive but more specific test than SGB. These two procedures provide complementary information and both may be needed to establish the diagnosis of sympathetically maintained pain.

  4. Upregulation of orexin receptor in paraventricular nucleus promotes sympathetic outflow in obese Zucker rats.

    Science.gov (United States)

    Zhou, Jing-Jing; Yuan, Fang; Zhang, Yi; Li, De-Pei

    2015-12-01

    Sympathetic vasomotor tone is elevated in obesity-related hypertension. Orexin importantly regulates energy metabolism and autonomic function. We hypothesized that alteration of orexin receptor in the paraventricular nucleus (PVN) of the hypothalamus leads to elevated sympathetic vasomotor tone in obesity. We used in vivo measurement of sympathetic vasomotor tone and microinjection into brain nucleus, whole-cell patch clamp recording in brain slices, and immunocytochemical staining in obese Zucker rats (OZRs) and lean Zucker rats (LZRs). Microinjection of orexin 1 receptor (OX1R) antagonist SB334867 into the PVN reduced basal arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA) in anesthetized OZRs but not in LZRs. Microinjection of orexin A into the PVN produced greater increases in ABP and RSNA in OZRs than in LZRs. Western blot analysis revealed that OX1R expression levels in the PVN were significantly increased in OZRs compared with LZRs. OX1R immunoreactivity was positive in retrogradely labeled PVN-spinal neurons. The basal firing rate of labeled PVN-spinal neurons was higher in OZRs than in LZRs. SB334867 decreased the basal firing activity of PVN-spinal neurons in OZRs but had no effect in LZRs. Orexin A induced a greater increase in the firing rate of PVN-spinal neurons in OZRs than in LZRs. In addition, orexin A induced larger currents in PVN-spinal neurons in OZRs than in LZRs. These data suggest that upregulation of OX1R in the PVN promotes hyperactivity of PVN presympathetic neurons and elevated sympathetic outflow in obesity.

  5. Sympathetic hyperinnervation of the uterus in the estrogen receptor alpha knock-out mouse.

    Science.gov (United States)

    Zoubina, E V; Smith, P G

    2001-01-01

    Uterine innervation undergoes cyclical remodeling in the adult virgin rat. Previous studies showed that ovariectomy leads to increased uterine sympathetic nerve density, and this can be reduced by estrogen administration. However, the receptor mechanism by which estrogen modulates sympathetic innervation is unknown. The present study assessed the role of the estrogen receptor alpha in establishing levels of uterine innervation by comparing the nerve abundance in mice with a null mutation of the estrogen receptor alpha with those of the wild-type cycling mouse. Immunostaining for total uterine innervation using antibodies against the pan-neuronal marker protein gene product 9.5 showed that nerve numbers in normally cycling wild-type mice were high in diestrus when circulating estrogen is at its nadir, and low at estrus, coincident with high plasma estrogen. Uteri of the estrogen receptor alpha knock-out mice were smaller than those of wild-type mice, but even when corrected for differences in size, total innervation was 188% and 355% greater than that of wild-type mice at diestrus and estrus, respectively. This hyperinnervation is associated with increased numbers of nerves immunoreactive for the noradrenergic enzyme dopamine beta-hydroxylase, without obvious differences in those containing calcitonin gene-related peptide or the vesicular acetylcholine transporter. While estrogen supplementation of the ovariectomized wild-type mice significantly reduced total uterine innervation, neither ovariectomy nor estrogen supplementation affected uterine nerve density in estrogen receptor alpha knock-out mice.We conclude that estrogen acting through the estrogen receptor alpha determines the number of sympathetic nerve terminal branches within uterine smooth muscle target. In mice with low circulating estrogen, or high estrogen but lacking the functional estrogen receptor alpha, the uterus contains abundant sympathetic nerves, whereas estrogen acts via the estrogen receptor

  6. Sympathetic activity of S-(+-ketamine low doses in the epidural space

    Directory of Open Access Journals (Sweden)

    Slobodan Mihaljevic

    2014-07-01

    Full Text Available BACKGROUND AND OBJECTIVES: S-(+-ketamine is an intravenous anaesthetic and sympathomimetic with properties of local anaesthetic. It has an effect of an analgetic and local anaesthetic when administered epidurally, but there are no data whether low doses of S-(+-ketamine have sympathomimetic effects. The aim of this study was to determine whether low doses of S-(+-ketamine, given epidurally together with local anaesthetic, have any effect on sympathetic nervous system, both systemic and below the level of anaesthetic block. METHODS: The study was conducted on two groups of patients to whom epidural anaesthesia was administered to. Local anaesthesia (0.5% bupivacaine was given to one group (control group while local anaesthesia and S-(+-ketamine were given to other group. Age, height, weight, systolic, diastolic and mean arterial blood pressure were measured. Non-competitive enzyme immunochemistry method (Cat Combi ELISA was used to determine the concentrations of catecholamines (adrenaline and noradrenaline. Immunoenzymometric determination with luminescent substrate on a machine called Vitros Eci was used to determine the concentration of cortisol. Pulse transit time was measured using photoplethysmography. Mann-Whitney U-test, Wilcoxon test and Friedman ANOVA were the statistical tests. Blood pressure, pulse, adrenaline, noradrenaline and cortisol concentrations were measured in order to estimate systemic sympathetic effects. RESULTS: 40 patients in the control group were given 0.5% bupivacaine and 40 patients in the test group were given 0.5% bupivacaine with S-(+-ketamine. Value p < 0.05 has been taken as a limit of statistical significance. CONCLUSIONS: Low dose of S-(+-ketamine administered epidurally had no sympathomimetic effects; it did not change blood pressure, pulse, serum hormones or pulse transit time. Low dose of S-(+-ketamine administered epidurally did not deepen sympathetic block. Adding 25 mg of S-(+-ketamine to 0

  7. Sympathetic activity in the rat: effects of anaesthesia on noradrenaline kinetics.

    Science.gov (United States)

    Maignan, E; Dong, W X; Legrand, M; Safar, M; Cuche, J L

    2000-04-12

    Noradrenaline (NA) kinetics represent an effective tool for evaluating the activity of the sympathetic system: thus plasma NA concentration, spillover rate (SOR) and metabolic clearance rate (MC) were measured in the rat. The dilution technique was adapted and validated: pithing that caused mechanical destruction of the spinal cord was shown to reduce drastically NA-SOR and plasma NA concentration with no effect on NA-MC. NA-SOR and plasma NA concentration were restored within their normal limits when 2.5 Hz electrical stimulation of the sympathetic roots was superimposed. Normal values of NA kinetics in non-anaesthetised normotensive 12-week-old rats are reported: NA-SOR=196.1+/-26.4 ng/kg/min, NA-MC=413.9+/-38.8 ml/kg/min and plasma NA=486+/-52 pg/ml. NA kinetic was investigated in response to anaesthesia, known to depress excitable tissues of the central nervous system and expected to depress the activity of the sympathetic system. When NA-SOR was significantly reduced during anaesthesia with either sodium pentobarbital or chloralose, plasma NA concentration was not changed because NA-MC was also reduced. Thus, plasma NA concentration can be a misleading marker of the sympathetic activity. The response of the sympathetic activity to four different anaesthetic agents is shown to be heterogeneous, ranging from inhibition to stimulation. Sodium pentobarbital anaesthesia was associated with a statistically significant reduction of both NA-SOR (105.6+/-14.1 ng/kg/min, P<0. 01) and NA-MC (239.3+/-18.7 ml/kg/min, P<0.001) while plasma NA was not changed (438+/-47 pg/ml). Chloralose reduced NA-SOR (101.6+/-20. 1 ng/kg/min, P<0.05) while ketamine did not (150.6+/-35.5 ng/kg/min, n.s.): both compounds reduced NA-MC (257.9+/-27.8 ml/kg/min, P<0.01 and 265.8+/-34.3 ml/kg/min, P<0.05, respectively). Diethyl ether was shown to increase both NA-SOR (472.2+/-111 ng/kg/min, P<0.05) and plasma NA concentration (1589+/-436 pg/ml, P<0.01), while NA-MC remained unchanged. Thus, any

  8. Effects of Antidepressants, but not Psychopathology, on Cardiac Sympathetic Control: A Longitudinal Study

    Science.gov (United States)

    Licht, Carmilla M M; Penninx, Brenda W J H; de Geus, Eco J C

    2012-01-01

    Increased sympathetic activity has been hypothesized to have a role in the elevated somatic disease risk in persons with depressive or anxiety disorders. However, it remains unclear whether increased sympathetic activity reflects a direct effect of anxiety or depression or an indirect effect of antidepressant medication. The aim of this study was to test longitudinally whether cardiac sympathetic control, measured by pre-ejection period (PEP), was increased by depression/anxiety status and by antidepressant use. Cross-sectional and longitudinal data were from a depression and anxiety cohort: the Netherlands Study of Depression and Anxiety (NESDA). Baseline data of 2838 NESDA subjects (mean age 41.7 years, 66.7% female) and 2-year follow-up data of 2226 subjects were available for analyses. Included were subjects with and without depressive/anxiety disorders, using or not using different antidepressants at baseline or follow-up. The PEP was measured non-invasively by 1.5 h of ambulatory impedance cardiography. Cross-sectional analyses compared PEP across psychopathology and antidepressant groups. Longitudinal analyses compared 2-year changes in PEP in relation to changes in psychopathology and antidepressant use. Cross-sectional analyses showed that antidepressant-naïve depressive/anxious subjects had comparable PEP as controls, whereas subjects using tricyclic (TCA) or combined serotonergic/noradrenergic antidepressants (SNRI) had significantly shorter PEP compared with controls. In contrast, subjects using selective serotonin re-uptake inhibitors (SSRIs) had longer PEP than controls. Longitudinal results confirmed these findings: compared with 2-year change in PEP in continuous non-users (+2 ms), subjects who started TCA or SNRI treatment showed significantly shortened PEP (−11 ms, p=0.005 and p<0.001), whereas subjects who started SSRI treatment showed significant prolongation of PEP (+9 ms, p=0.002). Reversed findings were observed among those who

  9. Anorexia nervosa depends on adrenal sympathetic hyperactivity: opposite neuroautonomic profile of hyperinsulinism syndrome

    Directory of Open Access Journals (Sweden)

    Lechin F

    2010-09-01

    Full Text Available Fuad Lechin1,2, Bertha van der Dijs1,2, Betty Pardey-Maldonado1, Jairo E Rivera1, Scarlet Baez1, Marcel E Lechin31Department of Pathophysiology, Sections of Neuroendocrinology, Neuropharmacology, and Neurochemistry, Instituto de Medicina Experimental, Faculty of Medicine, Universidad Central de Venezuela, Caracas; 2Instituto de Vias Digestivas Caracas, Centro Clínico Profesional, Caracas, Venezuela; 3Department of Internal Medicine, Texas A and M Health Science Center, College of Medicine, Texas, USAObjective: The aim of our study was to determine the central and peripheral autonomic nervous system profiles underlying anorexia nervosa (AN syndrome, given that affected patients present with the opposite clinical profile to that seen in the hyperinsulinism syndrome.Design: We measured blood pressure and heart rate, as well as circulating neurotransmitters (noradrenaline, adrenaline, dopamine, plasma serotonin, and platelet serotonin, using high-performance liquid chromatography with electrochemical detection, during supine resting, one minute of orthostasis, and after five minutes of exercise. In total, 22 AN patients (12 binge-eating/purging type and 10 restricting type and age-, gender-, and race-matched controls (70 ± 10.1% versus 98 ± 3.0% of ideal body weight were recruited.Results: We found that patients with AN had adrenal sympathetic overactivity and neural sympathetic underactivity, demonstrated by a predominance of circulating adrenaline over noradrenaline levels, not only during the supine resting state (52 ± 2 versus 29 ± 1 pg/mL but also during orthostasis (67 ± 3 versus 32 ± 2 pg/mL, P < 0.05 and after exercise challenge (84 ± 4 versus 30 ± 3 pg/mL, P < 0.01.Conclusion: Considering that this peripheral autonomic nervous system disorder depends on the absolute predominance of adrenomedullary C1 adrenergic nuclei over A5 noradrenergic pontine nucleus, let us ratify the abovementioned findings. The AN syndrome depends on the

  10. Effects of deep and superficial experimentally induced acute pain on muscle sympathetic nerve activity in human subjects

    National Research Council Canada - National Science Library

    A. R. Burton; I. Birznieks; P. S. Bolton; L. A. Henderson; V. G. Macefield

    2009-01-01

    ...), whereas deep pain is believed to cause vasodepression. To date, no studies have addressed whether deep or superficial pain produces such differential effects on muscle sympathetic nerve activity (MSNA...

  11. A model-based approach for the evaluation of vagal and sympathetic activities in a newborn lamb

    Science.gov (United States)

    Le Rolle, Virginie; Ojeda, David; Beuchee, Alain; Praud, Jean-Paul; Pladys, Patrick; Hernandez, Alfredo I.

    2013-01-01

    This paper proposes a baroreflex model and a recursive identification method to estimate the time-varying vagal and sympathetic contributions to heart rate variability during autonomic maneuvers. The baroreflex model includes baroreceptors, cardiovascular control center, parasympathetic and sympathetic pathways. The gains of the global afferent sympathetic and vagal pathways are identified recursively. The method has been validated on data from newborn lambs, which have been acquired during the application of an autonomic maneuver, without medication and under beta-blockers. Results show a close match between experimental and simulated signals under both conditions. The vagal and sympathetic contributions have been simulated and, as expected, it is possible to observe different baroreflex responses under beta-blockers compared to baseline conditions. PMID:24110579

  12. Cilnidipine suppresses cardiac sympathetic nerve activation induced-electical stimulation in canine blood-perfused papillary muscle preparation

    National Research Council Canada - National Science Library

    Kazuyuki Daitoku; Kazuhiko Seya; Shigeru Motomura

    1999-01-01

    ...) and the NE release in the same preparation. When the intracardiac sympathetic nerves were electricaly stimulated by the field stimulation through silver electrode which was attached to the base of PM, the DT and NE release were voltage...

  13. Changes in plasma catecholamine and neuropeptide Y levels after sympathetic activation in dogs.

    Science.gov (United States)

    Poncet, M. F.; Damase-Michel, C.; Tavernier, G.; Tran, M. A.; Berlan, M.; Montastruc, J. L.; Montastruc, P.

    1992-01-01

    1. Plasma levels of noradrenaline (NA) and neuropeptide Y (NPY) were evaluated in two experimental models associated with an increase in sympathetic tone: conscious dogs which were subject to either sinoaortic denervation or acute administration of the alpha 2-adrenoceptor antagonist yohimbine. 2. Dogs that had undergone sinoaortic denervation exhibited a two fold increase in plasma NA without any change in NPY levels. 3. Yohimbine (0.05 mg kg-1 i.v. as a bolus) produced similar effects. A higher dose of yohimbine (0.5 mg kg-1 i.v.) increased both plasma NA (7 fold) and NPY (6.5 fold) levels. 4. The present results indicate that changes in plasma catecholamines and NPY are not always concomitant. They suggest that the simultaneous release of NA and NPY is only observed under in vivo conditions for a marked increase in sympathetic tone. PMID:1596679

  14. Central and cerebrovascular effects of leg crossing in humans with sympathetic failure

    DEFF Research Database (Denmark)

    Harms, Mark P M; Wieling, Wouter; Colier, Willy N J M;

    2010-01-01

    MCA Vmean (middle cerebral artery blood velocity; using transcranial Doppler ultrasound), frontal lobe oxygenation [O2Hb (oxyhaemoglobin)] and MAP (mean arterial pressure), CO (cardiac output) and TPR (total peripheral resistance) in six patients (aged 37-67 years; three women) and age- and gender.......12 (0.52-3.27)] in the patients compared with the controls [0.83 (-0.11 to 2.04) micromol/l]. In the control subjects, CO increased 11% (PTPR. By contrast, in the patients, CO increased 9% (PTPR increased by 13% (P... cerebral perfusion and oxygenation both in patients with sympathetic failure and in healthy subjects. However, in healthy subjects, cerebral perfusion and oxygenation were improved by a rise in CO without significant changes in TPR or MAP, whereas in patients with sympathetic failure, cerebral perfusion...

  15. Value of sympathetic skin response test in the early diagnosis of diabetic neuropathy

    Institute of Scientific and Technical Information of China (English)

    黄一宁; 贾志荣; 石昕; 孙相如

    2004-01-01

    Background Diabetic neuropathy is common in diabetes mellitus. The early stage of diabetic neuropathy is often symptomless and difficult to be treated. The aim of this study was to assess the correlation between the results of the sympathetic skin response (SSR) test and the development of diabetic neuropathy, and explore the use of SSR as an objective basis for the early diagnosis of diabetic neuropathy.Methods The latencies and amplitudes of initiation and of the N and P waves were determined by SSR testing of the extremities of 80 diabetic patients and 30 healthy controls. Results The latencies of initiation and of the N and P waves were significantly (P0.05). All but two patients (97.5%) demonstrated abnormal SSR in at least one limb. Conclusions SSR can detect early dysfunction of the small sympathetic fibers in people affected by diabetes mellitus, and may be a useful electrophysiological test for the early diagnosis of diabetic neuropathy.

  16. Regional sympathetic denervation after myocardial infarction: a follow-up study using [123I]MIBG.

    Science.gov (United States)

    Podio, V; Spinnler, M T; Spandonari, T; Moretti, C; Castellano, G; Bessone, M; Brusca, A

    1995-12-01

    Previous studies in dogs have shown that experimental infarction produces myocardial sympathetic denervation not only in the infarcted area, but also in a region apical to the infarction. In these dogs MIBG myocardial scintigraphy detected denervation but returned to normal in a few months at which time reinnervation was shown to have occurred. Myocardial sympathetic denervation was studied with MIBG scintigraphy in ten patients after their first acute transmural myocardial infarction; scans were repeated at 4 months, one year and 30 months to follow the time course of possible reinnervation. Except during the first 48 hours following the infarction, no therapy except for antiaggregants was administered to the patients; during this follow-up period no cardiac events were seen. One week after infarction, comparison of MIBG images with perfusion scans revealed that the denervated area was larger than the infarcted area; no difference in MIBG uptake by the infarcted myocardium was found during the 30 months follow-up.

  17. Effect of regional myocardial ischemia on sympathetic nervous system as assessed by fluorine-18-metaraminol

    Energy Technology Data Exchange (ETDEWEB)

    Schwaiger, M.; Guibourg, H.; Rosenspire, K.; McClanahan, T.; Gallagher, K.; Hutchins, G.; Wieland, D.M. (Univ. of Michigan Medical Center, Ann Arbor (USA))

    1990-08-01

    With the introduction of radiolabeled catecholamine analogues, the noninvasive evaluation of the cardiac sympathetic nervous system has become possible. This study evaluated the effect of regional ischemia on myocardial retention of the new norepinephrine analogue 6-({sup 18}F) fluorometaraminol (FMR) in the open chest dog model. Six dogs were injected intravenously with FMR following 30-min occlusion of the left anterior descending artery. Six sham animals served as control group. Regional myocardial blood flow as determined by microspheres decreased 87% during ischemia (p less than 0.01), but was not significantly different from control myocardium following reperfusion. Regional myocardial 18F activity as determined postmortem was significantly reduced in reperfused myocardium (-34%), which paralleled an 18% reduction of tissue norepinephrine concentration. Thus, short time periods of coronary occlusion affect neuronal function indicating the sensitivity of the sympathetic nerve terminals to ischemia. FMR provides a new tracer approach for the characterization of neuronal integrity in postischemic myocardium.

  18. An achondroplasic case with foramen magnum stenosis, hydrocephaly, cortical atrophy, respiratory failure and sympathetic dysfunction.

    Science.gov (United States)

    Ozcetin, Mustafa; Arslan, Mehmet Tayip; Karapinar, Bulent

    2012-03-01

    Achondroplasia is a relatively frequent genetic disorder that may lead to limb weakness, motor-mental retardation, hydrocephaly, and respiratory disorders. In this pathology, foramen magnum stenosis and accompanying disorders like respiratory depression is well documented. A 2.5 year-old child with the diagnosis of achondroplasia admitted to our clinic with severe respiratory depression, limb weakness, and motor mental retardation as well as sympathetic dysfunction. In radiologic evaluations, severe foramen magnum stenosis was detected. The patient was operated and posterior fossa decompression was accomplished to prevent compression of respiratory centers and neurons. This case is unique with the narrowest foramen magnum reported up to date and the sympathetic dysfunction which is not reported as a complication in achondroplasic patients. The authors review the relevant literature, focusing on the indications for cervicomedullary decompression in infants with achondroplasia.

  19. The facial massage reduced anxiety and negative mood status, and increased sympathetic nervous activity.

    Science.gov (United States)

    Hatayama, Tomoko; Kitamura, Shingo; Tamura, Chihiro; Nagano, Mayumi; Ohnuki, Koichiro

    2008-12-01

    The aim of this study was to clarify the effects of 45 min of facial massage on the activity of autonomic nervous system, anxiety and mood in 32 healthy women. Autonomic nervous activity was assessed by heart rate variability (HRV) with spectral analysis. In the spectral analysis of HRV, we evaluated the high-frequency components (HF) and the low- to high-frequency ratio (LF/HF ratio), reflecting parasympathetic nervous activity and sympathetic nervous activity, respectively. The State Trait Anxiety Inventory (STAI) and the Profile of Mood Status (POMS) were administered to evaluate psychological status. The score of STAI and negative scale of POMS were significantly reduced following the massage, and only the LF/HF ratio was significantly enhanced after the massage. It was concluded that the facial massage might refresh the subjects by reducing their psychological distress and activating the sympathetic nervous system.

  20. Autonomic Nervous System Responses to Viewing Green and Built Settings: Differentiating Between Sympathetic and Parasympathetic Activity.

    Science.gov (United States)

    van den Berg, Magdalena M H E; Maas, Jolanda; Muller, Rianne; Braun, Anoek; Kaandorp, Wendy; van Lien, René; van Poppel, Mireille N M; van Mechelen, Willem; van den Berg, Agnes E

    2015-12-14

    This laboratory study explored buffering and recovery effects of viewing urban green and built spaces on autonomic nervous system activity. Forty-six students viewed photos of green and built spaces immediately following, and preceding acute stress induction. Simultaneously recorded electrocardiogram and impedance cardiogram signal was used to derive respiratory sinus arrhythmia (RSA) and pre-ejection period (PEP), indicators of respectively parasympathetic and sympathetic activity. The findings provide support for greater recovery after viewing green scenes, as marked by a stronger increase in RSA as a marker of parasympathetic activity. There were no indications for greater recovery after viewing green scenes in PEP as a marker of sympathetic activity, and there were also no indications of greater buffering effects of green space in neither RSA nor PEP. Overall, our findings are consistent with a predominant role of the parasympathetic nervous system in restorative effects of viewing green space.

  1. Sympathetic skin response in patients with myasthenia gravis A comparative analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: The examination of sympathetic skin response is an important index for assessing the autonomic nerve function, and patients with myasthenia gravis are always accompanied by dysautonomia.Therefore, it will be important to know whether sympathetic skin response can be used as the index for the clinical evaluation of myasthenia gravis.OBJECTIVE: To investigate the diagnostic value of sympathetic skin response in the damage of autonomic nerve function of patients with myasthenia gravis.DESIGN: A case-controlled comparative observation.SETTING: Department of Neurology and Room of Nerve Electromyogram, the Affiliated Hospital of North Sichuan Medical College.PARTICIPANTS: Thirty outpatients or inpatients with myasthenia gravis were selected from the Department of Neurology, the Affiliated Hospital of North Sichuan Medical College from May 2006 to May 2007, including 9 males and 21 females, aged 8 - 72 years with a mean age of (28±5) years old. They were all accorded with the diagnostic standards of myasthenia gravis, accompanied by different severity of autonomic nerve symptoms, including poor skin nutrition, sweating of hands and feet, pyknocardia,persistent hypotension, abdominal pain, constipation, etc. They all had not taken any drug affecting the autonomic nerve function before the examination. Informed consents were obtained from all the patients.Meanwhile, 30 healthy physical examinees were enrolled as the normal control group, including 10 males and 20 females, aged 10 - 75 years with a mean age of (31±5) years old. Approval was obtained from the hospital ethic committee.METHODS: After admission, the patients were examined with sympathetic skin response using DANTEC keypoint 2.0 electromyography evoked potential apparatus (Danmark). The changes of the latency and wave amplitude of sympathetic skin response were observed. The subjects in the normal control group were examined with the same methods at physical examination. Abnormality was judged by

  2. Autonomic Nervous System Responses to Viewing Green and Built Settings: Differentiating Between Sympathetic and Parasympathetic Activity

    Science.gov (United States)

    van den Berg, Magdalena M.H.E.; Maas, Jolanda; Muller, Rianne; Braun, Anoek; Kaandorp, Wendy; van Lien, René; van Poppel, Mireille N.M.; van Mechelen, Willem; van den Berg, Agnes E.

    2015-01-01

    This laboratory study explored buffering and recovery effects of viewing urban green and built spaces on autonomic nervous system activity. Forty-six students viewed photos of green and built spaces immediately following, and preceding acute stress induction. Simultaneously recorded electrocardiogram and impedance cardiogram signal was used to derive respiratory sinus arrhythmia (RSA) and pre-ejection period (PEP), indicators of respectively parasympathetic and sympathetic activity. The findings provide support for greater recovery after viewing green scenes, as marked by a stronger increase in RSA as a marker of parasympathetic activity. There were no indications for greater recovery after viewing green scenes in PEP as a marker of sympathetic activity, and there were also no indications of greater buffering effects of green space in neither RSA nor PEP. Overall, our findings are consistent with a predominant role of the parasympathetic nervous system in restorative effects of viewing green space. PMID:26694426

  3. Autonomic Nervous System Responses to Viewing Green and Built Settings: Differentiating Between Sympathetic and Parasympathetic Activity

    Directory of Open Access Journals (Sweden)

    Magdalena M.H.E. van den Berg

    2015-12-01

    Full Text Available This laboratory study explored buffering and recovery effects of viewing urban green and built spaces on autonomic nervous system activity. Forty-six students viewed photos of green and built spaces immediately following, and preceding acute stress induction. Simultaneously recorded electrocardiogram and impedance cardiogram signal was used to derive respiratory sinus arrhythmia (RSA and pre-ejection period (PEP, indicators of respectively parasympathetic and sympathetic activity. The findings provide support for greater recovery after viewing green scenes, as marked by a stronger increase in RSA as a marker of parasympathetic activity. There were no indications for greater recovery after viewing green scenes in PEP as a marker of sympathetic activity, and there were also no indications of greater buffering effects of green space in neither RSA nor PEP. Overall, our findings are consistent with a predominant role of the parasympathetic nervous system in restorative effects of viewing green space.

  4. The role of the sympathetic nervous system in obesity-related hypertension.

    Science.gov (United States)

    da Silva, Alexandre A; do Carmo, Jussara; Dubinion, John; Hall, John E

    2009-06-01

    Obesity is recognized as a major health problem throughout the world. Excess weight is a major cause of increased blood pressure in most patients with essential hypertension and greatly increases the risk for diabetes, cardiovascular diseases, and end-stage renal disease. Although the mechanisms by which obesity raises blood pressure are not completely understood, increased renal sodium reabsorption, impaired pressure natriuresis, and volume expansion appear to play important roles. Several potential mechanisms have been suggested to contribute to altered kidney function and hypertension in obesity, including activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system, as well as physical compression of the kidneys, especially when visceral obesity is present. Activation of the sympathetic nervous system in obesity may be due, in part, to hyperleptinemia and other factors secreted by adipocytes and the gastrointestinal tract, activation of the central nervous system melanocortin pathway, and baroreceptor dysfunction.

  5. Heart Rate Changes in Response to Mechanical Pressure Stimulation of Skeletal Muscles Are Mediated by Cardiac Sympathetic Nerve Activity

    Science.gov (United States)

    Watanabe, Nobuhiro; Hotta, Harumi

    2017-01-01

    Stimulation of mechanoreceptors in skeletal muscles such as contraction and stretch elicits reflexive autonomic nervous system changes which impact cardiovascular control. There are pressure-sensitive mechanoreceptors in skeletal muscles. Mechanical pressure stimulation of skeletal muscles can induce reflex changes in heart rate (HR) and blood pressure, although the neural mechanisms underlying this effect are unclear. We examined the contribution of cardiac autonomic nerves to HR responses induced by mechanical pressure stimulation (30 s, ~10 N/cm2) of calf muscles in isoflurane-anesthetized rats. Animals were artificially ventilated and kept warm using a heating pad and lamp, and respiration and core body temperature were maintained within physiological ranges. Mechanical stimulation was applied using a stimulation probe 6 mm in diameter with a flat surface. Cardiac sympathetic and vagus nerves were blocked to test the contribution of the autonomic nerves. For sympathetic nerve block, bilateral stellate ganglia, and cervical sympathetic nerves were surgically sectioned, and for vagus nerve block, the nerve was bilaterally severed. In addition, mass discharges of cardiac sympathetic efferent nerve were electrophysiologically recorded. Mechanical stimulation increased or decreased HR in autonomic nerve-intact rats (range: −56 to +10 bpm), and the responses were negatively correlated with pre-stimulus HR (r = −0.65, p = 0.001). Stimulation-induced HR responses were markedly attenuated by blocking the cardiac sympathetic nerve (range: −9 to +3 bpm, p mechanical stimulation increased, or decreased the frequency of sympathetic nerve activity in parallel with HR (r = 0.77, p = 0.0004). Furthermore, the changes in sympathetic nerve activity were negatively correlated with its tonic level (r = −0.62, p = 0.0066). These results suggest that cardiac sympathetic nerve activity regulates HR responses to muscle mechanical pressure stimulation and the direction of HR

  6. Oestrogen regulates sympathetic neurite outgrowth by modulating brain derived neurotrophic factor synthesis and release by the rodent uterus.

    Science.gov (United States)

    Krizsan-Agbas, D; Pedchenko, T; Hasan, W; Smith, P G

    2003-11-01

    Sympathetic innervation of the adult rodent uterus undergoes cyclic remodelling. Terminal sympathetic axons degenerate when oestrogen levels rise and regenerate when oestrogen levels decline. This study examined the role of neurotrophins in oestrogen-mediated uterine sympathetic nerve remodelling. Oestrogen injection of ovariectomized female rats did not affect uterine NT-3 levels 24 h postinjection, and increased endometrial NGF protein, indicating that reduced NGF or NT-3 is not responsible for the oestrogen-induced denervation. Oestrogen also raised BDNF protein and mRNA in myometrium and endometrium. To assess whether increased BDNF affects uterine receptivity to sympathetic outgrowth, sympathetic ganglion explants were co-cultured with myometrium. Myometrium from ovariectomized rats induced neuritogenesis in oestrogen-free conditions, and this was abolished when BDNF was added to the medium. Neuritogenesis induced by ovariectomized myometrium was suppressed by oestrogen, and restored by a BDNF function-blocking antibody. To determine if target BDNF synthesis is required for oestrogen to suppress sympathetic neurite outgrowth, uteri from wild-type mice and mice homozygous or heterozygous for recombinant mutations of the BDNF gene were cultured with rat sympathetic ganglia. Neuritogenesis induced by wild-type uteri was diminished by oestrogen. Neurite formation in the presence of homozygous BDNF mutant uteri was not affected by oestrogen, but was lower than that of wild-type mice. Uteri from mice heterozygous for the BDNF mutation, who have reduced BDNF synthesis, showed normal neuritogenic properties, but were not affected by oestrogen. These findings suggest that oestrogen alters neuritogenic properties of the rodent uterus by regulating BDNF synthesis, which inhibits sympathetic neurite outgrowth.

  7. Stroke Volume and Sympathetic Responses to Lower-Body Negative Pressure Reveal New Insight into Circulatory Shock in Humans

    Science.gov (United States)

    2004-01-01

    of SBP and twice DBP by three. 2.4. Measurement of stroke volume Stroke volume was measured noninvasively using tho- racic electrical bioimpedance ...received in revised form 25 February 2004; accepted 26 February 2004 Abstract We measured various hemodynamic responses and muscle sympathetic nerve...responses to central hypovolemia. We measured heart rates, arterial blood pressures, sympathetic neural activity (MSNA; peroneal nerve microneurography), and

  8. Incomplete Horner syndrome: Report of a case and description of the sympathetic nervous system anatomy involved in Horner syndrome.

    Science.gov (United States)

    Garbo, Grant M; Harmatz, Alexander J; Isaacson, Glenn

    2011-02-01

    Horner syndrome, in which ptosis, miosis, and anhidrosis occur concomitantly, can arise from injury to the sympathetic nerve pathways anywhere from the brain to the end organs. Incomplete Horner syndrome lacks the sign of anhidrosis. We present a case of incomplete Horner syndrome caused by internal carotid artery dissection and provide a road map of the cervical sympathetic nerves involved in Horner syndrome to explain its etiology. We also discuss the imaging of and therapy for internal carotid artery dissections.

  9. 1.5 T augmented reality navigated interventional MRI: paravertebral sympathetic plexus injections.

    Science.gov (United States)

    Marker, David R; U Thainual, Paweena; Ungi, Tamas; Flammang, Aaron J; Fichtinger, Gabor; Iordachita, Iulian I; Carrino, John A; Fritz, Jan

    2017-01-01

    The high contrast resolution and absent ionizing radiation of interventional magnetic resonance imaging (MRI) can be advantageous for paravertebral sympathetic nerve plexus injections. We assessed the feasibility and technical performance of MRI-guided paravertebral sympathetic injections utilizing augmented reality navigation and 1.5 T MRI scanner. A total of 23 bilateral injections of the thoracic (8/23, 35%), lumbar (8/23, 35%), and hypogastric (7/23, 30%) paravertebral sympathetic plexus were prospectively planned in twelve human cadavers using a 1.5 Tesla (T) MRI scanner and augmented reality navigation system. MRI-conditional needles were used. Gadolinium-DTPA-enhanced saline was injected. Outcome variables included the number of control magnetic resonance images, target error of the needle tip, punctures of critical nontarget structures, distribution of the injected fluid, and procedure length. Augmented-reality navigated MRI guidance at 1.5 T provided detailed anatomical visualization for successful targeting of the paravertebral space, needle placement, and perineural paravertebral injections in 46 of 46 targets (100%). A mean of 2 images (range, 1-5 images) were required to control needle placement. Changes of the needle trajectory occurred in 9 of 46 targets (20%) and changes of needle advancement occurred in 6 of 46 targets (13%), which were statistically not related to spinal regions (P = 0.728 and P = 0.86, respectively) and cadaver sizes (P = 0.893 and P = 0.859, respectively). The mean error of the needle tip was 3.9±1.7 mm. There were no punctures of critical nontarget structures. The mean procedure length was 33±12 min. 1.5 T augmented reality-navigated interventional MRI can provide accurate imaging guidance for perineural injections of the thoracic, lumbar, and hypogastric sympathetic plexus.

  10. Neutral gas sympathetic cooling of an ion in a Paul trap

    CERN Document Server

    Chen, Kuang; Hudson, Eric R

    2013-01-01

    A single ion immersed in a neutral buffer gas is studied. An analytical model is developed that gives a complete description of the dynamics and steady-state properties of the ions. An extension of this model, using techniques borrowed from the mathematics of finance, is used to explain the recent observation of non-Maxwellian statistics for these systems. Taken together, these results offer an explanation of the longstanding issues associated with sympathetic cooling of an ion by a neutral buffer gas.

  11. Parachute Jumping Induces More Sympathetic Activation Than Cortisol Secretion in First-Time Parachutists

    OpenAIRE

    Chieffi; Viggiano; Tafuri; Cibelli; Valenzano; Triggiani; Messina; Luca; Monda

    2016-01-01

    Background The word “stress” describes the status of the body affected by external or internal forces, or “stressors”, threatening to alter its dynamic balance or homeostasis. The adaptive changes which occur in reply to stressors are either behavioral or physical. Once a given threshold is surpassed, a systemic reaction takes place involving the “stress system” in the brain together with its peripheral components, the hypothalamic-pituitary-adrenal axis and autonomic sympathetic...

  12. Muscle sympathetic nerve activity during cold stress and isometric exercise in healthy older adults.

    Science.gov (United States)

    Greaney, Jody L; Stanhewicz, Anna E; Kenney, W Larry; Alexander, Lacy M

    2014-09-15

    Cardiovascular mortality increases in cold weather in older adults, and physical activity may impart even greater cardiovascular risk than cold exposure alone. Human aging is associated with exaggerated pressor responses to whole body cooling; however, the sympathetic response to cold stress alone and in combination with isometric exercise is unknown. We hypothesized that cold stress would 1) increase muscle sympathetic nerve activity (MSNA) and 2) augment the MSNA response to isometric handgrip in older adults. Whole body cooling (water-perfused suit) was conducted in 11 young (23 ± 1 yr) and 12 healthy older adults (60 ± 2 yr). Blood pressure (BP; Finometer) and MSNA (microneurography) were measured throughout cooling and during isometric handgrip at 30% maximal voluntary contraction performed at a mean skin temperature (Tsk) of 34 and 30.5°C. MSNA was greater in older adults at Tsk = 34.0°C and throughout cooling (P 0.05) or older adults (Δ12 ± 1 Tsk 34°C vs. Δ8 ± 1 Tsk 30.5°C bursts/min; Δ18 ± 3 Tsk 34°C vs. Δ17 ± 2 Tsk 30.5°C mmHg; both P > 0.05). In summary, MSNA increased during cold stress in older, but not young, adults. Furthermore, concomitant cold stress did not alter the sympathetic responses to isometric exercise in either age group, suggesting preserved sympathetic responsiveness during exercise in the cold in healthy aging. Copyright © 2014 the American Physiological Society.

  13. Cholinergic Signaling Exerts Protective Effects in Models of Sympathetic Hyperactivity-Induced Cardiac Dysfunction

    Science.gov (United States)

    Gavioli, Mariana; Lara, Aline; Almeida, Pedro W. M.; Lima, Augusto Martins; Damasceno, Denis D.; Rocha-Resende, Cibele; Ladeira, Marina; Resende, Rodrigo R.; Martinelli, Patricia M.; Melo, Marcos Barrouin; Brum, Patricia C.; Fontes, Marco Antonio Peliky; Souza Santos, Robson A.; Prado, Marco A. M.; Guatimosim, Silvia

    2014-01-01

    Cholinergic control of the heart is exerted by two distinct branches; the autonomic component represented by the parasympathetic nervous system, and the recently described non-neuronal cardiomyocyte cholinergic machinery. Previous evidence has shown that reduced cholinergic function leads to deleterious effects on the myocardium. Yet, whether conditions of increased cholinergic signaling can offset the pathological remodeling induced by sympathetic hyperactivity, and its consequences for these two cholinergic axes are unknown. Here, we investigated two models of sympathetic hyperactivity: i) the chronic beta-adrenergic receptor stimulation evoked by isoproterenol (ISO), and ii) the α2A/α2C-adrenergic receptor knockout (KO) mice that lack pre-synaptic adrenergic receptors. In both models, cholinergic signaling was increased by administration of the cholinesterase inhibitor, pyridostigmine. First, we observed that isoproterenol produces an autonomic imbalance characterized by increased sympathetic and reduced parasympathetic tone. Under this condition transcripts for cholinergic proteins were upregulated in ventricular myocytes, indicating that non-neuronal cholinergic machinery is activated during adrenergic overdrive. Pyridostigmine treatment prevented the effects of ISO on autonomic function and on the ventricular cholinergic machinery, and inhibited cardiac remodeling. α2A/α2C-KO mice presented reduced ventricular contraction when compared to wild-type mice, and this dysfunction was also reversed by cholinesterase inhibition. Thus, the cardiac parasympathetic system and non-neuronal cardiomyocyte cholinergic machinery are modulated in opposite directions under conditions of increased sympathetic drive or ACh availability. Moreover, our data support the idea that pyridostigmine by restoring ACh availability is beneficial in heart disease. PMID:24992197

  14. Cholinergic signaling exerts protective effects in models of sympathetic hyperactivity-induced cardiac dysfunction.

    Directory of Open Access Journals (Sweden)

    Mariana Gavioli

    Full Text Available Cholinergic control of the heart is exerted by two distinct branches; the autonomic component represented by the parasympathetic nervous system, and the recently described non-neuronal cardiomyocyte cholinergic machinery. Previous evidence has shown that reduced cholinergic function leads to deleterious effects on the myocardium. Yet, whether conditions of increased cholinergic signaling can offset the pathological remodeling induced by sympathetic hyperactivity, and its consequences for these two cholinergic axes are unknown. Here, we investigated two models of sympathetic hyperactivity: i the chronic beta-adrenergic receptor stimulation evoked by isoproterenol (ISO, and ii the α2A/α2C-adrenergic receptor knockout (KO mice that lack pre-synaptic adrenergic receptors. In both models, cholinergic signaling was increased by administration of the cholinesterase inhibitor, pyridostigmine. First, we observed that isoproterenol produces an autonomic imbalance characterized by increased sympathetic and reduced parasympathetic tone. Under this condition transcripts for cholinergic proteins were upregulated in ventricular myocytes, indicating that non-neuronal cholinergic machinery is activated during adrenergic overdrive. Pyridostigmine treatment prevented the effects of ISO on autonomic function and on the ventricular cholinergic machinery, and inhibited cardiac remodeling. α2A/α2C-KO mice presented reduced ventricular contraction when compared to wild-type mice, and this dysfunction was also reversed by cholinesterase inhibition. Thus, the cardiac parasympathetic system and non-neuronal cardiomyocyte cholinergic machinery are modulated in opposite directions under conditions of increased sympathetic drive or ACh availability. Moreover, our data support the idea that pyridostigmine by restoring ACh availability is beneficial in heart disease.

  15. Muscle Sympathetic Nerve Activity During Intense Lower Body Negative Pressure to Presyncope in Humans

    Science.gov (United States)

    2009-08-24

    Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology, 1996). As diastolic arterial pressure... dogs . Am J Physiol Heart Circ Physiol 274, H1099–H1105. Preiss G & Polosa C (1974). Patterns of sympathetic neuron activity associated with Mayer waves...Society of Cardiology and the North American Society of Pacing and Electrophysiology (1996). Heart rate variability: standards of measurement

  16. Sex Comparisons in Muscle Sympathetic Nerve Activity and Arterial Pressure Oscillations During Progressive Central Hypovolemia

    Science.gov (United States)

    2015-01-01

    sympathetic activity in humans. Am. J. Physiol. 287:H1658–H1662. Convertino, V. A. 1996. Clinical aspects of the control of plasma volume at microgravity and...standards of measurement, physiological interpretation, and clinical use. Circulation 93:1043–1065. Ichinose, M., M. Saito, A. Kitano, K. Hayashi, N...G. Huang, S. A. Smith, R. Zhang, and K. J. Formes. 2003. Aging and arterial blood pressure variability during orthostatic challenge. Gerontology 49

  17. Estrogen up-regulation of semaphorin 3F correlates with sympathetic denervation of the rat uterus.

    Science.gov (United States)

    Richeri, Analía; Chalar, Cora; Martínez, Gaby; Greif, Gonzalo; Bianchimano, Paola; Brauer, M Mónica

    2011-10-28

    Current evidence indicates that rises in systemic levels of estrogen create in the uterus an inhibitory environment for sympathetic nerves. However, molecular insights of these changes are far from complete. We evaluated if semaphorin 3F mRNA, a sympathetic nerve repellent, was produced by the rat uterus and if its expression was modulated by estrogen. We also analyzed whether uterine nerves express the semaphorin 3F binding receptor, neuropilin-2. Uterine levels of semaphorin 3F mRNA were measured using real time reverse transcriptase-polymerase chain reaction in prepubertal rat controls and following chronic estrogen treatment. Localization of semaphorin 3F transcripts was determined by in situ hybridization and the expression of neuropilin-2 was assessed by immunohistochemistry. These studies showed that: (1) chronic estrogen treatment led to a 5-fold induction of semaphorin 3F mRNA in the immature uterus; (2) estrogen provoked a tissue-specific induction of semaphorin 3F which was particularly localized in the connective tissue that borders muscle bundles and surrounds intrauterine blood vessels; (3) two major cell-types were recognized in the areas where transcripts were concentrated, fibroblast-like cells and infiltrating eosinophil leukocytes; and (4) some delicate nerve terminal profiles present in the estrogenized uterus were immunoreactive for neuropilin-2. Temporal and spatial expression patterns of semaphorin 3F/neuropilin-2 are consistent with a possible role of this guidance cue in the remodeling of uterine sympathetic innervation by estrogen. Though correlative in its nature, these data support a model whereby semaphorin 3F, in combination with other inhibitory molecules, converts the estrogenized myometrium to an inhospitable environment for sympathetic nerves.

  18. Effects of dexamethasone on estrogen- and pregnancy-induced plasticity in rat uterine sympathetic nerves.

    Science.gov (United States)

    Bianchimano, P; Frías, A I; Richeri, A; Brauer, M M

    2007-12-01

    Estrogen and glucocorticoids are known to evoke opposing effects on the uterus. We analyzed the effects of dexamethasone (DEX) on uterine sympathetic denervation elicited by short- and long-term exposure to estrogen of intact prepubertal rats. We also studied the effects of DEX on the physiological degeneration of uterine sympathetic nerves at term pregnancy. Changes in innervation were assessed quantitatively by using computer-assisted methods on uterine cryostat tissue sections stained for tyrosine hydroxylase. At 24 h following treatment of prepubertal rats (25 days of age) with 1 microg or 2.5 microg estrogen, marked increases in uterine size and reductions in the percentage nerve area were observed. Co-administration of DEX (4 mg/kg) attenuated both these short-term estrogen-induced effects. Treatment of 19-day-old rats with a single dose of 25 mug estrogen provoked, at 26 days of age, a 54% reduction in the total nerve area. This reduction was abolished by the co-administration of nine doses of DEX (0.5 mg/kg) at 18-26 days of age. Treatment of rats with the same regime of DEX alone increased the total nerve area by 46% of the control values. Studies of control pregnant rats revealed the unexpected presence of intrauterine nerve fibers at term. Treatment of pregnant rats with six doses of DEX (4 mg/kg) at 16-21 days of age had no effects on the density of uterine sympathetic nerves. These results suggest that DEX has growth-promoting effects on immature uterine sympathetic nerves and may antagonize the degenerative effects elicited by long-term exposure to estrogen.

  19. Increased Efferent Cardiac Sympathetic Nerve Activity and Defective Intrinsic Heart Rate Regulation in Type 2 Diabetes.

    Science.gov (United States)

    Thaung, H P Aye; Baldi, J Chris; Wang, Heng-Yu; Hughes, Gillian; Cook, Rosalind F; Bussey, Carol T; Sheard, Phil W; Bahn, Andrew; Jones, Peter P; Schwenke, Daryl O; Lamberts, Regis R

    2015-08-01

    Elevated sympathetic nerve activity (SNA) coupled with dysregulated β-adrenoceptor (β-AR) signaling is postulated as a major driving force for cardiac dysfunction in patients with type 2 diabetes; however, cardiac SNA has never been assessed directly in diabetes. Our aim was to measure the sympathetic input to and the β-AR responsiveness of the heart in the type 2 diabetic heart. In vivo recording of SNA of the left efferent cardiac sympathetic branch of the stellate ganglion in Zucker diabetic fatty rats revealed an elevated resting cardiac SNA and doubled firing rate compared with nondiabetic rats. Ex vivo, in isolated denervated hearts, the intrinsic heart rate was markedly reduced. Contractile and relaxation responses to β-AR stimulation with dobutamine were compromised in externally paced diabetic hearts, but not in diabetic hearts allowed to regulate their own heart rate. Protein levels of left ventricular β1-AR and Gs (guanine nucleotide binding protein stimulatory) were reduced, whereas left ventricular and right atrial β2-AR and Gi (guanine nucleotide binding protein inhibitory regulatory) levels were increased. The elevated resting cardiac SNA in type 2 diabetes, combined with the reduced cardiac β-AR responsiveness, suggests that the maintenance of normal cardiovascular function requires elevated cardiac sympathetic input to compensate for changes in the intrinsic properties of the diabetic heart. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  20. Bombesin-like receptor 3 regulates blood pressure and heart rate via a central sympathetic mechanism.

    Science.gov (United States)

    Lateef, Dalya M; Xiao, Cuiying; Brychta, Robert J; Diedrich, André; Schnermann, Jurgen; Reitman, Marc L

    2016-04-01

    Bombesin-like receptor 3 (BRS-3) is an orphan G protein-coupled receptor that regulates energy expenditure, food intake, and body weight. We examined the effects of BRS-3 deletion and activation on blood pressure and heart rate. In free-living, telemetered Brs3 null mice the resting heart rate was 10% lower than wild-type controls, while the resting mean arterial pressure was unchanged. During physical activity, the heart rate and blood pressure increased more in Brs3 null mice, reaching a similar heart rate and higher mean arterial pressure than control mice. When sympathetic input was blocked with propranolol, the heart rate of Brs3 null mice was unchanged, while the heart rate in control mice was reduced to the level of the null mice. The intrinsic heart rate, measured after both sympathetic and parasympathetic blockade, was similar in Brs3 null and control mice. Intravenous infusion of the BRS-3 agonist MK-5046 increased mean arterial pressure and heart rate in wild-type but not in Brs3 null mice, and this increase was blocked by pretreatment with clonidine, a sympatholytic, centrally acting α2-adrenergic agonist. In anesthetized mice, hypothalamic infusion of MK-5046 also increased both mean arterial pressure and heart rate. Taken together, these data demonstrate that BRS-3 contributes to resting cardiac sympathetic tone, but is not required for activity-induced increases in heart rate and blood pressure. The data suggest that BRS-3 activation increases heart rate and blood pressure via a central sympathetic mechanism.

  1. Intracerebroventricular Administration of Neuropeptide Y Induces Hepatic Insulin Resistance via Sympathetic Innervation

    OpenAIRE

    Anita M van den Hoek; Van Heijningen, Caroline; Schröder-van der Elst, Janny P.; Ouwens, D. Margriet; Havekes, Louis M.; Johannes A Romijn; Kalsbeek, Andries; Pijl, Hanno

    2008-01-01

    OBJECTIVE—We recently showed that intracerebroventricular infusion of neuropeptide Y (NPY) hampers inhibition of endogenous glucose production (EGP) by insulin in mice. The downstream mechanisms responsible for these effects of NPY remain to be elucidated. Therefore, the aim of this study was to establish whether intracerebroventricular NPY administration modulates the suppressive action of insulin on EGP via hepatic sympathetic or parasympathetic innervation. RESEARCH DESIGN AND METHODS—The ...

  2. Effect of generalised sympathetic activation by cold pressor test on cerebral haemodynamics in healthy humans.

    Science.gov (United States)

    Roatta, S; Micieli, G; Bosone, D; Losano, G; Bini, R; Cavallini, A; Passatore, M

    1998-07-15

    There is no general agreement regarding several aspects of the role of the sympathetic system on cerebral haemodynamics such as extent of effectiveness, operational range and site of action. This study was planned to identify the effect of a generalised sympathetic activation on the cerebral haemodynamics in healthy humans before it is masked by secondary corrections, metabolic or myogenic in nature. A total of 35 healthy volunteers aged 20-35 underwent a 5 min lasting cold pressor test (CPT) performed on their left hand. The cerebral blood flow (CBF) velocity in the middle cerebral arteries and arterial blood pressure were recorded with transcranial Doppler sonography and with a non-invasive finger-cuff method, respectively. The ratio of arterial blood pressure to mean blood velocity (ABP/Vm) and Pulsatility Index (PI) were calculated throughout each trial. CPT induced an increase in mean ABP (range 2-54 mmHg depending on the subject) and only a slight, though significant, increase in blood velocity in the middle cerebral artery (+2.4 and +4.4% on ipsi- and contralateral side, respectively). During CPT, the ratio ABP/Vm increased and PI decreased in all subjects on both sides. These changes began simultaneously with the increase in blood pressure. The increase in ABP/Vm ratio is attributed to an increase in the cerebrovascular resistance, while the concomitant reduction in PI is interpreted as due to the reduction in the compliance of the middle cerebral artery. The results suggest that generalised increases in the sympathetic discharge, causing increases in ABP, can prevent concomitant increases in CBF by acting on both small resistance and large compliant vessels. This effect is also present when a slight increase in blood pressure occurs, which suggests a moderate increase in the sympathetic discharge, i.e. when ABP remains far below the upper limit of CBF autoregulation.

  3. Modulation operated by the sympathetic nervous system on jaw reflexes and masticatory movement.

    Science.gov (United States)

    Passatore, Magda; Roatta, Silvestro

    2007-04-01

    The sympathetic nervous system (SNS), that is activated under condition of physical, psychological and psychosocial stress, affects force production and fatigability of muscles by controlling both muscle blood flow and the intracellular contractile mechanism. In addition SNS may affect motor function by modulating afferent activity from muscle spindles that are highly concentrated in jaw-closing muscles. Possible implications of these actions on masticatory function and myofascial pain are discussed.

  4. EP3 receptors mediate PGE2-induced hypothalamic paraventricular nucleus excitation and sympathetic activation

    Science.gov (United States)

    Zhang, Zhi-Hua; Yu, Yang; Wei, Shun-Guang; Nakamura, Yoshiko; Nakamura, Kazuhiro

    2011-01-01

    Prostaglandin E2 (PGE2), an important mediator of the inflammatory response, acts centrally to elicit sympathetic excitation. PGE2 acts on at least four E-class prostanoid (EP) receptors known as EP1, EP2, EP3, and EP4. Since PGE2 production within the brain is ubiquitous, the different functions of PGE2 depend on the expression of these prostanoid receptors in specific brain areas. The type(s) and location(s) of the EP receptors that mediate sympathetic responses to central PGE2 remain unknown. We examined this question using PGE2, the relatively selective EP receptor agonists misoprostol and sulprostone, and the available selective antagonists for EP1, EP3, and EP4. In urethane-anesthetized rats, intracerebroventricular (ICV) administration of PGE2, sulprostone or misoprostol increased renal sympathetic nerve activity, blood pressure, and heart rate. These responses were significantly reduced by ICV pretreatment with the EP3 receptor antagonist; the EP1 and EP4 receptor antagonists had little or no effect. ICV PGE2 or misoprostol increased the discharge of neurons in the hypothalamic paraventricular nucleus (PVN). ICV misoprostol increased the c-Fos immunoreactivity of PVN neurons, an effect that was substantially reduced by the EP3 receptor antagonist. Real-time PCR detected EP3 receptor mRNA in PVN, and immunohistochemical studies revealed sparsely distributed EP3 receptors localized in GABAergic terminals and on a few PVN neurons. Direct bilateral PVN microinjections of PGE2 or sulprostone elicited sympathoexcitatory responses that were significantly reduced by the EP3 receptor antagonist. These data suggest that EP3 receptors mediate the central excitatory effects of PGE2 on PVN neurons and sympathetic discharge. PMID:21803943

  5. Effects of tiotropium on sympathetic activation during exercise in stable chronic obstructive pulmonary disease patients

    Directory of Open Access Journals (Sweden)

    Kitada S

    2012-05-01

    Full Text Available Kenji Yoshimura, Ryoji Maekura, Toru Hiraga, Seigo Kitada, Keisuke Miki, Mari Miki, Yoshitaka TateishiDepartment of Respiratory Medicine, Toneyama National Hospital, Osaka, JapanBackground: Tiotropium partially relieves exertional dyspnea and reduces the risk of congestive heart failure in chronic obstructive pulmonary disease (COPD patients. However, its effect on the sympathetic activation response to exercise is unknown.Aims: This study aimed to determine whether tiotropium use results in a sustained reduction in sympathetic activation during exercise.Methods: We conducted a 12-week, open-label (treatments: tiotropium 18 µg or oxitropium 0.2 mg × 3 mg, crossover study in 17 COPD patients. Treatment order was randomized across subjects. The subjects underwent a pulmonary function test and two modes of cardiopulmonary exercise (constant work rate and incremental exercise testing using a cycle ergometer, with measurement of arterial catecholamines after each treatment period.Results: Forced expiratory volume in 1 second and forced vital capacity were significantly larger in the tiotropium treatment group. In constant exercise testing, exercise endurance time was longer, with improvement in dyspnea during exercise and reduction in dynamic hyperinflation in the tiotropium treatment group. Similarly, in incremental exercise testing, exercise time, carbon dioxide production, and minute ventilation at peak exercise were significantly higher in the tiotropium treatment group. Plasma norepinephrine concentrations and dyspnea intensity were also lower during submaximal isotime exercise and throughout the incremental workload exercise in the tiotropium treatment group.Conclusion: Tiotropium suppressed the increase of sympathetic activation during exercise at the end of the 6-week treatment, as compared with the effect of oxipropium. This effect might be attributed to improvement in lung function and exercise capacity and reduction in exertional dyspnea

  6. Excessive parasympathetic responses to sympathetic challenges: a treatable, hidden, dynamic autonomic imbalance

    OpenAIRE

    David L. Bellin; Nicholas L. DePace; Robert J. Bulgarelli; Peng Li; Joe Colombo

    2015-01-01

    Background: A common assumption with autonomic assessment is that one branch opposes the other. With independent measures of parasympathetic (P) and sympathetic (S) activity, based on concurrent time-frequency analysis of respiratory activity and heart rate variability, this assumption has been challenged. Clinical observations of unprovoked P-excess during S-stimulation have been associated with treatable, abnormal responses. Method: Serial autonomic profiling of 12,967 patients was perfo...

  7. Giving support to others reduces sympathetic nervous system-related responses to stress

    OpenAIRE

    Inagaki, TK; Eisenberger, NI

    2015-01-01

    © 2015 Society for Psychophysiological Research. Social support is a major contributor to the link between social ties and beneficial health outcomes. Research to date has focused on how receiving support from others might be good for us; however, we know less about the health effects of giving support to others. Based on prior work in animals showing that stimulating neural circuitry important for caregiving behavior can reduce sympathetic-related responses to stressors, it is possible that,...

  8. Prox1 identifies proliferating neuroblasts and nascent neurons during neurogenesis in sympathetic ganglia.

    Science.gov (United States)

    Holzmann, Julia; Hennchen, Melanie; Rohrer, Hermann

    2015-12-01

    Neurogenesis in embryonic sympathetic ganglia involves neuroblasts that resume proliferation following neuronal differentiation. As cell cycle exit is not associated with neuronal differentiation, the identity of proliferating neuroblasts is incompletely understood. Here, we use sympathetic ganglia of chick embryos to define the timing of neurogenesis and neuroblast identity focusing on the expression and function of the transcription factor Prox1. We show that a large fraction of neuroblasts has initially withdrawn from the cell cycle at embryonic day 3 (E3), which is reflected by a high proportion of p27(+)/Islet1(+) neuroblasts (63%) and low numbers of EdU(+)/Islet1(+) cells (12%). The proportion of proliferating Islet1(+) neuroblasts, identified by EdU pulse labeling and by the absence of the postmitotic marker p27 increases to reach maximal levels at E5, when virtually all neuroblasts are in the cell cycle (95%). Subsequently, the proportion of EdU-labeled and p27(-) neuroblasts is reduced to reach low levels at E11. Interestingly, the expression of the transcription factor Prox1 is restricted to the neuronal lineage, that is, Sox10(+)/Phox2b(+) neuron progenitors, proliferating p27(-)/Islet1(+) neuroblasts and nascent neurons but is rapidly lost in postmitotic neurons. In vitro and in vivo knockdown and overexpression experiments demonstrate effects of Prox1 in the support of neuroblast proliferation and survival. Taken together, these results define the neurogenesis period in the chick paravertebral sympathetic ganglia including an initial cell cycle withdrawal and identify Prox1 as a marker and regulator of proliferating sympathetic neuroblasts.

  9. A brain leptin-renin angiotensin system interaction in the regulation of sympathetic nerve activity

    Science.gov (United States)

    Hilzendeger, Aline M.; Morgan, Donald A.; Brooks, Leonard; Dellsperger, David; Liu, Xuebo; Grobe, Justin L.; Rahmouni, Kamal; Sigmund, Curt D.

    2012-01-01

    The sympathetic nervous system, leptin, and renin-angiotensin system (RAS) have been implicated in obesity-associated hypertension. There is increasing evidence for the presence of both leptin and angiotensin II receptors in several key brain cardiovascular and metabolic control regions. We tested the hypothesis that the brain RAS plays a facilitatory role in the sympathetic nerve responses to leptin. In rats, intracerebroventricular (ICV) administration of losartan (5 μg) selectively inhibited increases in renal and brown adipose tissue (BAT) sympathetic nerve activity (SNA) produced by leptin (10 μg ICV) but did not reduce the SNA responses to corticotrophin-releasing factor (CRF) or the melanocortin receptor agonist MTII. In mice with deletion of angiotensin II type-1a receptors (AT1aR−/−), increases in renal and BAT SNA induced by leptin (2 μg ICV) were impaired whereas SNA responses to MTII were preserved. Decreases in food intake and body weight with ICV leptin did not differ in AT1aR−/− vs. AT1aR+/+ mice. ICV leptin in rats increased AT1aR and angiotensin-converting enzyme (ACE) mRNA in the subfornical organ and AT1aR mRNA in the arcuate nucleus, suggesting leptin-induced upregulation of the brain RAS in specific brain regions. To evaluate the role of de novo production of brain angiotensin II in SNA responses to leptin, we treated rats with captopril (12.5 μg ICV). Captopril attenuated leptin effects on renal and BAT SNA. In conclusion, these studies provide evidence that the brain RAS selectively facilitates renal and BAT sympathetic nerve responses to leptin while sparing effects on food intake. PMID:22610169

  10. Vestibular Modulation of Sympathetic Nerve Activity to Muscle and Skin in Humans

    Directory of Open Access Journals (Sweden)

    Elie Hammam

    2017-07-01

    Full Text Available We review the existence of vestibulosympathetic reflexes in humans. While several methods to activate the human vestibular apparatus have been used, galvanic vestibular stimulation (GVS is a means of selectively modulating vestibular afferent activity via electrodes over the mastoid processes, causing robust vestibular illusions of side-to-side movement. Sinusoidal GVS (sGVS causes partial entrainment of sympathetic outflow to muscle and skin. Modulation of muscle sympathetic nerve activity (MSNA from vestibular inputs competes with baroreceptor inputs, with stronger temporal coupling to the vestibular stimulus being observed at frequencies remote from the cardiac frequency; “super entrainment” was observed in some individuals. Low-frequency (<0.2 Hz sGVS revealed two peaks of modulation per cycle, with bilateral recordings of MSNA or skin sympathetic nerve activity, providing evidence of lateralization of sympathetic outflow during vestibular stimulation. However, it should be noted that GVS influences the firing of afferents from the entire vestibular apparatus, including the semicircular canals. To identify the specific source of vestibular input responsible for the generation of vestibulosympathetic reflexes, we used low-frequency (<0.2 Hz sinusoidal linear acceleration of seated or supine subjects to, respectively, target the utricular or saccular components of the otoliths. While others had discounted the semicircular canals, we showed that the contributions of the utricle and saccule to the vestibular modulation of MSNA are very similar. Moreover, that modulation of MSNA occurs at accelerations well below levels at which subjects are able to perceive any motion indicates that, like vestibulospinal control of posture, the vestibular system contributes to the control of blood pressure through potent reflexes in humans.

  11. Severe hemorrhage attenuates cardiopulmonary chemoreflex control of regional sympathetic outputs via NTS adenosine receptors.

    Science.gov (United States)

    Minic, Zeljka; Li, Cailian; O'Leary, Donal S; Scislo, Tadeusz J

    2014-09-15

    Selective stimulation of inhibitory A1 and facilitatory A2a adenosine receptor subtypes located in the nucleus of the solitary tract (NTS) powerfully inhibits cardiopulmonary chemoreflex (CCR) control of regional sympathetic outputs via different mechanisms: direct inhibition of glutamate release and facilitation of an inhibitory neurotransmitter release, respectively. However, it remains unknown whether adenosine naturally released into the NTS has similar inhibitory effects on the CCR as the exogenous agonists do. Our previous study showed that adenosine is released into the NTS during severe hemorrhage and contributes to reciprocal changes of renal (decreases) and adrenal (increases) sympathetic nerve activity observed in this setting. Both A1 and A2a adenosine receptors are involved. Therefore, we tested the hypothesis that, during severe hemorrhage, CCR control of the two sympathetic outputs is attenuated by adenosine naturally released into the NTS. We compared renal and adrenal sympathoinhibitory responses evoked by right atrial injections of 5HT3 receptor agonist phenylbiguanide (2-8 μg/kg) under control conditions, during hemorrhage, and during hemorrhage preceded by blockade of NTS adenosine receptors with bilateral microinjections of 8-(p-sulfophenyl) theophylline (1 nmol/100 nl) in urethane/chloralose anesthetized rats. CCR-mediated inhibition of renal and adrenal sympathetic activity was significantly attenuated during severe hemorrhage despite reciprocal changes in the baseline activity levels, and this attenuation was removed by bilateral blockade of adenosine receptors in the caudal NTS. This confirmed that adenosine endogenously released into the NTS has a similar modulatory effect on integration of cardiovascular reflexes as stimulation of NTS adenosine receptors with exogenous agonists.

  12. Spinal Cord Injury-Induced Dysautonomia via Plasticity in Paravertebral Sympathetic Postganglionic

    Science.gov (United States)

    2016-10-01

    the preparation to isolate the thoracic chain and after ribs and vertebrae are trimmed (see 1a.1 methods, *) the entire tissue is incubated at 37°C in...operational principles are inferred from studies in cervical and lumbar chain ganglia (Percy and Krier, 1987; Bratton et al., 2010; Campanucci et al...postganglionics in superior cervical (Rimmer and Horn, 2010) and lumbar sympathetic chain ganglia (McLachlan, 2003). Consequently, SPNs have traditionally

  13. White Matter Changes Associated with Resting Sympathetic Tone in Frontotemporal Dementia vs. Alzheimer's Disease.

    Directory of Open Access Journals (Sweden)

    Mario F Mendez

    Full Text Available Resting sympathetic tone, a measure of physiological arousal, is decreased in patients with apathy and inertia, such as those with behavioral variant frontotemporal dementia (bvFTD and other frontally-predominant disorders.To identify the neuroanatomical correlates of skin conductance levels (SCLs, an index of resting sympathetic tone and apathy, among patients with bvFTD, where SCLs is decreased, compared to those with Alzheimer's disease (AD, where it is not.This study analyzed bvFTD (n = 14 patients and a comparison group with early-onset AD (n = 19. We compared their resting SCLs with gray matter and white matter regions of interest and white matter measures of fiber integrity on magnetic resonance imaging and diffusion tensor imaging.As expected, bvFTD patients, compared to AD patients, had lower SCLs, which correlated with an apathy measure, and more gray matter loss and abnormalities of fiber integrity (fractional anisotropy and mean diffusivity in frontal-anterior temporal regions. After controlling for group membership, the SCLs were significantly correlated with white matter volumes in the cingulum and inferior parietal region in the right hemisphere.Among dementia patients, SCLs, and resting sympathetic tone, may correlate with quantity of white matter, rather than with gray matter or with white matter fiber integrity. Loss of white matter volumes, especially involving a right frontoparietal network, may reflect chronic loss of cortical axons that mediate frontal control of resting sympathetic tone, changes that could contribute to the apathy and inertia of bvFTD and related disorders.

  14. Sympathetic nervous system in obesity-related hypertension: mechanisms and clinical implications.

    Science.gov (United States)

    Kalil, Graziela Z; Haynes, William G

    2012-01-01

    Obesity markedly increases the risk of hypertension and cardiovascular disease, which may be related to activation of the sympathetic nervous system (SNS). Sympathetic overactivity directly and indirectly contributes to blood pressure (BP) elevation in obesity, including stimulation of the renin-angiotensin-aldosterone system (RAAS). The adipocyte-derived peptide leptin suppresses appetite, increases thermogenesis, but also raises SNS activity and BP. Obese individuals exhibit hyperleptinemia but are resistant to its appetite-suppressing actions. Interestingly, animal models of obesity exhibit preserved sympathoexcitatory and pressor actions of leptin, despite resistance to its anorexic and metabolic actions, suggesting selective leptin resistance. Disturbance of intracellular signaling at specific hypothalamic neural networks appears to underlie selective leptin resistance. Delineation of these pathways should lead to novel approaches to treatment. In the meantime, treatment of obesity-hypertension has relied on antihypertensive drugs. Although sympathetic blockade is mechanistically attractive in obesity-hypertension, in practice its effects are disappointing because of adverse metabolic effects and inferior outcomes. On the basis of subgroup analyses of obese patients in large randomized clinical trials, drugs such as diuretics and RAAS blockers appear superior in preventing cardiovascular events in obesity--hypertension. An underused alternative approach to obesity-hypertension is induction of weight loss, which reduces circulating leptin and insulin, partially reverses resistance to these hormones, decreases sympathetic activation and improves BP and other risk factors. Though weight loss induced by lifestyle is often modest and transient, carefully selected pharmacological weight loss therapies can produce substantial and sustained antihypertensive effects additive to lifestyle interventions.

  15. Sympathetic re-innervation after heart transplantation: dual-isotope neurotransmitter scintigraphy, norepinephrine content and historical examination

    Energy Technology Data Exchange (ETDEWEB)

    Guertner, C. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Nuclear Medicine; Krause, B.J. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Nuclear Medicine; Klepzig, H. Jr. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Cardiology; Herrmann, G. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Pathology; Lelbach, S. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Nuclear Medicine; Vockert, E.K. [Biocenter Niederursel, Frankfurt am Main (Germany). Dept. of Pharmacology; Hartmann, A. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Cardiology; Maul, F.D. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Nuclear Medicine; Kranert, T.W. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Nuclear Medicine; Mutschler, E. [Biocenter Niederursel, Frankfurt am Main (Germany). Dept. of Pharmacology; Huebner, K. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Pathology; Hoer, G. [Univ. Hospital Frankfurt am Main (Germany). Dept. of Nuclear Medicine

    1995-05-01

    Cardiac transplantation entails surgical disruption of the sympathetic nerve fibres from their somata, resulting in sympathetic denervation. In order to investigate the occurrence of sympathetic re-innervation, neurotransmitter scintigraphy using the norepinephrine analogue iodine-123 metaiodobenzylguanidine (MIBG) was performed in 15 patients 2-69 months after transplantation. In addition, norepinephrine content and immunohistochemical reactions of antibodies to Schwann cell-associated S100 protein, to neuron-specific enolase (NSE) and to norepinephrine were examined in 34 endomyocardial biopsies of 29 patients 1-88 months after transplantation. Anterobasal {sup 123}I-MIBG uptake indicating partial sympathetic re-innervation could be shown in 40% of the scintigraphically investigated patients 37-69 months after transplantation. In immunohistochemical studies 83% of the patients investigated 1-72 Months after transplantation showed nerve fibres in their biopsies but not positive reaction to norepinephrine. Significant norepinephrine content indicating re-innervation could not be detected in any biopsy. It was concluded that in spite of the lack of norepinephrine content there seemed to be immunohistological and scintigraphic evidence of sympathetic re-innervation. An explanation for this contradictory finding may be the reduced or missing norepinephrine storage ability compared to the restored uptake ability of regenerated sympathetic nerve fibres. (orig.)

  16. Influence of sympathetic tone on heart rate during vagal stimulation and nitroprusside induced hypotension in ovine fetus.

    Science.gov (United States)

    Gaillot, Théophile; Beuchée, Alain; Jaillard, Sophie; Storme, Laurent; Nuyt, Anne Monique; Carré, François; Pladys, Patrick

    2005-12-30

    To characterize effects of sympathetic tone on fetal heart rate (FHR) reflex responses and FHR variability in late gestation. Changes in FHR and autonomic tones were studied (i) after electrical vagal stimulation and (ii) during nitroprusside-induced hypotension, in seven late gestation ovine fetus in control condition (ctrl), after dobutamine (beta1-activation) and atenolol (beta1-blockade). Results are expressed as mean +/- SEM. (i) Minimal FHR after vagal stimulation was not influenced by atenolol or dobutamine but dobutamine accelerated FHR normalization. (ii) During nitroprusside induced hypotension atenolol inhibited the initial increases in FHR and FHR variability (measured by SD and LFnu) but not the bradycardia occurring below a mean arterial pressure of 38 +/- 2 mmHg. Dobutamine did not abolish the depressor reflex. During hypotension the positive chronotropic effect of sympathetic tone increased from 15 +/- 2 to 42 +/- 7 bpm then decreased at a rate of -7.6 +/- 1.5 bpm mmHg(-1), vagal negative chronotropic influence steadily increased at a rate of 1.9 +/- 0.4 bpm mmHg(-1). Changes in FHR variability were not correlated with vagal or sympathetic chronotropic effects. beta1-stimulation does not affect sinus-node response to vagal stimulation but improves the speed of FHR normalization. FHR response to hypotension depends on an initial increase in both sympathetic and parasympathetic chronotropic effects that is associated with a sympathetic dependent increase in FHR variability and is followed by a withdrawal of sympathetic tone.

  17. Sympathetic nervous system promotes hepatocarcinogenesis by modulating inflammation through activation of alpha1-adrenergic receptors of Kupffer cells.

    Science.gov (United States)

    Huan, Hong-Bo; Wen, Xu-Dong; Chen, Xue-Jiao; Wu, Lin; Wu, Li-Li; Zhang, Liang; Yang, Da-Peng; Zhang, Xia; Bie, Ping; Qian, Cheng; Xia, Feng

    2017-01-01

    The sympathetic nervous system (SNS) is known to play a significant role in tumor initiation and metastasis. Hepatocellular carcinoma (HCC) frequently occurs in cirrhotic livers after chronic inflammation, and the SNS is hyperactive in advanced liver cirrhosis. However, it remains unclear whether the SNS promotes hepatocarcinogenesis by modulating chronic liver inflammation. In this study, a retrospective pathological analysis and quantification of sympathetic nerve fiber densities (tyrosine hydroxylase, TH(+)) in HCC patients, and diethylnitrosamine (DEN)-induced hepatocarcinogenesis in rats were performed. Our data showed that high density of sympathetic nerve fibers and α1-adrenergic receptors (ARs) of Kupffer cells (KCs) were associated with a poor prognosis of HCC. Sympathetic denervation or blocking of α1-ARs decreased DEN-induced HCC incidence and tumor development. In addition, synergistic effects of interleukin-6 (IL-6) and transforming growth factor-beta (TGF-β) in hepatocarcinogenesis were observed. The suppression of the SNS reduced IL-6 and TGF-β expression, which suppressed hepatocarcinogenesis, and KCs play a key role in this process. After the ablation of KCs, IL-6 and TGF-β expression and the development of HCC were inhibited. This study demonstrates that sympathetic innervation is crucial for hepatocarcinogenesis and that the SNS promotes hepatocarcinogenesis by activating α1-ARs of KCs to boost the activation of KCs and to maintain the inflammatory microenvironment. These results indicate that sympathetic denervation or α1-ARs blockage may represent novel treatment approaches for HCC.

  18. Comparison of 2% mepivacaine, clipping, and radiofrequency thermocoagulation for duration and magnitude of action in peripheral arterial blood flow induced by sympathetic block in anesthetized dogs.

    Science.gov (United States)

    Otani, Taro; Shinozaki, Mio; Takahashi, Yoshiyuki; Ikeda, Tomohito; Kimura, Yoshiyuki; Nagao, Masaru; Yamaguchi, Shigeki; Kitajima, Toshimitsu

    2010-01-01

    Thoracic sympathetic block has recently been performed by placement of the clips on the sympathetic chain to interrupt nerve conduction. The aim of this study was to compare clipping with 2% mepivacaine and radiofrequency thermocoagulation for the potency of sympathetic block from the results of the duration and magnitude of the vasodilation effect induced by thoracic sympathetic block in dogs. We measured mean arterial pressure, heart rate, and right and left brachial artery blood flow (BABF) before and after thoracic sympathetic block in 24 dogs. The experimental protocol was designed as follows: (1) left thoracic sympathetic block by 1.0 mL of 2% mepivacaine (n = 8), (2) left thoracic sympathetic block by clipping (n = 8), and (3) left thoracic sympathetic block by radiofrequency thermocoagulation (n = 8). Mean arterial pressure and heart rate did not change significantly throughout the study in either group. Left thoracic sympathetic block by 2% mepivacaine increased left BABF significantly from 5 to 70 mins after the block (baseline, 100%; peak at 10 mins after the block, 179% ± 33%; P mepivacaine and a less potency compared with radiofrequency thermocoagulation in thoracic sympathetic block in dogs.

  19. Independence of connexin expression and vasomotor conduction from sympathetic innervation in hamster feed arteries.

    Science.gov (United States)

    Looft-Wilson, Robin C; Haug, Sara J; Neufer, P Darrell; Segal, Steven S

    2004-01-01

    Vasomotor responses can travel along the wall of resistance microvessels by two distinct mechanisms: cell-to-cell conduction through gap junctions or the release of neurotransmitter along perivascular nerves. It is unknown whether vascular innervation influences the expression of connexin molecules which comprise gap junctions, or the conduction of vasomotor responses. In feed arteries of the hamster retractor muscle (RFA), the authors tested whether sympathetic denervation would alter the expression of connexin isoforms and the conduction of vasomotor responses. Using intact vessels with sympathetic innervation and those 7-8 days following denervation surgery, mRNA expression was quantified using real-time PCR, cellular localization of Cx protein was characterized using immunohistochemistry, and vasomotor responses to dilator and constrictor stimuli were evaluated in isolated pressurized RFA. Connexin protein localization and mRNA expression were similar between innervated and denervated vessels. mRNA levels were Cx43 = Cx37 > Cx45 > Cx40. Vasodilation to acetylcholine conducted >/=2000 microm along innervated and denervated vessels, as did the biphasic conduction of vasoconstriction and vasodilation in response to KCl. Vasoconstriction to phenylephrine conducted <500 microm and was attenuated (p <.05) in denervated vessels. The profile of connexin expression and the conduction of vasomotor responses are largely independent of sympathetic innervation in feed arteries of the hamster retractor muscle (RFA).

  20. Functional sympatholysis and sympathetic escape in a theoretical model for blood flow regulation

    Directory of Open Access Journals (Sweden)

    Tuhin K Roy

    2014-05-01

    Full Text Available A mathematical simulation of flow regulation in vascular networks is used to investigate the interaction between arteriolar vasoconstriction due to sympathetic nerve activity (SNA and vasodilation due to increased oxygen demand. A network with thirteen vessel segments in series is used, each segment representing a different size range of arterioles or venules. The network includes five actively regulating arteriolar segments with time-dependent diameters influenced by shear stress, wall tension, metabolic regulation, and SNA. Metabolic signals are assumed to be propagated upstream along vessel walls via a conducted response. The model exhibits functional sympatholysis, in which sympathetic vasoconstriction is partially abrogated by increases in metabolic demand, and sympathetic escape, in which SNA elicits an initial vasoconstriction followed by vasodilation. In accordance with experimental observations, these phenomena are more prominent in small arterioles than in larger arterioles when SNA is assumed to act equally on arterioles of all sizes. The results imply that a mechanism based on the competing effects on arteriolar tone of SNA and conducted metabolic signals can account for several observed characteristics of functional sympatholysis, including the different responses of large and small arterioles.

  1. Thematic review series: adipocyte biology. Sympathetic and sensory innervation of white adipose tissue.

    Science.gov (United States)

    Bartness, Timothy J; Song, C K

    2007-08-01

    During our study of the reversal of seasonal obesity in Siberian hamsters, we found an interaction between receptors for the pineal hormone melatonin and the sympathetic nervous system (SNS) outflow from brain to white adipose tissue (WAT). This ultimately led us and others to conclude that the SNS innervation of WAT is the primary initiator of lipid mobilization in these as well as other animals, including humans. There is strong neurochemical (norepinephrine turnover), neuroanatomical (viral tract tracing), and functional (sympathetic denervation-induced blockade of lipolysis) evidence for the role of the SNS in lipid mobilization. Recent findings suggest the presence of WAT sensory innervation based on strong neuroanatomical (viral tract tracing, immunohistochemical markers of sensory nerves) and suggestive functional (capsaicin sensory denervation-induced WAT growth) evidence, the latter implying a role in conveying adiposity information to the brain. By contrast, parasympathetic nervous system innervation of WAT is characterized by largely negative neuroanatomical evidence (viral tract tracing, immunohistochemical and biochemical markers of parasympathetic nerves). Functional evidence (intraneural stimulation and in situ microdialysis) for the role of the SNS innervation in lipid mobilization in human WAT is convincing, with some controversy regarding the level of sympathetic nerve activity in human obesity.

  2. Functional role of lumbar sympathetic nerves and supraspinal mechanism in the defecation reflex of the cat.

    Directory of Open Access Journals (Sweden)

    Takaki,Miyako

    1987-12-01

    Full Text Available The role of the lumbar sympathetic nerves and supraspinal mechanism in the defecation reflex was investigated in 30 adult cats and 6 kittens. One or two propulsive contractions, whose mean pressure evoked was more than about 90 cmH2O (adult cats and 50 cmH2O (kittens, were induced in the rectum of all animals by rectal distension. These propulsive contractions could be generated at the descending and the transverse colons. The removal of the supraspinal influence by spinal transection at T13 or removal of pelvic afferents to the supraspinal center by spinal transection at L abolished the propulsive contractions. Successive lumbar sympathectomy restored the contractions. Lumbar sympathectomy and the successive removal of the supraspinal influence did not affect the propulsive contractions. In both cases, the final exclusion of the sacral segments by pithing of the spinal cord abolished the propulsive contractions. These results suggest that the sacral excitatory reflex mediated via pelvic nerves and the lumbar inhibitory reflex mediated via lumbar sympathetic nerves can function during rectal distension in spinal cats and that the lumbar inhibitory reflex is suppressed by the supraspinal sympathetic inhibitory reflex activated by pelvic afferents in intact cats, as in guinea pigs, resulting in propulsive contractions.

  3. Three-phase bone studies in hemiplegia with reflex sympathetic dystrophy and the effect of disuse

    Energy Technology Data Exchange (ETDEWEB)

    Greyson, N.D.; Tepperman, P.S.

    1984-04-01

    Eighty-five patients with cerebral vascular accidents were assessed with three-phase bone scintigraphy of the hands and with whole-body delayed bone imaging. Nine patients (10%) had normal three-phase bone images. Fifty-five patients (65%) showed decreased blood flow and blood-pool images of the hands and wrists with normal delayed bone scintigrams, indicating the effect of paralysis or disuse. Twenty-one patients (25%) had diffuse increased uptake with periarticular accentuation, felt to be bone-scintigraphic evidence of reflex sympathetic dystrophy of the hands and wrists; in two patients this occurred before its clinical appearance. Thriteen of the 21 reflex sympathetic dystrophy syndromes (RDS)-involved limbs (62%) had increased blood flow, whereas 8 (38%) had decreased flow. Gross limb blood flow appears to be related to the degree of muscle activity, but flow may be altered by the presence of sympathetic changes. A possible dissociation between whole-limb flow and bone blood flow in paralyzed limbs involved with RDS is discussed.

  4. Axon guidance of sympathetic neurons to cardiomyocytes by glial cell line-derived neurotrophic factor (GDNF.

    Directory of Open Access Journals (Sweden)

    Keiko Miwa

    Full Text Available Molecular signaling of cardiac autonomic innervation is an unresolved issue. Here, we show that glial cell line-derived neurotrophic factor (GDNF promotes cardiac sympathetic innervation in vitro and in vivo. In vitro, ventricular myocytes (VMs and sympathetic neurons (SNs isolated from neonatal rat ventricles and superior cervical ganglia were cultured at a close distance. Then, morphological and functional coupling between SNs and VMs was assessed in response to GDNF (10 ng/ml or nerve growth factor (50 ng/ml. As a result, fractions of neurofilament-M-positive axons and synapsin-I-positive area over the surface of VMs were markedly increased with GDNF by 9-fold and 25-fold, respectively, compared to control without neurotrophic factors. Pre- and post-synaptic stimulation of β1-adrenergic receptors (BAR with nicotine and noradrenaline, respectively, resulted in an increase of the spontaneous beating rate of VMs co-cultured with SNs in the presence of GDNF. GDNF overexpressing VMs by adenovirus vector (AdGDNF-VMs attracted more axons from SNs compared with mock-transfected VMs. In vivo, axon outgrowth toward the denervated myocardium in adult rat hearts after cryoinjury was also enhanced significantly by adenovirus-mediated GDNF overexpression. GDNF acts as a potent chemoattractant for sympathetic innervation of ventricular myocytes, and is a promising molecular target for regulation of cardiac function in diseased hearts.

  5. Effect of postnatal lead exposure on the development of sympathetic innervation of the heart. [Rats

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, M.E.

    1983-01-01

    To determine possible mechanisms for this Pb-induced cardiotoxicity, several neutrochemical parameters indicative of cardiac sympathetic innervation were measured in developing rats. Presynaptic indices of nerve terminal development which were studied included steady-state levels of norepinephrine, neuronal uptake and vesicular storage of /sup 3/H-norepinephrine. Analysis of postsynaptic development was accomplished by quantitating the density of ..beta..-adrenergic receptors and by measuring the activity of adenylate cyclase. Rat pups were exposed to Pb from birth to weaning (21 days) via the milk of dams whose drinking water contained 0.2% Pb acetate. This method and level of Pb treatment had no effect on body or heart weight development, however, it did result in a seven-fold increase in the blood Pb content (70-75 ..mu..g/dl) of the treated pups during the period of exposure. Pb exposure accelerated the development of sympathetic innervation of the heart as detected by significant increases in the vesicular uptake of /sup 3/H-norepinephrine and the steady-state concentration of norepinephrine measured at postnatal day 4. On the other hand, ontogeny of the neutronal uptake of /sup 3/H-norepinephrine in the heart and in the forebrain was not affected by Pb treatment. The apparent premature development of sympathetic innervation induced by Pb treatment was not reflected in significant alterations in either the density or the affinity of ..beta..-adrenergic receptor sites determined by the binding kinetics of /sup 3/H-dihydroalprenolol.

  6. Impaired cardiac sympathetic innervation in symptomatic patients with long QT syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kies, Peter; Stegger, Lars; Schober, Otmar [University Hospital Muenster, Department of Nuclear Medicine, Muenster (Germany); Paul, Matthias; Moennig, Gerold [University Hospital Muenster, Department for Cardiology and Angiology, Muenster (Germany); Gerss, Joachim [University of Muenster, Institute of Biostatistics and Clinical Research, Muenster (Germany); Wichter, Thomas [Marienhospital Osnabrueck, Department of Cardiology, Niels-Stensen-Kliniken, Osnabrueck (Germany); Schaefers, Michael [University of Muenster, European Institute of Molecular Imaging - EIMI, Muenster (Germany); Schulze-Bahr, Eric [University Hospital Muenster, Department for Cardiology and Angiology, Muenster (Germany); University Hospital Muenster, Institute for Genetics of Heart Diseases, Muenster (Germany)

    2011-10-15

    Increased sympathetic activation is a key modifier for arrhythmogenesis in patients with long QT syndrome (LQTS), a congenital channelopathy. Therefore, we investigated cardiac sympathetic function using {sup 123}I-metaiodobenzylguanidine (MIBG) single photon emission computed tomography (SPECT) in a cohort of symptomatic LQTS patients and correlated these findings with the underlying genotype. [{sup 123}I]MIBG SPECT was performed in 28 LQTS patients. Among these, 18 patients (64%) had a previous syncope and 10 patients (36%) survived sudden cardiac arrest. Patients were characterized in terms of genetic subtypes and QTc interval on surface ECGs. SPECT images were analysed for regional [{sup 123}I]MIBG uptake in a 33-segment bullseye scheme and compared to those obtained from 10 age-matched healthy control subjects (43 {+-} 12 years). An abnormal {sup 123}I-MIBG scan was found in 17 of 28 LQTS patients (61%) with a tracer reduction mainly located in the anteroseptal segments of the left ventricle. This finding was independent of the genetic LQTS subtype. In addition, no differences were found between LQTS patients with a QTc >500 ms vs <500 ms or those suffering from syncope vs VF (p > 0.05). A distinct regional pattern of impaired cardiac sympathetic function was identified in the majority of symptomatic LQTS patients. This innervation defect was independent of the underlying genotype and clinical disease expression. (orig.)

  7. Effect of age on the hemodynamic and sympathetic responses at the onset of isometric handgrip exercise.

    Science.gov (United States)

    Lalande, Sophie; Sawicki, Carolyn P; Baker, Jacquie R; Shoemaker, J Kevin

    2014-01-15

    Cardiac and peripheral vasomotor factors contribute to the rapid pressor response at the onset of isometric handgrip exercise. We tested the hypothesis that age enhances the sympathetic and vasoconstrictor response at the onset of isometric handgrip exercise so that the pressor response is maintained, despite a diminished cardiac function. Twelve young and twelve older (24 ± 3 and 63 ± 8 yr) individuals performed 20-s isometric handgrip exercise at 30, 40, or 50% of maximal voluntary contraction force. Muscle sympathetic nerve activity (MSNA) was measured using microneurography. Mean arterial pressure (MAP) and cardiac output (Q) were assessed continuously by finger plethysmography and total peripheral resistance was calculated. MAP increased with the onset of handgrip; this increase was associated with handgrip intensity and was similar in both groups. Heart rate and Q increased with increasing handgrip intensity in both groups, but increases were greater in young vs. older individuals (age × handgrip intensity interaction, P change in MSNA between baseline and handgrip, for both frequency and incidence, increased with increasing handgrip intensity for both groups. There was no effect of handgrip intensity or age on total peripheral resistance. The smaller heart rate and Q response during the first 20 s of handgrip exercise in older individuals was not accompanied by a greater sympathetic activation or vasoconstrictor response. However, increases in MAP were similar between groups, indicating that the pressor response at the onset of handgrip exercise is preserved with aging.

  8. Leptin signaling in the nucleus tractus solitarii increases sympathetic nerve activity to the kidney.

    Science.gov (United States)

    Mark, Allyn L; Agassandian, Khristofor; Morgan, Donald A; Liu, Xuebo; Cassell, Martin D; Rahmouni, Kamal

    2009-02-01

    The hypothalamic arcuate nucleus was initially regarded as the principal site of leptin action, but there is increasing evidence for functional leptin receptors in extrahypothalamic sites, including the nucleus tractus solitarii (NTS). We demonstrated previously that arcuate injection of leptin increases sympathetic nerve activity (SNA) to brown adipose tissue and kidney. In this study, we tested the hypothesis that leptin signaling in the NTS affects sympathetic neural outflow. Using a stereotaxic device in anesthetized rats, we microinjected leptin (0.25 to 1.00 microg) or saline into the NTS while recording SNA to kidney and brown adipose tissue. Microinjection of leptin into the commissural and medial subnuclei of the caudal NTS at the level of the area postrema in Sprague-Dawley rats produced a dose-related increase in renal SNA (+112+/-15% with leptin 1 microg; n=7; Pleptin receptors, because it was not observed in Zucker obese rats that have a missense mutation in the leptin receptor. Rostral NTS injection of leptin failed to increase SNA, indicating that leptin signaling in the NTS is probably confined to the caudal NTS at the level of the area postrema. In summary, this study demonstrates that leptin signaling in the caudal NTS increases SNA to the kidney but not to the brown adipose tissue. The study strengthens the concept of a distributed brain network of leptin action and demonstrates that these distributed brain sites can mediate contrasting sympathetic responses to leptin.

  9. MR-guided Periarterial Ethanol Injection for Renal Sympathetic Denervation: A Feasibility Study in Pigs

    Energy Technology Data Exchange (ETDEWEB)

    Streitparth, F., E-mail: florian.streitparth@charite.de; Walter, A.; Stolzenburg, N.; Heckmann, L.; Breinl, J. [Charite, Humboldt University, Department of Radiology (Germany); Rinnenthal, J. L. [Charite, Humboldt University, Department of Neuropathology (Germany); Beck, A.; De Bucourt, M.; Schnorr, J. [Charite, Humboldt University, Department of Radiology (Germany); Bernhardt, U. [InnoRa GmbH (Germany); Gebauer, B.; Hamm, B.; Guenther, R. W. [Charite, Humboldt University, Department of Radiology (Germany)

    2013-06-15

    Purpose. To evaluate the feasibility and efficacy of image-guided periarterial ethanol injection as an alternative to transluminal radiofrequency ablation. Methods. Unilateral renal periarterial ethanol injection was performed under general anesthesia in 6 pigs with the contralateral kidney serving as control. All interventions were performed in an open 1.0 T MRI system under real-time multiplanar guidance. The injected volume was 5 ml (95 % ethanol labelled marked MR contrast medium) in 2 pigs and 10 ml in 4 pigs. Four weeks after treatment, the pigs underwent MRI including MRA and were killed. Norepinephrine (NE) concentration in the renal parenchyma served as a surrogate parameter to analyze the efficacy of sympathetic denervation. In addition, the renal artery and sympathetic nerves were examined histologically to identify evidence of vascular and neural injury. Results. In pigs treated with 10 ml ethanol, treatment resulted in neural degeneration. We found a significant reduction of NE concentration in the kidney parenchyma of 53 % (p < 0.02) compared with the untreated contralateral kidney. In pigs treated with 5 ml ethanol, no significant changes in histology or NE were observed. There was no evidence of renal arterial stenosis in MRI, macroscopy or histology in any pig. Conclusion. MR-guided periarterial ethanol injection was feasible and efficient for renal sympathetic denervation in a swine model. This technique may be a promising alternative to the catheter-based approach in the treatment of resistant arterial hypertension.

  10. Basis for the preferential activation of cardiac sympathetic nerve activity in heart failure

    Science.gov (United States)

    Ramchandra, Rohit; Hood, Sally G.; Denton, Derek A.; Woods, Robin L.; McKinley, Michael J.; McAllen, Robin M.; May, Clive N.

    2009-01-01

    In heart failure (HF), sympathetic nerve activity is increased. Measurements in HF patients of cardiac norepinephrine spillover, reflecting cardiac sympathetic nerve activity (CSNA), indicate that it is increased earlier and to a greater extent than sympathetic activity to other organs. This has important consequences because it worsens prognosis, provoking arrhythmias and sudden death. To elucidate the mechanisms responsible for the activation of CSNA in HF, we made simultaneous direct neural recordings of CSNA and renal SNA (RSNA) in two groups of conscious sheep: normal animals and animals in HF induced by chronic, rapid ventricular pacing. In normal animals, the level of activity, measured as burst incidence (bursts of pulse related activity/100 heart beats), was significantly lower for CSNA (30 ± 5%) than for RSNA (94 ± 2%). Furthermore, the resting level of CSNA, relative to its maximum achieved while baroreceptors were unloaded by reducing arterial pressure, was set at a much lower percentage than RSNA. In HF, burst incidence of CSNA increased from 30 to 91%, whereas burst incidence of RSNA remained unaltered at 95%. The sensitivity of the control of both CSNA and RSNA by the arterial baroreflex remained unchanged in HF. These data show that, in the normal state, the resting level of CSNA is set at a lower level than RSNA, but in HF, the resting levels of SNA to both organs are close to their maxima. This finding provides an explanation for the preferential increase in cardiac norepinephrine spillover observed in HF. PMID:19136635

  11. Is baroreflex control of sympathetic activity and heart rate active in the preterm fetal sheep?

    Science.gov (United States)

    Booth, Lindsea C; Malpas, Simon C; Barrett, Carolyn J; Guild, Sarah-Jane; Gunn, Alistair J; Bennet, Laura

    2009-03-01

    The arterial baroreflex is a fundamental reflex that buffers rapid changes in arterial blood pressure (BP) via regulation of the heart rate and sympathetic nerve activity to the vasculature. In adults a sigmoidal relationship between BP and both heart rate and sympathetic nerve activity is well documented. Its role in blood pressure control before birth is unclear. Preterm babies have a high incidence of low BP, especially in the first few days of life, which could be related, in part, to immaturity of the baroreflex. In the present study, we investigated the baroreflex control of fetal heart rate and renal sympathetic nerve activity (RSNA) in preterm fetal sheep in utero (102 +/- 1 days of gestation; term 140 days). Phenylephrine was associated with a significant increase in BP from 38 +/- 2 to 58 +/- 3 mmHg and a decrease in heart rate (HR) from 177 +/- 4 to 116 +/- 8 beats per minute (bpm). Sodium nitroprusside was associated with a significant fall in BP from 38 +/- 2 to 26 +/- 1 mmHg and an increase in HR from 182 +/- 4 to 274 +/- 8 bpm. However, the time between the 50% changes in BP and HR was significantly greater after hypotension than hypertension (31 +/- 8 s vs. 14 +/- 5 s, P < 0.05). No significant changes in RSNA occurred with either stimulus. This suggests that there are different maturational tempos for the components of the central autonomic response to altered blood pressure.

  12. Cardiac-locked bursts of muscle sympathetic nerve activity are absent in familial dysautonomia.

    Science.gov (United States)

    Macefield, Vaughan G; Norcliffe-Kaufmann, Lucy; Axelrod, Felicia B; Kaufmann, Horacio

    2013-02-01

    Familial dysautonomia (Riley-Day syndrome) is an hereditary sensory and autonomic neuropathy (HSAN type III), expressed at birth, that is associated with reduced pain and temperature sensibilities and absent baroreflexes, causing orthostatic hypotension as well as labile blood pressure that increases markedly during emotional excitement. Given the apparent absence of functional baroreceptor afferents, we tested the hypothesis that the normal cardiac-locked bursts of muscle sympathetic nerve activity (MSNA) are absent in patients with familial dysautonomia. Tungsten microelectrodes were inserted percutaneously into muscle or cutaneous fascicles of the common peroneal nerve in 12 patients with familial dysautonomia. Spontaneous bursts of MSNA were absent in all patients, but in five patients we found evidence of tonically firing sympathetic neurones, with no cardiac rhythmicity, that increased their spontaneous discharge during emotional arousal but not during a manoeuvre that unloads the baroreceptors. Conversely, skin sympathetic nerve activity (SSNA), recorded in four patients, appeared normal. We conclude that the loss of phasic bursts of MSNA and the loss of baroreflex modulation of muscle vasoconstrictor drive contributes to the poor control of blood pressure in familial dysautonomia, and that the increase in tonic firing of muscle vasoconstrictor neurones contributes to the increase in blood pressure during emotional excitement.

  13. Effect of percutaneous renal sympathetic nerve radiofrequency ablation in patients with severe heart failure.

    Science.gov (United States)

    Dai, Qiming; Lu, Jing; Wang, Benwen; Ma, Genshan

    2015-01-01

    This study aimed to investigate the clinical feasibility and effects of percutaneous renal sympathetic nerve radiofrequency ablation in patients with heart failure. A total of 20 patients with heart failure were enrolled, aged from 47 to 75 years (63±10 years). They were divided into the standard therapy (n = 10), and renal nerve radiofrequency ablation groups (n = 10). There were 15 males and 5 female patients, including 8 ischemic cardiomyopathy, 8 dilated cardiomyopathy, and 8 hypertensive cardiopathy. All of the patients met the criteria of New York Heart Association classes III-IV cardiac function. Patients with diabetes and renal failure were excluded. Percutaneous renal sympathetic nerve radiofrequency ablation was performed on the renal artery wall under X-ray guidance. Serum electrolytes, neurohormones, and 24 h urine volume were recorded 24 h before and after the operation. Echocardiograms were performed to obtain left ventricular ejection fraction at baseline and 6 months. Heart rate, blood pressure, symptoms of dyspnea and edema were also monitored. After renal nerve ablation, 24 h urine volume was increased, while neurohormone levels were decreased compared with those of pre-operation and standard therapy. No obvious change in heart rate or blood pressure was recorded. Symptoms of heart failure were improved in patients after the operation. No complications were recorded in the study. Percutaneous renal sympathetic nerve radiofrequency ablation may be a feasible, safe, and effective treatment for the patients with severe congestive heart failure.

  14. Axon guidance of sympathetic neurons to cardiomyocytes by glial cell line-derived neurotrophic factor (GDNF).

    Science.gov (United States)

    Miwa, Keiko; Lee, Jong-Kook; Takagishi, Yoshiko; Opthof, Tobias; Fu, Xianming; Hirabayashi, Masumi; Watabe, Kazuhiko; Jimbo, Yasuhiko; Kodama, Itsuo; Komuro, Issei

    2013-01-01

    Molecular signaling of cardiac autonomic innervation is an unresolved issue. Here, we show that glial cell line-derived neurotrophic factor (GDNF) promotes cardiac sympathetic innervation in vitro and in vivo. In vitro, ventricular myocytes (VMs) and sympathetic neurons (SNs) isolated from neonatal rat ventricles and superior cervical ganglia were cultured at a close distance. Then, morphological and functional coupling between SNs and VMs was assessed in response to GDNF (10 ng/ml) or nerve growth factor (50 ng/ml). As a result, fractions of neurofilament-M-positive axons and synapsin-I-positive area over the surface of VMs were markedly increased with GDNF by 9-fold and 25-fold, respectively, compared to control without neurotrophic factors. Pre- and post-synaptic stimulation of β1-adrenergic receptors (BAR) with nicotine and noradrenaline, respectively, resulted in an increase of the spontaneous beating rate of VMs co-cultured with SNs in the presence of GDNF. GDNF overexpressing VMs by adenovirus vector (AdGDNF-VMs) attracted more axons from SNs compared with mock-transfected VMs. In vivo, axon outgrowth toward the denervated myocardium in adult rat hearts after cryoinjury was also enhanced significantly by adenovirus-mediated GDNF overexpression. GDNF acts as a potent chemoattractant for sympathetic innervation of ventricular myocytes, and is a promising molecular target for regulation of cardiac function in diseased hearts.

  15. Nerve growth factor receptor from rabbit sympathetic ganglia membranes. Relationship between subforms.

    Science.gov (United States)

    Kouchalakos, R N; Bradshaw, R A

    1986-12-05

    The receptor for nerve growth factor (NGF) was purified from Triton X-100 extracts of sympathetic ganglia membranes by affinity chromatography on NGF-Sepharose. Elution of purified receptor was accomplished at pH 5 in the presence of 1 M NaCl. Sodium dodecyl sulfate gel electrophoresis of the purified iodinated receptor showed three major bands at Mr = 126,000, Mr = 105,000, and Mr = 81,000. Affinity labeling of the purified receptor using 125I-NGF and the photoreactive agent N-hydroxysuccinimidyl-p-azidobenzoate resulted in two major cross-linked complexes corresponding to Mr = 135,000 and Mr = 110,000. This labeling pattern is similar to that observed with sympathetic ganglia membranes (Massague, J., Guillette, B. J., Czech, M. P., Morgan, C. J., and Bradshaw, R. A. (1981) J. Biol. Chem. 256, 9419-9424) and indicates that these two forms do not arise from the cross-linking procedure. Reaction of the photoaffinity labeled NGF receptors with increasing amounts of trypsin resulted in a progressive decrease in the high molecular weight complex with a concomitant increase in the low molecular weight form. When the larger complex was isolated by electroelution from a sodium dodecyl sulfate gel and treated with trypsin, a species corresponding to Mr = 100,000 was generated. These observations are best explained by a precursor-product relationship for the two NGF receptor species of sympathetic neurons.

  16. Bed rest attenuates sympathetic and pressor responses to isometric exercise in antigravity leg muscles in humans.

    Science.gov (United States)

    Kamiya, Atsunori; Michikami, Daisaku; Shiozawa, Tomoki; Iwase, Satoshi; Hayano, Junichiro; Kawada, Toru; Sunagawa, Kenji; Mano, Tadaaki

    2004-05-01

    Although spaceflight and bed rest are known to cause muscular atrophy in the antigravity muscles of the legs, the changes in sympathetic and cardiovascular responses to exercises using the atrophied muscles remain unknown. We hypothesized that bed rest would augment sympathetic responses to isometric exercise using antigravity leg muscles in humans. Ten healthy male volunteers were subjected to 14-day 6 degrees head-down bed rest. Before and after bed rest, they performed isometric exercises using leg (plantar flexion) and forearm (handgrip) muscles, followed by 2-min postexercise muscle ischemia (PEMI) that continues to stimulate the muscle metaboreflex. These exercises were sustained to fatigue. We measured muscle sympathetic nerve activity (MSNA) in the contralateral resting leg by microneurography. In both pre- and post-bed-rest exercise tests, exercise intensities were set at 30 and 70% of the maximum voluntary force measured before bed rest. Bed rest attenuated the increase in MSNA in response to fatiguing plantar flexion by approximately 70% at both exercise intensities (both P antigravity leg muscles.

  17. Paring down on Descartes: a review of brain noradrenaline and sympathetic nervous function.

    Science.gov (United States)

    Lambert, G W

    2001-12-01

    1. The conceptual framework of mind-body interaction can be traced back to the seminal observations of the French philosopher and mathematician René Descartes (1596-1650). Descartes succeeded in eliminating the soul's apparent physiological role and established the brain as the body's control centre. 2. While the pivotal role played by the central nervous system (CNS) in the maintenance of physiological and psychological health has long been recognized, the development of methods designed for the direct examination of human CNS processes has only recently come to fruition. 3. There exists a substantial body of evidence derived from clinical and experimental studies indicating that CNS monoaminergic cell groups, in particular those using noradrenaline as their neurotransmitter, participate in the excitatory regulation of the sympathetic nervous system and the development and maintenance of the hypertensive state. 4. In essential hypertension, particularly in younger patients, there occurs an activation of sympathetic nervous outflows to the kidneys, heart and skeletal muscle. The existence of a correlation between subcortical brain noradrenaline turnover and total body noradrenaline spillover to plasma, resting blood pressure and heart rate provides further support for the observation that elevated subcortical noradrenergic activity subserves a sympathoexcitatory role in the regulation of sympathetic preganglionic neurons of the thorocolumbar cord.

  18. Giving support to others reduces sympathetic nervous system-related responses to stress.

    Science.gov (United States)

    Inagaki, Tristen K; Eisenberger, Naomi I

    2016-04-01

    Social support is a major contributor to the link between social ties and beneficial health outcomes. Research to date has focused on how receiving support from others might be good for us; however, we know less about the health effects of giving support to others. Based on prior work in animals showing that stimulating neural circuitry important for caregiving behavior can reduce sympathetic-related responses to stressors, it is possible that, in humans, giving to others can reduce stressor-evoked sympathetic nervous system responding, which has implications for health outcomes. To test the effect of giving support on the physiological stress response, participants either wrote a supportive note to a friend (support-giving condition) or wrote about their route to school/work (control condition) before undergoing a standard laboratory-based stress task. Physiological responses (heart rate, blood pressure, salivary alpha-amylase, salivary cortisol), and self-reported stress were collected throughout the protocol. In line with hypotheses, support giving (vs. control) reduced sympathetic-related responses (systolic blood pressure and alpha-amylase) to the stressor. No effects of support giving were found on self-reported psychological stress or cortisol levels. Results add to existing knowledge of the pathways by which support giving may lead to health benefits and highlight the contribution of giving to others in the broader social support-health link.

  19. Heart rate modulation by sympathetic nerves in dogs with heart failure.

    Science.gov (United States)

    Uechi, Masami; Shimizu, Akira; Mizuno, Masashi

    2002-11-01

    To clarify heart rate modulation by the sympathetic nervous system, dogs with naturally acquired and experimentally induced heart failure were examined. Heart rate and plasma catecholamine concentrations were measured in clinically healthy dogs (control dogs) and dogs with mitral regurgitation (MR) during a resting period, a standing period, a period of standing in a medical examination room (to which the dogs were unaccustomed), a running period, and a period of recovery after running. The heart rate and plasma catecholamine concentration increased in control dogs during the standing period and the medical examination room period, relative to the resting period. However, dogs with MR did not exhibit any clear increase in heart rate or catecholamine concentration under these light stress conditions. Running stress increased plasma catecholamine levels in control dogs; however, dogs with MR did not exhibit any significant changes. Thirty-two dogs with naturally acquired heart disease were classified as grades I to III on the ISACHC scale. The degree of increase in heart rate and plasma catecholamine levels in dogs with naturally acquired heart failure depended on their degree of heart failure. In conclusion, an increased heart rate and an activated sympathetic nervous system were observed, even in mild heart failure. This chronically activated sympathetic activity is expected to increase myocardial oxygen consumption, myocardial hypertrophy, and fibrosis, and to portend a poorer prognosis in heart failure.

  20. Lower Bone Mass and Higher Bone Resorption in Pheochromocytoma: Importance of Sympathetic Activity on Human Bone.

    Science.gov (United States)

    Kim, Beom-Jun; Kwak, Mi Kyung; Ahn, Seong Hee; Kim, Hyeonmok; Lee, Seung Hun; Song, Kee-Ho; Suh, Sunghwan; Kim, Jae Hyeon; Koh, Jung-Min

    2017-08-01

    Despite the apparent biological importance of sympathetic activity on bone metabolism in rodents, its role in humans remains questionable. To clarify the link between the sympathetic nervous system and the skeleton in humans. Among 620 consecutive subjects with newly diagnosed adrenal incidentaloma, 31 patients with histologically confirmed pheochromocytoma (a catecholamine-secreting neuroendocrine tumor) and 280 patients with nonfunctional adrenal incidentaloma were defined as cases and controls, respectively. After adjustment for confounders, subjects with pheochromocytoma had 7.2% lower bone mass at the lumbar spine and 33.5% higher serum C-terminal telopeptide of type 1 collagen (CTX) than those without pheochromocytoma (P = 0.016 and 0.001, respectively), whereas there were no statistical differences between groups in bone mineral density (BMD) at the femur neck and total hip and in serum bone-specific alkaline phosphatase (BSALP) level. The odds ratio (OR) for lower BMD at the lumbar spine in the presence of pheochromocytoma was 3.31 (95% confidence interval, 1.23 to 8.56). However, the ORs for lower BMD at the femur neck and total hip did not differ according to the presence of pheochromocytoma. Serum CTX level decreased by 35.2% after adrenalectomy in patients with pheochromocytoma, whereas serum BSALP level did not change significantly. This study provides clinical evidence showing that sympathetic overstimulation in pheochromocytoma can contribute to adverse effects on human bone through the increase of bone loss (especially in trabecular bone), as well as bone resorption.

  1. Influence of ventilation and hypocapnia on sympathetic nerve responses to hypoxia in normal humans.

    Science.gov (United States)

    Somers, V K; Mark, A L; Zavala, D C; Abboud, F M

    1989-11-01

    The sympathetic response to hypoxia depends on the interaction between chemoreceptor stimulation (CRS) and the associated hyperventilation. We studied this interaction by measuring sympathetic nerve activity (SNA) to muscle in 13 normal subjects, while breathing room air, 14% O2, 10% O2, and 10% O2 with added CO2 to maintain isocapnia. Minute ventilation (VE) and blood pressure (BP) increased significantly more during isocapnic hypoxia (IHO) than hypocapnic hypoxia (HHO). In contrast, SNA increased more during HHO [40 +/- 10% (SE)] than during IHO (25 +/- 19%, P less than 0.05). To determine the reason for the lesser increase in SNA with IHO, 11 subjects underwent voluntary apnea during HHO and IHO. Apnea potentiated the SNA responses to IHO more than to HHO. SNA responses to IHO were 17 +/- 7% during breathing and 173 +/- 47% during apnea whereas SNA responses to HHO were 35 +/- 8% during breathing and 126 +/- 28% during apnea. During ventilation, the sympathoexcitation of IHO (compared with HHO) is suppressed, possibly for two reasons: 1) because of the inhibitory influence of activation of pulmonary afferents as a result of a greater increase in VE, and 2) because of the inhibitory influence of baroreceptor activation due to a greater rise in BP. Thus in humans, the ventilatory response to chemoreceptor stimulation predominates and restrains the sympathetic response. The SNA response to chemoreceptor stimulation represents the net effect of the excitatory influence of the chemoreflex and the inhibitory influence of pulmonary afferents and baroreceptor afferents.

  2. Less of insulin desensitization in sympathetic nerve terminals from wistar rats with insulin resistance.

    Science.gov (United States)

    Chi, T C; Liu, I M; Cheng, J T

    2000-04-12

    In an attempt to determine the effect of hyperinsulinemia on sympathetic function, release of norepinephrine (NE) from isolated aorta by insulin was measured in Wistar rats with insulin resistance. Insulin resistance was produced when the hypoglycemic action of glibenclamide at a dose of 10 mg/kg was almost abolished in rats that received daily injections of long-acting insulin for 15 days. Moreover, the stimulatory effect of insulin on glucose uptake was markedly reduced in both skeletal muscle strips and white adipocytes obtained from these rats with insulin resistance. However, the stimulatory effects of insulin at concentrations from 5 to 15 U/l on the release of NE from the aortic strip of insulin-resistant rats were not modified in the same manner but only slightly reduced compared with that of normal rats. These results suggest that insulin desensitization was produced later in sympathetic nerve terminals than in other organs in insulin-resistant rats and this may be helpful to explain the sympathetic hyperactivity associated with diabetes in clinics.

  3. Distinct Nav1.7-dependent pain sensations require different sets of sensory and sympathetic neurons.

    Science.gov (United States)

    Minett, Michael S; Nassar, Mohammed A; Clark, Anna K; Passmore, Gayle; Dickenson, Anthony H; Wang, Fan; Malcangio, Marzia; Wood, John N

    2012-04-24

    Human acute and inflammatory pain requires the expression of voltage-gated sodium channel Nav1.7 but its significance for neuropathic pain is unknown. Here we show that Nav1.7 expression in different sets of mouse sensory and sympathetic neurons underlies distinct types of pain sensation. Ablating Nav1.7 gene (SCN9A) expression in all sensory neurons using Advillin-Cre abolishes mechanical pain, inflammatory pain and reflex withdrawal responses to heat. In contrast, heat-evoked pain is retained when SCN9A is deleted only in Nav1.8-positive nociceptors. Surprisingly, responses to the hotplate test, as well as neuropathic pain, are unaffected when SCN9A is deleted in all sensory neurons. However, deleting SCN9A in both sensory and sympathetic neurons abolishes these pain sensations and recapitulates the pain-free phenotype seen in humans with SCN9A loss-of-function mutations. These observations demonstrate an important role for Nav1.7 in sympathetic neurons in neuropathic pain, and provide possible insights into the mechanisms that underlie gain-of-function Nav1.7-dependent pain conditions.

  4. Liver Afferents Contribute to Water Drinking-Induced Sympathetic Activation in Human Subjects: A Clinical Trial

    Science.gov (United States)

    May, Marcus; Gueler, Faikah; Barg-Hock, Hannelore; Heiringhoff, Karl-Heinz; Engeli, Stefan; Heusser, Karsten; Diedrich, André; Brandt, André; Strassburg, Christian P.; Tank, Jens; Sweep, Fred C. G. J.; Jordan, Jens

    2011-01-01

    Water drinking acutely increases sympathetic activity in human subjects. In animals, the response appears to be mediated through transient receptor potential channel TRPV4 activation on osmosensitive hepatic spinal afferents, described as osmopressor response. We hypothesized that hepatic denervation attenuates water drinking-induced sympathetic activation. We studied 20 liver transplant recipients (44±2.6 years, 1.2±0.1 years post transplant) as model of hepatic denervation and 20 kidney transplant recipients (43±2.6 years, 0.8±0.1 years post transplant) as immunosuppressive drug matched control group. Before and after 500 ml water ingestion, we obtained venous blood samples for catecholamine analysis. We also monitored brachial and finger blood pressure, ECG, and thoracic bioimpedance. Plasma norepinephrine concentration had changed by 0.01±0.07 nmol/l in liver and by 0.21±0.07 nmol/l in kidney transplant recipients (pwater drinking. While blood pressure and systemic vascular resistance increased in both groups, the responses tended to be attenuated in liver transplant recipients. Our findings support the idea that osmosensitive hepatic afferents are involved in water drinking-induced sympathetic activation in human subjects. Trial Registration ClinicalTrials.gov NCT01237431 PMID:22016786

  5. Important GABAergic mechanism within the NTS and the control of sympathetic baroreflex in SHR.

    Science.gov (United States)

    Moreira, Thiago S; Takakura, Ana C; Colombari, Eduardo

    2011-01-20

    Inhibitory neurotransmission has an important role in the processing of sensory afferent signals in the nucleus of the solitary tract (NTS), particularly in spontaneously hypertensive rats (SHR). In the present study, we tested the hypothesis that γ-aminobutyric acid (GABA) mediated neurotransmission within the NTS produces an inhibition of the baroreflex response of splanchnic sympathetic nerve discharge (sSND). In urethane-anesthetized, artificially ventilated and vagotomized male SHR and Wistar Kyoto (WKY) rats we compared baroreflex-response curves evoked after bilateral injections into the NTS of the GABA-A antagonist bicuculline (25pmol/50nl) or the GABA-B antagonist CGP 35348 (5nmol/50nl). Baseline MAP in SHR was higher than the WKY rats (SHR: 153±5, vs. WKY: 112±6mm Hg, pNTS induced a transient (5min) reduction in MAP (∆=-26±4 and -41±6mm Hg, respectively vs. saline ∆=+4±3mmHg, pNTS in WKY rats did not change MAP, sSND and sympathetic baroreflex gain. These data indicate that GABAergic mechanisms within the NTS act tonically reducing sympathetic baroreflex gain in SHR.

  6. Augmented supraorbital skin sympathetic nerve activity responses to symptom trigger events in rosacea patients.

    Science.gov (United States)

    Metzler-Wilson, Kristen; Toma, Kumika; Sammons, Dawn L; Mann, Sarah; Jurovcik, Andrew J; Demidova, Olga; Wilson, Thad E

    2015-09-01

    Facial flushing in rosacea is often induced by trigger events. However, trigger causation mechanisms are currently unclear. This study tested the central hypothesis that rosacea causes sympathetic and axon reflex-mediated alterations resulting in trigger-induced symptomatology. Twenty rosacea patients and age/sex-matched controls participated in one or a combination of symptom triggering stressors. In protocol 1, forehead skin sympathetic nerve activity (SSNA; supraorbital microneurography) was measured during sympathoexcitatory mental (2-min serial subtraction of novel numbers) and physical (2-min isometric handgrip) stress. In protocol 2, forehead skin blood flow (laser-Doppler flowmetry) and transepithelial water loss/sweat rate (capacitance hygrometry) were measured during sympathoexcitatory heat stress (whole body heating by perfusing 50°C water through a tube-lined suit). In protocol 3, cheek, forehead, forearm, and palm skin blood flow were measured during nonpainful local heating to induce axon reflex vasodilation. Heart rate (HR) and mean arterial pressure (MAP) were recorded via finger photoplethysmography to calculate cutaneous vascular conductance (CVC; flux·100/MAP). Higher patient transepithelial water loss was observed (rosacea 0.20 ± 0.02 vs. control 0.10 ± 0.01 mg·cm(-2)·min(-1), P rosacea and controls, respectively) stress was augmented in rosacea (both P rosacea compared with controls. No axon reflex vasodilation differences were observed between groups. These data indicate that rosacea affects SSNA and that hyperresponsiveness to trigger events appears to have a sympathetic component.

  7. Liver afferents contribute to water drinking-induced sympathetic activation in human subjects: a clinical trial.

    Directory of Open Access Journals (Sweden)

    Marcus May

    Full Text Available UNLABELLED: Water drinking acutely increases sympathetic activity in human subjects. In animals, the response appears to be mediated through transient receptor potential channel TRPV4 activation on osmosensitive hepatic spinal afferents, described as osmopressor response. We hypothesized that hepatic denervation attenuates water drinking-induced sympathetic activation. We studied 20 liver transplant recipients (44±2.6 years, 1.2±0.1 years post transplant as model of hepatic denervation and 20 kidney transplant recipients (43±2.6 years, 0.8±0.1 years post transplant as immunosuppressive drug matched control group. Before and after 500 ml water ingestion, we obtained venous blood samples for catecholamine analysis. We also monitored brachial and finger blood pressure, ECG, and thoracic bioimpedance. Plasma norepinephrine concentration had changed by 0.01±0.07 nmol/l in liver and by 0.21±0.07 nmol/l in kidney transplant recipients (p<0.05 between groups after 30-40 minutes of water drinking. While blood pressure and systemic vascular resistance increased in both groups, the responses tended to be attenuated in liver transplant recipients. Our findings support the idea that osmosensitive hepatic afferents are involved in water drinking-induced sympathetic activation in human subjects. TRIAL REGISTRATION: ClinicalTrials.gov NCT01237431.

  8. Estrogen-induced collagen reorientation correlates with sympathetic denervation of the rat myometrium.

    Science.gov (United States)

    Martínez, G F; Bianchimano, P; Brauer, M M

    2016-12-01

    Estrogen inhibits the growth and causes the degeneration (pruning) of sympathetic nerves supplying the rat myometrium. Previous cryoculture studies evidenced that substrate-bound signals contribute to diminish the ability of the estrogenized myometrium to support sympathetic nerve growth. Using electron microscopy, here we examined neurite-substrate interactions in myometrial cryocultures, observing that neurites grew associated to collagen fibrils present in the surface of the underlying cryosection. In addition, we assessed quantitatively the effects of estrogen on myometrial collagen organization in situ, using ovariectomized rats treated with estrogen and immature females undergoing puberty. Under low estrogen levels, most collagen fibrils were oriented in parallel to the muscle long axis (83% and 85%, respectively). Following estrogen treatment, 89% of fibrils was oriented perpendicularly to the muscle main axis; while after puberty, 57% of fibrils acquired this orientation. Immunohistochemistry combined with histology revealed that the vast majority of fine sympathetic nerve fibers supplying the myometrium courses within the areas where collagen realignment was observed. Finally, to assess whether depending on their orientation collagen fibrils can promote or inhibit neurite outgrowth, we employed cryocultures, now using as substrate tissue sections of rat-tail tendon. We observed that neurites grew extensively in the direction of the parallel-aligned collagen fibrils in the tendon main axis but were inhibited to grow perpendicularly to this axis. Collectively, these findings support the hypothesis that collagen reorientation may be one of the factors contributing to diminish the neuritogenic capacity of the estrogen-primed myometrial substrate.

  9. Is reduced myocardial sympathetic innervation associated with clinical symptoms of autonomic impairment in idiopathic Parkinson's disease?

    Science.gov (United States)

    Guidez, Daniel; Behnke, Stefanie; Halmer, Ramona; Dillmann, Ulrich; Faßbender, Klaus; Kirsch, Carl M; Hellwig, Dirk; Spiegel, Jörg

    2014-01-01

    Patients with idiopathic Parkinson's disease (IPD) have a reduced myocardial MIBG uptake in MIBG scintigraphy, indicating myocardial sympathetic denervation. We were interested whether this myocardial sympathetic denervation coincides with clinical symptoms of autonomic impairment in IPD patients. We performed MIBG scintigraphy, the SCOPA-AUT scale, a standardized medical history (developed in our clinic) and autonomic nervous system testing in 47 IPD patients (21 female, 26 male patients). We correlated myocardial MIBG uptake with the results of the SCOPA-AUT scale, the standardized medical history and the autonomic nervous system testing through the use of Spearman's correlation. Myocardial MIBG uptake correlated significantly (p autonomic nervous system testing (all patients: sum score, Ewing orthostasis test). Remarkably, we found more significant correlations in male than in female patients. Reduced myocardial sympathetic innervation-as revealed by MIBG scintigraphy-is associated with clinical symptoms of autonomic impairment. This association is more pronounced in male than in female patients. The cause for this gender-specific phenomenon is unclear.

  10. Direct conscious telemetry recordings demonstrate increased renal sympathetic nerve activity in rats with chronic kidney disease.

    Science.gov (United States)

    Salman, Ibrahim M; Sarma Kandukuri, Divya; Harrison, Joanne L; Hildreth, Cara M; Phillips, Jacqueline K

    2015-01-01

    Chronic kidney disease (CKD) is associated with sympathetic hyperactivity and impaired blood pressure control reflex responses, yet direct evidence demonstrating these features of autonomic dysfunction in conscious animals is still lacking. Here we measured renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) using telemetry-based recordings in a rat model of CKD, the Lewis Polycystic Kidney (LPK) rat, and assessed responses to chemoreflex activation and acute stress. Male LPK and Lewis control animals (total n = 16) were instrumented for telemetric recording of RSNA and MAP. At 12-13 weeks-of-age, resting RSNA and MAP, sympathetic and haemodynamic responses to both peripheral (hypoxia: 10% O2) and central chemoreflex (hypercapnia: 7% CO2) activation and acute stress (open-field exposure), were measured. As indicators of renal function, urinary protein (UPro) and creatinine (UCr) levels were assessed. LPK rats had higher resting RSNA (1.2 ± 0.1 vs. 0.6 ± 0.1 μV, p dual conscious telemetry recording of RSNA and MAP in a genetic rodent model of CKD. Elevated RSNA is likely a key contributor to the marked hypertension in this model, while attenuated RSNA and MAP responses to central chemoreflex activation and acute stress in the LPK indicate possible deficits in the neural processing of autonomic outflows evoked by these sympathoexcitatory pathways.

  11. Sympathetic cardiac hyperinnervation and atrial autonomic imbalance in diet-induced obesity promote cardiac arrhythmias.

    Science.gov (United States)

    McCully, Belinda H; Hasan, Wohaib; Streiff, Cole T; Houle, Jennifer C; Woodward, William R; Giraud, George D; Brooks, Virginia L; Habecker, Beth A

    2013-11-15

    Obesity increases the risk of arrhythmias and sudden cardiac death, but the mechanisms are unknown. This study tested the hypothesis that obesity-induced cardiac sympathetic outgrowth and hyperinnervation promotes the development of arrhythmic events. Male Sprague-Dawley rats (250-275 g), fed a high-fat diet (33% kcal/fat), diverged into obesity-resistant (OR) and obesity-prone (OP) groups and were compared with rats fed normal chow (13% kcal/fat; CON). In vitro experiments showed that both OR and OP rats exhibited hyperinnervation of the heart and high sympathetic outgrowth compared with CON rats, even though OR rats are not obese. Despite the hyperinnervation and outgrowth, we showed that, in vivo, OR rats were less susceptible to arrhythmic events after an intravenous epinephrine challenge compared with OP rats. On examining total and stimulus-evoked neurotransmitter levels in an ex vivo system, we demonstrate that atrial acetylcholine content and release were attenuated in OP compared with OR and CON groups. OP rats also expressed elevated atrial norepinephrine content, while norepinephrine release was suppressed. These findings suggest that the consumption of a high-fat diet, even in the absence of overt obesity, stimulates sympathetic outgrowth and hyperinnervation of the heart. However, normalized cardiac parasympathetic nervous system control may protect the heart from arrhythmic events.

  12. Should the sympathetic nervous system be a target to improve cardiometabolic risk in obesity?

    Science.gov (United States)

    Lambert, Elisabeth A; Straznicky, Nora E; Dixon, John B; Lambert, Gavin W

    2015-07-15

    The sympathetic nervous system (SNS) plays a key role in both cardiovascular and metabolic regulation; hence, disturbances in SNS regulation are likely to impact on both cardiovascular and metabolic health. With excess adiposity, in particular when visceral fat accumulation is present, sympathetic activation commonly occurs. Experimental investigations have shown that adipose tissue releases a large number of adipokines, cytokines, and bioactive mediators capable of stimulating the SNS. Activation of the SNS and its interaction with adipose tissue may lead to the development of hypertension and end-organ damage including vascular, cardiac, and renal impairment and in addition lead to metabolic abnormalities, especially insulin resistance. Lifestyle changes such as weight loss and exercise programs considerably improve the cardiovascular and metabolic profile of subjects with obesity and decrease their cardiovascular risk, but unfortunately weight loss is often difficult to achieve and sustain. Pharmacological and device-based approaches to directly or indirectly target the activation of the SNS may offer some benefit in reducing the cardiometabolic consequences of obesity. Preliminary evidence is encouraging, but more trials are needed to investigate whether sympathetic inhibition could be used in obesity to reverse or prevent cardiometabolic disease development. The purpose of this review article is to highlight the current knowledge of the role that SNS plays in obesity and its associated metabolic disorders and to review the potential benefits of sympathoinhibition on metabolic and cardiovascular functions.

  13. Sympathetic nervous system activity is associated with obesity-induced subclinical organ damage in young adults.

    Science.gov (United States)

    Lambert, Elisabeth; Sari, Carolina Ika; Dawood, Tye; Nguyen, Julie; McGrane, Mariee; Eikelis, Nina; Chopra, Reena; Wong, Chiew; Chatzivlastou, Kanella; Head, Geoff; Straznicky, Nora; Esler, Murray; Schlaich, Markus; Lambert, Gavin

    2010-09-01

    Excess weight is established as a major risk factor for cardiovascular diseases, particularly in young individuals. To get a better understanding of the pathophysiology underlying increased cardiovascular disease risk, we evaluated early signs of organ damage and their possible relationship to sympathetic nervous activity. Eighteen lean (body mass index obese (body mass index >25 kg/m(2)) healthy university students were included in the study. We comprehensively assessed subclinical target organ damage, including the following: (1) assessment of renal function; (2) left ventricular structure and systolic and diastolic function; and (3) endothelial function. Muscle sympathetic nervous activity was assessed by microneurography. Participants with excess weight had decreased endothelial function (Pnervous activity (Pnervous activity (R(2)=0.244; Pnervous activity, after adjustment for body mass index, sex, and blood pressure (R(2)=0.318, P<0.01 and R(2)=0.312, P<0.05, respectively). Excess weight in young individuals is associated with subclinical alterations in renal and endothelial function, as well as in the structure of the heart, even in the absence of hypertension. Sympathetic activity is closely associated with cardiovascular and renal alterations observed in these subjects.

  14. Maturational changes in sympathetic and sensory innervation of the rat uterus: effects of neonatal capsaicin treatment.

    Science.gov (United States)

    Brauer, M M; Lincoln, J; Sarner, S; Blundell, D; Milner, P; Passaro, M; Burnstock, G

    1994-04-01

    The plasticity of the sympathetic and sensory innervation of the rat uterus was examined, before and after puberty, in controls and in animals where primary sensory nerves had been destroyed by neonatal capsaicin treatment. Immunohistochemical and histochemical methods were used in association with nerve density measurements and biochemical assays. The main findings were as follows: (1) Puberty was associated with a marked increase in the weight of the uterine horn, uterine cervix and parametrial tissue. This was unaffected by capsaicin treatment. (2) The sympathetic innervation of the uterine horn and parametrial tissue was reduced following puberty as revealed by a decrease in the density of noradrenaline-containing nerves and a marked decrease in the tissue concentration of noradrenaline. Sympathetic nerves supplying the uterine cervix and the blood vessels of the uterus appeared to be unaffected by puberty. (3) In contrast, the sensory supply of the uterus by substance P and calcitonin gene-related peptide-containing nerves increased in parallel with uterine growth during puberty resulting in no change in nerve density and only a slight reduction in peptide concentration. (4) Neonatal capsaicin treatment caused a long-lasting depletion of substance P- and calcitonin gene-related peptide-containing nerves. In the uterine horn and parametrial tissue, capsaicin-resistant calcitonin gene-related peptide, but not substance P, still increased with tissue weight during puberty, indeed, in the uterine horn, the relative increase was greater than in controls. (5) Sensory denervation resulted in an increase in the non-vascular sympathetic supply of the uterus, although there was a regional variation in the time course of the response. Perivascular sympathetic nerves were unaffected by capsaicin treatment. The pattern of change in non-vascular noradrenaline-containing nerves associated with puberty was similar in nature to controls. Thus, there is considerable plasticity

  15. A Case Report of Renal Sympathetic Denervation for the Treatment of Polymorphic Ventricular Premature Complexes

    Science.gov (United States)

    Kiuchi, Márcio Galindo; Vitorio, Frederico Puppim; da Silva, Gustavo Ramalho; Paz, Luis Marcelo Rodrigues; Souto, Gladyston Luiz Lima

    2015-01-01

    Abstract Premature ventricular complexes are very common, appearing most frequently in patients with hypertension, obesity, sleep apnea, and structural heart disease. Sympathetic hyperactivity plays a critical role in the development, maintenance, and aggravation of ventricular arrhythmias. Recently, Armaganijan et al reported the relevance of sympathetic activation in patients with ventricular arrhythmias and suggested a potential role for catheter-based renal sympathetic denervation in reducing the arrhythmic burden. In this report, we describe a 32-year-old hypertensive male patient presenting with a high incidence of polymorphic premature ventricular complexes on a 24 hour Holter monitor. Beginning 1 year prior, the patient experienced episodes of presyncope, syncope, and tachycardia palpitations. The patient was taking losartan 100 mg/day, which kept his blood pressure (BP) under control, and sotalol 160 mg twice daily. Bisoprolol 10 mg/day was used previously but was not successful for controlling the episodes. The 24 hour Holter performed after the onset of sotalol 160 mg twice daily showed a heart rate ranging between 48 (minimum)–78 (average)–119 (maximum) bpm; 14,286 polymorphic premature ventricular complexes; 3 episodes of nonsustained ventricular tachycardia, the largest composed of 4 beats at a rate of 197 bpm; and 14 isolated atrial ectopic beats. Cardiac magnetic resonance imaging with gadolinium perfusion performed at rest and under pharmacological stress with dipyridamole showed increased left atrial internal volume, preserved systolic global biventricular function, and an absence of infarcted or ischemic areas. The patient underwent bilateral renal sympathetic denervation. The only drug used postprocedure was losartan 25 mg/day. Three months after the patient underwent renal sympathetic denervation, the mean BP value dropped to 132/86 mmHg, the mean systolic/diastolic 24 hour ambulatory BP measurement was reduced to 128/83

  16. Lin28B and Let-7 in the Control of Sympathetic Neurogenesis and Neuroblastoma Development.

    Science.gov (United States)

    Hennchen, Melanie; Stubbusch, Jutta; Abarchan-El Makhfi, Ikram; Kramer, Marco; Deller, Thomas; Pierre-Eugene, Cécile; Janoueix-Lerosey, Isabelle; Delattre, Olivier; Ernsberger, Uwe; Schulte, Johannes B; Rohrer, Hermann

    2015-12-16

    The RNA binding protein Lin28B is expressed in developing tissues and sustains stem and progenitor cell identity as a negative regulator of the Let-7 family of microRNAs, which induces differentiation. Lin28B is activated in neuroblastoma (NB), a childhood tumor in sympathetic ganglia and adrenal medulla. Forced expression of Lin28B in embryonic mouse sympathoadrenal neuroblasts elicits postnatal NB formation. However, the normal function of Lin28B in the development of sympathetic neurons and chromaffin cells and the mechanisms involved in Lin28B-induced tumor formation are unclear. Here, we demonstrate a mirror-image expression of Lin28B and Let-7a in developing chick sympathetic ganglia. Lin28B expression is not restricted to undifferentiated progenitor cells but, is observed in proliferating noradrenergic neuroblasts. Lin28 knockdown in cultured sympathetic neuroblasts decreases proliferation, whereas Let-7 inhibition increases the proportion of neuroblasts in the cell cycle. Lin28B overexpression enhances proliferation, but only during a short developmental period, and it does not reduce Let-7a. Effects of in vivo Lin28B overexpression were analyzed in the LSL-Lin28B(DBHiCre) mouse line. Sympathetic ganglion and adrenal medulla volume and the expression level of Let-7a were not altered, although Lin28B expression increased by 12- to 17-fold. In contrast, Let-7a expression was strongly reduced in LSL-Lin28B(DbhiCre) NB tumor tissue. These data demonstrate essential functions for endogenous Lin28 and Let-7 in neuroblast proliferation. However, Lin28B overexpression neither sustains neuroblast proliferation nor affects let-7 expression. Thus, in contrast to other pediatric tumors, Lin28B-induced NB is not due to expansion of proliferating embryonic neuroblasts, and Let-7-independent functions are implicated during initial NB development. Lin28A/B proteins are highly expressed in early development and maintain progenitor cells by blocking the biogenesis and

  17. Effects of sympathetic stimulation on the rhythmical jaw movements produced by electrical stimulation of the cortical masticatory areas of rabbits.

    Science.gov (United States)

    Roatta, S; Windhorst, U; Djupsjöbacka, M; Lytvynenko, S; Passatore, M

    2005-03-01

    The somatomotor and sympathetic nervous systems are intimately linked. One example is the influence of peripheral sympathetic fibers on the discharge characteristics of muscle spindles. Since muscle spindles play important roles in various motor behaviors, including rhythmic movements, the working hypothesis of this research was that changes in sympathetic outflow to muscle spindles can change rhythmic movement patterns. We tested this hypothesis in the masticatory system of rabbits. Rhythmic jaw movements and EMG activity induced by long-lasting electrical cortical stimulation were powerfully modulated by electrical stimulation of the peripheral stump of the cervical sympathetic nerve (CSN). This modulation manifested itself as a consistent and marked reduction in the excursion of the mandibular movements (often preceded by a transient modest enhancement), which could be attributed mainly to corresponding changes in masseter muscle activity. These changes outlasted the duration of CSN stimulation. In some of the cortically evoked rhythmic jaw movements (CRJMs) changes in masticatory frequency were also observed. When the jaw-closing muscles were subjected to repetitive ramp-and-hold force pulses, the CRMJs changed characteristics. Masseter EMG activity was strongly enhanced and digastric EMG slightly decreased. This change was considerably depressed during CSN stimulation. These effects of CSN stimulation are similar in sign and time course to the depression exerted by sympathetic activity on the jaw-closing muscle spindle discharge. It is suggested that the change in proprioceptive information induced by an increase in sympathetic outflow (a) has important implications even under normal conditions for the control of motor function in states of high sympathetic activity, and (b) is one of the mechanisms responsible for motor impairment under certain pathological conditions such as chronic musculoskeletal head-neck disorders, associated with stress conditions.

  18. Expression of sympathetic nervous system genes in Lamprey suggests their recruitment for specification of a new vertebrate feature.

    Directory of Open Access Journals (Sweden)

    Daniela Häming

    Full Text Available The sea lamprey is a basal, jawless vertebrate that possesses many neural crest derivatives, but lacks jaws and sympathetic ganglia. This raises the possibility that the factors involved in sympathetic neuron differentiation were either a gnathostome innovation or already present in lamprey, but serving different purposes. To distinguish between these possibilities, we isolated lamprey homologues of transcription factors associated with peripheral ganglion formation and examined their deployment in lamprey embryos. We further performed DiI labeling of the neural tube combined with neuronal markers to test if neural crest-derived cells migrate to and differentiate in sites colonized by sympathetic ganglia in jawed vertebrates. Consistent with previous anatomical data in adults, our results in lamprey embryos reveal that neural crest cells fail to migrate ventrally to form sympathetic ganglia, though they do form dorsal root ganglia adjacent to the neural tube. Interestingly, however, paralogs of the battery of transcription factors that mediate sympathetic neuron differentiation (dHand, Ascl1 and Phox2b are present in the lamprey genome and expressed in various sites in the embryo, but fail to overlap in any ganglionic structures. This raises the intriguing possibility that they may have been recruited during gnathostome evolution to a new function in a neural crest derivative.

  19. Perfusion of isolated carotid sinus with hydrogen sulfide attenuated the renal sympathetic nerve activity in anesthetized male rats.

    Science.gov (United States)

    Guo, Q; Wu, Y; Xue, H; Xiao, L; Jin, S; Wang, R

    2016-07-18

    The purpose of the present study was to define the indirect central effect of hydrogen sulfide (H(2)S) on baroreflex control of sympathetic outflow. Perfusing the isolated carotid sinus with sodium hydrosulfide (NaHS), a H(2)S donor, the effect of H(2)S was measured by recording changes of renal sympathetic nerve activity (RSNA) in anesthetized male rats. Perfusion of isolated carotid sinus with NaHS (25, 50, 100 micromol/l) dose and time-dependently inhibited sympathetic outflow. Preconditioning of glibenclamide (20 micromol/l), a ATP-sensitive K(+) channels (K(ATP)) blocker, the above effect of NaHS was removed. With 1, 4-dihydro-2, 6-dimethyl-5-nitro-4-(2-[trifluoromethyl] phenyl) pyridine-3-carboxylic acid methyl ester (Bay K8644, 500 nmol/l) pretreatment, which is an agonist of L-calcium channels, the effect of NaHS was eliminated. Perfusion of cystathionine gamma-lyase (CSE) inhibitor, DL-propargylglycine (PPG, 200 micromol/l), increased sympathetic outflow. The results show that exogenous H(2)S in the carotid sinus inhibits sympathetic outflow. The effect of H(2)S is attributed to opening K(ATP) channels and closing the L-calcium channels.

  20. Noninvasive assessment of sympathetic vasoconstriction in human and rodent skeletal muscle using near-infrared spectroscopy and Doppler ultrasound.

    Science.gov (United States)

    Fadel, Paul J; Keller, David M; Watanabe, Hitoshi; Raven, Peter B; Thomas, Gail D

    2004-04-01

    The precise role of the sympathetic nervous system in the regulation of skeletal muscle blood flow during exercise has been challenging to define in humans, partly because of the limited techniques available for measuring blood flow in active muscle. Recent studies using near-infrared (NIR) spectroscopy to measure changes in tissue oxygenation have provided an alternative method to evaluate vasomotor responses in exercising muscle, but this approach has not been fully validated. In this study, we tested the hypothesis that sympathetic activation would evoke parallel changes in tissue oxygenation and blood flow in resting and exercising muscle. We simultaneously measured tissue oxygenation with NIR spectroscopy and blood flow with Doppler ultrasound in skeletal muscle of conscious humans (n = 13) and anesthetized rats (n = 9). In resting forearm of humans, reflex activation of sympathetic nerves with the use of lower body negative pressure produced graded decreases in tissue oxygenation and blood flow that were highly correlated (r = 0.80, P blood flow velocity that were highly correlated (r = 0.93, P blood flow evoked by sympathetic activation were significantly attenuated (P < 0.05 vs. rest) but remained highly correlated in both humans (r = 0.80, P < 0.006) and rats (r = 0.92, P < 0.0001). These data indicate that, during steady-state metabolic conditions, changes in tissue oxygenation can be used to reliably assess sympathetic vasoconstriction in both resting and exercising skeletal muscle.

  1. Marked loss of sympathetic nerve fibers in chronic Charcot foot of diabetic origin compared to ankle joint osteoarthritis.

    Science.gov (United States)

    Koeck, Franz-Xaver; Bobrik, Verena; Fassold, Alexander; Grifka, Joachim; Kessler, Sigurd; Straub, Rainer H

    2009-06-01

    The pathogenesis of Charcot foot is based on three disputed factors: (1) loss of neurotrophic influence, (2) microtraumatic lesions, and (3) neurovascular disturbances. These etiological causes were uncovered by clinicophysiological tests. However, no results of quantitative nerve density studies of sympathetic and sensory substance P-positive (SP+) nerve fibers are available. We studied the density of sympathetic and SP+ nerve fibers in three distinct areas of the tarsus. Fifteen patients with ankle osteoarthritis (OA) and 15 patients with diabetic Charcot foot were included. Patients with OA did not differ from those with Charcot foot in SP+ sensory nerve fiber density. However, at all three areas, the density of sympathetic nerve fibers was significantly lower in patients with Charcot foot compared to OA (p = 0.006). In addition, we found that the sympathetic nerve repellent factor semaphorin 3C was highly expressed in inflamed tissue in Charcot patients. In Charcot foot of diabetic origin a severe loss of sympathetic nerve fibers was observed. These findings in chronically inflamed Charcot foot lend support to the neurovascular theory in the late chronic phase, which probably depends on the inflammatory upregulation of nerve repellent factors.

  2. Sympathetic control of skeletal muscle function: possible co-operation between noradrenaline and neuropeptide Y in rabbit jaw muscles.

    Science.gov (United States)

    Grassi, C; Deriu, F; Roatta, S; Santarelli, R; Azzena, G B; Passatore, M

    1996-07-19

    Stimulation of the cervical sympathetic nerve at 10/s increases by 12.9 +/- 0.7% peak tension of maximal twitches in the directly stimulated jaw muscles and markedly depresses (41.6 +/- 1.3%) the tonic vibration reflex (TVR) elicited in the same muscles by vibration of the mandible. Both effects are not significantly influenced by administration of beta-adrenoceptor antagonists. When both alpha- and beta-adrenergic receptors are blocked, sympathetic stimulation induces a very small increase in twitch tension (3.8 +/- 0.7%), while no detectable change in the TVR is observed. Close arterial injection of alpha 1-adrenoceptor agonist phenylephrine mimics the effects induced by sympathetic stimulation on twitch tension and TVR, dose-dependently. The noradrenaline co-transmitter neuropeptide Y also produces a long-lasting, dose-dependent increase in the twitch tension which is unaffected by blockade of adrenergic receptors as well as of the neuromuscular junctions. Contribution of neuropeptide Y to the sympathetically-induced reduction of the stretch reflex is not clearly demonstrated. These data suggest that co-operation between noradrenaline and neuropeptide Y may be effective in determining sympathetic modulation of skeletal muscle function.

  3. Sympathetically-induced changes in microvascular cerebral blood flow and in the morphology of its low-frequency waves.

    Science.gov (United States)

    Deriu, F; Roatta, S; Grassi, C; Urciuoli, R; Micieli, G; Passatore, M

    1996-06-10

    The effect of bilateral cervical sympathetic nerve stimulation on microvascular cerebral blood flow, recorded at various depths in the parietal lobe and in ponto-mesencephalic areas, was investigated by laser-Doppler flowmetry in normotensive rabbits. These areas were chosen as representative of the vascular beds supplied by the carotid and vertebro-basilar systems, which exhibit different degrees of sympathetic innervation, the former being richer than the latter. Sympathetic stimulation at 30 imp/s affects cerebral blood flow in 77% of the parietal lobe and in 43% of the ponto-mesencephalic tested areas. In both cases the predominant effect was a reduction in blood flow (14.7 +/- 5.1% and 4.1 +/- 2.4%, respectively). The extent of the reduction in both areas was less if the stimulation frequency was decreased. Sometimes mean cerebral blood flow showed a small and transient increase, mainly in response to low-frequency stimulation. The morphology was analysed of low-frequency spontaneous oscillations in cerebral blood flow, attributed to vasomotion. Present in 41% of the tested areas (frequency 4-12 cycles/min, peak-to-peak amplitude 10-40% of mean value), these waves decreased in amplitude and increased in frequency during sympathetic stimulation, irrespective of changes in mean flow. The possibility has been proposed that the sympathetic action on low-frequency spontaneous oscillations may contribute to the protective influence that this system is known to exert on the blood-brain barrier in hypertension.

  4. A systematic review concerning the relation between the sympathetic nervous system and heart failure with preserved left ventricular ejection fraction.

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    Willemien L Verloop

    Full Text Available Heart failure with preserved left ventricular ejection fraction (HFPEF affects about half of all patients diagnosed with heart failure. The pathophysiological aspect of this complex disease state has been extensively explored, yet it is still not fully understood. Since the sympathetic nervous system is related to the development of systolic HF, we hypothesized that an increased sympathetic nerve activation (SNA is also related to the development of HFPEF. This review summarizes the available literature regarding the relation between HFPEF and SNA.Electronic databases and reference lists through April 2014 were searched resulting in 7722 unique articles. Three authors independently evaluated citation titles and abstracts, resulting in 77 articles reporting about the role of the sympathetic nervous system and HFPEF. Of these 77 articles, 15 were included for critical appraisal: 6 animal and 9 human studies. Based on the critical appraisal, we selected 9 articles (3 animal, 6 human for further analysis. In all the animal studies, isoproterenol was administered to mimic an increased sympathetic activity. In human studies, different modalities for assessment of sympathetic activity were used. The studies selected for further evaluation reported a clear relation between HFPEF and SNA.Current literature confirms a relation between increased SNA and HFPEF. However, current literature is not able to distinguish whether enhanced SNA results in HFPEF, or HFPEF results in enhanced SNA. The most likely setting is a vicious circle in which HFPEF and SNA sustain each other.

  5. Developmental androgen excess programs sympathetic tone and adipose tissue dysfunction and predisposes to a cardiometabolic syndrome in female mice.

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    Nohara, Kazunari; Waraich, Rizwana S; Liu, Suhuan; Ferron, Mathieu; Waget, Aurélie; Meyers, Matthew S; Karsenty, Gérard; Burcelin, Rémy; Mauvais-Jarvis, Franck

    2013-06-15

    Among women, the polycystic ovarian syndrome (PCOS) is considered a form of metabolic syndrome with reproductive abnormalities. Women with PCOS show increased sympathetic tone, visceral adiposity with enlarged adipocytes, hypoadiponectinemia, insulin resistance, glucose intolerance, increased inactive osteocalcin, and hypertension. Excess fetal exposure to androgens has been hypothesized to play a role in the pathogenesis of PCOS. Previously, we showed that neonatal exposure to the androgen testosterone (NT) programs leptin resistance in adult female mice. Here, we studied the impact of NT on lean and adipose tissues, sympathetic tone in cardiometabolic tissues, and the development of metabolic dysfunction in mice. Neonatally androgenized adult female mice (NTF) displayed masculinization of lean tissues with increased cardiac and skeletal muscle as well as kidney masses. NTF mice showed increased and dysfunctional white adipose tissue with increased sympathetic tone in both visceral and subcutaneous fat as well as increased number of enlarged and insulin-resistant adipocytes that displayed altered expression of developmental genes and hypoadiponectinemia. NTF exhibited dysfunctional brown adipose tissue with increased mass and decreased energy expenditure. They also displayed decreased undercarboxylated and active osteocalcin and were predisposed to obesity during chronic androgen excess. NTF showed increased renal sympathetic tone associated with increased blood pressure, and they developed glucose intolerance and insulin resistance. Thus, developmental exposure to testosterone in female mice programs features of cardiometabolic dysfunction, as can be observed in women with PCOS, including increased sympathetic tone, visceral adiposity, insulin resistance, prediabetes, and hypertension.

  6. Effect of pioglitazone on muscle sympathetic nerve activity in type 2 diabetes mellitus with α-glucosidase inhibitor.

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    Kobayashi, Daisuke; Takamura, Masayuki; Murai, Hisayoshi; Usui, Soichiro; Ikeda, Tatsunori; Inomata, Jun-ichiro; Takashima, Shin-ichiro; Kato, Takeshi; Furusho, Hiroshi; Takeshita, Yumie; Ota, Tsuguhito; Takamura, Toshinari; Kaneko, Shuichi

    2010-12-08

    Activation of the sympathetic nervous system is augmented in patients with type 2 diabetes mellitus (DM). Pioglitazone, an anti-diabetic drug, improves insulin resistance, but its influence on sympathetic nerve activity is not clear. To identify the relationship between insulin resistance and sympathetic activity, we examined muscle sympathetic nerve activity (MSNA) in controlled type 2 DM patients with alpha-glucosidase inhibitor (GI). We measured MSNA and calculated homeostasis model assessment of insulin resistance index (HOMA-IR) in twelve DM patients treated with alpha-GI and thirteen age-matched healthy subjects. In DM patients with alpha-GI, all parameters were reexamined after three months of treatment with pioglitazone. MSNA and HOMA-IR were significantly greater in DM patients with alpha-GI compared to healthy subjects. Hemoglobin A1c did not differ in DM patients before and after pioglitazone. However, pioglitazone significantly decreased MSNA in DM patients compared with alpha-GI (21.7±5.2 vs. 32.0±6.8 burst/min, ppioglitazone was similar to that in healthy subjects. HOMA-IR significantly decreased after pioglitazone, and a significant relationship was found between the absolute change in MSNA and HOMA-IR (r=0.65, ppioglitazone provides an additional effect on inhibition of sympathetic nerve activity.

  7. Acupuncture Attenuates Renal Sympathetic Activity and Blood Pressure via Beta-Adrenergic Receptors in Spontaneously Hypertensive Rats

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    Ye, Yang; Wang, Xue-Rui; Li, Fang; Xiao, Ling-Yong; Shi, Guang-Xia

    2017-01-01

    The sympathetic nervous system, via epinephrine and norepinephrine, regulates β-adrenergic receptor (β-AR) expression, and renal sympathetic activation causes sustained increases in blood pressure by enhanced renin release. In this study, we aim to investigate the effect and underlying mechanism of acupuncture at Taichong (LR3) on renal sympathetic activity in spontaneously hypertensive rats. Unanesthetized rats were subject to daily acupuncture for 2 weeks. Mean blood pressure (MBP) and heart rate variability (HRV) were monitored at days 0, 7, and 14 by radiotelemetry. After euthanasia on the 14th day, blood and the kidneys were collected and subject to the following analyses. Epinephrine and norepinephrine were detected by ELISA. The expression of β-ARs was studied by western blotting and PCR. The renin content was analyzed by radioimmunoassay. 14-day acupuncture significantly attenuates the increase of MBP. The HRV indices, the standard deviation of all normal NN intervals (SDNN), and the ratio of the low-frequency component to the high-frequency component (LF/HF) were improved following acupuncture. Renal sympathetic activation induced upregulation of epinephrine, norepinephrine, and renin content were attenuated by acupuncture. In addition, acupuncture decreased β1-AR expression and improved β2-AR expression. These results indicated that acupuncture relieves the increased MBP via the regulation of renal sympathetic activity and β-ARs. PMID:28270938

  8. The role of NGF in pregnancy-induced degeneration and regeneration of sympathetic nerves in the guinea pig uterus.

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    Brauer, M M; Shockley, K P; Chávez, R; Richeri, A; Cowen, T; Crutcher, K A

    2000-02-14

    In the guinea pig, pregnancy is associated with a generalised depletion of noradrenaline in uterine sympathetic nerves and, in the areas of the uterus surrounding the foetus, by a complete degeneration of sympathetic nerve fibres. These pregnancy-induced changes have been interpreted as a selective effect of placental hormones on the system of short sympathetic fibres arising from the paracervical ganglia. An alternative explanation is that pregnancy affects the neurotrophic capacity of the uterus. We measured NGF-protein levels in the guinea pig uterine horn, tubal end and cervix at early pregnancy, late pregnancy and early postpartum, using a two-site enzyme-linked immunosorbent assay. For comparative purposes the distribution and relative density of noradrenaline-containing sympathetic nerve fibres were assessed histochemically, and tissue levels of noradrenaline were measured biochemically, using high-performance liquid chromatography with electrochemical detection. In all the uterine regions analysed, NGF-protein levels showed a decline at term pregnancy, but in no case was this change statistically significant. After delivery, NGF-protein levels showed a marked increase in the cervix as well as in both the fertile and empty horns. These results suggest that alterations in NGF-protein do not account for the impairment of uterine sympathetic innervation during pregnancy, but may contribute to their recovery after delivery.

  9. Sympathetic nervous system activation reduces contraction-induced rapid vasodilation in the leg of humans independent of age.

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    Hughes, William E; Kruse, Nicholas T; Casey, Darren P

    2017-07-01

    Contraction-induced rapid vasodilation is attenuated similarly in the upper and lower limbs of older adults. In the forearm, this attenuation is in part due to a greater sympathetic vasoconstriction. We examined whether the age-related reduction in contraction-induced vasodilation in the leg is also due to a sympathetic vasoconstrictive mechanism. Thirteen young (24 ± 1 yr) and twelve older adults (67 ± 1 yr) performed single-leg knee extension at 20 and 40% of work-rate maximum (WRmax) during control and cold-pressor test (CPT) conditions. Femoral artery diameter and blood velocity were measured using Doppler ultrasound. Vascular conductance (VC; ml·min(-1)·mmHg(-1)) was calculated using blood flow (ml/min) and mean arterial pressure (mmHg). Peak (ΔVC from baseline) and total VC were blunted in older adults during control conditions across exercise intensities (P ROV). Within the forearm, this attenuation is partially due to enhanced sympathetic vasoconstriction. In the current study, we found that sympathetic vasoconstriction reduces contraction-induced ROV within the leg of both young and older adults, with the magnitude of change being similar between age groups. Our current results suggest that age-related attenuations in contraction-induced ROV within the leg are not fully explained by a sympathetic vasoconstrictor mechanism. Copyright © 2017 the American Physiological Society.

  10. Arachidonic acid incorporation and turnover is decreased in sympathetically denervated rat heart.

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    Patrick, Casey B; McHowat, Jane; Rosenberger, Thad A; Rapoport, Stanley I; Murphy, Eric J

    2005-06-01

    Heart sympathetic denervation can accompany Parkinson's disease, but the effect of this denervation on cardiac lipid-mediated signaling is unknown. To address this issue, rats were sympathetically denervated with 6-hydroxydopamine (6-OHDA, 50 mg/kg ip) and infused with 170 muCi/kg of either [1-(14)C]palmitic acid ([1-(14)C]16:0) or [1-(14)C]arachidonic acid ([1-(14)C]20:4 n-6), and kinetic parameters were assessed using a steady-state radiotracer model. Heart norepinephrine and epinephrine levels were decreased 82 and 85%, respectively, in denervated rats, and this correlated with a 34% reduction in weight gain in treated rats. Fatty acid tracer uptake was not significantly different between groups for either tracer, although the dilution coefficient lambda was increased in [1-(14)C]20:4 n-6-infused rats, which indicates that less 20:4 n-6 was recycled in denervated rats. In [1-(14)C]16:0-infused rats, incorporation rate and turnover values of 16:0 in stable lipid compartments were unchanged, which is indicative of preservation of beta-oxidation. In [1-(14)C]20:4 n-6-infused rats, there were dramatic reductions in incorporation rate (60-84%) and turnover value (56-85%) in denervated rats that were dependent upon the lipid compartment. In addition, phospholipase A(2) activity was reduced 40% in treated rats, which is consistent with the reduction observed in 20:4 n-6 turnover. These results demonstrate marked reductions in 20:4 n-6 incorporation rate and turnover in sympathetic denervated rats and thereby suggest an effect on lipid-mediated signal transduction mediated by a reduction in phospholipase A(2) activity.

  11. Effects of mildly increasing dialysis sodium removal on renin and sympathetic system in hemodialysis patients

    Institute of Scientific and Technical Information of China (English)

    Shen Yang; Sun Fang; Liu Jing; Ma Lijie; Huang Jing; Zhou Yilun; Liu Wenhu

    2014-01-01

    Background It has been argued that the benefits of reducing sodium loading may be offset by increased activation of the renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system.This study aimed to investigate the long-term effects of an increase in dialysis sodium removal on circulating RAAS and sympathetic system in hypertensive hemodialysis (HD) patients with "normal" post-HD volume status.Methods Thirty hypertensive HD patients were enrolled in this pilot trial.After one month period of dialysis with standard dialysate sodium of 138 mmol/L,the patients were followed up for a four months period with dialysate sodium set at 136 mmol/L,without changes in instructions regarding dietary sodium control.During the period of study,the dry weight was adjusted monthly under the guidance of bioimpedance spectroscopy to maintain post-HD volume status in a steady state; 44-hour ambulatory blood pressure,plasma renin,angiotensin Ⅱ (Ang Ⅱ),aldosterone,and norepinephrine (NE) were measured.Results After four months of HD with low dialysate sodium of 136 mmol/L,44-hour systolic and diastolic blood pressures (BPs) were significantly lower (-10 and-6 mmHg),in the absence of changes in antihypertensive medications.No significant changes were observed in plasma renin,Ang Ⅱ,aldosterone,and NE concentrations.The post-HD volume parameters were kept constant.Conclusion Mildly increasing dialysis sodium removal over 4 months can significantly improve BP control and does not activate circulating RAAS and sympathetic nervous system in hypertensive HD patients.

  12. Muscle afferent receptors engaged in augmented sympathetic responsiveness in peripheral artery disease

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    Jianhua eLi

    2012-07-01

    Full Text Available The exercise pressor reflex (EPR is a neural control mechanism responsible for the cardiovascular responses to exercise. As exercise is initiated, thin fiber muscle afferent nerves are activated by mechanical and metabolic stimuli arising in the contracting muscles. This leads to reflex increases in arterial blood pressure and heart rate primarily through activation of sympathetic nerve activity (SNA. Studies of humans and animals have indicated that the EPR is exaggerated in a number of cardiovascular diseases. For the last several years, studies have specifically employed a rodent model to examine the mechanisms at receptor and cellular levels by which responses of SNA and blood pressure to static exercise are heightened in peripheral artery disease (PAD, one of the most common cardiovascular disorders. A rat model of this disease has well been established. Specifically, femoral artery occlusion is used to study intermittent claudication that is observed in human PAD. The receptors on thin fiber muscle afferents that are engaged in this disease include transient receptor potential vanilloid type 1 (TRPV1, purinergic P2X and acid sensing ion channel (ASIC. The role played by nerve growth factor (NGF in regulating those sensory receptors in the processing of amplified EPR was also investigated. The purpose of this review is to focus on a theme namely that PAD accentuates autonomic reflex responses to exercise and further address regulatory mechanisms leading to abnormal sympathetic responsiveness. This review will present some of recent results in regard with several receptors in muscle sensory neurons in contribution to augmented autonomic reflex responses in PAD. Review of the findings from recent studies would lead to a better understanding in integrated processing of sympathetic nervous system in PAD.

  13. Reduced sympathetic nervous activity. A potential mechanism predisposing to body weight gain.

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    Spraul, M; Ravussin, E; Fontvieille, A M; Rising, R; Larson, D E; Anderson, E A

    1993-01-01

    The sympathetic nervous system is recognized to play a role in the etiology of animal and possibly human obesity through its impact on energy expenditure and/or food intake. We, therefore, measured fasting muscle sympathetic nerve activity (MSNA) in the peroneal nerve and its relationship with energy expenditure and body composition in 25 relatively lean Pima Indian males (means +/- SD; 26 +/- 6 yr, 82 +/- 19 kg, 28 +/- 10% body fat) and 19 Caucasian males (29 +/- 5 yr, 81 +/- 13 kg, 24 +/- 9% body fat). 24-h energy expenditure, sleeping metabolic rate, and resting metabolic rate were measured in a respiratory chamber, whereas body composition was estimated by hydrodensitometry. Pima Indians had lower MSNA than Caucasians (23 +/- 6 vs 33 +/- 10 bursts/min, P = 0.0007). MSNA was significantly related to percent body fat in Caucasians (r = 0.55, P = 0.01) but not in Pimas. MSNA also correlated with energy expenditure adjusted for fat-free mass, fat mass, and age in Caucasians (r = 0.51, P = 0.03; r = 0.54, P = 0.02; and r = 0.53, P = 0.02 for adjusted 24-h energy expenditure, sleeping metabolic rate, and resting metabolic rate, respectively) but not in Pima Indians. In conclusion, the activity of the sympathetic nervous system is a determinant of energy expenditure in Caucasians. Individuals with low resting MSNA may be at risk for body weight gain resulting from a lower metabolic rate. A low resting MSNA and the lack of impact of MSNA on metabolic rate might play a role in the etiology of obesity in Pima Indians. PMID:8408625

  14. Sympathetic skin responses in hemiplegic patients with and without complex regional pain syndrome

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    Selçuk Barin

    2006-01-01

    Full Text Available Background and Aims: To investigate whether there were changes in the sympathetic skin responses (SSR in the limbs with complex regional pain syndrome (CRPS type I in hemiplegic patients. Setting: A physical medicine and rehabilitation center in Turkey . Materials and Methods: Sympathetic skin responses were evaluated in 69 stroke patients (41 with CRPS and 28 without CRPS and 20 healthy volunteers. SSR were recorded on the paretic and healthy hands after stimulation of the ipsilateral median nerve. Patients′ ages ranged from 33 to 77 years, with a mean of 60.0 ± 12.9 years. Results: The SSR were obtained in all patients with CRPS, whereas SSR was absent in 9 of 28 patients with hemiplegia who did not have CRPS after stimulation of the plegic side and the difference was statistically significant ( P =0.023. SSR amplitudes were increased at the hemiplegic limbs in patients affected by CRPS compared to individuals unaffected; this group difference was statistically significant ( P =0.014. The mean amplitude of the SSR in the advanced stage of CRPS was greater than lower stage and the difference was statistically significant ( P =0.035. Conclusion: Our results suggest that SSR can be obtained in stroke patients with CRPS even in the early stages of CRPS. SSR acquirability and amplitude increase as the stage of the disease advances. As an electrophysiologic technique, SSR may be used in the evaluation of the sympathetic function in hemiplegic patients and also in the diagnosis of CRPS and in monitoring of its treatment.

  15. Sympathetic nervous system contributes to enhanced corticosterone levels following chronic stress.

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    Lowrance, Steven A; Ionadi, Amy; McKay, Erin; Douglas, Xavier; Johnson, John D

    2016-06-01

    Exposure to chronic stress often elevates basal circulating glucocorticoids during the circadian nadir and leads to exaggerated glucocorticoid production following exposure to subsequent stressors. While glucocorticoid production is primarily mediated by the hypothalamic-pituitary-adrenal (HPA) axis, there is evidence that the sympathetic nervous system can affect diurnal glucocorticoid production by direct actions at the adrenal gland. Experiments here were designed to examine the role of the HPA and sympathetic nervous system in enhancing corticosterone production following chronic stress. Rats were exposed to a four-day stress paradigm or control conditions then exposed to acute restraint stress on the fifth day to examine corticosterone and ACTH responses. Repeated stressor exposure resulted in a small increase in corticosterone, but not ACTH, during the circadian nadir, and also resulted in exaggerated corticosterone production 5, 10, and 20min following restraint stress. While circulating ACTH levels increased after 5min of restraint, levels were not greater in chronic stress animals compared to controls until following 20min. Administration of astressin (a CRH antagonist) prior to restraint stress significantly reduced ACTH responses but did not prevent the sensitized corticosterone response in chronic stress animals. In contrast, administration of chlorisondamine (a ganglionic blocker) returned basal corticosterone levels in chronic stress animals to normal levels and reduced early corticosterone production following restraint (up to 10min) but did not block the exaggerated corticosterone response in chronic stress animals at 20min. These data indicate that increased sympathetic nervous system tone contributes to elevated basal and rapid glucocorticoid production following chronic stress, but HPA responses likely mediate peak corticosterone responses to stressors of longer duration. Copyright © 2016. Published by Elsevier Ltd.

  16. The effect of inflammation on sympathetic nerve mediated contractions in rat isolated caudal artery.

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    Fotso Soh, Jocelyn; Strong, Hilary R; Daneshtalab, Noriko; Tabrizchi, Reza

    2016-12-05

    Chronic inflammatory process(es) contributes to changes in vascular function in a variety of diseases. Sympathetic nerve-mediated responses in blood vessels play a pivotal role in regular physiological functions. We tested the hypothesis that sympathetic neuro-effector function will be altered as consequence of inflammatory state. Sympathetic nerve-mediated contractions and alpha adrenergic receptor expressions were evaluated in isolated caudal arteries of rats treated with saline and Complete Freund's adjuvant (CFA). While CFA-treated animals had significantly higher plasma levels of tumor necrosis factor-alpha compared to saline, blood pressure remained unchanged. Immunofluorescence revealed increased expression of ionized calcium adapter binding molecule-1 in the adventitia of blood vessels from CFA-treated animals compared to saline. In isolated arteries, electrical field stimulations between 1.25 and 40Hz resulted in frequency-dependent contractions that wasabolished by tetrodotoxin. Neurogenic contractions from CFA groups were significantly greater than saline. While the presence of alpha1-adrenoceptor antagonist (prazosin) significantly inhibited contractions at lower frequencies of stimulation (1.25-5Hz) in isolated arteries of CFA-treated rats compared to controls, alpha2-adrenoceptor antagonist (rauwolscine) had modest effects. Inhibition of neuronal reuptake by cocaine comparably enhanced field-stimulated responses in vessels of experimental and control animals. Immunofluorescence revealed a difference in expression of alpha1- and alpha2-adrenoceptors in the endothelium of blood vessels of CFA compared to saline controls. Collectively, our observations lend support to enhanced neurogenic contractions in blood vessels of inflamed animals possibly attributing to alterations in responsiveness and/or distribution of post-junctional alpha1-adrenoceptors.

  17. Atrophy and neuron loss: effects of a protein-deficient diet on sympathetic neurons.

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    Gomes, Silvio Pires; Nyengaard, Jens Randel; Misawa, Rúbia; Girotti, Priscila Azevedo; Castelucci, Patrìcia; Blazquez, Francisco Hernandez Javier; de Melo, Mariana Pereira; Ribeiro, Antonio Augusto Coppi

    2009-12-01

    Protein deficiency is one of the biggest public health problems in the world, accounting for about 30-40% of hospital admissions in developing countries. Nutritional deficiencies lead to alterations in the peripheral nervous system and in the digestive system. Most studies have focused on the effects of protein-deficient diets on the enteric neurons, but not on sympathetic ganglia, which supply extrinsic sympathetic input to the digestive system. Hence, in this study, we investigated whether a protein-restricted diet would affect the quantitative structure of rat coeliac ganglion neurons. Five male Wistar rats (undernourished group) were given a pre- and postnatal hypoproteinic diet receiving 5% casein, whereas the nourished group (n = 5) was fed with 20% casein (normoproteinic diet). Blood tests were carried out on the animals, e.g., glucose, leptin, and triglyceride plasma concentrations. The main structural findings in this study were that a protein-deficient diet (5% casein) caused coeliac ganglion (78%) and coeliac ganglion neurons (24%) to atrophy and led to neuron loss (63%). Therefore, the fall in the total number of coeliac ganglion neurons in protein-restricted rats contrasts strongly with no neuron losses previously described for the enteric neurons of animals subjected to similar protein-restriction diets. Discrepancies between our figures and the data for enteric neurons (using very similar protein-restriction protocols) may be attributable to the counting method used. In light of this, further systematic investigations comparing 2-D and 3-D quantitative methods are warranted to provide even more advanced data on the effects that a protein-deficient diet may exert on sympathetic neurons. (c) 2009 Wiley-Liss, Inc.

  18. Pulmonary vein isolation in patients with paroxysmal atrial fibrillation is associated with regional cardiac sympathetic denervation

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    2013-01-01

    Background Circumferential pulmonary vein isolation (PVI) is the cornerstone of the current state-of-the-art management of atrial fibrillation (AF). However, the precise mechanisms behind AF relapses post PVI are still unknown. Since the activity of the autonomous nervous system is crucial in triggering paroxysmal AF, we hypothesized that PVI is associated with changes of cardiac sympathetic activity. Methods Sixteen patients with paroxysmal AF underwent cardiac iodine-123-meta-iodobenzylguanidine (123I-mIBG) planar cardiac imaging and single-photon emission computed tomography with low-dose computed tomography (SPECT/CT) for attenuation correction before and 4 weeks after PVI. The heart-to-mediastinum ratio (H/M ratio), washout rate (WR), regional myocardial uptake, and regional washout were analyzed. Results The late H/M ratio was unchanged by PVI (pre, 2.9 ± 0.5 vs. post, 2.7 ± 0.6, p = 0.53). Four of the 16 patients (25%) displayed regional deficits before PVI. After PVI, regional deficits were present in ten patients (62.5%) with newly emerging deficits localized in the inferolateral wall. In a 6-month follow-up, four out of the ten patients (40%) with regional 123I-mIBG defects suffered from a recurrence of AF, while only one of the six patients (16.7%) without a regional 123I-mIBG defect experienced a recurrence. Conclusion A significant number of patients with paroxysmal AF show regional cardiac sympathetic innervation deficits at baseline. In addition, PVI is associated with newly emerging defects. The presence of regional sympathetic denervation after PVI may correlate with the risk of AF relapses. PMID:24360192

  19. Bone morphogenetic protein-5 (BMP-5 promotes dendritic growth in cultured sympathetic neurons

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    Higgins Dennis

    2001-09-01

    Full Text Available Abstract Background BMP-5 is expressed in the nervous system throughout development and into adulthood. However its effects on neural tissues are not well defined. BMP-5 is a member of the 60A subgroup of BMPs, other members of which have been shown to stimulate dendritic growth in central and peripheral neurons. We therefore examined the possibility that BMP-5 similarly enhances dendritic growth in cultured sympathetic neurons. Results Sympathetic neurons cultured in the absence of serum or glial cells do not form dendrites; however, addition of BMP-5 causes these neurons to extend multiple dendritic processes, which is preceded by an increase in phosphorylation of the Smad-1 transcription factor. The dendrite-promoting activity of BMP-5 is significantly inhibited by the BMP antagonists noggin and follistatin and by a BMPR-IA-Fc chimeric protein. RT-PCR and immunocytochemical analyses indicate that BMP-5 mRNA and protein are expressed in the superior cervical ganglia (SCG during times of initial growth and rapid expansion of the dendritic arbor. Conclusions These data suggest a role for BMP-5 in regulating dendritic growth in sympathetic neurons. The signaling pathway that mediates the dendrite-promoting activity of BMP-5 may involve binding to BMPR-IA and activation of Smad-1, and relative levels of BMP antagonists such as noggin and follistatin may modulate BMP-5 signaling. Since BMP-5 is expressed at relatively high levels not only in the developing but also the adult nervous system, these findings suggest the possibility that BMP-5 regulates dendritic morphology not only in the developing, but also the adult nervous system.

  20. Jaw-thrust induces sympathetic responses during induction of general anesthesia.

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    Park, Sang-Jin; Kim, Bum Soo; Jee, Dae-Lim

    2013-08-01

    Jaw-thrust is a noxious stimulus that might induce sympathetic responses. The purpose of this study, was to evaluate the effects of jaw-thrust on sympathetic responses. We investigated seventy three patients. Patients who received general anesthesia were randomly divided into a control group (maintenance of combined airway maneuver with head tilt, open mouth by mouthpiece, and chin-lift, n = 30) and jaw-thrust group (maintenance of head tilt, open mouth and jaw-thrust, n = 30). In the jaw-thrust group, four minutes of endoscopy-guided force to the mandible to get the best laryngeal view were applied. For the control group, the combined airway maneuver was maintained during the same period. Arterial blood pressure (AP) and heart rate (HR) were recorded at predetermined time points (1 min before anesthesia induction, 2 min after fiberoptic bronchoscopy placement, and thereafter 1 min-interval during each airway maneuver) during jaw-thrust and chin-lift maneuver. The force amplitude applied for best laryngeal view during jaw-thrust was also measured. Peak systolic and diastolic AP increased 39.0 ± 17.6 and 39.9 ± 22.8 mmHg from the baseline (P thrust group. HR was also 32.5 ± 19.4 beats/min from the baseline (P thrust group. These remained high at all time points, compared with the control group (P thrust was not correlated to the AP and HR changes (P > 0.05). Performing the jaw-thrust maneuver induces significant sympathetic responses, irrespective of the force magnitude.

  1. Cardiac Dysregulation and Myocardial Injury in a 6-Hydroxydopamine-Induced Rat Model of Sympathetic Denervation.

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    Yue-Hua Jiang

    Full Text Available Cardiac sympathetic denervation is found in various cardiac pathologies; however, its relationship with myocardial injury has not been thoroughly investigated.Twenty-four rats were assigned to the normal control group (NC, sympathectomy control group (SC, and a sympathectomy plus mecobalamin group (SM. Sympathectomy was induced by injection of 6-OHDA, after which, the destruction and distribution of sympathetic and vagal nerve in the left ventricle (LV myocardial tissue were determined by immunofluorescence and ELISA. Heart rate variability (HRV, ECG and echocardiography, and assays for myocardial enzymes in serum before and after sympathectomy were examined. Morphologic changes in the LV by HE staining and transmission electron microscope were used to estimate levels of myocardial injury and concentrations of inflammatory cytokines were used to reflect the inflammatory reaction.Injection of 6-OHDA decreased NE (933.1 ± 179 ng/L for SC vs. 3418.1± 443.6 ng/L for NC, P < 0.01 and increased NGF (479.4± 56.5 ng/mL for SC vs. 315.85 ± 28.6 ng/mL for NC, P < 0.01 concentrations. TH expression was reduced, while ChAT expression showed no change. Sympathectomy caused decreased HRV and abnormal ECG and echocardiography results, and histopathologic examinations showed myocardial injury and increased collagen deposition as well as inflammatory cell infiltration in the cardiac tissue of rats in the SC and SM groups. However, all pathologic changes in the SM group were less severe compared to those in the SC group.Chemical sympathectomy with administration of 6-OHDA caused dysregulation of the cardiac autonomic nervous system and myocardial injuries. Mecobalamin alleviated inflammatory and myocardial damage by protecting myocardial sympathetic nerves.

  2. Transcriptional responses of cultured rat sympathetic neurons during BMP-7-induced dendritic growth.

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    Michelle M Garred

    Full Text Available BACKGROUND: Dendrites are the primary site of synapse formation in the vertebrate nervous system; however, relatively little is known about the molecular mechanisms that regulate the initial formation of primary dendrites. Embryonic rat sympathetic neurons cultured under defined conditions extend a single functional axon, but fail to form dendrites. Addition of bone morphogenetic proteins (BMPs triggers these neurons to extend multiple dendrites without altering axonal growth or cell survival. We used this culture system to examine differential gene expression patterns in naïve vs. BMP-treated sympathetic neurons in order to identify candidate genes involved in regulation of primary dendritogenesis. METHODOLOGY/PRINCIPAL FINDINGS: To determine the critical transcriptional window during BMP-induced dendritic growth, morphometric analysis of microtubule-associated protein (MAP-2-immunopositive processes was used to quantify dendritic growth in cultures exposed to the transcription inhibitor actinomycin-D added at varying times after addition of BMP-7. BMP-7-induced dendritic growth was blocked when transcription was inhibited within the first 24 hr after adding exogenous BMP-7. Thus, total RNA was isolated from sympathetic neurons exposed to three different experimental conditions: (1 no BMP-7 treatment; (2 treatment with BMP-7 for 6 hr; and (3 treatment with BMP-7 for 24 hr. Affymetrix oligonucleotide microarrays were used to identify differential gene expression under these three culture conditions. BMP-7 significantly regulated 56 unique genes at 6 hr and 185 unique genes at 24 hr. Bioinformatic analyses implicate both established and novel genes and signaling pathways in primary dendritogenesis. CONCLUSIONS/SIGNIFICANCE: This study provides a unique dataset that will be useful in generating testable hypotheses regarding transcriptional control of the initial stages of dendritic growth. Since BMPs selectively promote dendritic growth in

  3. Increased Feeding Speed Is Associated with Higher Subsequent Sympathetic Activity in Dogs.

    Directory of Open Access Journals (Sweden)

    Nobuyo Ohtani

    Full Text Available Although the domestication process has altered the feeding behavior of dogs, some breeds still demonstrate a remarkable ability to gorge, and will eat exceptionally large quantities of food whenever it is available. Lesions in the ventromedial hypothalamus increase appetite and lead to obesity, suggesting that the autonomic nervous system plays an important role in feeding. Focusing on the autonomic activities closely involved in food intake, we investigated sympathetic activities before and after feeding in dogs. The subjects were 56 healthy dogs of 21 different breeds (29 males and 27 females. Based on feeding habits, the 56 dogs were divided into three groups: Fast (n = 19, Slow (n = 24 and Leftover (n = 13. The feeding speed and the amount of food per mouthful of the Fast dogs were significantly greater than those of the Slow and the Leftover dogs. The plasma norepinephrine level in dogs of the Fast group was significantly increased after feeding, while those in the Slow and Leftover groups were significantly decreased after feeding, compared with the pre-feeding concentrations. The low frequency/high frequency ratio of heart rate variability is a good indicator of sympathetic activity and was also significantly higher in the Fast group than in the other groups. Delayed feeding using automatic feeding equipment decreased the plasma norepinephrine concentration and low frequency/high frequency ratio observed after feeding in dogs of the Fast group. In conclusion, dogs eating rapidly with less chewing, which indicates increased sympathetic activity during feeding, may benefit from delayed feeding. The slow eating may activate the parasympathetic nervous system after feeding, which could enhance the activity of the digestive system.

  4. SYMPATHETIC SKIN RESPONSE AND GALVANIC SKIN RESISTANCE IN MALES WITH TYPE 2 DIABETES MELLITUS

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    Saravanan Mohanraj

    2016-06-01

    Full Text Available BACKGROUND Diabetes mellitus, a metabolic disorder affects the nervous system due to alteration in various metabolic pathways. As neuropathy manifests in longstanding diabetes mellitus, autonomic nervous system also gets affected. The study was started based on the hypothesis that the sweat glands innervated by autonomic nervous system will be affected in patients with type 2 diabetes mellitus patients with clinical features of neuropathy. This study was undertaken to compare the sympathetic skin response (SSR and galvanic skin resistance (GSR in males with type 2 diabetes mellitus and in controls. METHODS Thirty males in the age group of 45-55 years, known to have diabetes mellitus and having a history of neuropathic symptoms served as subjects and thirty males in the same age group with no history of diabetes mellitus and neuropathy served as controls. SSR and GSR were recorded using Recorders and Medicare Systems 4 channel polygraph in the noise and light reduced research laboratory, Department of Physiology. All the recordings were done between 10-12 noon at ambient temperature. SSR was measured by deep inspiration and the GSR was measured in the supine and standing response. Comparison of latency and amplitude of the sympathetic skin response and the percentage of decrease in galvanic skin resistance was done. RESULT A statistically significant delay in the latency and a reduction in the amplitude of sympathetic skin response was observed in the diabetes patients. There was a lesser percentage of decrease in GSR in the diabetic patients. CONCLUSION This study shows that the SSR and GSR responses are significantly reduced in diabetic individuals and can be used as a diagnostic tool in the detection of diabetic autonomic neuropathy.

  5. Direct conscious telemetry recordings demonstrate increased renal sympathetic nerve activity in rats with chronic kidney disease

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    Ibrahim M Salman

    2015-08-01

    Full Text Available Chronic kidney disease (CKD is associated with sympathetic hyperactivity and impaired blood pressure control reflex responses, yet direct evidence demonstrating these features of autonomic dysfunction in conscious animals is still lacking. Here we measured renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP using telemetry-based recordings in a rat model of CKD, the Lewis Polycystic Kidney (LPK rat, and assessed responses to chemoreflex activation and acute stress. Male LPK and Lewis control animals (total n=16 were instrumented for telemetric recording of RSNA and MAP. At 12–13 weeks-of-age, resting RSNA and MAP, sympathetic and haemodynamic responses to both peripheral (hypoxia: 10% O2 and central chemoreflex (hypercapnia: 7% CO2 activation and acute stress (open-field exposure, were measured. As indicators of renal function, urinary protein (UPro and creatinine (Ucr levels were assessed. LPK rats had higher resting RSNA (1.2±0.1 vs. 0.6±0.1 µV, p<0.05 and MAP (151±8 vs. 97±2 mmHg, p<0.05 compared to Lewis. MAP was negatively correlated with Ucr (r=-0.80, p=0.002 and positively correlated with RSNA (r=0.66, p=0.014, with multiple linear regression modeling indicating the strongest correlation was with Ucr. RSNA and MAP responses to activation of the central chemoreflex and open-field stress were reduced in the LPK relative to the Lewis (all p<0.05. This is the first description of dual conscious telemetry recording of RSNA and MAP in a genetic rodent model of CKD. Elevated RSNA is likely a key contributor to the marked hypertension in this model, while attenuated RSNA and MAP responses to central chemoreflex activation and acute stress in the LPK indicate possible deficits in the neural processing of autonomic outflows evoked by these sympathoexcitatory pathways.

  6. Intermedin in paraventricular nucleus attenuates sympathetic activity and blood pressure via nitric oxide in hypertensive rats.

    Science.gov (United States)

    Zhou, Ye-Bo; Sun, Hai-Jian; Chen, Dan; Liu, Tong-Yan; Han, Ying; Wang, Jue-Jin; Tang, Chao-Shu; Kang, Yu-Ming; Zhu, Guo-Qing

    2014-02-01

    Intermedin (IMD) is a member of calcitonin/calcitonin gene-related peptide family, which shares the receptor system consisting of calcitonin receptor-like receptor (CRLR) and receptor activity-modifying proteins (RAMPs). This study investigated the effects of IMD in paraventricular nucleus (PVN) on renal sympathetic nerve activity and mean arterial pressure and its downstream mechanism in hypertension. Rats were subjected to 2-kidney 1-clip (2K1C) surgery to induce renovascular hypertension or sham operation. Acute experiments were performed 4 weeks later under anesthesia. IMD mRNA and protein were downregulated in 2K1C rats. Bilateral PVN microinjection of IMD caused greater decreases in renal sympathetic nerve activity and mean arterial pressure in 2K1C rats than in sham-operated rats, which were prevented by pretreatment with adrenomedullin receptor antagonist AM22-52 or nonselective nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester, and attenuated by selective neuronal NO synthase inhibitor N(ω)-propyl-l-arginine hydrochloride or endothelial NO synthase inhibitor N(5)-(1-iminoethyl)-l-ornithine dihydrochloride. AM22-52 increased renal sympathetic nerve activity and mean arterial pressure in 2K1C rats but not in sham-operated rats, whereas calcitonin/calcitonin gene-related peptide receptor antagonist calcitonin/calcitonin gene-related peptide 8-37 had no significant effect. CRLR and RAMP3 mRNA, as well as CRLR, RAMP2, and RAMP3 protein expressions, in the PVN were increased in 2K1C rats. Microinjection of IMD into the PVN increased the NO metabolites (NOx) level in the PVN in 2K1C rats, which was prevented by AM22-52. Chronic PVN infusion of IMD reduced, but AM22-52 increased, blood pressure in conscious 2K1C rats. These results indicate that IMD in the PVN inhibits sympathetic activity and attenuates hypertension in 2K1C rats, which are mediated by adrenomedullin receptors (CRLR/RAMP2 or CRLR/RAMP3) and its downstream NO.

  7. Percutaneous phenol block of the upper thoracic sympathetic chain with computed tomography guidance. A new technique

    Energy Technology Data Exchange (ETDEWEB)

    Dondelinger, R.F.; Kurdziel, J.C.

    Twenty-one percutaneous neurolyses of the upper thoracic sympathetic chain were performed in 12 patients with CT guidance by a single injection of 1 to 3 ml of phenol at the level of Th3. Results were assessed after a follow-up period varying from 4 to 33 months. Three patients with hyperhidrosis had immediate and complete disappearance of symptoms, but only one patient remained dry. In 7/14 procedures done for Raynaud's disease symptoms disappeared or diminished. These long term results are competitive with surgery. Three transitory Horner syndromes and one pneumothorax occurred.

  8. Neutral gas sympathetic cooling of an ion in a Paul trap.

    Science.gov (United States)

    Chen, Kuang; Sullivan, Scott T; Hudson, Eric R

    2014-04-11

    A single ion immersed in a neutral buffer gas is studied. An analytical model is developed that gives a complete description of the dynamics and steady-state properties of the ions. An extension of this model, using techniques employed in the mathematics of economics and finance, is used to explain the recent observation of non-Maxwellian statistics for these systems. Taken together, these results offer an explanation of the long-standing issues associated with sympathetic cooling of an ion by a neutral buffer gas.

  9. Study of nerve fibers nature reinforcing duodenal contractions by electrical stimulation of sympathetic nerve

    Directory of Open Access Journals (Sweden)

    Sveshnikov D.S.

    2011-09-01

    Full Text Available The subject of the article is to investigate the mechanism of increased reactions by electrical stimulation of the sympathetic nerve. Materials and methods: Experiments on dogs have shown that stimulant reactions during blockade of a-adrenergic by phentolamine and (3-adrenergic receptors with propranolol were completely eliminated by lizer-gol —the blocker of 5-HT12-receptors. Results: Infusion of lizergol did not influence on duodenal motor activity and the function of the vagus nerve. Conclusion: Effector neuron is found out to be serotonergic and its action is provided by 5-HT1 2 receptors

  10. A perspective on sympathetic renal denervation in chronic congestive heart failure.

    Science.gov (United States)

    Madanieh, Raef; El-Hunjul, Mohammed; Alkhawam, Hassan; Kosmas, Constantine E; Madanieh, Abed; Vittorio, Timothy J

    2016-01-01

    Medical therapy has indisputably been the mainstay of management for chronic congestive heart failure. However, a significant percentage of patients continue to experience worsening heart failure (HF) symptoms despite treatment with multiple therapeutic agents. Recently, catheter-based interventional strategies that interrupt the renal sympathetic nervous system have shown promising results in providing better symptom control in patients with HF. In this article, we will review the pathophysiology of HF for better understanding of the interplay between the cardiovascular system and the kidney. Subsequently, we will briefly discuss pivotal renal denervation (RDN) therapy trials in patients with resistant hypertension and then present the available evidence on the role of RDN in HF therapy.

  11. Development of nNOS-positive neurons in the rat sensory and sympathetic ganglia.

    Science.gov (United States)

    Masliukov, P M; Emanuilov, A I; Madalieva, L V; Moiseev, K Y; Bulibin, A V; Korzina, M B; Porseva, V V; Korobkin, A A; Smirnova, V P

    2014-01-03

    Neurochemical features in sympathetic and afferent neurons are subject to change during development. Nitric oxide (NO) plays a developmental role in the nervous system. To better understand the neuroplasticity of sympathetic and afferent neurons during postnatal ontogenesis, the distribution of neuronal NO synthase (nNOS) immunoreactivity was studied in the sympathetic para- and prevertebral, nodose ganglion (NG) and Th2 and L4 dorsal root ganglia (DRG) from female Wistar rats of different ages (newborn, 10-day-old, 20-day-old, 30-day-old, 2-month-old, 6-month-old, 1-year-old, and 3-year-old). nNOS-positive neurons were revealed in all sensory ganglia but not in sympathetic ones from birth onward. The percentage of nNOS-immunoreactive (IR) neurons increased during first 10 days of life from 41.3 to 57.6 in Th2 DRG, from 40.9 to 59.1 in L4 DRG and from 31.6 to 38.5 in NG. The percentage of nNOS-IR neurons did not change in the NG later during development and senescence. However, in Th2 and L4 DRG the proportion of nNOS-IR neurons was high in animals between 10 and 30days of life and decreased up to the second month of life. In 2-month-old rats, the percentage of nNOS-IR neurons was 52.9 in Th2 DRG and 51.3 in L4 DRG. We did not find statistically significant differences in the percentage of nNOS-IR neurons between Th2 and L4 DRG and between young and aged rats. In NG and DRG of 10-day-old and older rats, a high proportion of nNOS-IR neurons binds isolectin B4. In newborn animals, only 41.3%, 45.3% and 28.4% of nNOS neuron profiles bind to IB4 in Th2, L4 DRG and NG, respectively. In 10-day-old and older rats, the number of sensory nNOS-IR neurons binding IB4 reached more than 90% in DRG and more than 80% in NG. Only a small number of nNOS-positive cells showed immunoreactivity to calcitonin gene-related peptide, neurofilament 200, calretinin. The information provided here will also serve as a basis for future studies investigating mechanisms of the development of

  12. Polysialic Acid Regulates Sympathetic Outflow by Facilitating Information Transfer within the Nucleus of the Solitary Tract.

    Science.gov (United States)

    Bokiniec, Phillip; Shahbazian, Shila; McDougall, Stuart J; Berning, Britt A; Cheng, Delfine; Llewellyn-Smith, Ida J; Burke, Peter G R; McMullan, Simon; Mühlenhoff, Martina; Hildebrandt, Herbert; Braet, Filip; Connor, Mark; Packer, Nicolle H; Goodchild, Ann K

    2017-07-05

    Expression of the large extracellular glycan, polysialic acid (polySia), is restricted in the adult, to brain regions exhibiting high levels of plasticity or remodeling, including the hippocampus, prefrontal cortex, and the nucleus of the solitary tract (NTS). The NTS, located in the dorsal brainstem, receives constant viscerosensory afferent traffic as well as input from central regions controlling sympathetic nerve activity, respiration, gastrointestinal functions, hormonal release, and behavior. Our aims were to determine the ultrastructural location of polySia in the NTS and the functional effects of enzymatic removal of polySia, both in vitro and in vivo polySia immunoreactivity was found throughout the adult rat NTS. Electron microscopy demonstrated polySia at sites that influence neurotransmission: the extracellular space, fine astrocytic processes, and neuronal terminals. Removing polySia from the NTS had functional consequences. Whole-cell electrophysiological recordings revealed altered intrinsic membrane properties, enhancing voltage-gated K(+) currents and increasing intracellular Ca(2+) Viscerosensory afferent processing was also disrupted, dampening low-frequency excitatory input and potentiating high-frequency sustained currents at second-order neurons. Removal of polySia in the NTS of anesthetized rats increased sympathetic nerve activity, whereas functionally related enzymes that do not alter polySia expression had little effect. These data indicate that polySia is required for the normal transmission of information through the NTS and that changes in its expression alter sympathetic outflow. polySia is abundant in multiple but discrete brain regions, including sensory nuclei, in both the adult rat and human, where it may regulate neuronal function by mechanisms identified here.SIGNIFICANCE STATEMENT All cells are coated in glycans (sugars) existing predominantly as glycolipids, proteoglycans, or glycoproteins formed by the most complex form of

  13. Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

    Energy Technology Data Exchange (ETDEWEB)

    Pua, Uei; Tan, Cher Heng [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore); Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong [Tan Tock Seng Hospital, Department of Cardiology, Singapore (Singapore)

    2014-08-28

    Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

  14. Distinct Nav1.7-dependent pain sensations require different sets of sensory and sympathetic neurons

    OpenAIRE

    Minett, Michael S.; Nassar, Mohammed A.; Clark, Anna K.; Passmore, Gayle; Dickenson, Anthony H.; Wang, Fan; Malcangio, Marzia; John N. Wood

    2012-01-01

    Human acute and inflammatory pain requires the expression of voltage-gated sodium channel Nav1.7 but its significance for neuropathic pain is unknown. Here we show that Nav1.7 expression in different sets of mouse sensory and sympathetic neurons underlies distinct types of pain sensation. Ablating Nav1.7 gene (SCN9A) expression in all sensory neurons using Advillin-Cre abolishes mechanical pain, inflammatory pain and reflex withdrawal responses to heat. In contrast, heat-evoked pain is retain...

  15. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF......, but increases during cycling exercise. The increase in CMRO(2) is unaffected by beta-adrenergic blockade even though CBF is reduced suggesting that cerebral oxygenation becomes critical and a limited cerebral mitochondrial oxygen tension may induce fatigue. Also, sympathetic activity may drive cerebral non...

  16. Obesity-induced hypertension: role of sympathetic nervous system, leptin, and melanocortins.

    Science.gov (United States)

    Hall, John E; da Silva, Alexandre A; do Carmo, Jussara M; Dubinion, John; Hamza, Shereen; Munusamy, Shankar; Smith, Grant; Stec, David E

    2010-06-04

    Excess weight gain contributes to increased blood pressure in most patients with essential hypertension. Although the mechanisms of obesity hypertension are not fully understood, increased renal sodium reabsorption and impaired pressure natriuresis play key roles. Several mechanisms contribute to altered kidney function and hypertension in obesity, including activation of the sympathetic nervous system, which appears to be mediated in part by increased levels of the adipocyte-derived hormone leptin, stimulation of pro-opiomelanocortin neurons, and subsequent activation of central nervous system melanocortin 4 receptors.

  17. Macrophage populations and cardiac sympathetic denervation during L-NAME-induced hypertension in rats

    DEFF Research Database (Denmark)

    Neves, S R S; Machado, C R S; Pinto, A M T;

    2006-01-01

    The rat model of hypertension induced by prolonged treatment with Nomega-nitro-L-arginine methyl ester (L-NAME) has been extensively used. However, the effects on cardiac autonomic innervation are unknown. Here, the cardiac sympathetic innervation is analyzed in parallel with myocardial lesions...... and macrophage infiltration at day 7. No denervation was detectable at day 14 of double treatment, using subcutaneous AG. Our findings favor a role for ED1+ macrophages and iNOS in the hypertension-induced denervation process....

  18. Estimated central blood volume in cirrhosis: relationship to sympathetic nervous activity, beta-adrenergic blockade and atrial natriuretic factor

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Bendtsen, F; Gerbes, A L

    1992-01-01

    The estimated central blood volume (i.e., blood volume in the heart cavities, lungs and central arterial tree) was determined by multiplying cardiac output by circulatory mean transit time in 19 patients with cirrhosis and compared with sympathetic nervous activity and circulating level of atrial...... natriuretic factor. Arterial norepinephrine level, an index of overall sympathetic nervous activity (3.08 nmol/L in patients vs. 1.36 nmol/L in controls; p blood volume (mean = 23 ml/kg in patients vs. 27 ml/kg in controls; p ....05). Similarly, renal venous norepinephrine level (an index of renal sympathetic tone; 4.26 nmol/L in patients vs. 1.78 nmol/L in controls; p blood volume (r = -0.53, n = 18, p

  19. Mirror Neurons and Literature: Empathy and the Sympathetic Imagination in the Fiction of J.M. Coetzee

    Directory of Open Access Journals (Sweden)

    Hilmar Heister

    2015-01-01

    Full Text Available In the two essays “The Philosophers and the Animals” and “The Poets and the Animals” (in The Lives of Animals, 1999 J.M. Coetzee lets Elizabeth Costello urge us to use our sympathetic imagination in order to access the experience of others—in particular, animals—and engage with them empathetically. Coetzee’s fiction illustrates how the use of the sympathetic imagination might evoke empathy in the reader. Narrative structure and the character’s mode of introspection engage the reader’s empathy through an ambivalent process of distancing and approximation, as Fritz Breithaupt puts forward in his narrative theory of empathy (Kulturen der Empathie, 2009. The sympathetic imagination and the complementary notion of embodiment feature prominently in Coetzee’s fictional discourse and resonate with neuroscience’s research on mirror neurons and their relation to empathy.

  20. Cervical sympathetic chain schwannoma masquerading as a carotid body tumour with a postoperative complication of first-bite syndrome.

    LENUS (Irish Health Repository)

    Casserly, Paula

    2012-01-31

    Carotid body tumours (CBT) are the most common tumours at the carotid bifurcation. Widening of the bifurcation is usually demonstrated on conventional angiography. This sign may also be produced by a schwannoma of the cervical sympathetic plexus. A 45-year-old patient presented with a neck mass. Investigations included contrast-enhanced CT, MRI and magnetic resonance arteriography with contrast enhancement. Radiologically, the mass was considered to be a CBT due to vascular enhancement and splaying of the internal and external carotid arteries. Intraoperatively, it was determined to be a cervical sympathetic chain schwannoma (CSCS). The patient had a postoperative complication of first-bite syndrome (FBS).Although rare, CSCS should be considered in the differential diagnosis for tumours at the carotid bifurcation. Damage to the sympathetic innervation to the parotid gland can result in severe postoperative pain characterised by FBS and should be considered in all patients undergoing surgery involving the parapharyngeal space.

  1. Neuropeptide Y level in paraventricular nucleus of experimental diabetic rats: correlation with sympathetic activity and body weight

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    Pallab K Ganguly

    2010-09-01

    Full Text Available Pallab K GangulyCollege of Medicine, Alfaisal University, Riyadh, Kingdom of Saudi ArabiaAbstract: Neuropeptide Y (NPY, colocalized with norepinephrine neuron, is known to modulate sympathetic activity and feeding behavior. Although experimental type 1 diabetes has increased sympathetic activity at the early part of the disease process, little effort was made so far to understand the correlation between NPY level in the hypothalamus and sympathetic activity in diabetes. Male Sprague Dawley rats were made diabetic by a single injection of streptozotocin (65 mg/kg body weight, IV. The animals were then studied after 2, 4, and 8 weeks. Control animals received only citrate vehicle. In an effort to clarify the modulatory effect of NPY at the early stage of diabetes, the paraventricular nucleus (PVN of hypothalamus was sampled by microdialysis for NPY and norepinephrine level. While NPY level was increased immediately within 2 weeks (along with feeding behavior, norepinephrine level was increased only after 8 weeks following injection of streptozotocin. The animals lost significant weight. These results are interpreted to mean that a strong correlation exists between the feeding behavior and NPY level in PVN. Since NPY is known to inhibit sympathetic activity it is possible that NPY receptors are down-regulated following diabetes. The higher level of norepinephrine indicating higher sympathetic activity did not allow the animals to gain weight. In addition, controversy exists regarding pleiotropic activities of NPY related to the feeding behavior of these animals.Keywords: streptozotocin-induced diabetes, increased sympathetic activity, feeding behavior, down-regulation of NPY receptors

  2. Mkp1 is a c-Jun target gene that antagonizes JNK-dependent apoptosis in sympathetic neurons.

    Science.gov (United States)

    Kristiansen, Mark; Hughes, Rosie; Patel, Pritika; Jacques, Thomas S; Clark, Andrew R; Ham, Jonathan

    2010-08-11

    Developing sympathetic neurons depend on NGF for survival. When sympathetic neurons are deprived of NGF in vitro, a well documented series of events, including c-Jun N-terminal kinase (JNK) pathway activation, release of cytochrome c from the mitochondria, and caspase activation, culminates in the death of the neuron by apoptosis within 24-48 h. This process requires de novo gene expression, suggesting that increased expression of specific genes activates the cell death program. Using rat gene microarrays, we found that NGF withdrawal induces the expression of many genes, including mkp1, which encodes a MAPK phosphatase that can dephosphorylate JNKs. The increase in mkp1 mRNA level requires the MLK-JNK-c-Jun pathway, and we show that Mkp1 is an important regulator of JNK-dependent apoptosis in sympathetic neurons. In microinjection experiments, Mkp1 overexpression can inhibit JNK-mediated phosphorylation of c-Jun and protect sympathetic neurons from apoptosis, while Mkp1 knockdown accelerates NGF withdrawal-induced death. Accordingly, the number of superior cervical ganglion (SCG) neurons is reduced in mkp1-/- mice at P1 during the period of developmental sympathetic neuron death. We also show that c-Jun and ATF2 bind to two conserved ATF binding sites in the mkp1 promoter in vitro and in chromatin. Both of these ATF sites contribute to basal promoter activity and are required for mkp1 promoter induction after NGF withdrawal. These results demonstrate that Mkp1 is part of a negative feedback loop induced by the MLK-JNK-c-Jun signaling pathway that modulates JNK activity and the rate of neuronal death in rat sympathetic neurons following NGF withdrawal.

  3. Relationship of cardiac sympathetic nerve innervation and excitability to cardiac hypertrophy in very elderly male hypertensive patients.

    Science.gov (United States)

    Li, Shijun; Zhang, Li; Guo, Yuanyuan; Li, Xiaoying

    2013-09-01

    Our study aimed to disclose the relationship of cardiac sympathetic nerve innervation and excitability to myocardial hypertrophy in very old elderly male hypertensive patients with low serum testosterone level. A total of 80 elderly male hypertensive patients aged from 80 to 95 years were recruited. Heart rate variability is determined by 24 h dynamic electrocardiogram and heart rate variability analysis system. Cardiac function and left ventricular mass index were determined using color Doppler ultrasound. Standard deviation of all normal sinus R-R intervals over 24 h (SDNN) significantly decreased in hypertensive cardiac hypertrophy patients as compared with those without cardiac hypertrophy. SDANN and Standard deviation of the average normal sinus R-R intervals for all 5-min segment index, time-domain index reflecting sympathetic nerve tension, obviously decreased and LFnu and LFnu/HFnu, frequency-domain index representing sympathetic nerve excitability, significantly increased in hypertensive cardiac hypertrophy patients as compared with those without cardiac hypertrophy. Myocardial norepinephrine content significantly increased while tyrosine hydroxylase expression significantly lowered in hypertensive cardiac hypertrophy patients, and a negative correlation between myocardial tyrosine hydroxylase expression and myocardial norepinephrine content was present. Serum total testosterone level decreased in hypertensive cardiac hypertrophy patients and was an independent risk factor for the increase in myocardial norepinephrine content and decrease in tyrosine hydroxylase expression. These data confirm that cardiac sympathetic nerve hypoinnervation and relative increase in cardiac sympathetic nerve excitability are closely related to cardiac hypertrophy in very old hypertensive patients. A lower serum total testosterone level was the independent risk factor of cardiac sympathetic nerve hypoinnervation and relative increase in excitability in very old male

  4. Sensory and sympathetic disorders in chronic non-specific neck pain.

    Science.gov (United States)

    Zaproudina, Nina; Ming, Zhiyong; Närhi, Matti

    2015-01-01

    The signs of sympathetic and sensory nerve-related disorders are not widely investigated in chronic nonspecific neck pain (NNP) patients. Thus, we performed skin temperature (Tsk), evaporation and touch threshold (TT) measurements to reveal possible dysfunctions at the fingertips of NNP patients (n=60) compared with healthy controls (n=11). Neck pain intensity was the main modifier of Tsk, and age the main modifier of TT in a multivariate model. On comparisons of the subgroups of NNP patients with unilateral (n=26) and bilateral (n=34) symptoms and controls, TT differed and Tsk tended to differ, the unilateral pain patients being found to demonstrate higher TT values on both sides. Interrelations between the measured parameters were found in the controls, but not in the patients. The NNP patients exhibited signs of functional impairment of innervation reflected in changes in tactile sensitivity and vasoactive sympathetic function. These changes may be based on both central and peripheral mechanisms, which possibly differ in patients with unilateral and bilateral symptoms.

  5. Influence of sympathetic nervous system on sensorimotor function: whiplash associated disorders (WAD) as a model.

    Science.gov (United States)

    Passatore, Magda; Roatta, Silvestro

    2006-11-01

    There is increasing interest about the possible involvement of the sympathetic nervous system (SNS) in initiation and maintenance of chronic muscle pain syndromes of different aetiology. Epidemiological data show that stresses of different nature, e.g. work-related, psychosocial, etc., typically characterised by SNS activation, may be a co-factor in the development of the pain syndrome and/or negatively affect its time course. In spite of their clear traumatic origin, whiplash associated disorders (WAD) appear to share many common features with other chronic pain syndromes affecting the musculo-skeletal system. These features do not only include symptoms, like type of pain or sensory and motor dysfunctions, but possibly also some of the pathophysiological mechanisms that may concur to establish the chronic pain syndrome. This review focuses on WAD, particular emphasis being devoted to sensorimotor symptoms, and on the actions exerted by the sympathetic system at muscle level. Besides its well-known action on muscle blood flow, the SNS is able to affect the contractility of muscle fibres, to modulate the proprioceptive information arising from the muscle spindle receptors and, under certain conditions, to modulate nociceptive information. Furthermore, the activity of the SNS itself is in turn affected by muscle conditions, such as its current state of activity, fatigue and pain signals originating in the muscle. The possible involvement of the SNS in the development of WAD is discussed in light of the several positive feedback loops in which it is implicated.

  6. Inclusion of Height and Limb Length when Interpreting Sympathetic Skin Response

    Directory of Open Access Journals (Sweden)

    Mohamadreza Emad

    2016-01-01

    Full Text Available It is more than a decade since scientists are making use of sympathetic skin response (SSR as a clinical and research method to evaluate sympathetic nervous system. A major portion of the efferent pathway of this response is composed of non-myelinated nerves. Thus, the latency of the response may be significantly different in normal individuals with different height and limb lengths. This study was designed to investigate the effect of these parameters on the SSR results. We measured the height and limb length of 65 normal individuals with different heights (divided into 3 groups of height ≤150 cm, 150-170 cm, and ≥170 cm. The participants had neither peripheral nor central neuropathy. They also had none of the exclusion criteria. Then, they underwent SSR testing of both palms and soles. The correlation between the height and limb length in relation to SSR parameters (latency and amplitude was analyzed statistically by Pearson’s correlation. No significant correlation was detected between the height and limb length and the SSR amplitude. However, the results showed significant correlation between SSR latency recorded from all four sites (both palms and soles and the height of participants. Furthermore, there was a significant correlation between SSR latency recorded from any limb and the length of that limb. Regarding the significant effect of the height and limb length on the SSR latency, both the height and limb length should be considered when interpreting the results of SSR.

  7. The Impact of Sympathetic Components of Emotional Intelligence on Citizenship Behavior of Physicians

    Directory of Open Access Journals (Sweden)

    Elham Sahafi

    2012-03-01

    Full Text Available Objective: One of the most important characteristics of an effective employee performance is person'sSympathetic components of emotional intelligence that has been increasingly considered in anenterprise environment. In this article, we will survey this component in promoting citizenship behaviorof physicians.Materials and methods: In a descriptive, co relational and statistical community approach Theoutstanding performance of an organization using simple random sampling method, 212 cases wereincluded as doctors having subspecialty of the infertility in the Islamic Republic of Iran. A questionnairewas used for data collection. After summarization, structural equation modeling techniques were usedfor analysis and interpretation of research data.Results: The Sympathetic component has a significant positive impact on organizational citizenshipbehavior (T=2.90 and this factor with the effect of 0.46% has the impact on organizational citizenshipbehavior.Conclusion: Considering the importance of sympathy aspect due to results of this research hospitalmanagers are recommended to consider the importance of emotional intelligence in order to enhancethe social capabilities of citizenship behaviors of physicians.

  8. Effect of moxonidine on putative sympathetic neurons in the rostral ventrolateral medulla of the rat.

    Science.gov (United States)

    Granata, Antonio R

    2004-01-01

    We used an intracellular recording technique in vitro to investigate the effects of moxonidine on neurons in the rostral ventrolateral medulla (RVLM) with electrophysiological properties similar to premotor sympathetic neurons in vivo. These neurons were classified as firing regularly and irregularly, according to previous reports. Moxonidine is a sympathoinhibitory and antihypertensive agent that is thought to be a ligand of alpha(2)-adrenergic receptors and imidazoline type-1 receptors in the RVLM. Moxonidine (2-10 microM) was applied to the perfusate on 4 irregularly firing neurons, and 2 regularly firing neurons. Moxonidine (2 microM) produced only minor depolarization in 2 of these neurons. However, on 4 tested neurons, moxonidine (10 microM) elicited a profound inhibitory effect with hyperpolarization (near -20 mV); these neurons practically ceased firing. These changes were partially reversible. The results would indicate that neurons in the RVLM, recorded in vitro and with similar electrophysiological characteristics to a group of neurons previously identified in vivo in the same bulbar region as barosensitive premotor sympathetic neurons, can be modulated by imidazoline-derivative adrenergic agonists. These results could help to understand the hypotensive effects of moxonidine.

  9. Sympathetic skin responses from the scalp evoked by electrical stimulation in seborrheic dermatitis.

    Science.gov (United States)

    Altunrende, Burcu; Yildiz, Serpil; Kandi, Basak; Yildiz, Nebil

    2013-06-01

    Although the role of autonomic nervous system in seborrheic dermatitis (SD) is still unclear, seborrhea is sometimes accepted as a sign of autonomic dysfunction in several nervous system diseases. Therefore, we aimed to investigate the sympathetic nervous system (SNS) activity in SD by recording sympathetic skin responses (SSR) from the scalp (S-SSR). Thirty-one control subjects and 22 SD patients were studied by evoking right and left S-SSR with electrical stimulation of the right median nerve at the wrist. Mean latencies and maximum amplitudes were calculated for both sides in each group. In seven out of 31 control subjects and in 13 out of 22 patients, the S-SSR could not be elicited on either side. There were four subjects with unilateral response in the patient group. There were significantly more non-responders among the patients with SD (P < 0.000). This study suggests that in SD, the autonomic nervous system may be involved. The S-SSR is a new site for recording SSR. The responses are relatively symmetrical and can be evoked easily by electrical stimulation, and may be used to evaluate the SNS function in SD patients and also in healthy subjects.

  10. Resonant multi-photon IR dissociation spectroscopy of a trapped and sympathetically cooled biomolecular ion species

    CERN Document Server

    Wellers, Ch; Vasilyev, S; Offenberg, D; Schiller, S

    2011-01-01

    In this work we demonstrate vibrational spectroscopy of polyatomic ions that are trapped and sympathetically cooled by laser-cooled atomic ions. We use the protonated dipeptide tryptophane-alanine (HTyrAla+) as a model system, cooled by Barium ions to less than 800mK secular temperature. The spectroscopy is performed on the fundamental vibrational transition of a local vibrational mode at 2.74 {\\mu}m using a continuous-wave optical parametric oscillator (OPO). Resonant multi-photon IR dissociation spectroscopy (without the use of a UV laser) generates charged molecular fragments, which are sympathetically cooled and trapped, and subsequently released from the trap and counted. We measured the cross section for R-IRMPD under conditions of low intensity, and found it to be approximately two orders smaller than the vibrational excitation cross section. The observed rotational bandwidth of the vibrational transition is larger than the one expected from the combined effects of 300 K black-body temperature, conform...

  11. Cardiac sympathetic nervous system imaging with (123)I-meta-iodobenzylguanidine: Perspectives from Japan and Europe.

    Science.gov (United States)

    Nakajima, Kenichi; Scholte, Arthur J H A; Nakata, Tomoaki; Dimitriu-Leen, Aukelien C; Chikamori, Taishiro; Vitola, João V; Yoshinaga, Keiichiro

    2017-03-13

    Cardiac sympathetic nervous system dysfunction is closely associated with risk of serious cardiac events in patients with heart failure (HF), including HF progression, pump-failure death, and sudden cardiac death by lethal ventricular arrhythmia. For cardiac sympathetic nervous system imaging, (123)I-meta-iodobenzylguanidine ((123)I-MIBG) was approved by the Japanese Ministry of Health, Labour and Welfare in 1992 and has therefore been widely used since in clinical settings. (123)I-MIBG was also later approved by the Food and Drug Administration (FDA) in the United States of America (USA) and it was expected to achieve broad acceptance. In Europe, (123)I-MIBG is currently used only for clinical research. This review article is based on a joint symposium of the Japanese Society of Nuclear Cardiology (JSNC) and the American Society of Nuclear Cardiology (ASNC), which was held in the annual meeting of JSNC in July 2016. JSNC members and a member of ASNC discussed the standardization of (123)I-MIBG parameters, and clinical aspects of (123)I-MIBG with a view to further promoting (123)I-MIBG imaging in Asia, the USA, Europe, and the rest of the world.

  12. Relationship between Sympathetic Skin Responses and Auditory Hypersensitivity to Different Auditory Stimuli.

    Science.gov (United States)

    Kato, Fumi; Iwanaga, Ryoichiro; Chono, Mami; Fujihara, Saori; Tokunaga, Akiko; Murata, Jun; Tanaka, Koji; Nakane, Hideyuki; Tanaka, Goro

    2014-07-01

    [Purpose] Auditory hypersensitivity has been widely reported in patients with autism spectrum disorders. However, the neurological background of auditory hypersensitivity is currently not clear. The present study examined the relationship between sympathetic nervous system responses and auditory hypersensitivity induced by different types of auditory stimuli. [Methods] We exposed 20 healthy young adults to six different types of auditory stimuli. The amounts of palmar sweating resulting from the auditory stimuli were compared between groups with (hypersensitive) and without (non-hypersensitive) auditory hypersensitivity. [Results] Although no group × type of stimulus × first stimulus interaction was observed for the extent of reaction, significant type of stimulus × first stimulus interaction was noted for the extent of reaction. For an 80 dB-6,000 Hz stimulus, the trends for palmar sweating differed between the groups. For the first stimulus, the variance became larger in the hypersensitive group than in the non-hypersensitive group. [Conclusion] Subjects who regularly felt excessive reactions to auditory stimuli tended to have excessive sympathetic responses to repeated loud noises compared with subjects who did not feel excessive reactions. People with auditory hypersensitivity may be classified into several subtypes depending on their reaction patterns to auditory stimuli.

  13. Horner syndrome after carotid sheath surgery in a pig: anatomic study of cervical sympathetic chain.

    Science.gov (United States)

    Ding, Peng; Tufano, Ralph P; Campbell-Malone, Regina; Feng, Wallace; Kim, Sang Jun; German, Rebecca Z

    2011-10-01

    In an experimental model, iatrogenic Horner syndrome developed after a right carotid sheath surgery in an infant pig (Sus scrofa). Horner syndrome is a classic clinical triad consisting of ipsilateral eyelid ptosis, pupil miosis, and facial anhydrosis. This syndrome results from cervical sympathetic chain (CSC) paresis and usually is acquired in humans. To determine whether the development of Horner syndrome in this situation could be attributed to pig anatomy, we compared the anatomy of the CSC in pigs and humans, by using 10 infant (age, 1 to 3 wk) pig cadavers. The CSC and cranial cervical sympathetic ganglion (CCG) were dissected bilaterally under a surgical microscope. These structures were consistently within the carotid sheaths of the pigs. In contrast, the CSC and CCG are outside the carotid sheath in humans. Awareness of the anatomic variation of the CSC and CCG within the carotid sheath in the pig and the possibility of the same variation in humans may help surgeons to identify and preserve important structures while performing cervical surgery in pigs and humans. Furthermore, this knowledge can aid in the diagnosis and prognosis of schwannoma.

  14. A vesicular sequestration to oxidative deamination shift in myocardial sympathetic nerves in Parkinson's disease.

    Science.gov (United States)

    Goldstein, David S; Sullivan, Patricia; Holmes, Courtney; Miller, Gary W; Sharabi, Yehonatan; Kopin, Irwin J

    2014-10-01

    In Parkinson's disease (PD), profound putamen dopamine (DA) depletion reflects denervation and a shift from vesicular sequestration to oxidative deamination of cytoplasmic DA in residual terminals. PD also involves cardiac sympathetic denervation. Whether PD entails myocardial norepinephrine (NE) depletion and a sequestration-deamination shift have been unknown. We measured apical myocardial tissue concentrations of NE, DA, and their neuronal metabolites 3,4-dihydroxyphenylglycol (DHPG), and 3,4-dihydroxyphenylacetic acid (DOPAC) from 23 PD patients and 23 controls and ascertained the extent of myocardial NE depletion in PD. We devised, validated in VMAT2-Lo mice, and applied 5 neurochemical indices of the sequestration-deamination shift-concentration ratios of DOPAC:DA, DA:NE, DHPG:NE, DOPAC:NE, and DHPG:DOPAC-and used a kinetic model to estimate the extent of the vesicular storage defect. The PD group had decreased myocardial NE content (p Parkinson's disease (PD) patients have profound (98%) myocardial norepinephrine depletion, because of both cardiac sympathetic denervation and a shift from vesicular sequestration to oxidative deamination of cytoplasmic catecholamines in the residual nerves. This shift may be part of a final common pathogenetic pathway in the loss of catecholaminergic neurons that characterizes PD.

  15. Strength training reduces arterial blood pressure but not sympathetic neural activity in young normotensive subjects

    Science.gov (United States)

    Carter, Jason R.; Ray, Chester A.; Downs, Emily M.; Cooke, William H.

    2003-01-01

    The effects of resistance training on arterial blood pressure and muscle sympathetic nerve activity (MSNA) at rest have not been established. Although endurance training is commonly recommended to lower arterial blood pressure, it is not known whether similar adaptations occur with resistance training. Therefore, we tested the hypothesis that whole body resistance training reduces arterial blood pressure at rest, with concomitant reductions in MSNA. Twelve young [21 +/- 0.3 (SE) yr] subjects underwent a program of whole body resistance training 3 days/wk for 8 wk. Resting arterial blood pressure (n = 12; automated sphygmomanometer) and MSNA (n = 8; peroneal nerve microneurography) were measured during a 5-min period of supine rest before and after exercise training. Thirteen additional young (21 +/- 0.8 yr) subjects served as controls. Resistance training significantly increased one-repetition maximum values in all trained muscle groups (P training did not affect MSNA or heart rate. Arterial blood pressures and MSNA were unchanged, but heart rate increased after 8 wk of relative inactivity for subjects in the control group (61 +/- 2 to 67 +/- 3 beats/min; P = 0.01). These results indicate that whole body resistance exercise training might decrease the risk for development of cardiovascular disease by lowering arterial blood pressure but that reductions of pressure are not coupled to resistance exercise-induced decreases of sympathetic tone.

  16. Mental fatigue caused by prolonged cognitive load associated with sympathetic hyperactivity

    Directory of Open Access Journals (Sweden)

    Kuratsune Hirohiko

    2011-05-01

    Full Text Available Abstract Background It is known that chronic fatigue is associated with sympathetic hyperactivity. However, the relationship between autonomic function and mental fatigue caused by a prolonged mental load in healthy humans is still unclear. Thus, in order to clarify the mechanisms underlying mental fatigue, we examined the association between mental fatigue and autonomic functions. Methods The study group comprised 10 healthy participants. To induce mental fatigue, participants performed mental tasks, which consisted of the advanced trail making test, kana pick-out test and mirror drawing test, for 8 hr, corresponding to a normal work day. Autonomic functions were measured by accelerated plethysmography before and after the fatigue-inducing mental tasks. As a control, the same participants completed an 8-hr relaxation session 4 weeks before the fatigue session. Results After the 8-hr relaxation session, low-frequency component power (LF, high-frequency component power (HF and low-frequency component power/high-frequency component power ratio (LF/HF ratio were not changed from baseline. In contrast, after the fatigue session, the HF and LF/HF ratio were significantly changed from baseline; specifically, the HF was lower and LF/HF ratio was higher as compared to those after the relaxation session. Conclusions Sympathetic hyperactivity based on decreased parasympathetic activity is associated with mental fatigue induced by prolonged cognitive load.

  17. Muscle sympathetic nerve activity and volume regulating factors in healthy pregnant and non-pregnant women.

    Science.gov (United States)

    Charkoudian, Nisha; Usselman, Charlotte W; Skow, Rachel J; Staab, Jeffery S; Julian, Colleen Glyde; Stickland, Michael K; Chari, Radha S; Khurana, Rshmi; Davidge, Sandra T; Davenport, Margie H; Steinback, Craig D

    2017-07-21

    Healthy, normotensive human pregnancies are associated with striking increases in both plasma volume and vascular sympathetic nerve activity (SNA). In non-pregnant humans, volume regulatory factors including plasma osmolality, vasopressin and the renin-angiotensin-aldosterone system have important modulatory effects on control of sympathetic outflow. We hypothesized that pregnancy would be associated with changes in the relationships between SNA (measured as muscle SNA) and volume regulating factors, including plasma osmolality, plasma renin activity and arginine vasopressin (AVP). We studied 46 healthy, normotensive young women (23 pregnant and 23 non-pregnant). We measured SNA, arterial pressure, plasma osmolality, plasma renin activity, AVP and other volume regulatory factors in resting, semi-recumbent posture. Pregnant women had significantly higher resting SNA (38 ± 12 vs. non-pregnant: 23 ± 6 bursts/minute), lower osmolality and higher plasma renin activity and aldosterone (all P pregnant] vs. 5.17 ± 2.03 [pregnant], P > 0.05). However, regression analysis detected a significant relationship between individual values for SNA and AVP in pregnant (r = 0.71, P pregnant women (r = 0.04). No relationships were found for other variables. These data suggest that the link between AVP release and resting SNA becomes stronger in pregnancy, which may contribute importantly to blood pressure regulation in healthy women during pregnancy. Copyright © 2017, American Journal of Physiology-Heart and Circulatory Physiology.

  18. Sympathetic Neurotransmitters Modulate Osteoclastogenesis and Osteoclast Activity in the Context of Collagen-Induced Arthritis.

    Directory of Open Access Journals (Sweden)

    Dominique Muschter

    Full Text Available Excessive synovial osteoclastogenesis is a hallmark of rheumatoid arthritis (RA. Concomitantly, local synovial changes comprise neuronal components of the peripheral sympathetic nervous system. Here, we wanted to analyze if collagen-induced arthritis (CIA alters bone marrow-derived macrophage (BMM osteoclastogenesis and osteoclast activity, and how sympathetic neurotransmitters participate in this process. Therefore, BMMs from Dark Agouti rats at different CIA stages were differentiated into osteoclasts in vitro and osteoclast number, cathepsin K activity, matrix resorption and apoptosis were analyzed in the presence of acetylcholine (ACh, noradrenaline (NA vasoactive intestinal peptide (VIP and assay-dependent, adenylyl cyclase activator NKH477. We observed modulation of neurotransmitter receptor mRNA expression in CIA osteoclasts without affecting protein level. CIA stage-dependently altered marker gene expression associated with osteoclast differentiation and activity without affecting osteoclast number or activity. Neurotransmitter stimulation modulated osteoclast differentiation, apoptosis and activity. VIP, NA and adenylyl cyclase activator NKH477 inhibited cathepsin K activity and osteoclastogenesis (NKH477, 10(-6 M NA whereas ACh mostly acted pro-osteoclastogenic. We conclude that CIA alone does not affect metabolism of in vitro generated osteoclasts whereas stimulation with NA, VIP plus specific activation of adenylyl cyclase induced anti-resorptive effects probably mediated via cAMP signaling. Contrary, we suggest pro-osteoclastogenic and pro-resorptive properties of ACh mediated via muscarinic receptors.

  19. Sympathetic dysfunction in vasovagal syncope and the postural orthostatic tachycardia syndrome.

    Science.gov (United States)

    Lambert, Elisabeth; Lambert, Gavin W

    2014-01-01

    Orthostatic intolerance is the inability to tolerate the upright posture and is relieved by recumbence. It most commonly affects young women and has a major impact on quality of life and psychosocial well-being. Several forms of orthostatic intolerance have been described. The most common one is the recurrent vasovagal syncope (VVS) phenotype which presents as a transient and abrupt loss of consciousness and postural tone that is followed by rapid recovery. Another common type of orthostatic intolerance is the postural orthostatic tachycardia syndrome (POTS) which is characterized by an excessive rise in heart rate upon standing and is associated with symptoms of presyncope such as light-headedness, fatigue, palpitations, and nausea. Maintenance of arterial pressure under condition of reduced central blood volume during the orthostasis is accomplished in large part through sympathetic efferent nerve traffic to the peripheral vasculature. Therefore sympathetic nervous system (SNS) dysfunction is high on the list of possible contributors to the pathophysiology of orthostatic intolerance. Investigations into the role of the SNS in orthostatic intolerance have yielded mixed results. This review outlines the current knowledge of the function of the SNS in both VVS and POTS.

  20. Sympathetic dysfunction in vasovagal syncope and the postural orthostatic tachycardia syndrome

    Directory of Open Access Journals (Sweden)

    Elisabeth eLambert

    2014-07-01

    Full Text Available Orthostatic intolerance is the inability to tolerate the upright posture and is relieved by recumbence. It most commonly affects young women and has a major impact on quality of life and psychosocial well being. Several forms of orthostatic intolerance have been described. The most common one is the recurrent vasovagal syncope (VVS phenotype which presents as a transient and abrupt loss of consciousness and postural tone that is followed by rapid recovery. Another common type of orthostatic intolerance is the postural orthostatic tachycardia syndrome (POTS which is characterized by an excessive rise in heart rate upon standing and is associated with symptoms of presyncope such as light-headedness, fatigue, palpitations and nausea. Maintenance of arterial pressure under condition of reduced central blood volume during the orthostasis is accomplished in large part through sympathetic efferent nerve traffic to the peripheral vasculature. Therefore sympathetic nervous system (SNS dysfunction is high on the list of possible contributors to the pathophysiology of orthostatic intolerance. Investigations into the role of the SNS in orthostatic intolerance have yielded mixed results. This review outlines the current knowledge of the function of the SNS in both VVS and POTS.

  1. Assessing the strength of cardiac and sympathetic baroreflex controls via transfer entropy during orthostatic challenge

    Science.gov (United States)

    Porta, Alberto; Marchi, Andrea; Bari, Vlasta; De Maria, Beatrice; Esler, Murray; Lambert, Elisabeth; Baumert, Mathias

    2017-05-01

    The study assesses the strength of the causal relation along baroreflex (BR) in humans during an incremental postural challenge soliciting the BR. Both cardiac BR (cBR) and sympathetic BR (sBR) were characterized via BR sequence approaches from spontaneous fluctuations of heart period (HP), systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and muscle sympathetic nerve activity (MSNA). A model-based transfer entropy method was applied to quantify the strength of the coupling from SAP to HP and from DAP to MSNA. The confounding influences of respiration were accounted for. Twelve young healthy subjects (20-36 years, nine females) were sequentially tilted at 0°, 20°, 30° and 40°. We found that (i) the strength of the causal relation along the cBR increases with tilt table inclination, while that along the sBR is unrelated to it; (ii) the strength of the causal coupling is unrelated to the gain of the relation; (iii) transfer entropy indexes are significantly and positively associated with simplified causality indexes derived from BR sequence analysis. The study proves that causality indexes are complementary to traditional characterization of the BR and suggests that simple markers derived from BR sequence analysis might be fruitfully exploited to estimate causality along the BR. This article is part of the themed issue `Mathematical methods in medicine: neuroscience, cardiology and pathology'.

  2. Cannabinoid-based drugs targeting CB1 and TRPV1, the sympathetic nervous system, and arthritis.

    Science.gov (United States)

    Lowin, Torsten; Straub, Rainer H

    2015-09-06

    Chronic inflammation in rheumatoid arthritis (RA) is accompanied by activation of the sympathetic nervous system, which can support the immune system to perpetuate inflammation. Several animal models of arthritis already demonstrated a profound influence of adrenergic signaling on the course of RA. Peripheral norepinephrine release from sympathetic terminals is controlled by cannabinoid receptor type 1 (CB1), which is activated by two major endocannabinoids (ECs), arachidonylethanolamine (anandamide) and 2-arachidonylglycerol. These ECs also modulate function of transient receptor potential channels (TRPs) located on sensory nerve fibers, which are abundant in arthritic synovial tissue. TRPs not only induce the sensation of pain but also support inflammation via secretion of pro-inflammatory neuropeptides. In addition, many cell types in synovial tissue express CB1 and TRPs. In this review, we focus on CB1 and transient receptor potential vanilloid 1 (TRPV1)-mediated effects on RA since most anti-inflammatory mechanisms induced by cannabinoids are attributed to cannabinoid receptor type 2 (CB2) activation. We demonstrate how CB1 agonism or antagonism can modulate arthritic disease. The concept of functional antagonism with continuous CB1 activation is discussed. Since fatty acid amide hydrolase (FAAH) is a major EC-degrading enzyme, the therapeutic possibility of FAAH inhibition is studied. Finally, the therapeutic potential of ECs is examined since they interact with cannabinoid receptors and TRPs but do not produce central side effects.

  3. Role of the Sympathetic Nervous System in Stress-Mediated Cardiovascular Disease.

    Science.gov (United States)

    Hering, Dagmara; Lachowska, Kamila; Schlaich, Markus

    2015-10-01

    A high incidence of acute cardiovascular events and sudden cardiac death following unexpected acute emotional stress or a natural catastrophic disaster has been well-documented over the past decades. Chronic psychosocial factors have been shown to be directly linked to the development of hypertension, cardiovascular disease and stroke. Activation of various neurogenic pathways is an important mediator of acute and chronic stress-induced hypertension and heart disease. Heightened sympathetic activation has been shown to be a critical contributor linking psychogenic effects on cardiovascular regulation to serious and often fatal CV outcomes. Accordingly, several therapeutic approaches that attenuate autonomic imbalance via modulation of increased sympathetic outflow by either non-pharmacological or interventional means have been shown to alleviate clinical symptoms. Likewise stress reduction per se achieved with transcendental medicine has been linked to improved patient outcomes. Therapies that oppose adrenergic activity and/or have the potential to attenuate negative emotions are likely to reduce cardiovascular risk and its adverse consequences attributable to chronic mental stress.

  4. Short-term sertraline treatment suppresses sympathetic nervous system activity in healthy human subjects.

    Science.gov (United States)

    Shores, M M; Pascualy, M; Lewis, N L; Flatness, D; Veith, R C

    2001-05-01

    Increased sympathetic nervous system (SNS) activity has been associated with stress, major depression, aging, and several medical conditions. This study assessed the effect of the selective serotonin reuptake inhibitor (SSRI), sertraline, on sympathetic nervous system (SNS) activity in healthy subjects. Twelve healthy volunteers participated in a double-blind, placebo-controlled, norepinephrine (NE) kinetic study, in which the effects of sertraline on SNS activity were ascertained by determining NE plasma concentrations and NE plasma appearance rates and clearance rates in sertraline or placebo conditions. Subjects received 50 mg of sertraline or placebo for two days and then one week later underwent the same protocol with the other drug. By single compartmental analysis, plasma NE appearance rates were significantly lower in the sertraline compared to the placebo condition (0.26+/-0.10 vs 0.40+/-0.23 microg/m(2)/min; P=0.04). Our study found that the net effect of short-term SSRI treatment is an apparent suppression of SNS activity as indicated by a decreased plasma NE appearance rate in the sertraline condition. If this preliminary finding can be extended to long-term treatment of patients, this could have significant therapeutic relevance for treating depression in elderly patients or those with cardiac disease, in which elevated SNS activity may exacerbate underlying medical conditions.

  5. Heart rate complexity and cardiac sympathetic dysinnervation in patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Baumert, Mathias; Sacre, Julian W

    2013-01-01

    Cardiovascular autonomic neuropathy (CAN) is one of the most severe complications of type 2 diabetes mellitus (T2DM). The aim of this study was to investigate associations of cardiac sympathetic dysinnervation (CSD; by (123)I-MIBG scintigraphy) with short-term heart rate variability (HRV) measured by traditional vs. complexity markers. ECG was measured in 31 diabetic patients during rest over a period of 5 minutes and HRV quantified in different domains (time and frequency domain, scaling properties, symbolic dynamics). (123)I-MIBG scintigraphy identified 16 patients with CSD. Resting heart rate was increased and HRV reduced in these patients. In a subgroup of 16 patients ECG was also measured during standing. Changes in several HRV measures upon standing demonstrated cardiac responsiveness to orthostatic stress. Strong correlations between HRV, measured during standing, and CSD were observed with metrics based on symbolic dynamics. In conclusion, HRV assessment during standing may be useful for assessing cardiac sympathetic dysinnervation in patients with type 2 diabetes mellitus.

  6. Periodic Repolarisation Dynamics: A Natural Probe of the Ventricular Response to Sympathetic Activation

    Science.gov (United States)

    Rizas, Konstantinos D; Hamm, Wolfgang; Kääb, Stefan; Schmidt, Georg; Bauer, Axel

    2016-01-01

    Periodic repolarisation dynamics (PRD) refers to low-frequency (≤0.1Hz) modulations of cardiac repolarisation instability. Spontaneous PRD can be assessed non-invasively from 3D high-resolution resting ECGs. Physiological and experimental studies have indicated that PRD correlates with efferent sympathetic nerve activity, which clusters in low-frequency bursts. PRD is increased by physiological provocations that lead to an enhancement of sympathetic activity, whereas it is suppressed by pharmacological β-blockade. Electrophysiological studies revealed that PRD occurs independently from heart rate variability. Increased PRD under resting conditions is a strong predictor of mortality in post-myocardial infarction (post-MI) patients, yielding independent prognostic value from left-ventricular ejection fraction (LVEF), heart rate variability, the Global Registry of Acute Coronary Events score and other established risk markers. The predictive value of PRD is particularly strong in post-MI patients with preserved LVEF (>35 %) in whom it identifies a new high-risk group of patients. The upcoming Implantable Cardiac Monitors in High-Risk Post-Infarction Patients with Cardiac Autonomic Dysfunction and Moderately Reduced Left Ventricular Ejection Fraction (SMART-MI) trial will test prophylactic strategies in high-risk post-MI patients with LVEF 36–50 % identified by PRD and deceleration capacity of heart rate (NCT02594488). PMID:27403291

  7. Reactive oxygen species in the paraventricular nucleus of the hypothalamus alter sympathetic activity during metabolic syndrome.