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Sample records for acute vasodilator effects

  1. Exercise-mediated vasodilation in human obesity and metabolic syndrome: effect of acute ascorbic acid infusion

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    Limberg, Jacqueline K.; Kellawan, J. Mikhail; Harrell, John W.; Johansson, Rebecca E.; Eldridge, Marlowe W.; Proctor, Lester T.; Sebranek, Joshua J.

    2014-01-01

    We tested the hypothesis that infusion of ascorbic acid (AA), a potent antioxidant, would alter vasodilator responses to exercise in human obesity and metabolic syndrome (MetSyn). Forearm blood flow (FBF, Doppler ultrasound) was measured in lean, obese, and MetSyn adults (n = 39, 32 ± 2 yr). A brachial artery catheter was inserted for blood pressure monitoring and local infusion of AA. FBF was measured during dynamic handgrip exercise (15% maximal effort) with and without AA infusion. To account for group differences in blood pressure and forearm size, and to assess vasodilation, forearm vascular conductance (FVC = FBF/mean arterial blood pressure/lean forearm mass) was calculated. We examined the time to achieve steady-state FVC (mean response time, MRT) and the rise in FVC from rest to steady-state exercise (Δ, exercise − rest) before and during acute AA infusion. The MRT (P = 0.26) and steady-state vasodilator responses to exercise (ΔFVC, P = 0.31) were not different between groups. Intra-arterial infusion of AA resulted in a significant increase in plasma total antioxidant capacity (174 ± 37%). AA infusion did not alter MRT or steady-state FVC in any group (P = 0.90 and P = 0.85, respectively). Interestingly, higher levels of C-reactive protein predicted longer MRT (r = 0.52, P < 0.01) and a greater reduction in MRT with AA infusion (r = −0.43, P = 0.02). We concluded that AA infusion during moderate-intensity, rhythmic forearm exercise does not alter the time course or magnitude of exercise-mediated vasodilation in groups of young lean, obese, or MetSyn adults. However, systemic inflammation may limit the MRT to exercise, which can be improved with AA. PMID:25038148

  2. Exercise-mediated vasodilation in human obesity and metabolic syndrome: effect of acute ascorbic acid infusion.

    Science.gov (United States)

    Limberg, Jacqueline K; Kellawan, J Mikhail; Harrell, John W; Johansson, Rebecca E; Eldridge, Marlowe W; Proctor, Lester T; Sebranek, Joshua J; Schrage, William G

    2014-09-15

    We tested the hypothesis that infusion of ascorbic acid (AA), a potent antioxidant, would alter vasodilator responses to exercise in human obesity and metabolic syndrome (MetSyn). Forearm blood flow (FBF, Doppler ultrasound) was measured in lean, obese, and MetSyn adults (n = 39, 32 ± 2 yr). A brachial artery catheter was inserted for blood pressure monitoring and local infusion of AA. FBF was measured during dynamic handgrip exercise (15% maximal effort) with and without AA infusion. To account for group differences in blood pressure and forearm size, and to assess vasodilation, forearm vascular conductance (FVC = FBF/mean arterial blood pressure/lean forearm mass) was calculated. We examined the time to achieve steady-state FVC (mean response time, MRT) and the rise in FVC from rest to steady-state exercise (Δ, exercise - rest) before and during acute AA infusion. The MRT (P = 0.26) and steady-state vasodilator responses to exercise (ΔFVC, P = 0.31) were not different between groups. Intra-arterial infusion of AA resulted in a significant increase in plasma total antioxidant capacity (174 ± 37%). AA infusion did not alter MRT or steady-state FVC in any group (P = 0.90 and P = 0.85, respectively). Interestingly, higher levels of C-reactive protein predicted longer MRT (r = 0.52, P exercise does not alter the time course or magnitude of exercise-mediated vasodilation in groups of young lean, obese, or MetSyn adults. However, systemic inflammation may limit the MRT to exercise, which can be improved with AA. Copyright © 2014 the American Physiological Society.

  3. [Effects of hot water bath or sauna on patients with congestive heart failure: acute hemodynamic improvement by thermal vasodilation].

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    Tei, C; Horikiri, Y; Park, J C; Jeong, J W; Chang, K S; Tanaka, N; Toyama, Y

    1994-01-01

    The acute hemodynamic effects of thermal vasodilation caused by exposure to hot water bath or sauna in chronic congestive heart failure were investigated in 32 patients (mean age 57 +/- 15 years old) with dilated cardiomyopathy (25 idiopathic and 7 ischemic). The clinical symptoms were New York Heart Association Class II in 2 patients, III in 17 and IV in 13, and the mean ejection fraction was 25 +/- 9% (9-44%). Exposure to hot water bath was for 10 minutes at 41 degrees C in a semi-sitting position, and to sauna for 15 minutes at 60 degrees C in a supine position using a special far infrared ray sauna chamber. Blood pressure, electrocardiogram, two-dimensional and Doppler echocardiograms, expiration gas, and intracardiac pressure tracings were recorded before (control), during, and 30 minutes after hot water bath or sauna. 1. The increase in oxygen consumption was only 0.3 Mets during hot water bath or sauna, and returned to the control level 30 minutes later. 2. The deep temperature in the main pulmonary artery increased by 1.0-1.2 degrees C on average at the end of hot water bath or sauna. 3. Heart rate increased significantly (p sauna, while, diastolic blood pressure decreased significantly during (p sauna (p < 0.01), and after hot water bath (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Vasodilators

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    ... directly on the vessel walls are hydralazine and minoxidil. Doctors prescribe vasodilators to prevent, treat or improve ... http://www.micromedexsolutions.com. Accessed May 23, 2016. Minoxidil. Micromedex 2.0 Healthcare Series. http://www.micromedexsolutions. ...

  5. Acute hemodynamic response to vasodilators in primary pulmonary hypertension.

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    Kulkarni H

    1996-01-01

    Full Text Available Acute hemodynamic effects of high flow oxygen (O2 inhalation, sublingual isosorbide dinitrate (ISDN, intravenous aminophylline (AMN and sublingual nifedipine (NIF were studied in 32 patients with primary pulmonary hypertension (PPH. In 30 out of 32 patients the basal ratio of pulmonary to systemic vascular resistance (Rp/Rs was > 0.5 (mean = 0.77 +/- 0.20. Oxygen caused significant decrease in the mean resistance ratio to 0.68 +/- 0.20 (p = 0.005. ISDN, AMN and NIF caused increase in the resistance ratio to 0.79 +/- 0.26; 0.78 +/- 0.26; and 0.80 +/- 0.23 respectively. O2, ISDN, AMN and NIF caused a fall of Rp/Rs in 21 (65.6%, 10 (31.2%, 10(31.2% and 9(28.1% patients respectively. Thus, of the four drugs tested high flow O2 inhalation resulted in fall of Rp/Rs in two thirds of patients whereas ISDN, AMN and NIF caused a mean rise in Rp/Rs. One third of patients did respond acutely to the latter three drugs. Acute hemodynamic studies are useful before prescribing vasodilators in patients with PPH since more of the commonly used drugs like ISDN, AMN, NIF could have detrimental hemodynamic responses in some patients. However, great caution should be exercised before performing hemodynamic study as the procedure has definite mortality and morbidity.

  6. Improvement of Acetylcholine-Induced Vasodilation by Acute Exercise in Ovariectomized Hypertensive Rats.

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    Cheng, Tsung-Lin; Lin, Yi-Yuan; Su, Chia-Ting; Hu, Chun-Che; Yang, Ai-Lun

    2016-06-30

    Postmenopause is associated with the development of cardiovascular disease, such as hypertension. However, limited information is available regarding effects of exercise on cardiovascular responses and its underlying mechanisms in the simultaneous postmenopausal and hypertensive status. We aimed to investigate whether acute exercise could enhance vasodilation mediated by acetylcholine (ACh) and sodium nitroprusside (SNP) in ovariectomized hypertensive rats. The fifteen-week-old female spontaneously hypertensive rats (SHR) were bilaterally ovariectomized, at the age of twenty-four weeks, and randomly divided into sedentary (SHR-O) and acute exercise (SHR-OE) groups. Age-matched WKY rats were used as the normotensive control group. The SHR-OE group ran on a motor-driven treadmill at a speed of 24 m/min for one hour in a moderate-intensity program. Following a single bout of exercise, rat aortas were isolated for the evaluation of the endothelium-dependent (ACh-induced) and endothelium-independent (SNP-induced) vasodilation by the organ bath system. Also, the serum levels of oxidative stress and antioxidant activities, including malondialdehyde (MDA), superoxide dismutase (SOD), and catalase, were measured after acute exercise among the three groups. We found that acute exercise significantly enhanced the ACh-induced vasodilation, but not the SNP-induced vasodilation, in ovariectomized hypertensive rats. This increased vasodilation was eliminated after the inhibition of nitric oxide synthase (NOS). Also, the activities of SOD and catalase were significantly increased after acute exercise, whereas the level of MDA was comparable among the three groups. These results indicated that acute exercise improved the endothelium-dependent vasodilating response to ACh through the NOS-related pathway in ovariectomized hypertensive rats, which might be associated with increased serum antioxidant activities.

  7. Acute dairy milk ingestion does not improve nitric oxide-dependent vasodilation in the cutaneous microcirculation.

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    Alba, Billie K; Stanhewicz, Anna E; Kenney, W Larry; Alexander, Lacy M

    2016-07-01

    In epidemiological studies, chronic dairy milk consumption is associated with improved vascular health and reduced age-related increases in blood pressure. Although milk protein supplementation augments conduit artery flow-mediated dilation, whether or not acute dairy milk intake may improve microvascular function remains unclear. We hypothesised that dairy milk would increase direct measurement of endothelial nitric oxide (NO)-dependent cutaneous vasodilation in response to local skin heating. Eleven men and women (61 (sem 2) years) ingested two or four servings (473 and 946 ml) of 1 % dairy milk or a rice beverage on each of 4 separate study days. In a subset of five subjects, an additional protocol was completed after 473 ml of water ingestion. Once a stable blood flow occurred, 15 mm-N G -nitro-l-arginine methyl ester was perfused (intradermal microdialysis) to quantify NO-dependent vasodilation. Red-blood-cell flux (RBF) was measured by laser-Doppler flowmetry, and cutaneous vascular conductance (CVC=RBF/mean arterial pressure) was calculated and normalised to maximum (%CVCmax; 28 mm-sodium nitroprusside). Full expression of cutaneous vasodilation was not different among dairy milk, rice beverage and water, and there was no effect of serving size on the total vasodilatory response. Contrary to our hypothesis, NO-dependent vasodilation was lower for dairy milk than rice beverage (D: 49 (sem 5), R: 55 (sem 5) %CVCmax; Pdairy milk ingestion does not augment NO-dependent vasodilation in the cutaneous microcirculation compared with a rice beverage control.

  8. Vasodilator drugs.

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    Gould, L; Gopalaswamy, C

    1984-02-01

    This article demonstrates conclusively that systemic vasodilator therapy is an important new medical treatment for acute and chronic heart failure. Initially, vasodilators were used only when digitalis and diuretics could not adequately treat congestive heart failure. Now many clinicians view the vasodilators as equal or even better alternatives than digitalis and diuretics. There is no doubt that vasodilator therapy is one of the major advances in the treatment of heart failure.

  9. Acute dietary nitrate supplementation enhances compensatory vasodilation during hypoxic exercise in older adults.

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    Casey, Darren P; Treichler, David P; Ganger, Charles T; Schneider, Aaron C; Ueda, Kenichi

    2015-01-15

    We have previously demonstrated that aging reduces the compensatory vasodilator response during hypoxic exercise due to blunted nitric oxide (NO) signaling. Recent evidence suggests that NO bioavailability can be augmented by dietary nitrate through the nitrate-nitrite pathway. Thus we tested the hypothesis that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise, particularly in older adults. Thirteen young (25 ± 1 yr) and 12 older (64 ± 2 yr) adults performed rhythmic forearm exercise at 20% of maximum voluntary contraction during normoxia and hypoxia (∼80% O2 saturation); both before (control) and 3 h after beetroot juice (BR) consumption. Forearm vascular conductance (FVC; ml·min(-1)·100 mmHg(-1)) was calculated from forearm blood flow (ml/min) and blood pressure (mmHg). Compensatory vasodilation was defined as the relative increase in FVC due to hypoxic exercise (i.e., % increase compared with respective normoxic exercise trial). Plasma nitrite was determined from venous blood samples obtained before the control trials and each of the exercise trials (normoxia and hypoxia) after BR. Consumption of BR increased plasma nitrite in both young and older adults (P vasodilator response to hypoxic exercise was attenuated in older compared with young adults (3.8 ± 1.7% vs. 14.2 ± 1.2%, P vasodilation did not change in young (13.7 ± 3.3%, P = 0.81) adults but was substantially augmented in older adults (11.4 ± 2.1%, P vasodilator response to hypoxic exercise in older but not young adults.

  10. Hemoglobin Effects on Nitric Oxide Mediated Hypoxic Vasodilation.

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    Rong, Zimei; Cooper, Chris E

    2016-01-01

    The brain responds to hypoxia with an increase in cerebral blood flow (CBF). However, such an increase is generally believed to start only after the oxygen tension decreases to a certain threshold level. Although many mechanisms (different vasodilator and different generation and metabolism mechanisms of the vasodilator) have been proposed at the molecular level, none of them has gained universal acceptance. Nitric oxide (NO) has been proposed to play a central role in the regulation of oxygen supply since it is a vasodilator whose production and metabolism are both oxygen dependent. We have used a computational model that simulates blood flow and oxygen metabolism in the brain (BRAINSIGNALS) to test mechanism by which NO may elucidate hypoxic vasodilation. The first model proposed that NO was produced by the enzyme nitric oxide synthase (NOS) and metabolized by the mitochondrial enzyme cytochrome c oxidase (CCO). NO production declined with decreasing oxygen concentration given that oxygen is a substrate for nitric oxide synthase (NOS). However, this was balanced by NO metabolism by CCO, which also declined with decreasing oxygen concentration. However, the NOS effect was dominant; the resulting model profiles of hypoxic vasodilation only approximated the experimental curves when an unfeasibly low K m for oxygen for NOS was input into the model. We therefore modified the model such that NO generation was via the nitrite reductase activity of deoxyhemoglobin instead of NOS, whilst keeping the metabolism of NO by CCO the same. NO production increased with decreasing oxygen concentration, leading to an improved reproduction of the experimental CBF versus PaO2 curve. However, the threshold phenomenon was not perfectly reproduced. In this present work, we incorporated a wider variety of oxygen dependent and independent NO production and removal mechanisms. We found that the addition of NO removal via oxidation to nitrate mediated by oxyhemoglobin resulted in the

  11. Oral sapropterin acutely augments reflex vasodilation in aged human skin through nitric oxide-dependent mechanisms.

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    Stanhewicz, Anna E; Alexander, Lacy M; Kenney, W Larry

    2013-10-01

    Functional constitutive nitric oxide synthase (NOS) and its cofactor tetrahydrobiopterin (BH4) are required for full reflex cutaneous vasodilation and are attenuated in primary aging. Acute, locally administered BH4 increases reflex vasodilation through NO-dependent mechanisms in aged skin. We hypothesized that oral sapropterin (Kuvan, shelf-stable pharmaceutical formulation of BH4) would augment reflex vasodilation in aged human skin during hyperthermia. Nine healthy human subjects (76 ± 1 yr) ingested sapropterin (10 mg/kg) or placebo in a randomized double-blind crossover design. Venous blood samples were collected prior to, and 3 h following, ingestion of sapropterin for measurement of plasma BH4. Three intradermal microdialysis fibers were placed in the forearm skin for local delivery of 1) lactated Ringer's solution, 2) 10 mM BH4, and 3) 20 mM N(G)-nitro-l-arginine methyl ester (l-NAME) to inhibit NOS. Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasodilation was induced using a water-perfused suit. At 1°C rise in oral temperature, mean body temperature was clamped and 20 mM l-NAME was perfused at each site. Cutaneous vascular conductance was calculated (CVC = LDF/MAP) and expressed as a percentage of maximum (%CVCmax 28 mM sodium nitroprusside and local heat 43°C). Plasma concentrations of BH4 were significantly elevated 3 h after ingestion of sapropterin (0 h: 19.1 ± 2 pmol/ml vs. 3 h: 43.8 ± 3 pmol/ml; P vasodilation at control site (placebo: 14 ± 1 %CVCmax vs. sapropterin: 25 ± 4 %CVCmax; P = 0.004). Local BH4 administration increased NO-dependent vasodilation compared with control in placebo trials only (control: 14 ± 1 %CVCmax vs. BH4-treated: 24 ± 3 %CVCmax; P = 0.02). These data suggest oral sapropterin increases bioavailable BH4 in aged skin microvasculature sufficiently to increase NO synthesis through NOS and that sapropterin may be a viable intervention to increase skin blood flow during hyperthermia

  12. Resveratrol induces acute endothelium-dependent renal vasodilation mediated through nitric oxide and reactive oxygen species scavenging

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    Gordish, Kevin L.

    2014-01-01

    Resveratrol is suggested to have beneficial cardiovascular and renoprotective effects. Resveratrol increases endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) synthesis. We hypothesized resveratrol acts as an acute renal vasodilator, mediated through increased NO production and scavenging of reactive oxygen species (ROS). In anesthetized rats, we found 5.0 mg/kg body weight (bw) of resveratrol increased renal blood flow (RBF) by 8% [from 6.98 ± 0.42 to 7.54 ± 0.17 ml·min−1·gram of kidney weight−1 (gkw); n = 8; P resveratrol before and after 10 mg/kg bw of the NOS inhibitor N-nitro-l-arginine methyl ester (l-NAME). l-NAME reduced the increase in RBF to resveratrol by 54% (from 0.59 ± 0.05 to 0.27 ± 0.06 ml·min−1·gkw−1; n = 10; P resveratrol before and after 1 mg/kg bw tempol, a superoxide dismutase mimetic. Resveratrol increased RBF 7.6% (from 5.91 ± 0.32 to 6.36 ± 0.12 ml·min−1·gkw−1; n = 7; P resveratrol-induced increase in RBF (from 0.45 ± 0.12 to 0.10 ± 0.05 ml·min−1·gkw−1; n = 7; P Resveratrol-induced vasodilation remained unaffected. We conclude intravenous resveratrol acts as an acute renal vasodilator, partially mediated by increased NO production/NO bioavailability and superoxide scavenging but not by inducing vasodilatory cyclooxygenase products. PMID:24431202

  13. Acute ingestion of beetroot bread increases endothelium-independent vasodilation and lowers diastolic blood pressure in healthy men: a randomized controlled trial.

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    Hobbs, Ditte A; Goulding, Marie G; Nguyen, Annie; Malaver, Thomas; Walker, Claire F; George, Trevor W; Methven, Lisa; Lovegrove, Julie A

    2013-09-01

    Dietary nitrate, from beetroot, has been reported to lower blood pressure (BP) by the sequential reduction of nitrate to nitrite and further to NO in the circulation. However, the impact of beetroot on microvascular vasodilation and arterial stiffness is unknown. In addition, beetroot is consumed by only 4.5% of the UK population, whereas bread is a staple component of the diet. Thus, we investigated the acute effects of beetroot bread (BB) on microvascular vasodilation, arterial stiffness, and BP in healthy participants. Twenty-three healthy men received 200 g bread containing 100 g beetroot (1.1 mmol nitrate) or 200 g control white bread (CB; 0 g beetroot, 0.01 mmol nitrate) in an acute, randomized, open-label, controlled crossover trial. The primary outcome was postprandial microvascular vasodilation measured by laser Doppler iontophoresis and the secondary outcomes were arterial stiffness measured by Pulse Wave Analysis and Velocity and ambulatory BP measured at regular intervals for a total period of 6 h. Plasma nitrate and nitrite were measured at regular intervals for a total period of 7 h. The incremental area under the curve (0-6 h after ingestion of bread) for endothelium-independent vasodilation was greater (P = 0.017) and lower for diastolic BP (DBP; P = 0.032) but not systolic (P = 0.99) BP after BB compared with CB. These effects occurred in conjunction with increases in plasma and urinary nitrate (P vasodilation and decreased DBP. Therefore, enriching bread with beetroot may be a suitable vehicle to increase intakes of cardioprotective beetroot in the diet and may provide new therapeutic perspectives in the management of hypertension.

  14. Role of vasodilators in regurgitant valve disease.

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    Evangelista, Artur; Tornos, Pilar; Sambola, Antonia; Permayer-Miralda, Gaieta

    2006-12-01

    Vasodilator therapy is designed to reduce regurgitant volume and improve left ventricular function. Acute administration reduces vascular resistance and decreases regurgitant volume and left ventricular filling pressure. These effects may be clinically useful in acute regurgitations, but less consistent results have been reported in long-term therapy. In chronic mitral functional regurgitation, vasodilator therapy has proved to have clinical or prognostic benefit only when heart failure or poor ventricular function is present. The indication of vasodilator treatment in aortic regurgitation has raised significant controversy. Several studies with small series have shown beneficial effects on regurgitant volume, ejection fraction, and mass of the left ventricle. Nevertheless, in the only two randomized long-term follow-up studies, results differed completely. In our experience, both nifedipine and enalapril failed to reduce the need for valvular surgery or show benefits in echocardiographic parameters. Vasodilator therapy would be indicated only in patients with severe aortic regurgitation and systemic hypertension, or when surgery is contraindicated.

  15. Differential effect of amylin on endothelial-dependent vasodilation in mesenteric arteries from control and insulin resistant rats.

    Directory of Open Access Journals (Sweden)

    Mariam El Assar

    Full Text Available Insulin resistance (IR is frequently associated with endothelial dysfunction and has been proposed to play a major role in cardiovascular disease (CVD. On the other hand, amylin has long been related to IR. However the role of amylin in the vascular dysfunction associated to IR is not well addressed. Therefore, the aim of the study was to assess the effect of acute treatment with amylin on endothelium-dependent vasodilation of isolated mesenteric arteries from control (CR and insulin resistant (IRR rats and to evaluate the possible mechanisms involved. Five week-old male Wistar rats received 20% D-fructose dissolved in drinking water for 8 weeks and were compared with age-matched CR. Plasmatic levels of glucose, insulin and amylin were measured. Mesenteric microvessels were dissected and mounted in wire myographs to evaluate endothelium-dependent vasodilation to acetylcholine. IRR displayed a significant increase in plasmatic levels of glucose, insulin and amylin and reduced endothelium-dependent relaxation when compared to CR. Acute treatment of mesenteric arteries with r-amylin (40 pM deteriorated endothelium-dependent responses in CR. Amylin-induced reduction of endothelial responses was unaffected by the H2O2 scavenger, catalase, but was prevented by the extracellular superoxide scavenger, superoxide dismutase (SOD or the NADPH oxidase inhibitor (VAS2870. By opposite, amylin failed to further inhibit the impaired relaxation in mesenteric arteries of IRR. SOD, or VAS2870, but not catalase, ameliorated the impairment of endothelium-dependent relaxation in IRR. At concentrations present in insulin resistance conditions, amylin impairs endothelium-dependent vasodilation in mircrovessels from rats with preserved vascular function and low levels of endogenous amylin. In IRR with established endothelial dysfunction and elevated levels of amylin, additional exposure to this peptide has no effect on endothelial vasodilation. Increased superoxide

  16. Selective renal vasodilation and active renal artery perfusion improve renal function in dogs with acute heart failure.

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    Suehiro, K; Shimizu, J; Yi, G H; Gu, A; Wang, J; Keren, G; Burkhoff, D

    2001-09-01

    Renal failure is common in heart failure due to renovascular constriction and hypotension. We tested whether selective pharmacological renal artery vasodilation and active renal artery perfusion (ARP) could improve renal function without adverse effects on systemic blood pressure in a canine model of acute heart failure (AHF). AHF was induced by coronary microembolization in 16 adult mongrel dogs. In five dogs, selective intrarenal (IR) papaverine (1, 2, and 4 mg/min) was administered into the left renal artery. In six dogs, ARP was performed in the left renal artery to normalize mean renal arterial pressure followed by administration of IR papaverine (2 mg/min). In five dogs, ARP plus intravenous furosemide was tested. Urine output (UO) and cortical renal blood flow decreased during AHF and were restored by 2 mg/min IR papaverine (UO: baseline 4.2 +/- 0.6, AHF 1.6 +/- 1.3, IR papaverine 5.8 +/- 1.1 ml/15 min; cortical blood flow: baseline 4.3 +/- 0.2, AHF 2.4 +/- 0.6, IR papaverine 4.2 +/- 1.2 ml/min/g) with no significant change in aortic pressure. ARP also increased urine output and cortical renal blood flow (UO: baseline 5.0 +/- 1.1, AHF 0.5 +/- 0.4, ARP 3.8 +/- 3.1 ml/15 min; cortical blood flow: baseline 4.0 +/- 0.5, AHF 2.0 +/- 0.8, ARP 3.52 +/- 1.1 ml/min/g). A combination of these methods in AHF further increased urine output to twice the normal baseline (10.5 +/- 7.5 ml/15 min). Addition of furosemide synergistically increased UO above that achieved with ARP alone (5.5 +/- 2.6 versus 40.3 +/- 24.7 ml/15 min, p = 0.03). In conclusion, ARP and selective renal vasodilation may effectively promote salt and water excretion in the setting of heart failure, particularly when systemic blood pressure is low.

  17. Vasodilator effects of adenosine on retinal arterioles in streptozotocin-induced diabetic rats.

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    Nakazawa, Taisuke; Mori, Asami; Saito, Maki; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2008-02-01

    Adenosine is a potent vasodilator of retinal blood vessels and is implicated to be a major regulator of retinal blood flow during metabolic stress, but little is known about the impact of diabetes on the role of adenosine in regulation of retinal hemodynamics. Therefore, we examined how diabetes affects adenosine-induced vasodilation of retinal arterioles. Male Wistar rats were treated with streptozotocin (80 mg/kg, intraperitoneally), and experiments were performed 6-8 weeks later. Rats were treated with tetrodotoxin (50 microg/kg, intravenously [i.v.]) to eliminate any nerve activity and prevent movement of the eye and infused with methoxamine continuously to maintain adequate systemic circulation. Fundus images were captured with a digital camera that was equipped with a special objective lens, and diameters of retinal arterioles were measured. Adenosine increased diameters of retinal arterioles and decreased systemic blood pressure. These responses were significantly attenuated by the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (30 mg/kg, i.v.) and the adenosine triphosphate-dependent K+ (K(ATP)) channel blocker glibenclamide (20 mg/kg, i.v.). The depressor responses to adenosine were reduced in diabetic rats, whereas diabetes did not alter vasodilation of retinal arterioles to adenosine. In contrast, both depressor response and vasodilation of retinal arteriole to acetylcholine were reduced in diabetic rats. The retinal vasodilator responses to adenosine and acetylcholine observed in diabetic rats were diminished by N(G)-nitro-L-arginine methyl ester. There were no differences in the responses to pinacidil, a K(ATP) channel opener, between the diabetic and nondiabetic rats. These results suggest that both the activation of nitric oxide synthase and opening of K(ATP) channels contribute to the vasodilator effects of adenosine in rats in vivo. However, diabetes has no significant impact on the vasodilation mediated by these mechanisms in

  18. Attenuation of hypoxic pulmonary vasoconstriction in acute oleic acid lung injury--significance of vasodilator prostanoids.

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    Yamaguchi, K; Mori, M; Kawai, A; Asano, K; Takasugi, T; Umeda, A; Yokoyama, T

    1992-01-01

    To assess a significant role of hypoxic pulmonary vasoconstriction, HPV, on maintaining the gas exchange efficiency in acute lung injury, 24 mongrel dogs were treated with intravenously injecting 0.07 ml/kg of oleic acid. Hemodynamic and gas-exchange parameters were investigated at varied inspired O2 concentration, FIO2. To know a possible contribution of vasoactive prostanoids in regulating vascular reactivity under these circumstances, observations were repeated after infusion of indomethacin. The impairment of gas exchange in injured lungs was examined by measuring the fractional retention, R, of the gas in arterial blood. For this evaluation, a normal saline containing five foreign inert gases such as sulfur hexafluoride, SF6, ethane, cyclopropane, halothane and diethyl ether was infused at a constant rate through a peripheral vein. After a steady state was established, the expired gas was collected and the samples of both arterial and mixed venous blood were simultaneously taken for the inert-gas analysis. The concentrations of the indicator gases in the samples were measured in terms of a gas chromatograph equipped with an electron capture detector for SF6 and a flame ionization detector for the other four gases. Although pulmonary vascular resistance, PVR, after injecting oleic acid at FIO2 0.60 was significantly smaller than that obtained at FIO2 0.21, cardiac output, QT as well as extravascular lung water were not different between the two conditions. R value for the indicator gas was consistently lower at FIO2 0.60 irrespective of the gas species. As increasing FIO2, R estimate concerning SF6, RSF6, rational index of the fractional blood flow perfusing shunt area, decreased significantly. Administration of indomethacin caused the rise in PVR without an appreciable change in either QT or extravascular lung water but a considerable diminution in R value for the inert gas. RSF6 after infusion of indomethacin decreased from 0.35 to 0.27, accompanied by a

  19. Vasodilation effect of 2-benzyl-5-hydroxy-6-methoxy-3, 4-dihydroisoquinolin-1-one.

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    Xu, Wei-Qi; Xiong, Zhi-Zheng; Chen, Ting-Ting; Gao, Xiao-Yan; Yu, Hang; Zhang, San-Qi; Cao, Yong-Xiao

    2012-08-01

    A 2-Benzyl-5-hydroxy-6-methoxy-3, 4-dihydroisoquinolin-1-one (ZC2) is a newly synthesized isoquinolinone compound. Its effect on vasodilation was evaluated in the present study. Isometric tension of rat artery rings was recorded by a sensitive myography system in vitro. The results showed that ZC2 relaxed rat mesenteric arteries pre-contracted by KCl, phenylephrine and 9, 11- dideoxy- 11α, 9α-epoxymethano-prostaglandin F2α (U46619), and abdominal aorta pre-contracted by KCl in a concentration-dependent manner. The ZC2-induced vasodilation was not affected by an endothelium denudation. ZC2 rightwards shifted the concentration-contraction curves, induced by KCl, phenylephrine, and 5-hydroxytryptamine (5-HT) in a non-parallel manner, which suggests that the vasodilation effects are most likely via voltage-dependent calcium channel (VDCC) and receptor-operated calcium channel (ROCC). Moreover, in Ca(2+)-free medium, ZC2 concentration-dependently depressed the vasoconstrictions induced by phenylephrine and CaCl(2), and decreased a contractile response induced by caffeine, which indicates a role of extracellular Ca(2+) influx inhibition through VDCC and ROCC, and intracellular Ca(2+) release from Ca(2+) store via the ryanodine receptors. Glibenclamide did not affect the vasodilation induced by ZC2, suggesting that ATP sensitive potassium channel is not involved in the vasodilation. The results indicate that ZC2 induces vasodilation by inhibiting the VDCC and ROCC, and receptormediated Ca(2+) influx and release. The inhibition of intracellular Ca(2+) release may be mediated via the ryanodine receptors.

  20. Pulmonary vasodilation in acute and chronic heart failure: empiricism and evidence.

    Science.gov (United States)

    Guglin, Maya

    2011-09-01

    Pulmonary hypertension in heart failure is associated with exercise intolerance and adverse outcomes. With the availability of multiple drugs that cause pulmonary vasodilation and decrease pulmonary arterial pressure, pulmonary hypertension becomes an attractive therapeutic target. Out of several classes of medications, oral phosphodiesterase inhibitors emerge as the most promising in terms of symptomatic improvement, hemodynamic benefits, reverse cardiac remodeling, and functional capacity. Future trials will show whether the use of these drugs translates to decreased morbidity and mortality in heart failure.

  1. Application of vasodilators in patients with acute heart failure%血管扩张药在急性心力衰竭中的应用

    Institute of Scientific and Technical Information of China (English)

    李延林; 李勇

    2011-01-01

    Therapy with vasodilators for the acute heart failure (AHF) can improve both hemodynamics and symptoms. However, none of those currently has been verified by large, placebo-controlled, prospectively randomized clinical trials to assess the effects on outcomes. This review discusses the role of vasodilators such as nitroprusside and nesiritide in AHF, and focuses on the potentially best indications and adverse drug reactions.%应用血管扩张药治疗急性心力衰竭(AHF)可改善血流动力学和临床症状,但血管扩张剂的临床效果尚未获得前瞻性大规模随机安慰剂对照临床研究验证.本文主要综述硝普钠和奈西立肽等常用血管扩张药在AHF治疗中的地位,并关注其临床应用的最佳指征以及可能导致的不良反应.

  2. Relationship between Vasodilation Effect of Anisodamine and Endothelial Target for Acetylcholine on Microvessels in Rat

    Institute of Scientific and Technical Information of China (English)

    鲍颖霞; 李庆平; 汪海

    2002-01-01

    Objective To study the effects of anisodamine on microvessels and its relatwn-ship with endothelium target for acetylcholine (ETA). Methods Norepinephrine precontracted mesen-teric vascular beds in rat were used to determine changes of tension of vessels in response to anisodamineafter removal of endothelium , coincubated with L-NAME, nitric oxide synthase (NOS) inhibitor, in-domethacin , cyclo-oxygenase inhibitor and glibenclamide , ATP-dependent K+ channels (K ATP ) inhibitor.Results Anisodamine produced a vasodilation effect on mesenteric vascular beds, which was remark-ably inhibited after removal of endothelium (P< 0.01). The vasodilation effect of anisodamine was al-so significantly inhibited after coincubated with indomethacin (1 μmol/ L), NG-nitro-L-arginine methylester ( L- NAME, 100 μrmol / L) and glibenclamide (1 μmol/L, P<0. 01, vs control). Conclu-sion The vasodilation effect of ani.sodamine on microvessels was mediated by ETA. This is related toprostacyclin , endothelium derived relaxing factor (EDRF) and KATP besides M, a-receptor on vascularmooth muscle cell (VSMC) and calcium-antagonistic effects.

  3. Hypoxia-induced vasodilation and effects of regional phentolamine in awake patients with sleep apnea.

    Science.gov (United States)

    Moradkhan, Raman; Spitnale, Brett; McQuillan, Patrick; Hogeman, Cynthia; Gray, Kristen S; Leuenberger, Urs A

    2010-05-01

    Obstructive sleep apnea (OSA) is associated with increased sympathetic nerve activity, endothelial dysfunction, and premature cardiovascular disease. To determine whether hypoxia is associated with impaired skeletal muscle vasodilation, we compared femoral artery blood flow (ultrasound) and muscle sympathetic nerve activity (peroneal microneurography) during exposure to acute systemic hypoxia (fraction of inspired oxygen 0.1) in awake patients with OSA (n=10) and controls (n=8). To assess the role of elevated sympathetic nerve activity, in a separate group of patients with OSA (n=10) and controls (n=10) we measured brachial artery blood flow during hypoxia before and after regional alpha-adrenergic block with phentolamine. Despite elevated sympathetic activity, in OSA the vascular responses to hypoxia in the leg did not differ significantly from those in controls [P=not significant (NS)]. Following regional phentolamine, in both groups the hypoxia-induced increase in brachial blood flow was markedly enhanced (OSA pre vs. post, 84+/-13 vs. 201+/-34 ml/min, Pphentolamine, the increase of brachial blood flow above baseline was similar (OSA vs. controls +61+/-16 vs. +48+/-6%; P=NS). We conclude that despite high sympathetic vasoconstrictor tone and prominent sympathetic responses to acute hypoxia, hypoxia-induced limb vasodilation is preserved in OSA.

  4. Vasodilator effects of L-arginine are stereospecific and augmented by insulin in humans.

    Science.gov (United States)

    Dallinger, Susanne; Sieder, Anna; Strametz, Jeanette; Bayerle-Eder, Michaela; Wolzt, Michael; Schmetterer, Leopold

    2003-06-01

    The amino acid l-arginine, the precursor of nitric oxide (NO) synthesis, induces vasodilation in vivo, but the mechanism behind this effect is unclear. There is, however, some evidence to assume that the l-arginine membrane transport capacity is dependent on insulin plasma levels. We hypothesized that vasodilator effects of l-arginine may be dependent on insulin plasma levels. Accordingly, we performed two randomized, double-blind crossover studies in healthy male subjects. In protocol 1 (n = 15), subjects received an infusion of insulin (6 mU x kg(-1) x min(-1) for 120 min) or placebo and, during the last 30 min, l-arginine or d-arginine (1 g/min for 30 min) x In protocol 2 (n = 8), subjects received l-arginine in stepwise increasing doses in the presence (1.5 mU x kg(-1) x min(-1)) or absence of insulin. Renal plasma flow and glomerular filtration rate were assessed by the para-aminohippurate and inulin plasma clearance methods, respectively. Pulsatile choroidal blood flow was assessed with laser interferometric measurement of fundus pulsation, and mean flow velocity in the ophthalmic artery was measured with Doppler sonography. l-arginine, but not d-arginine, significantly increased renal and ocular hemodynamic parameters. Coinfusion of l-arginine with insulin caused a dose-dependent leftward shift of the vasodilator effect of l-arginine. This stereospecific renal and ocular vasodilator potency of l-arginine is enhanced by insulin, which may result from facilitated l-arginine membrane transport, enhanced intracellular NO formation, or increased NO bioavailability.

  5. Editor's Choice-Recent therapeutic trials on fluid removal and vasodilation in acute heart failure.

    Science.gov (United States)

    Ennezat, Pierre V; Stewart, Merrill; Samson, Rohan; Bouabdallaoui, Nadia; Maréchaux, Sylvestre; Banfi, Carlo; Bouvaist, Hélène; Le Jemtel, Thierry H

    2016-02-01

    Recent therapeutic trials regarding the management of acute heart failure (AHF) failed to demonstrate the efficacy of newer therapeutic modalities and agents. Low- versus high-dose and continuous administration of furosemide were shown not to matter. Ultrafiltration was not found to be more efficacious than sophisticated diuretic therapy including dose-adjusted intravenous furosemide and metolazone. Dopamine and nesiritide were not shown to be superior to current therapy. Tezosentan and tovalptan had no effect on mortality. The development of rolofylline was terminated due to adverse effect (seizures). Lastly, preliminary experience with serelaxin indicates a mortality improvement at six months that remains to be confirmed. The disappointing findings of these recent trials may reflect the lack of efficacy of newer therapeutic modalities and agents. Alternatively the disappointing findings of these recent trials may be in part due to methodological issues. The AHF syndrome is complex with many clinical phenotypes. Failure to match clinical phenotypes and therapeutic modalities is likely to be partly responsible for the disappointing findings of recent AHF trials. © The European Society of Cardiology 2014.

  6. Acute ascorbic acid ingestion increases skeletal muscle blood flow and oxygen consumption via local vasodilation during graded handgrip exercise in older adults.

    Science.gov (United States)

    Richards, Jennifer C; Crecelius, Anne R; Larson, Dennis G; Dinenno, Frank A

    2015-07-15

    Human aging is associated with reduced skeletal muscle perfusion during exercise, which may be a result of impaired endothelium-dependent dilation and/or attenuated ability to blunt sympathetically mediated vasoconstriction. Intra-arterial infusion of ascorbic acid (AA) increases nitric oxide-mediated vasodilation and forearm blood flow (FBF) during handgrip exercise in older adults, yet it remains unknown whether an acute oral dose can similarly improve FBF or enhance the ability to blunt sympathetic vasoconstriction during exercise. We hypothesized that 1) acute oral AA would improve FBF (Doppler ultrasound) and oxygen consumption (V̇o2) via local vasodilation during graded rhythmic handgrip exercise in older adults (protocol 1), and 2) AA ingestion would not enhance sympatholysis in older adults during handgrip exercise (protocol 2). In protocol 1 (n = 8; 65 ± 3 yr), AA did not influence FBF or V̇o2 during rest or 5% maximal voluntary contraction (MVC) exercise, but increased FBF (199 ± 13 vs. 248 ± 16 ml/min and 343 ± 24 vs. 403 ± 33 ml/min; P vasodilation.

  7. The Anti-Inflammatory and Vasodilating Effects of Three Selected Dietary Organic Sulfur Compounds from Allium Species

    Science.gov (United States)

    Chu, Chin-Chen; Wu, Wen-Shiann; Shieh, Ja-Ping; Chu, Heuy-Ling; Lee, Chia-Pu; Duh, Pin-Der

    2017-01-01

    The anti-inflammatory and vasodilating effects of three selected dietary organic sulfur compounds (OSC), including diallyl disulfide (DADS), dimethyl disulfide (DMDS), and propyl disulfide (PDS), from Allium species were investigated. In the anti-inflammatory activity assay, the three OSC demonstrated significant inhibition of nitric oxide (NO) and prostaglandin E2 (PGE2) production in LPS-induced RAW 264.7 cells. The expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) in activated RAW 264.7 cells was inhibited by the three OSC, indicating that the three OSC prevented the LPS-induced inflammatory response in RAW 264.7 cells. For the vasodilative assay, the three OSC were ineffective in producing NO in SVEC4-10 cells, but they did enhance prostacyclin (PGI2) production. The expression of COX-2 in SVEC4-10 cells was activated by DADS and DMDS. Pretreatment of SVEC4-10 cells with the three OSC decreased ROS generation in H2O2-induced SVEC4-10 cells. In addition, the three OSC significantly inhibited angiotensin-I converting enzyme (ACE). The up-regulation of PGI2 production and COX-2 expression by DADS and DMDS and the reduction of ROS generation by DADS, DMDS, and PDS in SVEC4-10 cells contributed to the vasodilative effect of the three OSC. Collectively, these findings suggest that DADS, DMDS, and PDS are potential anti-inflammatory and vasodilative mediators. PMID:28134777

  8. Jabuticaba-Induced Endothelium-Independent Vasodilating Effect on Isolated Arteries

    Directory of Open Access Journals (Sweden)

    Daniela Medeiros Lobo de Andrade

    2016-01-01

    Full Text Available Abstract Background: Despite the important biological effects of jabuticaba, its actions on the cardiovascular system have not been clarified. Objectives: To determine the effects of jabuticaba hydroalcoholic extract (JHE on vascular smooth muscle (VSM of isolated arteries. Methods: Endothelium-denuded aortic rings of rats were mounted in isolated organ bath to record isometric tension. The relaxant effect of JHE and the influence of K+ channels and Ca2+ intra- and extracellular sources on JHE-stimulated response were assessed. Results: Arteries pre-contracted with phenylephrine showed concentration-dependent relaxation (0.380 to 1.92 mg/mL. Treatment with K+ channel blockers (tetraethyl-ammonium, glibenclamide, 4-aminopyridine hindered relaxation due to JHE. In addition, phenylephrine-stimulated contraction was hindered by previous treatment with JHE. Inhibition of sarcoplasmic reticulum Ca2+ ATPase did not change relaxation due to JHE. In addition, JHE inhibited the contraction caused by Ca2+ influx stimulated by phenylephrine and KCl (75 mM. Conclusion: JHE induces endothelium-independent vasodilation. Activation of K+ channels and inhibition of Ca2+ influx through the membrane are involved in the JHE relaxant effect.

  9. Jabuticaba-Induced Endothelium-Independent Vasodilating Effect on Isolated Arteries

    Science.gov (United States)

    de Andrade, Daniela Medeiros Lobo; Borges, Leonardo Luis; Torres, Ieda Maria Sapateiro; da Conceição, Edemilson Cardoso; Rocha, Matheus Lavorenti

    2016-01-01

    Background: Despite the important biological effects of jabuticaba, its actions on the cardiovascular system have not been clarified. Objectives: To determine the effects of jabuticaba hydroalcoholic extract (JHE) on vascular smooth muscle (VSM) of isolated arteries. Methods: Endothelium-denuded aortic rings of rats were mounted in isolated organ bath to record isometric tension. The relaxant effect of JHE and the influence of K+ channels and Ca2+ intra- and extracellular sources on JHE-stimulated response were assessed. Results: Arteries pre-contracted with phenylephrine showed concentration-dependent relaxation (0.380 to 1.92 mg/mL). Treatment with K+ channel blockers (tetraethyl-ammonium, glibenclamide, 4-aminopyridine) hindered relaxation due to JHE. In addition, phenylephrine-stimulated contraction was hindered by previous treatment with JHE. Inhibition of sarcoplasmic reticulum Ca2+ ATPase did not change relaxation due to JHE. In addition, JHE inhibited the contraction caused by Ca2+ influx stimulated by phenylephrine and KCl (75 mM). Conclusion: JHE induces endothelium-independent vasodilation. Activation of K+ channels and inhibition of Ca2+ influx through the membrane are involved in the JHE relaxant effect. PMID:27533258

  10. Safety and Efficacy of Intracoronary Vasodilators in the Treatment of No-Reflow after Primary Percutaneous Intervention in Patients with Acute ST-Elevation Myocardial Infarction: A Literature Review

    Directory of Open Access Journals (Sweden)

    Mostafa Dastani

    2016-04-01

    Full Text Available Introduction: The investigation of no-reflow phenomenon after Percutaneous Coronary Intervention (PCI in patients with acute ST-segment Elevation Myocardial Infarction (STEMI has therapeutic implications. Several vasodilators were administered through intracoronary injection to treat this phenomenon. We aimed to elucidate the risk factors, predictors, and long-term effects of no-reflow phenomenon, and to compare the effects of various vasodilators on re-opening the obstructed vessels. Materials and Methods: All the reviewed articles were retrieved from MEDLINE and Science Direct (up to October 2014. All no-reflow cases were determined through Thrombolysis in Myocardial Infarction grading (TIMI system. Results: Four articles were included, two of which mainly focused on risk factors, predictors, and long-term prognosis of no-reflow phenomenon, and its association with patient mortality and morbidity. The other two articles evaluated therapeutic interventions and compared their efficacy in treating no-reflow. Conclusion: Development of no-reflow in patients with STEMI after primary PCI is associated with low myocardial salvage by primary PCI, large scintigraphic infarct size, deteriorated left ventricle ejection fraction at six months, and increased risk of first-year mortality. During primary PCI, intracoronary infusion of diltiazem and verapamil can reverse no-reflow more effectively than nitroglycerin.

  11. Effect of functional electrostimulation on impaired skin vasodilator responses to local heating in spinal cord injury.

    NARCIS (Netherlands)

    Duijnhoven, N.T.L. van; Janssen, T.W.; Green, D.J.; Minson, C.T.; Hopman, M.T.E.; Thijssen, D.H.J.

    2009-01-01

    Spinal cord injury (SCI) induces vascular adaptations below the level of the lesion, such as impaired cutaneous vasodilation. However, the mechanisms underlying these differences are unclear. The aim of this study is to examine arm and leg cutaneous vascular conductance (CVC) responses to local heat

  12. Effect of subchronic exposure to mainstream cigarette smoke on endothelium-dependent vasodilation in rat arteries

    Directory of Open Access Journals (Sweden)

    Helena Lenasi

    2005-07-01

    Full Text Available Background: Cigarette smoking is reported to impair endothelium-dependent vasodilation. The aim of the present study was to assess the effect of 30-day exposure to mainstream cigarette smoke on vascular reactivity of rat abdominal aorta, carotid, renal and mesenteric artery. Separately, the NO-mediated and the EDHF-mediated, endothelium-dependent vascular relaxations were determined.Methods: Two groups of »Whistar Kyoto« rats were exposed to mainstream cigarette smoke (2 hours/day, 5 days/week for 30 days and to fresh conditioned air, respectively. Rats were sacrificed on the second day after the last exposition to cigarette smoke. Vascular reactivity studies were performed on isolated, endothelium-intact, phenylephrine-preconstricted rat artery rings. Cumulative concentration-relaxation curves to acetylcholine (ACh were obtained in the absence and presence of the endothelial NO synthase (eNOS inhibitor N ω nitro L-arginine (L-NA and the cyclo-oxygenase (COX inhibitor diclofenac, respectively. After washing period of 1 hour, vessels were exposed either to the intracellular superoxide scavenger tiron, to the cytochrome P450 (CYP inhibitor miconazole or the Na-K-ATPase inhibitor ouabain before being preconstricted with phenylephrine and determining the concentration-response curve to ACh.Results: ACh induced concentration-dependent relaxations. In none of the vessels investigated did we observe a significant difference in the relaxations obtained in arteries from control rats and rats exposed to cigarettee smoke. Although smoking is known to cause an increase in oxidative stress, treatment of the vessels with tiron did not affect the NOmediated relaxations. To evaluate the contribution of EDHF to endothelium-dependent vasodilation rings were preincubated with L-NA. The EDHF-mediated relaxations were significantly attenuated compared to the NO-mediated relaxations in renal and mesenteric artery and almost completely abolished in aorta and

  13. 过度使用血管扩张剂治疗对急性脑梗死疗效的影响%Impact of Excess Use Vasodilator Agent on Acute Cerebral Infarction

    Institute of Scientific and Technical Information of China (English)

    刘宏利; 张中东; 尹延伟

    2009-01-01

    Objective: To observe impact of excess use vasodilator agent therapy to curative effect with acute cerebral infarction. Method: 497 patients with acute cerebral infarction was fractionated 2 groups, First group had accepted therapy with 2 kinds or 1 kind of vasodilator agent; second group had accepted therapy with 3 or overtopping 3 kinds of vasodilator agent. To compare score of neurologic impairment, incidence of the patient's condition transient exacerbation and stroke in progression. Result: The score of neurologic impairment in 16.3±1.8 the first group patients is outweigh second group patient that is 19.4±1.7 ,P <0.01 ; Incidence of condition transient exacerbation is 8.42% in the first group patient is lower than 21.86%in the second group patient, P <0.01 ;Incidence of stroke in progression is 11.36% in the first group patient is lower than 19.2% in the second group patient, P <0.05. Conclusion: Excess use vasodilator agent has negative influence on curative effect with acute cerebral infarction.%目的:观察过度使用血管扩张荆治疗对急性脑梗死疗效的影响.方法:依据血管扩张剂的使用情况,将497例急性脑梗死患者分成两组,第一组使用血管扩张荆2种(含)以下,第二组使用血管扩张剂3种(含)以上.总结分析两组病例急性期治疗阶段的疗效,包括神经功能缺损评分、短暂病情加重病例数(发生率)、进展性脑卒中病例数(发生率).结果:第一组患者的临床神经经功能缺损评分16.3±1.8优于第二组19.4±1.7,P<0.01;第一组患者的短暂病情加重发生率(8.42%)低于第二组(21.86%),P<0.01;第一组患者的进展性脑卒中的发生率(11.36%)低于第二组(19.2%),P<0.05.结论:过度使用血管扩张剂对急性脑梗死的疗效有负面影响.

  14. High oxygen modifies vasodilator effect of cysteine via enhanced oxidative stress and thromboxane production in the rat mesenteric artery.

    Science.gov (United States)

    Yasuda, Yoshitaka; Feng, Guo-Gang; Li, Jiazheng; Nakamura, Emi; Hayashi, Hisaki; Sato, Motohiko; Fujiwara, Yoshihiro; Kinoshita, Hiroyuki

    2016-09-01

    Whether high oxygen is harmful to the vascular function is unclear. The present study examined if high oxygen modifies vasodilator effect of cysteine via enhanced oxidative stress and thromboxane production. Rat mesenteric arteries with endothelium at 95 or 50 % oxygen were subjected to isometric force recordings, measurement of thromboxane B2 levels, determination of superoxide and peroxynitrite levels and evaluation of NADPH oxidase subunit protein expression, respectively. L-cysteine (0.01-3 mM) constricted or dilated arteries at 95 and 50 % oxygen, respectively. Thromboxane receptor antagonist SQ-29,548 (1 μM) abolished the constriction at 95 % oxygen. L-cysteine (3 mM) increased levels of thromboxane B2 in arteries upon 95 % oxygen application. L-cysteine relaxed arteries treated with superoxide inhibitor tiron (2 mM) or NADPH oxidase inhibitor gp91ds-tat (1 μM) irrespective of the oxygen concentration while ATP-sensitive K(+) channel inhibitor glibenclamide (1 μM) and cystathionine-γ-lyase (CSE) inhibitor DL-propargylglycine (10 mM) similarly abolished the relaxation. L-cysteine (3 mM) with 95 % oxygen augmented levels of superoxide as well as nitrotyrosine within the artery, concomitantly with enhanced membrane protein expression of NADPH oxidase subunit p47phox. The higher concentration of oxygen attenuates L-cysteine-induced vasodilation via superoxide production mediated by NADPH oxidase along with thromboxane A2 production, resulting in vasoconstriction. The increased levels of superoxide, as well as peroxynitrite, coexist with the impaired vasodilation related to ATP-sensitive K(+) channels and CSE. Higher oxygen with plasma cysteine may cause oxidative stress and vasoconstrictor prostanoid production in blood vessels.

  15. Effects of hindlimb unloading and ionizing radiation on skeletal muscle resistance artery vasodilation and its relation to cancellous bone in mice.

    Science.gov (United States)

    Prisby, Rhonda D; Alwood, Joshua S; Behnke, Brad J; Stabley, John N; McCullough, Danielle J; Ghosh, Payal; Globus, Ruth K; Delp, Michael D

    2016-01-15

    Spaceflight has profound effects on vascular function as a result of weightlessness that may be further compounded by radiation exposure. The purpose of the present study was to assess the individual and combined effects of hindlimb unloading (HU) and radiation (Rad) on vasodilator responses in the skeletal muscle vasculature. Adult male C57BL/6J mice were randomized to one of four groups: control (Con), HU (tail suspension for 15 days), Rad (200 cGy of (137)Cs), and HU-Rad (15-day tail suspension and 200 cGy of (137)Cs). Endothelium-dependent vasodilation of gastrocnemius feed arteries was assessed in vitro using acetylcholine (ACh, 10(-9)-10(-4) M) and inhibitors of nitric oxide synthase (NOS) and cyclooxygenase (COX). Endothelium-independent vasodilation was assessed using Dea-NONOate (10(-9)-10(-4) M). Endothelium-dependent and -independent vasodilator responses were impaired relative to Con responses in all treatment groups; however, there was no further impairment from the combination of treatments (HU-Rad) relative to that in the HU and Rad groups. The NOS-mediated contribution to endothelium-dependent vasodilation was depressed with HU and Rad. This impairment in NOS signaling may have been partially compensated for by an enhancement of PGI2-mediated dilation. Changes in endothelium-dependent vasodilation were also associated with decrements in trabecular bone volume in the proximal tibia metaphysis. These data demonstrate that the simulated space environment (i.e., radiation exposure and unloading of muscle and bone) significantly impairs skeletal muscle artery vasodilation, mediated through endothelium-dependent reductions in NOS signaling and decrements in vascular smooth muscle cell responsiveness to NO.

  16. Jabuticaba-Induced Endothelium-Independent Vasodilating Effect on Isolated Arteries.

    Science.gov (United States)

    Andrade, Daniela Medeiros Lobo de; Borges, Leonardo Luis; Torres, Ieda Maria Sapateiro; Conceição, Edemilson Cardoso da; Rocha, Matheus Lavorenti

    2016-09-01

    Despite the important biological effects of jabuticaba, its actions on the cardiovascular system have not been clarified. To determine the effects of jabuticaba hydroalcoholic extract (JHE) on vascular smooth muscle (VSM) of isolated arteries. Endothelium-denuded aortic rings of rats were mounted in isolated organ bath to record isometric tension. The relaxant effect of JHE and the influence of K+ channels and Ca2+ intra- and extracellular sources on JHE-stimulated response were assessed. Arteries pre-contracted with phenylephrine showed concentration-dependent relaxation (0.380 to 1.92 mg/mL). Treatment with K+ channel blockers (tetraethyl-ammonium, glibenclamide, 4-aminopyridine) hindered relaxation due to JHE. In addition, phenylephrine-stimulated contraction was hindered by previous treatment with JHE. Inhibition of sarcoplasmic reticulum Ca2+ ATPase did not change relaxation due to JHE. In addition, JHE inhibited the contraction caused by Ca2+ influx stimulated by phenylephrine and KCl (75 mM). JHE induces endothelium-independent vasodilation. Activation of K+ channels and inhibition of Ca2+ influx through the membrane are involved in the JHE relaxant effect. Embora a jabuticaba apresente importantes efeitos biológicos, suas ações sobre o sistema cardiovascular ainda não foram esclarecidas. Determinar os efeitos do extrato de jabuticaba (EHJ) sobre o músculo liso vascular (MLV) em artérias isoladas. Aortas (sem endotélio) de ratos foram montadas em banho de órgãos isolados para registro de tensão isométrica. Foram verificados o efeito relaxante, a influência dos canais de K+ e das fontes de Ca2+ intra- e extracelular sob a resposta estimulada pelo EHJ. Artérias pré-contraídas com fenilefrina apresentaram relaxamento concentração-dependente (0,380 a 1,92 mg/mL). O tratamento com bloqueadores de canais de K+ (tetraetilamônio, glibenclamida, 4-aminopiridina) prejudicaram o relaxamento pelo EHJ. A contração estimulada com fenilefrina tamb

  17. [Effects of vasodilators on cyclic contraction induced by 3,4-diaminopyridine in isolated porcine coronary arteries].

    Science.gov (United States)

    Ogawa, Y; Imai, S

    1987-06-01

    3,4-Diaminopyridine (3,4-DAP), which is known to decrease K conductance, produced spontaneous repetitive phasic contractions of a regular (28/60) and an irregular (15/60) cycle or tonic contraction (16/60) following a latent period of 5-100 min in isolated porcine coronary arteries. Effects of pinacidil, a newly-synthesized vasodilator, were investigated using the preparation in which 3,4-DAP produced phasic contractions of the regular cycle in comparison with those of various vasodilators. Pinacidil produced dose-dependent prolongation of the cycle and reduced the peak tension and the tension at the relaxation phase, a mode of action that closely resembles that of nicorandil, suggesting the increase in K conductance and hyperpolarization. Nifedipine (10(-8) M) and dilazep (10(-4) M) markedly reduced the peak tension, while adenosine, dipyridamole and nitroglycerin did not produce such effects. The latter three drugs produced a prolongation of the cycle and reduced the tension of the relaxation phase. These data suggest that reduction of K conductance and activation of the voltage-dependent Ca channel may play an important role in initiation of the spontaneous repetitive phasic contraction in porcine coronary artery.

  18. Synergistic effects of free radical scavengers and cochlear vasodilators: a new otoprotective strategy for age-related hearing loss

    Science.gov (United States)

    Alvarado, Juan Carlos; Fuentes-Santamaría, Verónica; Melgar-Rojas, Pedro; Valero, María Llanos; Gabaldón-Ull, María Cruz; Miller, Josef M.; Juiz, José M.

    2015-01-01

    The growing increase in age-related hearing loss (ARHL), with its dramatic reduction in quality of life and significant increase in health care costs, is a catalyst to develop new therapeutic strategies to prevent or reduce this aging-associated condition. In this regard, there is extensive evidence that excessive free radical formation along with diminished cochlear blood flow are essential factors involved in mechanisms of other stress-related hearing loss, such as that associated with noise or ototoxic drug exposure. The emerging view is that both play key roles in ARHL pathogenesis. Therapeutic targeting of excessive free radical formation and cochlear blood flow regulation may be a useful strategy to prevent onset of ARHL. Supporting this idea, micronutrient-based therapies, in particular those combining antioxidants and vasodilators like magnesium (Mg2+), have proven effective in reducing the impact of noise and ototoxic drugs in the inner ear, therefore improving auditory function. In this review, the synergistic effects of combinations of antioxidant free radicals scavengers and cochlear vasodilators will be discussed as a feasible therapeutic approach for the treatment of ARHL. PMID:26029103

  19. Dissociation between vasodilation and Leishmania infection-enhancing effects of sand fly saliva and maxadilan

    Directory of Open Access Journals (Sweden)

    Fábio Castro-Sousa

    2001-10-01

    Full Text Available In this study, the ability of maxadilan and Lutzomyia longipalpis salivary gland lysate to enhance the infection of CBA mice by Leishmania major and of BALB/c mice by L. braziliensis was tested. No difference was observed between sizes of lesion in CBA mice infected with L. major and treated or not with salivary gland lysate or maxadilan, although they were injected in concentrations that induced cutaneous vasodilation. Although parasites were more frequently observed in foot pads and spleens of animals treated with maxadilan than in the animals treated with salivary gland lysate or saline, the differences were small and not statistically significant. The lesions in BALB/c mice infected with L. braziliensis and treated with maxadilan were slightly larger than in animals that received Leishmania alone. Such differences disappeared 14 weeks after infection, and were statistically significant only in one of two experiments.

  20. PI3K/Akt-independent NOS/HO activation accounts for the facilitatory effect of nicotine on acetylcholine renal vasodilations: modulation by ovarian hormones.

    Directory of Open Access Journals (Sweden)

    Eman Y Gohar

    Full Text Available We investigated the effect of chronic nicotine on cholinergically-mediated renal vasodilations in female rats and its modulation by the nitric oxide synthase (NOS/heme oxygenase (HO pathways. Dose-vasodilatory response curves of acetylcholine (0.01-2.43 nmol were established in isolated phenylephrine-preconstricted perfused kidneys obtained from rats treated with or without nicotine (0.5-4.0 mg/kg/day, 2 weeks. Acetylcholine vasodilations were potentiated by low nicotine doses (0.5 and 1 mg/kg/day in contrast to no effect for higher doses (2 and 4 mg/kg/day. The facilitatory effect of nicotine was acetylcholine specific because it was not observed with other vasodilators such as 5'-N-ethylcarboxamidoadenosine (NECA, adenosine receptor agonist or papaverine. Increases in NOS and HO-1 activities appear to mediate the nicotine-evoked enhancement of acetylcholine vasodilation because the latter was compromised after pharmacologic inhibition of NOS (L-NAME or HO-1 (zinc protoporphyrin, ZnPP. The renal protein expression of phosphorylated Akt was not affected by nicotine. We also show that the presence of the two ovarian hormones is necessary for the nicotine augmentation of acetylcholine vasodilations to manifest because nicotine facilitation was lost in kidneys of ovariectomized (OVX and restored after combined, but not individual, supplementation with medroxyprogesterone acetate (MPA and estrogen (E2. Together, the data suggests that chronic nicotine potentiates acetylcholine renal vasodilation in female rats via, at least partly, Akt-independent HO-1 upregulation. The facilitatory effect of nicotine is dose dependent and requires the presence of the two ovarian hormones.

  1. Effect of pregnancy and nitric oxide on the myogenic vasodilation of posterior cerebral arteries and the lower limit of cerebral blood flow autoregulation.

    Science.gov (United States)

    Chapman, Abbie C; Cipolla, Marilyn J; Chan, Siu-Lung

    2013-09-01

    Hemorrhage during parturition can lower blood pressure beyond the lower limit of cerebral blood flow (CBF) autoregulation that can cause ischemic brain injury. However, the impact of pregnancy on the lower limit of CBF autoregulation is unknown. We measured myogenic vasodilation, a major contributor of CBF autoregulation, in isolated posterior cerebral arteries (PCAs) from nonpregnant and late-pregnant rats (n = 10/group) while the effect of pregnancy on the lower limit of CBF autoregulation was studied in the posterior cerebral cortex during controlled hemorrhage (n = 8). Pregnancy enhanced myogenic vasodilation in PCA and shifted the lower limit of CBF autoregulation to lower pressures. Inhibition of nitric oxide synthase (NOS) prevented the enhanced myogenic vasodilation during pregnancy but did not affect the lower limit of CBF autoregulation. The shift in the autoregulatory curve to lower pressures during pregnancy is likely protective of ischemic injury during hemorrhage and appears to be independent of NOS.

  2. Endothelium- and smooth muscle-dependent vasodilator effects of Citrus aurantium L. var. amara: Focus on Ca(2+) modulation.

    Science.gov (United States)

    Kang, Purum; Ryu, Kang-Hyun; Lee, Jeong-Min; Kim, Hyo-Keun; Seol, Geun Hee

    2016-08-01

    Neroli, the essential oil of Citrus aurantium L. var. amara, is a well-characterized alleviative agent used to treat cardiovascular symptoms. However, because it has been found to have multiple effects, its mechanism of action requires further exploration. We sought to clarify the mechanism underlying the actions of neroli in mouse aorta. In aortic rings from mice precontracted with prostaglandin F2 alpha, neroli induced vasodilation. However, relaxation effect of neroli was decreased in endothelium-denuded ring or pre-incubation with the nitric oxide synthase inhibitor NG-Nitro-l-arginine-methyl ester (L-NAME). And also, neroli-induced relaxation was also partially reversed by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ), a soluble guanylyl cyclase (sGC) inhibitor. In addition, neroli inhibited extracellular Ca(2+)-dependent, depolarization-induced contraction, an effect that was concentration dependent. Pretreatment with the non-selective cation channel blocker, Ni(2+), attenuated neroli-induced relaxation, whereas the K(+) channel blocker, tetraethylammonium chloride, had no effect. In the presence of verapamil, added to prevent Ca(2+) influx via smooth muscle voltage-gated Ca(2+) channels, neroli-induced relaxation was reduced by the ryanodine receptor (RyR) inhibitor ruthenium red. Our findings further indicate that the endothelial component of neroli-induced vasodilation is partly mediated by the NO-sGC pathway, whereas the smooth muscle component involves modulation of intracellular Ca(2+) concentration through inhibition of cation channel-mediated extracellular Ca(2+) influx and store-operated Ca(2+) release mediated by the RyR signaling pathway.

  3. Differences between negative inotropic and vasodilator effects of calcium antagonists acting on extra- and intracellular calcium movements in rat and guinea-pig cardiac preparations

    NARCIS (Netherlands)

    Hugtenburg, J.G.; Mathy, M.-J.; Boddeke, H.W.G.M.; Beckeringh, J.J.; Van Zwieten, P.A.

    1989-01-01

    In order to get more insight into the utilization of calcium in the mammalian heart and the influence of calcium antagonists on this process we have evaluated the negative inotropic and vasodilator effect of nifedipine, diltiazem, verapamil, bepridil and lidoflazine as well as of the intracellularly

  4. Skeletal muscle vasodilation during systemic hypoxia in humans.

    Science.gov (United States)

    Dinenno, Frank A

    2016-01-15

    In humans, the net effect of acute systemic hypoxia in quiescent skeletal muscle is vasodilation despite significant reflex increases in muscle sympathetic vasoconstrictor nerve activity. This vasodilation increases tissue perfusion and oxygen delivery to maintain tissue oxygen consumption. Although several mechanisms may be involved, we recently tested the roles of two endothelial-derived substances during conditions of sympathoadrenal blockade to isolate local vascular control mechanisms: nitric oxide (NO) and prostaglandins (PGs). Our findings indicate that 1) NO normally plays a role in regulating vascular tone during hypoxia independent of the PG pathway; 2) PGs do not normally contribute to vascular tone during hypoxia, however, they do affect vascular tone when NO is inhibited; 3) NO and PGs are not independently obligatory to observe hypoxic vasodilation when assessed as a response from rest to steady-state hypoxia; and 4) combined NO and PG inhibition abolishes hypoxic vasodilation in human skeletal muscle. When the stimulus is exacerbated via combined submaximal rhythmic exercise and systemic hypoxia to cause further red blood cell (RBC) deoxygenation, skeletal muscle blood flow is augmented compared with normoxic exercise via local dilator mechanisms to maintain oxygen delivery to active tissue. Data obtained in a follow-up study indicate that combined NO and PG inhibition during hypoxic exercise blunts augmented vasodilation and hyperemia compared with control (normoxic) conditions by ∼50%; however, in contrast to hypoxia alone, the response is not abolished, suggesting that other local substances are involved. Factors associated with greater RBC deoxygenation such as ATP release, or nitrite reduction to NO, or both likely play a role in regulating this response.

  5. Effects of hyperosmolality and diuretics on heat-induced limb vasodilation in baboons.

    Science.gov (United States)

    Proppe, D W

    1990-02-01

    Dehydration attenuates the increase in limb skin blood flow elicited by environmental heating (EH). This study sought to determine which of the two primary effects of dehydration, increased body fluid osmolality or decreased body fluid volume, was primarily responsible for this cutaneous vasoconstrictor bias in baboons. Unanesthetized chronically instrumented baboons were exposed to EH while in euhydrated state, after 65-69 h of water deprivation (dehydration), after infusion of a small volume of hypertonic (20%) saline to raise plasma osmolality and sodium concentration to dehydration levels, and after injections of the diuretic furosemide over a 64-h period to produce an isosmotic fall in extracellular fluid volume. EH consisted of an acute elevation of ambient temperature to 39.5-42.0 degrees C until internal temperature reached 39.5-39.8 degrees C. The normal increases in external iliac artery blood flow and iliac vascular conductance during EH were unchanged by hyperosmolality but were attenuated by 39 and 31%, respectively, after furosemide treatment and by 42 and 46%, respectively, during dehydration. Thus the fall in extracellular fluid volume is the component of dehydration that attenuates the increase in hindlimb blood flow during EH in the same way as dehydration itself.

  6. Improved functional vasodilation in obese Zucker rats following exercise training.

    Science.gov (United States)

    Sebai, Mohamad; Lu, Silu; Xiang, Lusha; Hester, Robert L

    2011-09-01

    Obese individuals exhibit impaired functional vasodilation and exercise performance. We have demonstrated in obese Zucker rats (OZ), a model of morbid obesity, that insulin resistance impairs functional vasodilation via an increased thromboxane receptor (TP)-mediated vasoconstriction. Chronic treadmill exercise training improves functional vasodilation in the spinotrapezius muscle of the OZ, but the mechanisms responsible for the improvement in functional vasodilation are not clear. Based on evidence that exercise training improves insulin resistance, we hypothesized that, in the OZ, exercise training increases functional vasodilation and exercise capability due to decreases TP-mediated vasoconstriction associated with improved insulin sensitivity. Six-week-old lean Zucker rats (LZ) and OZ were exercised on a treadmill (24 m/min, 30 min/day, 5 days/wk) for 6 wk. An oral glucose tolerance test was performed at the end of the training period. We measured functional vasodilation in both exercise trained (spinotrapezius) and nonexercise trained (cremaster) muscles to determine whether the improved functional vasodilation following exercise training in OZ is due to a systemic improved insulin resistance. Compared with LZ, the sedentary OZ exhibited impairments in glucose tolerance and functional vasodilation in both muscles. The TP antagonist SQ-29548 improved the vasodilator responses in the sedentary OZ with no effect in the LZ. Exercising training of the LZ increased the functional vasodilation in spinotrapezius muscle, with no effect in the cremaster muscle. Exercising training of the OZ improved glucose tolerance, along with increased functional vasodilation, in both the spinotrapezius and cremaster muscles. SQ-29548 treatment had no effect on the vasodilator responses in either cremaster or spinotrapezius muscles of the exercise-trained OZ. These results suggest that, in the OZ, there is a global effect of exercising training to improve insulin resistance and

  7. Finger cold-induced vasodilation of older Korean female divers, haenyeo: effects of chronic cold exposure and aging

    Science.gov (United States)

    Lee, Joo-Young; Park, Joonhee; Koh, Eunsook; Cha, Seongwon

    2017-07-01

    The aim of the present study was to evaluate the local cold tolerance of older Korean female divers, haenyeo ( N = 22) in terms of cold acclimatization and ageing. As control groups, older non-diving females ( N = 25) and young females from a rural area ( N = 15) and an urban area ( N = 51) participated in this study. To evaluate local cold tolerance, finger cold-induced vasodilation (CIVD) during finger immersion of 4 °C water was examined. As a result, older haenyeos showed greater minimum finger temperature and recovery finger temperature than older non-diving females ( P heart rate, blood pressure, and thermal and pain sensations as those of older non-diving females. Another novel finding was that young urban females showed more vulnerable responses to local cold in CIVD variables and subjective sensations when compared to older females, whereas young rural females had the most excellent cold tolerance in terms of maximum temperature and frequency of CIVD among the four groups ( P < 0.05). The present results imply that older haenyeos still retain cold acclimatized features on the periphery even though they changed their cotton diving suits to wet suits in the early 1980s. However, cardiovascular responses and subjective sensations to cold reflect aging effects. In addition, we suggest that young people who have been adapted to highly insulated clothing and indoor heating systems in winter should be distinguished from young people who were exposed to less modern conveniences when compared to the aged in terms of cold tolerance.

  8. Role of Nitric Oxide and Hydrogen Sulfide in the Vasodilator Effect of Ursolic Acid and Uvaol from Black Cherry Prunus serotina Fruits.

    Science.gov (United States)

    Luna-Vázquez, Francisco J; Ibarra-Alvarado, César; Rojas-Molina, Alejandra; Romo-Mancillas, Antonio; López-Vallejo, Fabián H; Solís-Gutiérrez, Mariana; Rojas-Molina, Juana I; Rivero-Cruz, Fausto

    2016-01-12

    The present research aimed to isolate the non-polar secondary metabolites that produce the vasodilator effects induced by the dichloromethane extract of Prunus serotina (P. serotina) fruits and to determine whether the NO/cGMP and the H2S/KATP channel pathways are involved in their mechanism of action. A bioactivity-directed fractionation of the dichloromethane extract of P. serotina fruits led to the isolation of ursolic acid and uvaol as the main non-polar vasodilator compounds. These compounds showed significant relaxant effect on rat aortic rings in an endothelium- and concentration-dependent manner, which was inhibited by NG-nitro-L-arginine methyl ester (L-NAME), DL-propargylglycine (PAG) and glibenclamide (Gli). Additionally, both triterpenes increased NO and H2S production in aortic tissue. Molecular docking studies showed that ursolic acid and uvaol are able to bind to endothelial NOS and CSE with high affinity for residues that form the oligomeric interface of both enzymes. These results suggest that the vasodilator effect produced by ursolic acid and uvaol contained in P. serotina fruits, involves activation of the NO/cGMP and H2S/KATP channel pathways, possibly through direct activation of NOS and CSE.

  9. Effect of water or saline intake on heat-induced limb vasodilation in dehydrated baboons.

    Science.gov (United States)

    Ryan, K L; Proppe, D W

    1990-02-01

    Dehydration markedly attenuates the increase in hindlimb blood flow elicited by environmental heating (EH) in baboons. This study sought to determine the importance of gradually produced increases in body fluid osmolality and decreases in body fluid volume in producing this attenuation. The hindlimb blood flow increases during EH of seven unanesthetized chronically instrumented baboons were examined during euhydration, dehydration (64-68 h of water deprivation), and after ad libitum oral rehydration with either water or a hyperosmotic saline solution. EH consisted of acute exposure to ambient temperatures of 38-42 degrees C until internal temperature reached 39.5 degrees C. Dehydration depressed the maximal external iliac artery blood flow (MIBF) and iliac vascular conductance (IVC) attained during EH in the euhydrated state by 37 and 43%, respectively. Rehydration with either water or saline solution, however, restored maximal MIBF and IVC to euhydrated levels. Because plasma osmolality remained at dehydrated levels after rehydration with saline, hyperosmolality does not produce the dehydration-induced attenuation in hindlimb blood flow.

  10. Chronic vasodilation produces plasma volume expansion and hemodilution in rats: consequences of decreased effective arterial blood volume

    National Research Council Canada - National Science Library

    Andrea Fekete; Jennifer M. Sasser; Chris Baylis

    2011-01-01

    .... We produced chronic vasodilation by 14 days administration of nifedipine (NIF; 10 mg·kg−1·day−1) or sodium nitrite (NaNO2; 70 mg·kg−1·day−1) to normal, nonpregnant female Sprague-Dawley rats...

  11. Trans monounsaturated fatty acids and saturated fatty acids have similar effects on postprandial flow-mediated vasodilation

    NARCIS (Netherlands)

    Roos, de N.M.; Siebelink, E.; Bots, M.L.; Tol, van A.; Schouten, E.G.; Katan, M.B.

    2002-01-01

    Objective: Several studies suggest that a fatty meal impairs flow-mediated vasodilation (FMD), a measur9e of endothelial function. We tested whether the impairment was greater for trans fats than for saturated fats. We did this because we previously showed that replacement of saturated fats by trans

  12. Trans monounsaturated fatty acids and saturated fatty acids have similar effects on postprandial flow-mediated vasodilation

    NARCIS (Netherlands)

    de Roos, NM; Siebelink, E; Bots, ML; van Tol, A; Katan, MB

    2002-01-01

    Objective: Several studies suggest that a fatty meal impairs flow-mediated vasodilation (FMD), a measure of endothelial function. We tested whether the impairment was greater for trans fats than for saturated fats. We did this because we previously showed that replacement of saturated fats by trans

  13. Trans monounsaturated fatty acids and saturated fatty acids have similar effects on postprandial flow-mediated vasodilation

    NARCIS (Netherlands)

    de Roos, NM; Siebelink, E; Bots, ML; van Tol, A; Katan, MB

    Objective: Several studies suggest that a fatty meal impairs flow-mediated vasodilation (FMD), a measure of endothelial function. We tested whether the impairment was greater for trans fats than for saturated fats. We did this because we previously showed that replacement of saturated fats by trans

  14. Trans monounsaturated fatty acids and saturated fatty acids have similar effects on postprandial flow-mediated vasodilation

    NARCIS (Netherlands)

    Roos, de N.M.; Siebelink, E.; Bots, M.L.; Tol, van A.; Schouten, E.G.; Katan, M.B.

    2002-01-01

    Objective: Several studies suggest that a fatty meal impairs flow-mediated vasodilation (FMD), a measur9e of endothelial function. We tested whether the impairment was greater for trans fats than for saturated fats. We did this because we previously showed that replacement of saturated fats by trans

  15. The key role of nitric oxide in hypoxia: hypoxic vasodilation and energy supply-demand matching.

    Science.gov (United States)

    Umbrello, Michele; Dyson, Alex; Feelisch, Martin; Singer, Mervyn

    2013-11-10

    A mismatch between energy supply and demand induces tissue hypoxia with the potential to cause cell death and organ failure. Whenever arterial oxygen concentration is reduced, increases in blood flow--hypoxic vasodilation--occur in an attempt to restore oxygen supply. Nitric oxide (NO) is a major signaling and effector molecule mediating the body's response to hypoxia, given its unique characteristics of vasodilation (improving blood flow and oxygen supply) and modulation of energetic metabolism (reducing oxygen consumption and promoting utilization of alternative pathways). This review covers the role of oxygen in metabolism and responses to hypoxia, the hemodynamic and metabolic effects of NO, and mechanisms underlying the involvement of NO in hypoxic vasodilation. Recent insights into NO metabolism will be discussed, including the role for dietary intake of nitrate, endogenous nitrite (NO₂⁻) reductases, and release of NO from storage pools. The processes through which NO levels are elevated during hypoxia are presented, namely, (i) increased synthesis from NO synthases, increased reduction of NO₂⁻ to NO by heme- or pterin-based enzymes and increased release from NO stores, and (ii) reduced deactivation by mitochondrial cytochrome c oxidase. Several reviews covered modulation of energetic metabolism by NO, while here we highlight the crucial role NO plays in achieving cardiocirculatory homeostasis during acute hypoxia through both vasodilation and metabolic suppression. We identify a key position for NO in the body's adaptation to an acute energy supply-demand mismatch.

  16. Finger cold-induced vasodilation of older Korean female divers, haenyeo: effects of chronic cold exposure and aging

    Science.gov (United States)

    Lee, Joo-Young; Park, Joonhee; Koh, Eunsook; Cha, Seongwon

    2017-02-01

    The aim of the present study was to evaluate the local cold tolerance of older Korean female divers, haenyeo (N = 22) in terms of cold acclimatization and ageing. As control groups, older non-diving females (N = 25) and young females from a rural area (N = 15) and an urban area (N = 51) participated in this study. To evaluate local cold tolerance, finger cold-induced vasodilation (CIVD) during finger immersion of 4 °C water was examined. As a result, older haenyeos showed greater minimum finger temperature and recovery finger temperature than older non-diving females (P < 0.05), but similar responses in onset time, peak time, maximum finger temperature, frequency of CIVD, heart rate, blood pressure, and thermal and pain sensations as those of older non-diving females. Another novel finding was that young urban females showed more vulnerable responses to local cold in CIVD variables and subjective sensations when compared to older females, whereas young rural females had the most excellent cold tolerance in terms of maximum temperature and frequency of CIVD among the four groups (P < 0.05). The present results imply that older haenyeos still retain cold acclimatized features on the periphery even though they changed their cotton diving suits to wet suits in the early 1980s. However, cardiovascular responses and subjective sensations to cold reflect aging effects. In addition, we suggest that young people who have been adapted to highly insulated clothing and indoor heating systems in winter should be distinguished from young people who were exposed to less modern conveniences when compared to the aged in terms of cold tolerance.

  17. Effects of Acidification and Alkalinization on the Lipid Emulsion-Mediated Reversal of Toxic Dose Levobupivacaine-Induced Vasodilation in the Isolated Rat Aorta.

    Science.gov (United States)

    Ok, Seong-Ho; Kim, Won Ho; Yu, Jongsun; Lee, Youngju; Choi, Mun-Jeoung; Lim, Dong Hoon; Hwang, Yeran; Kim, Yeon A; Sohn, Ju-Tae

    2016-01-01

    The goal of this in vitro study was to examine the effects of pre-acidification and pre-akalinization on the lipid emulsion-mediated reversal of toxic dose levobupivacaine-induced vasodilation in isolated rat aorta. Isolated aortic rings with and without the nitric oxide synthase inhibitor N(ω)-nitro-L-arginine methyl ester (L-NAME) were exposed to four types of Krebs solution (pH 7.0, 7.2, 7.4, and 7.6), followed by the addition of 60 mM potassium chloride. When the toxic dose of levobupivacaine (3 × 10(-4) M) produced a stable and sustained vasodilation in the isolated aortic rings that were precontracted with 60 mM potassium chloride, increasing lipid emulsion concentrations (SMOFlipid(®): 0.24, 0.48, 0.95 and 1.39%) were added to generate concentration-response curves. The effects of mild pre-acidification alone and mild pre-acidification in combination with a lipid emulsion on endothelial nitric oxide synthase (eNOS) phosphorylation in human umbilical vein endothelial cells were investigated by Western blotting. Mild pre-acidification caused by the pH 7.2 Krebs solution enhanced the lipid emulsion-mediated reversal of levobupivacaine-induced vasodilation in isolated endothelium-intact aortic rings, whereas mild pre-acidification caused by the pH 7.2 Krebs solution did not significantly alter the lipid emulsion-mediated reversal of the levobupivacaine-induced vasodilation in isolated endothelium-denuded aortic rings or endothelium-intact aortic rings with L-NAME. A lipid emulsion attenuated the increased eNOS phosphorylation induced by the pH 7.2 Krebs solution. Taken together, these results suggest that mild pre-acidification enhances the lipid emulsion-mediated reversal of toxic dose levobupivacaine-induced vasodilation in the endothelium-intact aorta via the inhibition of nitric oxide.

  18. THE EFFECTS OF ALPHA-ADRENOCEPTOR BLOCKADE ON DOPAMINE-INDUCED RENAL VASODILATION AND NATRIURESIS

    NARCIS (Netherlands)

    SMIT, AJ; MEIJER, S; WESSELING, H; DONKER, AJM; REITSMA, WD

    1991-01-01

    To establish the effects of alpha-adrenoceptor blockade on dopamine-induced changes in renal hemodynamics and sodium excretion, dopamine dose-response curves were performed without and with pre-treatment with the selective postsynaptic alpha-1-adrenoceptor antagonist prazosin in normal volunteers an

  19. Antihypertensive and endothelium-dependent vasodilator effects of aqueous extract of Cistus ladaniferus.

    Science.gov (United States)

    Belmokhtar, Mounia; Bouanani, Nour Elhouda; Ziyyat, Abderrahim; Mekhfi, Hassane; Bnouham, Mohamed; Aziz, Mohamed; Matéo, Philippe; Fischmeister, Rodolphe; Legssyer, Abdelkhaleq

    2009-11-06

    Cistus ladaniferus L. (Cistaceae) is a medicinal plant originated from the Mediterranean region which exerts different pharmacological effects. In the present study, our goal was to examine whether the plant possessed antihypertensive properties. Aqueous extract of Cistus leaves (AEC, 500mg/kg/day) reduced systemic blood pressure (SBP) in two animal models of hypertension, the l-NAME and renovascular two kidney-one clip (2K-1C) hypertensive rats. In the former, AEC prevented the increase in SBP when co-administered with l-NAME during four weeks (164+/-3mm Hg in l-NAME vs. 146+/-1mm Hg in l-NAME+AEC, p<0.001). In the latter, AEC reversed the increase in SBP when administered during four weeks after installation of the hypertension (146+/-5mm Hg with AEC vs. 179+/-6mm Hg without, p<0.05). AEC treatment also reversed the endothelial dysfunction observed in both animal models of hypertension. A direct effect on cardiac and vascular tissue was also tested by examining the contractile effects of AEC in rat isolated aortic rings and Langendorff perfused hearts. AEC (10mg/L) had no effect on left ventricular developed pressure and heart rate in isolated perfused heart. However, AEC produced a strong relaxation of pre-contracted rat aortic rings (80+/-2% relaxation, n=25). When the rings were denuded from endothelium or were incubated with 1mM Nomega-nitro-l-arginine (l-NNA), the relaxant effect of AEC was lost. We conclude that C. ladaniferus possesses antihypertensive properties which are mainly due to an endothelium-dependent vasodilatory action.

  20. Contrasting effects of vasodilators on blood pressure and sodium balance in the hypertension of autonomic failure

    Science.gov (United States)

    Jordan, J.; Shannon, J. R.; Pohar, B.; Paranjape, S. Y.; Robertson, D.; Robertson, R. M.; Biaggioni, I.

    1999-01-01

    Supine hypertension, which is very common in patients with autonomic failure, limits the use of pressor agents and induces nighttime natriuresis. In 13 patients with severe orthostatic hypotension due to autonomic failure (7 women, 6 men, 72 +/- 3 yr) and supine hypertension, the effect of 30 mg nifedipine (n = 10) and 0.025 to 0.2 mg/h nitroglycerin patch (n = 11) on supine BP, renal sodium handling, and orthostatic tolerance was determined. Medications were given at 8 p.m.; patients stood up at 8 a.m. Nitroglycerin was removed at 6 a.m. Compared with placebo, nifedipine and nitroglycerin decreased systolic BP during the night by a maximum of 37 +/- 9 and 36 +/- 10 mmHg, respectively (P hypertension in patients with autonomic failure. However, nifedipine has a prolonged depressor effect and worsens orthostatic hypotension in the morning. The decrease in pressure natriuresis that would be expected with the substantial decrease in BP obtained with nitroglycerin and nifedipine may be offset by a direct effect of both drugs on renal sodium handling.

  1. Direct Vasodilators and Sympatholytic Agents.

    Science.gov (United States)

    McComb, Meghan N; Chao, James Y; Ng, Tien M H

    2016-01-01

    Direct vasodilators and sympatholytic agents were some of the first antihypertensive medications discovered and utilized in the past century. However, side effect profiles and the advent of newer antihypertensive drug classes have reduced the use of these agents in recent decades. Outcome data and large randomized trials supporting the efficacy of these medications are limited; however, in general the blood pressure-lowering effect of these agents has repeatedly been shown to be comparable to other more contemporary drug classes. Nevertheless, a landmark hypertension trial found a negative outcome with a doxazosin-based regimen compared to a chlorthalidone-based regimen, leading to the removal of α-1 adrenergic receptor blockers as first-line monotherapy from the hypertension guidelines. In contemporary practice, direct vasodilators and sympatholytic agents, particularly hydralazine and clonidine, are often utilized in refractory hypertension. Hydralazine and minoxidil may also be useful alternatives for patients with renal dysfunction, and both hydralazine and methyldopa are considered first line for the treatment of hypertension in pregnancy. Hydralazine has also found widespread use for the treatment of systolic heart failure in combination with isosorbide dinitrate (ISDN). The data to support use of this combination in African Americans with heart failure are particularly robust. Hydralazine with ISDN may also serve as an alternative for patients with an intolerance to angiotensin antagonists. Given these niche indications, vasodilators and sympatholytics are still useful in clinical practice; therefore, it is prudent to understand the existing data regarding efficacy and the safe use of these medications. © The Author(s) 2015.

  2. Subacute effects of a maximal exercise bout on endothelium-mediated vasodilation in healthy subjects

    Directory of Open Access Journals (Sweden)

    K. Bousquet-Santos

    2005-04-01

    Full Text Available We evaluated vascular reactivity after a maximal exercise test in order to determine whether the effect of exercise on the circulation persists even after interruption of the exercise. Eleven healthy sedentary volunteers (six women, age 28 ± 5 years were evaluated before and after (10, 60, and 120 min a maximal exercise test on a treadmill. Forearm blood flow (FBF was measured by venous occlusion plethysmography before and during reactive hyperemia (RH. Baseline FBF, analyzed by the area under the curve, increased only at 10 min after exercise (P = 0.01. FBF in response to RH increased both at 10 and 60 min vs baseline (P = 0.004. Total excess flow for RH above baseline showed that vascular reactivity was increased up to 60 min after exercise (mean ± SEM, before: 526.4 ± 48.8; 10 min: 1053.0 ± 168.2; 60 min: 659.4 ± 44.1 ml 100 ml-1 min-1 . s; P = 0.01 and 0.02, respectively, vs before exercise. The changes in FBF were due to increased vascular conductance since mean arterial blood pressure did not change. In a time control group (N = 5, 34 ± 3 years, three women that did not exercise, FBF and RH did not change significantly (P = 0.07 and 0.7, respectively. These results suggest that the increased vascular reactivity caused by chronic exercise may result, at least in part, from a summation of the subacute effects of successive exercise bouts.

  3. Inhibitory effects of coronary vasodilator papaverine on heterologously-expressed HERG currents in Xenopus oocytes

    Institute of Scientific and Technical Information of China (English)

    Cuk-seong KIM; Jin-bong PARK; Nam LEE; Sook-jin SON; Kyu-seung LEE; Hyo-shin KIM; Yong-geun KWAK; Soo-wan CHAE; Sang-do LEE; Byeong-hwa JEON

    2007-01-01

    Aim: To characterize the effects of papaverine on HERG channels expressed in Xenopus oocytes as well as cardiac action potential in rabbit ventricular myocytes.Methods: Conventional microelectrodes were used to record action potential in rabbit ventricular myocytes. HERG currents were recorded by 2-electrode voltage clamp technique in Xenopus oocytes injected with HERG cRNA. Results: Papa-verine increased the cardiac action potential duration in rabbit ventricular myocytes.It blocked heterologously-expressed HERG currents in a concentration-depen-dent manner (IC50 71.03±4.75 μmol/L, NH 0.80, n=6), whereas another phosphodi-esterase inhibitor, theophyUine (500 μmol/L), did not. The blockade of papaverine on HERG currents was not voltage-dependent. The slope conductance measured as a slope of the fully activated HERG current-voltage curves decreased from 78.03±4.25 μS of the control to 56.84±5.33, 36.06±6.53, and 27.09±5.50 μS (n=4) by 30, 100, and 300 μmol/L of papaverine, respectively. Papaverine (100 μmol/L)caused a 9 mV hyperpolarizing shift in the voltage-dependence of steady-state inactivation, but there were no changes in the voltage-dependence of HERG cur-rent activation. Papaverine blocked HERG channels in the closed, open, and inactivated states. Conclusion: These results showed that papaverine blocked HERG channels in a voltage- and state-independent manner, which may most likely be the major mechanism of papaverine-induced cardiac arrhythmia reported in humans.

  4. Effects of handgrip training with venous restriction on brachial artery vasodilation.

    Science.gov (United States)

    Credeur, Daniel P; Hollis, Brandon C; Welsch, Michael A

    2010-07-01

    Previous studies have shown that resistance training with restricted venous blood flow (Kaatsu) results in significant strength gains and muscle hypertrophy. However, few studies have examined the concurrent vascular responses following restrictive venous blood flow training protocols. The purpose of this study was to examine the effects of 4 wk of handgrip exercise training, with and without venous restriction, on handgrip strength and brachial artery flow-mediated dilation (BAFMD). Twelve participants (mean +/- SD: age = 22 +/- 1 yr, men = 5, women = 7) completed 4 wk of bilateral handgrip exercise training (duration = 20 min, intensity = 60% of the maximum voluntary contraction, cadence = 15 grips per minute, frequency = three sessions per week). During each session, venous blood flow was restricted in one arm (experimental (EXP) arm) using a pneumatic cuff placed 4 cm proximal to the antecubital fossa and inflated to 80 mm Hg for the duration of each exercise session. The EXP and the control (CON) arms were randomly selected. Handgrip strength was measured using a hydraulic hand dynamometer. Brachial diameters and blood velocity profiles were assessed, using Doppler ultrasonography, before and after 5 min of forearm occlusion (200 mm Hg) before and at the end of the 4-wk exercise. After exercise training, handgrip strength increased 8.32% (P = 0.05) in the CON arm and 16.17% (P = 0.05) in the EXP arm. BAFMD increased 24.19% (P = 0.0001) in the CON arm and decreased 30.36% (P = 0.0001) in the EXP arm. The data indicate handgrip training combined with venous restriction results in superior strength gains but reduced BAFMD compared with the nonrestricted arm.

  5. Effects of Handgrip Training With Venous Restriction on Brachial Artery Vasodilation

    Science.gov (United States)

    Credeur, Daniel P.; Hollis, Brandon C.; Welsch, Michael A.

    2010-01-01

    Previous studies have shown that resistance training with restricted venous blood flow (Kaatsu) results in significant strength gains and muscle hypertrophy. However, few studies have examined the concurrent vascular responses following restrictive venous blood flow training protocols. Purpose To examine the effects of 4 weeks of handgrip exercise training, with and without venous restriction, on handgrip strength and brachial artery flow mediated dilation (BAFMD). Methods Twelve participants (age=22±1yr; male = 5, female = 7), completed 4 weeks of bilateral handgrip exercise training (Duration: 20 min; Intensity: 60% of the MVC; Cadence: 15 grips*min−1; Frequency: 3 sessions*week−1). During each session venous blood flow was restricted in one arm (Experimental arm = EXP) using a pneumatic cuff placed 4 cm proximal to the antecubital fossa, and inflated to 80 mmHg for the duration of each exercise session. The EXP and control (CON) arm were randomly selected. Handgrip strength was measured using a hydraulic hand dynamometer. Brachial diameters and blood velocity profiles were assessed, using Doppler ultrasonography, before and after 5 min of forearm occlusion (200 mmHg), prior to and at the end of 4 weeks exercise. Results Following exercise training, handgrip strength increased 8.32% (p=0.05) in the CON arm and 16.17% (p=0.05) in the EXP arm. BAFMD increased 24.19% (p=0.0001) in the CON arm, and decreased 30.36% (p=0.0001) in the EXP arm. Conclusion The data indicate handgrip training combined with venous restriction results in superior strength gains, but reduced BAFMD compared to the non-restricted arm. PMID:20019641

  6. Modulatory Effect of 2-(4-Hydroxyphenyl)amino-1,4-naphthoquinone on Endothelial Vasodilation in Rat Aorta

    Science.gov (United States)

    Palacios, Javier; Cifuentes, Fredi; Valderrama, Jaime A.; Benites, Julio; Ríos, David; González, Constanza; Cartes-Saavedra, Benjamín; Wyneken, Ursula; González, Pamela; Owen, Gareth I.; Pardo, Fabián; Sobrevia, Luis

    2016-01-01

    The vascular endothelium plays an essential role in the control of the blood flow. Pharmacological agents like quinone (menadione) at various doses modulate this process in a variety of ways. In this study, Q7, a 2-phenylamino-1,4-naphthoquinone derivative, significantly increased oxidative stress and induced vascular dysfunction at concentrations that were not cytotoxic to endothelial or vascular smooth muscle cells. Q7 reduced nitric oxide (NO) levels and endothelial vasodilation to acetylcholine in rat aorta. It also blunted the calcium release from intracellular stores by increasing the phenylephrine-induced vasoconstriction when CaCl2 was added to a calcium-free medium but did not affect the influx of calcium from extracellular space. Q7 increased the vasoconstriction to BaCl2 (10−3 M), an inward rectifying K+ channels blocker, and blocked the vasodilation to KCl (10−2 M) in aortic rings precontracted with BaCl2. This was recovered with sodium nitroprusside (10−8 M), a NO donor. In conclusion, Q7 induced vasoconstriction was through a modulation of cellular mechanisms involving calcium fluxes through K+ channels, and oxidative stress induced endothelium damage. These findings contribute to the characterization of new quinone derivatives with low cytotoxicity able to pharmacologically modulate vasodilation. PMID:27672420

  7. Vasodilator Compounds Derived from Plants and Their Mechanisms of Action

    Directory of Open Access Journals (Sweden)

    Francisco J. Luna-Vázquez

    2013-05-01

    Full Text Available The present paper reviews vasodilator compounds isolated from plants that were reported in the past 22 years (1990 to 2012 and the different mechanisms of action involved in their vasodilator effects. The search for reports was conducted in a comprehensive manner, intending to encompass those metabolites with a vasodilator effect whose mechanism of action involved both vascular endothelium and arterial smooth muscle. The results obtained from our bibliographic search showed that over half of the isolated compounds have a mechanism of action involving the endothelium. Most of these bioactive metabolites cause vasodilation either by activating the nitric oxide/cGMP pathway or by blocking voltage-dependent calcium channels. Moreover, it was found that many compounds induced vasodilation by more than one mechanism. This review confirms that secondary metabolites, which include a significant group of compounds with extensive chemical diversity, are a valuable source of new pharmaceuticals useful for the treatment and prevention of cardiovascular diseases.

  8. Role of Vasodilator Testing in Pulmonary Hypertension.

    Science.gov (United States)

    Sharma, Abhishek; Obiagwu, Chukwudi; Mezue, Kenechukwu; Garg, Aakash; Mukherjee, Debabrata; Haythe, Jennifer; Shetty, Vijay; Einstein, Andrew J

    2016-01-01

    Pulmonary hypertension is clinically defined by a mean pulmonary artery (PA) pressure of 25mm Hg or more at rest, as measured by right heart catheterization. To identify patients who are likely to have a beneficial response to calcium channel blockers (CCBs) and therefore a better prognosis, acute vasodilator testing should be performed in patients in certain subsets of pulmonary arterial hypertension (PAH). A near normalization of pulmonary hemodynamics is needed before patients can be considered for therapy with CCBs. Intravenous adenosine, intravenous epoprostenol, inhaled nitric oxide, or inhaled iloprost are the standard agents used for vasoreactivity testing in patients with idiopathic PAH. In this review we describe the various aspects of vasodilator testing including the rationale, pathophysiology and agents used in the procedure.

  9. The effect of acute mental stress on limb vasodilation is unrelated to total peripheral resistance

    NARCIS (Netherlands)

    N.J. Paine; C. Ring; J.A. Bosch; D. McIntyre; J.J.C.S. Veldhuijzen van Zanten

    2013-01-01

    Mental stress can trigger myocardial infarction, with poor vascular responses to stress implicated as a pathway. Vascular stress reactivity can be assessed by different methods, such as total peripheral resistance (TPR) and forearm blood flow (FBF). Little is known about how these vascular assessmen

  10. The effect of acute mental stress on limb vasodilation is unrelated to total peripheral resistance.

    Science.gov (United States)

    Paine, Nicola J; Ring, Christopher; Bosch, Jos A; McIntyre, David; Veldhuijzen van Zanten, Jet J C S

    2013-07-01

    Mental stress can trigger myocardial infarction, with poor vascular responses to stress implicated as a pathway. Vascular stress reactivity can be assessed by different methods, such as total peripheral resistance (TPR) and forearm blood flow (FBF). Little is known about how these vascular assessments are linked. This was examined in two separate studies. Healthy men (Study 1: N = 29, Study 2: N = 23) completed rest and mental arithmetic (Study 1: 8 min, Study 2: 16 min). In both studies, heart rate, mean arterial pressure, and FBF increased in response to stress. In Study 1, no changes in TPR were seen, but Study 2 found stress-induced increases in TPR. FBF was not linked to TPR at any time (all ps > .05). It appears that limb vasculature and TPR responses to stress do not give the same information about impairments of the vasculature. These findings are relevant to the interpretation of prior research findings and the design of future studies on stress and vascular responses.

  11. The effect of 48 weeks of aerobic exercise training on cutaneous vasodilator function in post-menopausal females.

    Science.gov (United States)

    Hodges, Gary J; Sharp, Lisa; Stephenson, Claire; Patwala, Ashish Y; George, Keith P; Goldspink, David F; Tim Cable, N

    2010-04-01

    Skin blood flow (SkBF) and endothelial-dependent vasodilatation decline with ageing and can be reversed with exercise training. We tested whether 48 weeks of training could improve SkBF and endothelial function in post-menopausal females; 20 post-menopausal subjects completed the study. SkBF was measured by laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was calculated as LDF/blood pressure. Resting CVC was measured at 32 degrees C and peak CVC at 42 degrees C. Cutaneous endothelial-dependent and -independent vasodilatations were determined by the iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP), respectively. All assessments described were performed at entry (week 0), and after 6, 12, 24, 36, and 48 weeks of training. Resting CVC measures did not change (P > 0.05) throughout the study. Peak CVC increased (P exercise produces positive adaptations in the cutaneous vasodilator function to local heating as well as in cutaneous endothelial and endothelial-independent vasodilator mechanisms. Aerobic capacity was also significantly improved. These adaptations were further enhanced with progressive increases in exercise intensity.

  12. 心肌梗死治疗中扩血管药物的应用效果%Application effect of vasodilators in the treatment of myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    雷艳

    2014-01-01

    Objective:To explore the application effect of vasodilators in the treatment of myocardial infarction.Methods:58 patients with myocardial infarction were selected from March 2012 to March 2014.We retrospectively analyzed the clinical datas of them,and they were randomly divided into the control group and the observation group with 29 cases in each.The control group received the routine drug treatment.The observation group received vasodilators on the basis of the control group.We compared the treatment effects of the patients between the two groups.Results:The total clinical curative effect of the observation group was 93.10% (27/29),and the total clinical curative effect of the control group was 65.52% (19/29).The difference was statistically significant(χ2=11.025,P<0.05).Conclusion:Vasodilator drugs in the treatment of myocardial infarction has significant effect.It is worthy of the clinical application.%目的:探讨扩血管药物治疗心肌梗死的应用效果。方法:2012年3月-2014年3月收治心肌梗死患者58例,对其临床资料进行回顾性分析,随机将其分为对照组和观察组各29例,对照组给予常规药物治疗,观察组在此基础上给予扩血管药物,比较两组患者治疗效果。结果:观察组临床总疗效93.10%(27/29),对照组临床总疗效65.52%(19/29),经比较,差异具有统计学意义(χ2=11.025,P<0.05)。结论:扩血管药物治疗心肌梗死具有显著疗效,值得临床推广应用。

  13. enhancing hippocampal blood lfow after cerebral ischemia and vasodilating basilar arteries:in vivo andin vitro neuroprotective effect of antihypertensive DDPH

    Institute of Scientific and Technical Information of China (English)

    Li Sun; Qin Li; Wei-ting Wang; Yu-hua Chen; Lian-jun Guo

    2015-01-01

    1-(2,6-Dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)-propane hydrochloride (DDPH) is a novel antihypertensive agent based on structural characteristics of mexiletine and verapamine. We investigated the effect of DDPH on vasodilatation and neuroprotection in a rat model of cerebral ischemiain vivo, and a rabbit model of isolated basilar arteriesin vitro. Our results show that DDPH (10 mg/kg) significantly increased hippocampal blood flowin vivo in cerebral ischemic rats, and exerted dose-dependent relaxation of isolated basilar arteries contracted by histamine or KCl in thein vitro rabbit model. DDPH (3 × 10–5 M) also inhibited histamine-stimulated extracellular calcium inlfux and intracellular calcium release. Our ifndings suggest that DDPH has a vasodilative effect bothin vivo andin vitro, which mediates a neuropro-tective effect on ischemic nerve tissue.

  14. Enhancing hippocampal blood flow after cerebral ischemia and vasodilating basilar arteries: in vivo and in vitro neuroprotective effect of antihypertensive DDPH

    Directory of Open Access Journals (Sweden)

    Li Sun

    2015-01-01

    Full Text Available 1-(2,6-Dimethylphenoxy-2-(3,4-dimethoxyphenylethylamino-propane hydrochloride (DDPH is a novel antihypertensive agent based on structural characteristics of mexiletine and verapamine. We investigated the effect of DDPH on vasodilatation and neuroprotection in a rat model of cerebral ischemia in vivo, and a rabbit model of isolated basilar arteries in vitro. Our results show that DDPH (10 mg/kg significantly increased hippocampal blood flow in vivo in cerebral ischemic rats, and exerted dose-dependent relaxation of isolated basilar arteries contracted by histamine or KCl in the in vitro rabbit model. DDPH (3 × 10 -5 M also inhibited histamine-stimulated extracellular calcium influx and intracellular calcium release. Our findings suggest that DDPH has a vasodilative effect both in vivo and in vitro, which mediates a neuroprotective effect on ischemic nerve tissue.

  15. Efferent pathways in sodium overload-induced renal vasodilation in rats.

    Science.gov (United States)

    Amaral, Nathalia O; de Oliveira, Thiago S; Naves, Lara M; Filgueira, Fernando P; Ferreira-Neto, Marcos L; Schoorlemmer, Gerard H M; de Castro, Carlos H; Freiria-Oliveira, André H; Xavier, Carlos H; Colugnati, Diego B; Rosa, Daniel A; Blanch, Graziela T; Borges, Clayton L; Soares, Célia M A; Reis, Angela A S; Cravo, Sergio L; Pedrino, Gustavo R

    2014-01-01

    Hypernatremia stimulates the secretion of oxytocin (OT), but the physiological role of OT remains unclear. The present study sought to determine the involvement of OT and renal nerves in the renal responses to an intravenous infusion of hypertonic saline. Male Wistar rats (280-350 g) were anesthetized with sodium thiopental (40 mg. kg(-1), i.v.). A bladder cannula was implanted for collection of urine. Animals were also instrumented for measurement of mean arterial pressure (MAP) and renal blood flow (RBF). Renal vascular conductance (RVC) was calculated as the ratio of RBF by MAP. In anesthetized rats (n = 6), OT infusion (0.03 µg • kg(-1), i.v.) induced renal vasodilation. Consistent with this result, ex vivo experiments demonstrated that OT caused renal artery relaxation. Blockade of OT receptors (OXTR) reduced these responses to OT, indicating a direct effect of this peptide on OXTR on this artery. Hypertonic saline (3 M NaCl, 1.8 ml • kg(-1) b.wt., i.v.) was infused over 60 s. In sham rats (n = 6), hypertonic saline induced renal vasodilation. The OXTR antagonist (AT; atosiban, 40 µg • kg(-1) • h(-1), i.v.; n = 7) and renal denervation (RX) reduced the renal vasodilation induced by hypernatremia. The combination of atosiban and renal denervation (RX+AT; n = 7) completely abolished the renal vasodilation induced by sodium overload. Intact rats excreted 51% of the injected sodium within 90 min. Natriuresis was slightly blunted by atosiban and renal denervation (42% and 39% of load, respectively), whereas atosiban with renal denervation reduced sodium excretion to 16% of the load. These results suggest that OT and renal nerves are involved in renal vasodilation and natriuresis induced by acute plasma hypernatremia.

  16. Efferent pathways in sodium overload-induced renal vasodilation in rats.

    Directory of Open Access Journals (Sweden)

    Nathalia O Amaral

    Full Text Available Hypernatremia stimulates the secretion of oxytocin (OT, but the physiological role of OT remains unclear. The present study sought to determine the involvement of OT and renal nerves in the renal responses to an intravenous infusion of hypertonic saline. Male Wistar rats (280-350 g were anesthetized with sodium thiopental (40 mg. kg(-1, i.v.. A bladder cannula was implanted for collection of urine. Animals were also instrumented for measurement of mean arterial pressure (MAP and renal blood flow (RBF. Renal vascular conductance (RVC was calculated as the ratio of RBF by MAP. In anesthetized rats (n = 6, OT infusion (0.03 µg • kg(-1, i.v. induced renal vasodilation. Consistent with this result, ex vivo experiments demonstrated that OT caused renal artery relaxation. Blockade of OT receptors (OXTR reduced these responses to OT, indicating a direct effect of this peptide on OXTR on this artery. Hypertonic saline (3 M NaCl, 1.8 ml • kg(-1 b.wt., i.v. was infused over 60 s. In sham rats (n = 6, hypertonic saline induced renal vasodilation. The OXTR antagonist (AT; atosiban, 40 µg • kg(-1 • h(-1, i.v.; n = 7 and renal denervation (RX reduced the renal vasodilation induced by hypernatremia. The combination of atosiban and renal denervation (RX+AT; n = 7 completely abolished the renal vasodilation induced by sodium overload. Intact rats excreted 51% of the injected sodium within 90 min. Natriuresis was slightly blunted by atosiban and renal denervation (42% and 39% of load, respectively, whereas atosiban with renal denervation reduced sodium excretion to 16% of the load. These results suggest that OT and renal nerves are involved in renal vasodilation and natriuresis induced by acute plasma hypernatremia.

  17. The vascular renin-angiotensin system contributes to blunted vasodilation induced by transient high pressure in human adipose microvessels.

    Science.gov (United States)

    Durand, Matthew J; Phillips, Shane A; Widlansky, Michael E; Otterson, Mary F; Gutterman, David D

    2014-07-01

    Increased intraluminal pressure can reduce endothelial function in resistance arterioles; however, the mechanism of this impairment is unknown. The purpose of this study was to determine the effect of local renin-angiotensin system inhibition on the pressure-induced blunting of endothelium-dependent vasodilation in human adipose arterioles. Arterioles (100-200 μm) were dissected from fresh adipose surgical specimens, cannulated onto glass micropipettes, pressurized to an intraluminal pressure of 60 mmHg, and constricted with endothelin-1. Vasodilation to ACh was assessed at 60 mmHg and again after a 30-min exposure to an intraluminal pressure of 150 mmHg. The vasodilator response to ACh was significantly reduced in vessels exposed to 150 mmHg. Exposure of the vessels to the superoxide scavenger polyethylene glycol-SOD (100 U/ml), the ANG II type 1 receptor antagonist losartan (10(-6) mol/l), or the angiotensin-converting enzyme inhibitor captopril (10(-5) mol/l) prevented the pressure-induced reduction in ACh-dependent vasodilation observed in untreated vessels. High intraluminal pressure had no effect on papaverine-induced vasodilation or ANG II sensitivity. Increased intraluminal pressure increased dihydroethidium fluorescence in cannulated vessels, which could be prevented by polyethylene glycol-SOD or losartan treatment and endothelial denudation. These data indicate that high intraluminal pressure can increase vascular superoxide and reduce nitric oxide-mediated vasodilation via activation of the vascular renin-angiotensin system. This study provides evidence showing that the local renin-angiotensin system in the human microvasculature may be pressure sensitive and contribute to endothelial dysfunction after acute bouts of hypertension.

  18. Unraveling the origin of the nitrite-mediated hypoxic vasodilation

    DEFF Research Database (Denmark)

    Fago, Angela; Dalsgaard, T.; Simonsen, U.

    2007-01-01

    Circulating nitrite has recently emerged as an important physiological metabolite that contributes to increase vasodilation during tissue hypoxia. Using a wire myograph, we have investigated how the nitrite-dependent vasodilation in rat aortic rings is controlled by oxygen tension, norepinephrine...... are sufficient to induce NO-mediated vasodilation independently of the nitrite reductase activities here investigated. These results further indicate that the vasoactive effect of nitrite is intrinsic to the vessel and may be due to S-nitrosothiols formed within the arterial smooth muscle....

  19. Telmisartan provides protection against development of impaired vasodilation independently of metabolic effects in SHRSP.Z-Lepr(fa)/IzmDmcr rats with metabolic syndrome.

    Science.gov (United States)

    Kagota, Satomi; Tada, Yukari; Nejime, Namie; Nakamura, Kazuki; Kunitomo, Masaru; Shinozuka, Kazumasa

    2011-05-01

    Metabolic syndrome is known to facilitate the development of cardiovascular disease. We have demonstrated that mesenteric arteries of SHRSP.Z-Lepr(fa)/IzmDmcr (SHRSP-fatty) rats with metabolic syndrome display an impaired vasorelaxation response mediated by nitric oxide. We examined whether the condition could be alleviated by treatment with telmisartan, an angiotensin II type 1 (AT1) receptor antagonist with PPAR-γ-activating properties and compared the results with those from pioglitazone, a PPAR-γ agonist. Telmisartan (5 mg·kg(-1)·day(-1)) or pioglitazone (2.5 mg·kg(-1)·day(-1)) was orally administered to male SHRSP-fatty rats for 8 weeks. Serum triglyceride and cholesterol levels were determined, and the oral glucose tolerance test was performed to evaluate insulin resistance. Vasodilations in response to acetylcholine and nitroprusside were determined by wire myographs under isometric tension conditions, protein expressions of soluble guanylyl cyclase in mesenteric arteries by Western blotting, and the contents of 3-nitrotyrosine in aortas by high-performance liquid chromatography with electrochemical detection. Telmisartan exerted antihypertensive effects, while pioglitazone ameliorated metabolic abnormalities in SHRSP-fatty rats. Telmisartan increased acetylcholine- and nitroprusside-induced relaxation and soluble guanylyl cyclase protein expression in mesenteric arteries and reduced 3-nitrotyrosine content in aortas. Pioglitazone displayed no such alleviating effects on vascular functions. These findings indicate that telmisartan protects against vasodilation disturbance through anti-oxidative and -nitrative stress independently of metabolic effects in SHRSP-fatty rats with metabolic syndrome.

  20. GABAB receptors in the NTS mediate the inhibitory effect of trigeminal nociceptive inputs on parasympathetic reflex vasodilation in the rat masseter muscle.

    Science.gov (United States)

    Ishii, Hisayoshi; Izumi, Hiroshi

    2012-03-15

    The present study was designed to examine whether trigeminal nociceptive inputs are involved in the modulation of parasympathetic reflex vasodilation in the jaw muscles. This was accomplished by investigating the effects of noxious stimulation to the orofacial area with capsaicin, and by microinjecting GABA(A) and GABA(B) receptor agonists or antagonists into the nucleus of the solitary tract (NTS), on masseter hemodynamics in urethane-anesthetized rats. Electrical stimulation of the central cut end of the cervical vagus nerve (cVN) in sympathectomized animals bilaterally increased blood flow in the masseter muscle (MBF). Increases in MBF evoked by cVN stimulation were markedly reduced following injection of capsaicin into the anterior tongue in the distribution of the lingual nerve or lower lip, but not when injected into the skin of the dorsum of the foot. Intravenous administration of either phentolamine or propranolol had no effect on the inhibitory effects of capsaicin injection on the increases of MBF evoked by cVN stimulation, which were largely abolished by microinjecting the GABA(B) receptor agonist baclofen into the NTS. Microinjection of the GABA(B) receptor antagonist CGP-35348 into the NTS markedly attenuated the capsaicin-induced inhibition of MBF increase evoked by cVN stimulation, while microinjection of the GABA(A) receptor antagonist bicuculline did not. Our results indicate that trigeminal nociceptive inputs inhibit vagal-parasympathetic reflex vasodilation in the masseter muscle and suggest that the activation of GABA(B) rather than GABA(A) receptors underlies the observed inhibition in the NTS.

  1. The vasodilative and antioxidative effects of Carvedilol——a new generation of β-receptor blockers%卡维地洛的扩张血管和抗氧化作用

    Institute of Scientific and Technical Information of China (English)

    杨继红; 缪东培

    2001-01-01

    Carvedilol is a novel β-receptor blocker with vasodilative and potent antioxidative effects. It may inhibit the activation of transduction factors induced by oxygen radicals, block the gene expression in cardiac remodeling, and decrease cardiomyocyte apoptosis. It is reported that carvedilol may reduce the in vivo oxidation of low density lipoprotein (LDL) and auto-antibody titre of antioxidant and increase the antioxidative capacity of LDL. Carvedilol and its metabolite BM-910228 may inhibit the inotropic response induced by oxygen radicals. Carvedilol may provide cardiac protection in acute myocardial ischemia and improve cardiac function, reduce the mortality rate of heart failure.%卡维地洛(Carvedilol)是新一代具有扩张血管和强有力的抗氧化作用的非选择性β受体阻滞剂,它在抗氧化作用、减少心肌细胞凋亡、改善左心功能和降低心力衰竭患者病死率方面,优于其他β-受体阻滞剂。

  2. 钩藤提取液致离体大鼠胸主动脉环舒张作用的研究%Vasodilative effect of FZA in vitro rat thoracic aorta

    Institute of Scientific and Technical Information of China (English)

    白洋; 许晗; 钱艳鑫

    2011-01-01

    Objective To investigate the vasodilative effect and underlying mechanism of FZA in isolated rat thoracic aorta rings.Methods The study was performed with the model of isolated rat thoracic aorta rings in organ bath.The vasodilative effect of FZA in aortic rings in resting tension or pre-constricted with Norepinephrine(lmM) was observed.Results FZA could direcetly vasodilate aortic rings P≤0.05,n=4.Conclusion FZA siganificantly induced the vasodilative effect of rat thoracic aorta.lt could directly relax the rat aortic rings.%目的 研究钩藤提取液(FZA)对离体大鼠胸主动脉环舒张力的作用与机制.方法 采用大鼠离体胸主动脉灌流技术,以累积浓度法观测钩藤提取液对基础状态血管环张力的影响.结果 单独加入钩藤提取液观察到离体血管张力的改变,有显著的舒展血管作用P≤0.05,n=6.结论 钩藤提取液具有明显的舒张血管的作用,其作用机制可能直接舒张血管.

  3. Mechanisms of magnesium-induced vasodilation in cerebral penetrating arterioles.

    Science.gov (United States)

    Murata, Takahiro; Dietrich, Hans H; Horiuchi, Tetsuyoshi; Hongo, Kazuhiro; Dacey, Ralph G

    2016-06-01

    We investigated in cerebral penetrating arterioles the signaling mechanisms and dose-dependency of extracellular magnesium-induced vasodilation and also its vasodilatory effects in vessels preconstricted with agonists associated with delayed cerebral vasospasm following SAH. Male rat penetrating arterioles were cannulated. Their internal diameters were monitored. To investigate mechanisms of magnesium-induced vasodilation, inhibitors of endothelial function, potassium channels and endothelial impairment were tested. To simulate cerebral vasospasm we applied several spasmogenic agonists. Increased extracellular magnesium concentration produced concentration-dependent vasodilation, which was partially attenuated by non-specific calcium-sensitive potassium channel inhibitor tetraethylammonium, but not by other potassium channel inhibitors. Neither the nitric oxide synthase inhibitor L-NNA nor endothelial impairment induced by air embolism reduced the dilation. Although the magnesium-induced vasodilation was slightly attenuated by the spasmogen ET-1, neither application of PF2α nor TXA2 analog effect the vasodilation. Magnesium induced a concentration- and smooth muscle cell-dependent dilation in cerebral penetrating arterioles. Calcium-sensitive potassium channels of smooth muscle cells may play a key role in magnesium-induced vasodilation. Magnesium also dilated endothelium-impaired vessels as well as vessels preconstricted with spasmogenic agonists. These results provide a fundamental background for the clinical use of magnesium, especially in treatment against delayed cerebral ischemia or vasospasm following SAH.

  4. Effects of Supplementation with the Fat-Soluble Vitamins E and D on Fasting Flow-Mediated Vasodilation in Adults: A Meta-Analysis of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Peter J. Joris

    2015-03-01

    Full Text Available The effects of fat-soluble vitamin supplementation on cardiovascular disease (CVD risk are not clear. Therefore, we performed a meta-analysis to quantify effects of fat-soluble vitamin supplements on fasting flow-mediated vasodilation (FMD of the brachial artery, a validated marker to assess CVD risk. Randomized placebo-controlled trials (RCTs were identified by a systematic search till July 2014. Seven RCTs studying the effects of vitamin E supplements (range: 300 to 1800 IU per day and nine RCTs examining the effects of vitamin D supplements, that involved, respectively, 303 and 658 adults, were included. No studies with carotenoid or vitamin K supplements were found. Vitamin E supplementation increased FMD vs. control by 2.42% (95% CI: 0.46% to 4.37%; p = 0.015. No effects of vitamin D supplementation were found (0.15%; 95% CI: −0.21% to 0.51%; p = 0.41. These effects did not depend on subject characteristics, treatment characteristics or technical aspects of the FMD measurement. However, no dose-response relationship was evident for vitamin E, statistical significance depended on one study, while the levels of supplement were far above recommended intakes. The current meta-analysis, therefore, does not provide unambiguous evidence to support the use of fat-soluble vitamin supplements to improve fasting FMD in adults.

  5. Short-term hypoxic vasodilation in vivo is mediated by bioactive nitric oxide metabolites, rather than free nitric oxide derived from haemoglobin-mediated nitrite reduction.

    Science.gov (United States)

    Umbrello, Michele; Dyson, Alex; Pinto, Bernardo Bollen; Fernandez, Bernadette O; Simon, Verena; Feelisch, Martin; Singer, Mervyn

    2014-03-01

    Local increases in blood flow--'hypoxic vasodilation'--confer cellular protection in the face of reduced oxygen delivery. The physiological relevance of this response is well established, yet ongoing controversy surrounds its underlying mechanisms. We sought to confirm that early hypoxic vasodilation is a nitric oxide (NO)-mediated phenomenon and to study putative pathways for increased levels of NO, namely production from NO synthases, intravascular nitrite reduction, release from preformed stores and reduced deactivation by cytochrome c oxidase. Experiments were performed on spontaneously breathing, anaesthetized, male Wistar rats undergoing short-term systemic hypoxaemia, who received pharmacological inhibitors and activators of the various NO pathways. Arterial blood pressure, cardiac output, tissue oxygen tension and the circulating pool of NO metabolites (oxidation, nitrosation and nitrosylation products) were measured in plasma and erythrocytes. Hypoxaemia caused a rapid and sustained vasodilation, which was only partially reversed by non-selective NO synthase inhibition. This was associated with significantly lower plasma nitrite, and marginally elevated nitrate levels, suggestive of nitrite bioinactivation. Administration of sodium nitrite had little effect in normoxia, but produced significant vasodilation and increased nitrosylation during hypoxaemia that could not be reversed by NO scavenging. Methodological issues prevented assessment of the contribution, if any, of reduced deactivation of NO by cytochrome c oxidase. In conclusion, acute hypoxic vasodilation is an adaptive NO-mediated response conferred through bioactive metabolites rather than free NO from haemoglobin-mediated reduction of nitrite.

  6. Implementation of the technique in isolated organ vascular as tool for the validation of medicinal plants: Study of the vasodilator effect of the S. scutellarioides

    Directory of Open Access Journals (Sweden)

    Jorge Hernán Ramírez

    2007-03-01

    Full Text Available Introduction: Salvia scutellarioides is a plant with antihypertensive and diuretic properties. In this study, its vasodilator effect is evaluated using the isolated organ technique.Objectives: To standardize the isolated vascular organ, and to study the effect of S. scutellarioides in vasoconstriction by a1 receptors stimulation.Methodology: Rat aortic rings were placed in an organ bath equipment (BIOPAC®, at 37o C temperature and constant carbogen gas bubbling. Tension changes were registered with an isometric tension transducer and data acquisition equipment. During the standardization, six curves of concentration-tension with phenylephrine at 1, 3 and 5 hours were registered, in order to determine maximum tension (TM, and the effective concentration 50 (EC50. Finally, three concentration-tension curves were obtained for phenylephrine with S. scutellarioides at a concentration of 10 mg/dl and 20 mg/dl. Results: During the technique standardization, no statistically significant differences were found in TM for phenylephrine at 1, 3 and 5 hours. The administration of S. scutellarioides produced a TM dose dependent reduction with no EC50 changes.Discussion: The implemented isolated organ technique is viable up to 5 hours, and does not produce a1 receptors desensibilization. The TM diminution by S. scutellarioides is explained by a non competitive a1 antagonism effect. Studies to isolate active principles for allowing the initiation of phase I human clinical trials are required.

  7. The selective PAC1 receptor agonist maxadilan inhibits neurogenic vasodilation and edema formation in the mouse skin.

    Science.gov (United States)

    Banki, E; Hajna, Zs; Kemeny, A; Botz, B; Nagy, P; Bolcskei, K; Toth, G; Reglodi, D; Helyes, Zs

    2014-10-01

    We have earlier shown that PACAP-38 decreases neurogenic inflammation. However, there were no data on its receptorial mechanism and the involvement of its PAC1 and VPAC1/2 receptors (PAC1R, VPAC1/2R) in this inhibitory effect. Neurogenic inflammation in the mouse ear was induced by topical application of the Transient Receptor Potential Ankyrin 1 (TRPA1) receptor activator mustard oil (MO). Consequent neurogenic edema, vasodilation and plasma leakage were assessed by measuring ear thickness with engineer's micrometer, detecting tissue perfusion by laser Doppler scanning and Evans blue or indocyanine green extravasation by intravital videomicroscopy or fluorescence imaging, respectively. Myeloperoxidase activity, an indicator of neutrophil infiltration, was measured from the ear homogenates with spectrophotometry. The selective PAC1R agonist maxadilan, the VPAC1/2R agonist vasoactive intestinal polypeptide (VIP) or the vehicle were administered i.p. 15 min before MO. Substance P (SP) concentration of the ear was assessed by radioimmunoassay. Maxadilan significantly diminished MO-induced neurogenic edema, increase of vascular permeability and vasodilation. These inhibitory effects of maxadilan may be partially due to the decreased substance P (SP) levels. In contrast, inhibitory effect of VIP on ear swelling was moderate, without any effect on MO-induced plasma leakage or SP release, however, activation of VPAC1/2R inhibited the increased microcirculation caused by the early arteriolar vasodilation. Neither the PAC1R, nor the VPAC1/2R agonist influenced the MO-evoked increase in tissue myeloperoxidase activity. These results clearly show that PAC1R activation inhibits acute neurogenic arterial vasodilation and plasma protein leakage from the venules, while VPAC1/2R stimulation is only involved in the attenuation of vasodilation.

  8. Effects of a novel ACE inhibitor, 3-(3-thienyl)-l-alanyl-ornithyl-proline, on endothelial vasodilation and hepatotoxicity in l-NAME-induced hypertensive rats.

    Science.gov (United States)

    Seth, Mahesh Kumar; Hussain, M Ejaz; Pasha, Santosh; Fahim, Mohammad

    2016-01-01

    Nitric oxide (NO) is a widespread biological mediator involved in many physiological and pathological processes, eg, in the regulation of vascular tone and hypertension. Chronic inhibition of NO synthase by N(G)-nitro-l-arginine methyl ester (l-NAME) hydrochloride results in the development of hypertension accompanied by an increase in vascular responsiveness to adrenergic stimuli. Recently, we developed a novel sulfur-containing angiotensin-converting enzyme inhibitor: 3-(3-thienyl)-l-alanyl-ornithyl-proline (TOP). Our previous studies indicated a superior nature of the molecule as an antihypertensive agent in spontaneously hypertensive rats (showing the involvement of renin-angiotensin-aldosterone system) in comparison to captopril. The aim of the present study was to investigate the effect of TOP on NO pathway in l-NAME-induced hypertensive rats, and captopril was included as the standard treatment group. Treatment with both TOP (20 mg/kg) and captopril (40 mg/kg) prevented the development of hypertension in l-NAME model, but TOP showed better restoration of NO and normal levels of angiotensin-converting enzyme. In addition, in vitro vasorelaxation assay showed an improvement in endothelium-dependent vasodilation in both the cases. Further, the biochemical (malondialdehyde, alanine aminotransferase, and aspartate aminotransferase) and the histopathological effects of TOP on rat liver tissues revealed a protective nature of TOP in comparison to captopril in the l-NAME model. In conclusion, TOP at 50% lesser dose than captopril was found to be better in the l-NAME model.

  9. Trainability of cold induced vasodilation

    NARCIS (Netherlands)

    Daanen, H.A.M.; Raymann, R.J.E.M.; Stoop, M.

    2007-01-01

    Peripheral cold injuries are often reported in mountaineers. Not only low ambient temperatures, but also the hypobaric circumstances are known to be major environmental risk factors. When the fingers are exposed to extreme cold for several minutes, cold induced vasodilation (CIVD) occurs, that is

  10. Trainability of cold induced vasodilation

    NARCIS (Netherlands)

    Daanen, H.A.M.; Raymann, R.J.E.M.; Stoop, M.

    2007-01-01

    Peripheral cold injuries are often reported in mountaineers. Not only low ambient temperatures, but also the hypobaric circumstances are known to be major environmental risk factors. When the fingers are exposed to extreme cold for several minutes, cold induced vasodilation (CIVD) occurs, that is re

  11. Comparison Between the Acute Pulmonary Vascular Effects of Oxygen with Nitric Oxide and Sildenafil

    Directory of Open Access Journals (Sweden)

    Ronald W. Day

    2015-03-01

    Full Text Available Objective. Right heart catheterization is performed in patients with pulmonary arterial hypertension to determine the severity of disease and their pulmonary vascular reactivity. The acute pulmonary vascular effect of inhaled nitric oxide is frequently used to identify patients who will respond favorably to vasodilator therapy. This study sought to determine whether the acute pulmonary vascular effects of oxygen with nitric oxide and intravenous sildenafil are similar. Methods. A retrospective, descriptive study of 13 individuals with pulmonary hypertension who underwent heart catheterization and acute vasodilator testing was performed. The hemodynamic measurements during five phases (21% to 53% oxygen, 100% oxygen, 100% oxygen with 20 ppm nitric oxide, 21% to 51% oxygen, and 21% to 51% oxygen with 0.05 mg/kg to 0.29 mg/kg intravenous sildenafil of the procedures were compared.Results. Mean pulmonary arterial pressure and pulmonary vascular resistance acutely decreased with 100% oxygen with nitric oxide, and 21% to 51% oxygen with sildenafil. Mean pulmonary arterial pressure (mm Hg, mean ± standard error of the mean was 38 ± 4 during 21% to 53% oxygen, 32 ± 3 during 100% oxygen, 29 ± 2 during 100% oxygen with nitric oxide, 37 ± 3 during 21% to 51% oxygen, and 32 ± 2 during 21% to 51% oxygen with sildenafil. There was not a significant correlation between the percent change in pulmonary vascular resistance from baseline with oxygen and nitric oxide, and from baseline with sildenafil (r2 = 0.011, p = 0.738. Conclusions. Oxygen with nitric oxide and sildenafil decreased pulmonary vascular resistance. However, the pulmonary vascular effects of oxygen and nitric oxide cannot be used to predict the acute response to sildenafil. Additional studies are needed to determine whether the acute response to sildenafil can be used to predict the long-term response to treatment with an oral phosphodiesterase V inhibitor.

  12. 绿茶多酚改善环孢素A抑制血管舒张的作用%Alleviation effect of green tea polyphenols on cyclosporine A-induced inhibition of vasodilation

    Institute of Scientific and Technical Information of China (English)

    高文波; 姚许平; 祁洪刚; 楼江涌; 张曙伟; 翁国斌

    2010-01-01

    Objective To observe the alleviation effect of green tea polyphenols (GTP) on cyclosporine A (CsA)-induced inhibition of vasodilation, and to study the underlying mechanism. Methods Thirty SD rats were randomly divided into three groups: CsA group, control group and CsA + GTP group. Five weeks after the treatment, the body weight, kidney function (BUN, Cr) of the rats were measured. Then thoracic aorta rings were mounted on a bath system, and the Ach-induced vasodilation, the effect of L-NAME and indomethacin pretreatment on the vasodilation and the denuded vasodilation were evaluated. The contents of nitric oxide (NO) in the vascular tissues were measured. Results Five weeks later, the body weight of the rats in CsA group (253.2 ±8.1) g was lighter than that in control group (292.1 ±9.5) g (P 0.05). In CsA group, the content of NO in vascular tissues was lower than that in control group and CsA + GTP group (both P 0.05).CsA组大鼠血管组织中NO含量显著低于对照组和CsA+GTP组,差异有统计学意义(P<0.05).结论 CsA可导致血管组织NO水平下降,引起NO介导的内皮依赖性血管舒张功能异常.应用绿茶多酚后,则升高其血管组织中NO水平,改善内皮依赖性的血管舒张功能.

  13. Effects of β-Blockers With and Without Vasodilating Properties on Central Blood Pressure: Systematic Review and Meta-Analysis of Randomized Trials in Hypertension.

    Science.gov (United States)

    Pucci, Giacomo; Ranalli, Maria Giovanna; Battista, Francesca; Schillaci, Giuseppe

    2016-02-01

    β-Blockers are less effective than other antihypertensive drug classes in reducing central systolic blood pressure (cSBP) as compared with peripheral SBP (pSBP). Whether this effect is less pronounced with vasodilating β-blockers (VBB) when compared with nonvasodilating β-blockers (NVBB) remains unsettled. We conducted a systematic review and meta-analysis of randomized trials exploring the effects of β-blockers on both pSBP and cSBP in hypertension. We selected 20 studies, for a total of 32 treatment arms (n=21 for NVBB, n=11 for VBB) and 1263 participants (n=962 for NVBB, n=301 for VBB). pSBP decreased from 150 to 133 mm Hg for NVBB and from 145 to 134 mm Hg for VBB. cSBP decreased from 137 to 126 mm Hg for NVBB and from 132 to 123 mm Hg for VBB. SBP amplification (pSBP-cSBP) decreased significantly under VBB (-5.6 mm Hg; 95% confidence interval, -7.8, -3.4 mm Hg), but not under NVBB (-1.1 mm Hg; 95% confidence interval, -3.4, +1.2 mm Hg; Phigh heterogeneity both within and between β-blockers subclasses. In a meta-regression model, the weighted difference in treatment-induced changes in SBP amplification between NVBB and VBB lost its significance after adjustment for mean age and baseline pSBP and heart rate (-2.9±2.3 mm Hg; P=0.22) and was almost abolished after adjustment for treatment-induced heart rate changes (-0.1±0.5 mm Hg; P=0.78). In conclusion, NVBBs, but not VBBs, determine a lower reduction in cSBP than in pSBP. However, the difference in treatment-induced SBP amplification changes between NVBB and VBB is nearly abolished after accounting for differences in heart rate changes.

  14. Effects of a novel ACE inhibitor, 3-(3-thienyl-L-alanyl-ornithyl-proline, on endothelial vasodilation and hepatotoxicity in L-NAME-induced hypertensive rats

    Directory of Open Access Journals (Sweden)

    Seth MK

    2016-04-01

    Full Text Available Mahesh Kumar Seth,1–3 M Ejaz Hussain,2 Santosh Pasha,1 Mohammad Fahim3 1Peptide Synthesis Laboratory, CSIR, Institute of Genomics and Integrative Biology, Delhi, India; 2Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia, New Delhi, India; 3Department of Physiology, Jamia Hamdard Deemed University, New Delhi, India Abstract: Nitric oxide (NO is a widespread biological mediator involved in many physiological and pathological processes, eg, in the regulation of vascular tone and hypertension. Chronic inhibition of NO synthase by NG-nitro-L-arginine methyl ester (ʟ-NAME hydrochloride results in the development of hypertension accompanied by an increase in vascular responsiveness to adrenergic stimuli. Recently, we developed a novel sulfur-containing angiotensin-converting enzyme inhibitor: 3-(3-thienyl-ʟ-alanyl-ornithyl-proline (TOP. Our previous studies indicated a superior nature of the molecule as an antihypertensive agent in spontaneously hypertensive rats (showing the involvement of renin–angiotensin–aldosterone system in comparison to captopril. The aim of the present study was to investigate the effect of TOP on NO pathway in ʟ-NAME-induced hypertensive rats, and captopril was included as the standard treatment group. Treatment with both TOP (20 mg/kg and captopril (40 mg/kg prevented the development of hypertension in ʟ-NAME model, but TOP showed better restoration of NO and normal levels of angiotensin-converting enzyme. In addition, in vitro vasorelaxation assay showed an improvement in endothelium-dependent vasodilation in both the cases. Further, the biochemical (malondialdehyde, alanine aminotransferase, and aspartate aminotransferase and the histopathological effects of TOP on rat liver tissues revealed a protective nature of TOP in comparison to captopril in the ʟ-NAME model. In conclusion, TOP at 50% lesser dose than captopril was found to be better in the ʟ-NAME model. Keywords: nitric oxide

  15. Mepivacaine attenuates vasodilation induced by ATP-sensitive potassium channels in rat aorta.

    Science.gov (United States)

    Baik, Jiseok; Ok, Seong-Ho; Kim, Eun-Jin; Kang, Dawon; Hong, Jeong-Min; Shin, Il-Woo; Lee, Heon Keun; Chung, Young-Kyun; Cho, Youngil; Lee, Soo Hee; Kang, Sebin; Sohn, Ju-Tae

    2016-07-05

    The goal of this in vitro study was to investigate the effect of mepivacaine on vasodilation induced by the ATP-sensitive potassium (KATP) channel opener levcromakalim in isolated endothelium-denuded rat aortas. The effects of mepivacaine and the KATP channel inhibitor glibenclamide, alone or in combination, on levcromakalim-induced vasodilation were assessed in the isolated aortas. The effects of mepivacaine or combined treatment with a protein kinase C (PKC) inhibitor, GF109203X, and mepivacaine on this vasodilation were also investigated. Levcromakalim concentration-response curves were generated for isolated aortas precontracted with phenylephrine or a PKC activator, phorbol 12,13-dibutyrate (PDBu). Further, the effects of mepivacaine and glibenclamide on levcromakalim-induced hyperpolarization were assessed in rat aortic vascular smooth muscle cells. Mepivacaine attenuated levcromakalim-induced vasodilation, whereas it had no effect on this vasodilation in isolated aortas pretreated with glibenclamide. Combined treatment with GF109203X and mepivacaine enhanced levcromakalim-induced vasodilation compared with pretreatment with mepivacaine alone. This vasodilation was attenuated in aortas precontracted with PDBu compared with those precontracted with phenylephrine. Mepivacaine and glibenclamide, alone or in combination, attenuated levcromakalim-induced membrane hyperpolarization. Taken together, these results suggest that mepivacaine attenuates vasodilation induced by KATP channels, which appears to be partly mediated by PKC.

  16. Hypotensive acute effect of photobiomodulation therapy on hypertensive rats.

    Science.gov (United States)

    Oishi, J C; De Moraes, T F; Buzinari, T C; Cárnio, E C; Parizotto, N A; Rodrigues, G J

    2017-06-01

    The purpose of this study was to evaluate the acute effect of photobiomodulation therapy (PBM) on arterial pressure in hypertensive and normotensive rats with application in an abdominal region. Normotensive (2K) and hypertensive (2K-1C) wistar rats were treated with PBM. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP) and heart rate (HR) were measured before, during and after PBM application. The nitric oxide (NO) serum concentration was measured before and after PBM application. Vascular reactivity study was performed in isolated thoracic aortas. Aluminum gallium arsenide (GaAlAs) diode laser was used, at 660nm wavelength and 100mW optical output. The PBM application induced a decrease of SAP in 2K-1C rats. In 2K rats, the PBM application had no effect on SAP, DAP and MAP. Moreover, the magnitude of hypotensive effect was higher in 2K-1C than in 2K rats. The PBM application induced a decrease of HR in 2K-1C and 2K, with higher effect in 2K-1C rats. In 2K-1C, the hypotensive effect induced by PBM was longer than that obtained in 2K rats. PBM application induced an elevation of NO concentration in serum from 2K-1C and 2K rats, with higher effect in 2K-1C. In isolated aortic rings PBM effect is dependent of NO release, and is not dependent of nitric oxide synthase (NOS) activation. Our results indicate that the abdominal acute application of PBM at 660nm is able to induce a long lasting hypotensive effect in hypertensive rats and vasodilation by a NO dependent mechanism. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. [Effect of peripheral vasodilators on pulmonary respiratory function and the indices of bicycle spiroergometry in heart failure patients].

    Science.gov (United States)

    Ordian, M M; Sobol', Iu S; Kassirskiĭ, S G

    1987-01-01

    The effect of corinfar and isosorbide on respiratory function of the lungs and indices of spirobicycle ergometry was studied in 40 patients with heart failure resulting from various heart diseases. The results have shown that despite difference in the mechanism of action, the use of these drugs at the given doses combined with digoxin is accompanied by a distinct and comparable positive influence on external respiratory function and indices of spirobicycle ergometry in patients with heart failure.

  18. Nocturnal lowering of thresholds for sweating and vasodilation

    Science.gov (United States)

    Wenger, C. B.; Roberts, M. F.; Stolwijk, J. A. J.; Nadel, E. R.

    1976-01-01

    The effect of the time of day on the relation of the heat-dissipating responses (sweating and vasodilation) to esophageal and mean skin temperatures was investigated. These parameters were measured in six subjects exercised at 60-70% of maximal aerobic power in a 25 deg C ambient. Results indicate that a circadian rhythm in the thresholds for sweating and vasodilation can account for much of the rhythm of internal body temperature. The circadian rhythm in the operation of the thermoregulatory system seems to be expressed through a reference point shared by vasomotor and sudomotor controls.

  19. Tumor necrosis factor-alpha inhibits insulin's stimulating effect on glucose uptake and endothelium-dependent vasodilation in humans

    DEFF Research Database (Denmark)

    Rask-Madsen, Christian; Domínguez, Helena; Ihlemann, Nikolaj

    2003-01-01

    -alpha was smaller (PTNF-alpha had no effect on the SNP response without insulin infusion. Thus, TNF-alpha inhibition of the combined response to insulin and ACh was likely mediated through inhibition of NO production. CONCLUSIONS: These results support the concept that TNF-alpha could play a role......BACKGROUND: Inflammatory mechanisms could be involved in the pathogenesis of both insulin resistance and atherosclerosis. Therefore, we aimed at examining whether the proinflammatory cytokine tumor necrosis factor (TNF)-alpha inhibits insulin-stimulated glucose uptake and insulin....../or TNF-alpha were coinfused. During infusion of insulin alone for 20 minutes, forearm glucose uptake increased by 220+/-44%. This increase was completely inhibited during coinfusion of TNF-alpha (started 10 min before insulin) with a more pronounced inhibition of glucose extraction than of blood flow...

  20. Hypoxia Impairs Vasodilation in the Lung

    OpenAIRE

    Norbert F Voelkel; McMurtry, Ivan F.; Reeves, John T.

    1981-01-01

    Alveolar hypoxia causes pulmonary vasoconstriction; we investigated whether hypoxia could also impair pulmonary vasodilation. We found in the isolated perfused rat lung a delay in vasodilation following agonist-induced vasoconstriction. The delay was not due to erythrocyte or plasma factors, or to alterations in base-line lung perfusion pressure. Pretreating lungs with arachidonic acid abolished hypoxic vasoconstriction, but did not influence the hypoxia-induced impairment of vasodilation aft...

  1. Cold induced peripheral vasodilation at high altitudes- a field study

    NARCIS (Netherlands)

    Daanen, H.A.M.; Ruiten, H.J.A. van

    2000-01-01

    A significant reduction in cold-induced vasodilation (CIVD) is observed at high altitudes. No agreement is found in the literature about acclimatization effects on CIVD. Two studies were performed to investigate the effect of altitude acclimatization on CIVD. In the first study 13 male subjects imme

  2. Cold induced peripheral vasodilation at high altitudes- a field study

    NARCIS (Netherlands)

    Daanen, H.A.M.; Ruiten, H.J.A. van

    2000-01-01

    A significant reduction in cold-induced vasodilation (CIVD) is observed at high altitudes. No agreement is found in the literature about acclimatization effects on CIVD. Two studies were performed to investigate the effect of altitude acclimatization on CIVD. In the first study 13 male subjects imme

  3. TRPV1 channels are involved in niacin-induced cutaneous vasodilation in mice.

    Science.gov (United States)

    Clifton, Heather L; Inceoglu, Bora; Ma, Linlin; Zheng, Jie; Schaefer, Saul

    2015-02-01

    Niacin is effective in treating dyslipidemias but causes cutaneous vasodilation or flushing, a side effect that limits its clinical use. Blocking prostaglandins in humans reduces but does not consistently eliminate flushing, indicating additional mechanisms may contribute to flushing. The transient receptor potential vanilloid 1 (TRPV1) channel, when activated, causes cutaneous vasodilation and undergoes tachyphylaxis similar to that seen with niacin. Using a murine model, early phase niacin-induced flushing was examined and TRPV1 channel involvement demonstrated using pharmacologic blockade, desensitization, and genetic knockouts (TRPV1 KO). The TRPV1 antagonist AMG9810 reduced the magnitude of the initial and secondary peaks and the rapidity of the vasodilatory response (slope). TRPV1 desensitization by chronic capsaicin reduced the initial peak and slope. TRPV1 KO mice had a lower initial peak, secondary peak, and slope compared with wild-type mice. Chronic niacin reduced the initial peak, secondary peak, and slope in wild-type mice but had no effect in knockout mice. Furthermore, chronic niacin diminished the response to capsaicin in wild-type mice. Overall, these data demonstrate an important role for TRPV1 channels in niacin-induced flushing, both in the acute response and with chronic administration. That niacin-induced flushing is a complex cascade of events, which should inform pharmacological intervention against this side effect.

  4. Chronic oxidative-nitrosative stress impairs coronary vasodilation in metabolic syndrome model rats.

    Science.gov (United States)

    Kagota, Satomi; Maruyama, Kana; Tada, Yukari; Fukushima, Kazuhito; Umetani, Keiji; Wakuda, Hirokazu; Shinozuka, Kazumasa

    2013-07-01

    Metabolic syndrome (MetS) is a combination of clinical disorders that together increase the risk for cardiovascular disease and diabetes. SHRSP.Z-Lepr(fa)/IzmDmcr (SHRSP.ZF) rats with MetS show impaired nitric oxide-mediated relaxation in coronary and mesenteric arteries, and angiotensin II receptor type 1 blockers protect against dysfunction and oxidative-nitrosative stress independently of metabolic effects. We hypothesize that superoxide contributes to functional deterioration in SHRSP.ZF rats. To test our hypothesis, we studied effects of treatment with tempol, a membrane-permeable radical scavenger, on impaired vasodilation in SHRSP.ZF rats. Tempol did not alter body weight, high blood pressure, or metabolic abnormalities, but prevented impairment of acetylcholine-induced and nitroprusside-induced vasodilation in the coronary and mesenteric arteries. Furthermore, tempol reduced the levels of serum thiobarbituric acid reactive substance (TBARS) and 3-nitrotyrosine content in mesenteric arteries. Systemic administration of tempol elevated the expression of soluble guanylate cyclase (sGC) above basal levels in mesenteric arteries of SHRSP.ZF rats. However, acute treatment with tempol or ebselen, a peroxynitrite scavenger, did not ameliorate impaired relaxation of isolated mesenteric arteries. No nitration of tyrosine residues in sGC was observed; however, sGC mRNA expression levels in the arteries of SHRSP.ZF rats were lower than those in the arteries of Wistar-Kyoto rats. Levels of Thr(496)- and Ser(1177)-phosphorylated endothelial nitric oxide synthase (eNOS) were lower in arteries of SHRSP.ZF rats, and acetylcholine decreased Thr(496)-phosphorylated eNOS levels. These results indicated that prolonged superoxide production, leading to oxidative-nitrosative stress, was associated with impaired vasodilation in SHRSP.ZF rats with MetS. Down-regulated sGC expression may be linked to dysfunction, while reduced NO bioavailability/eNOS activity and modified s

  5. Vasodilation effect of total saponins of achyranthes bidentata blume on rat aorta in vitro%牛膝总皂苷对大鼠离体胸主动脉环舒张作用的机制研究

    Institute of Scientific and Technical Information of China (English)

    李兰娥; 卞筱泓; 许激扬; 赵刚刚; 周恒源

    2012-01-01

    Objective To investigate the vasodilation effect of total saponins of achyranthes bidentata blume (ABS) on thoracic aortic of rat and to study its mechanism .Methods The effects of ABS on the NE and KCl-preconstricted aorta rings were determined by organ bath technique ,and some inhibitors was used to explore the mechanism .Results ABS caused relaxation in NE-preconstricted thoracic aortas with or without endothelium .NG-nitro-L-arginine methylester(Z,-NAME),methylene blue(MB),indomethacin(IN-DO) significantly inhibited the vasodilation of ABS action on thoracic aortas preconstricted by NE .Tetraethyl ammonium (TEA), BaCL and glibenclamide(Gli) attenuated the vasodilation effect of ABS ,and ABS also vasodilated thoracic aortas preconstricted by KC1 .Conclusion The results indicate that ABS relaxes vascular smooth muscle in a certain endothelium -dependent manner ,and the mechanisms seem to be related with the openness of K channels as well as the blockage of receptor-dependent and potential-dependent calcium channels in the cell membrane of smooth muscles .%目的 研究牛膝总皂苷(ABS)对大鼠离体胸主动脉血管环舒张作用及其作用机制.方法 采用累积加药法,通过观察ABS对去甲肾上腺素(NE)和KCl预收缩的血管环张力的影响,并观察几种抑制剂对其作用的影响.结果 ABS对NE预收缩的内皮完整和去内皮血管环均有舒张作用,L-硝基精氨酸甲酯(L-NAME)、亚甲蓝(MB)、吲哚美辛(INDO)能显著减弱ABS诱导的血管环舒张作用;钾离子通道阻滞剂对ABS的舒血管效应有明显抑制作用(P<0.05);ABS对KCl预收缩的血管环有良好的舒张作用.结论 ABS的舒血管作用与NO介导途径有关,同时与钾离子通道的开放及血管平滑肌细胞上受体依赖性钙通道和电压依赖性钙通道有关.

  6. Contractile effect of endothelin - 1 on isolated artery and the antagonistic effect of vasodilators%内皮素 - 1对离体动脉的收缩作用及舒张药物的对抗效应

    Institute of Scientific and Technical Information of China (English)

    王涛; 顾玉东; 沈忆文

    2001-01-01

    Objective To observe the characteristics of vasoconstriction caused by endothelin - 1 and determine the antagonistic effect of vasodilators. Methods Vasomotory test of the isolated rat common carotid artery was done to compare the influence of endothelin - 1 (ET - 1) and noradrenaline (NE)on artery tension in vitro, and detect the antagonistic effects of vasodilators on ET - 1 induced vasoconstriction. Results Endothelin - 1 resulted in a constant constriction which was concentration - dependent in isolated rat common carotid arteries. The median effective concentration (EC50) of endothelin - 1 and noradrenaline were 1.8 × 10-9mol/L and 3.4 × 10-8mol/L respectively. The EC50 of noradrenaline was 18.9 times of that of endothelin - 1. Lidocaine, nifedipine, papaverine, sodium nitroprusside, and anisodamine all relaxed endothelin - 1 - induced vasoconstriction. The strongest among those vasodilators was sodium nitroprusside, whereas lidocaine and anisodamine weaker. Conclusions Endothelin - 1 induces potent and persistent vasoconstriction of isolated arteries. Vasodilators can reduce endothelin - 1 - induced vasoconstriction.%目的 研究内皮素 - 1(Endothelin - 1,ET - 1)收缩血管的特性及显微血管外科常用舒张药物的对抗效应。方法 采用离体血管舒缩功能的实验技术比较ET - 1与去甲肾上腺素(noradrenaline,NE)对离体动脉张力的影响,同时检测舒张药物对ET - 1收缩血管的拮抗作用。结果 ET - 1使离体大鼠颈总动脉环产生浓度依赖性的恒定收缩,ET - 1与NE的半数有效浓度(median effective concentration,EC50)分别为1.8 × 10-9 mol/L和3.4 × 10-8 mol/L,NE的EC50值为ET - 1的18.9倍。血管舒张药如利多卡因、硝苯啶、罂粟硷、硝普钠、山莨菪硷,能有效对抗ET - 1的缩血管作用。其中以硝普钠最强,利多卡因与山莨菪硷较弱。结论 ET - 1对离体动脉具有强大而持久的收缩效应。

  7. Acute Effects of T'ai Chi Chuan Exercise on Blood Pressure and Heart Rate in Peripheral Artery Disease Patients.

    Science.gov (United States)

    Dantas, Filipe Fernandes Oliveira; da Silva Santana, Fábio; da Silva, Thiago Souza Rosas; Cucato, Gabriel Grizzo; Farah, Breno Quintella; Ritti-Dias, Raphael Mendes

    2016-05-01

    To investigate the acute effect of a t'ai chi chuan session on blood pressure and heart rate in patients with peripheral artery disease (PAD). Randomized crossover intervention study. Outpatient therapy center. Seven patients with PAD, aged 50-79 years, not using β-blockers, calcium-channel blockers, or nondihidropiridinic vasodilators. T'ai chi chuan and control session (both sessions lasted 40 minutes). Systolic and diastolic blood pressure and heart rate, which were evaluated before and after the intervention (10, 30, and 50 minutes). T'ai chi chuan exercise acutely decreased systolic blood pressure at 30 minutes after exercise (p = 0.042) and increased diastolic blood pressure at 50 minutes after exercise (p = 0.041). Heart rate did not change after t'ai chi chuan exercise. T'ai chi chuan acutely decreases systolic blood pressure in patients with PAD.

  8. Angiotensin II type 1 receptor blockade restores angiotensin-(1-7)-induced coronary vasodilation in hypertrophic rat hearts.

    Science.gov (United States)

    Souza, Álvaro P S; Sobrinho, Deny B S; Almeida, Jônathas F Q; Alves, Gisele M M; Macedo, Larissa M; Porto, Juliana E; Vêncio, Eneida F; Colugnati, Diego B; Santos, Robson A S; Ferreira, Anderson J; Mendes, Elizabeth P; Castro, Carlos H

    2013-11-01

    The aim of the present study was to investigate the coronary effects of Ang-(1-7) [angiotensin-(1-7)] in hypertrophic rat hearts. Heart hypertrophy was induced by abdominal aorta CoA (coarctation). Ang-(1-7) and AVE 0991, a non-peptide Mas-receptor agonist, at picomolar concentration, induced a significant vasodilation in hearts from sham-operated rats. These effects were blocked by the Mas receptor antagonist A-779. Pre-treatment with L-NAME (N(G)-nitro-L-arginine methyl ester) or ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinozalin-1-one) [NOS (NO synthase) and soluble guanylate cyclase inhibitors respectively] also abolished the effect of Ang-(1-7) in control hearts. The coronary vasodilation produced by Ang-(1-7) and AVE 0991 was completely blunted in hypertrophic hearts. Chronic oral administration of losartan in CoA rats restored the coronary vasodilation effect of Ang-(1-7). This effect was blocked by A-779 and AT2 receptor (angiotensin II type 2 receptor) antagonist PD123319. Acute pre-incubation with losartan also restored the Ang-(1-7)-induced, but not BK (bradykinin)-induced, coronary vasodilation in hypertrophic hearts. This effect was inhibited by A-779, PD123319 and L-NAME. Chronic treatment with losartan did not change the protein expression of Mas and AT2 receptor and ACE (angiotensin-converting enzyme) and ACE2 in coronary arteries from CoA rats, but induced a slight increase in AT2 receptor in aorta of these animals. Ang-(1-7)-induced relaxation in aortas from sham-operated rats was absent in aortas from CoA rats. In vitro pre-treatment with losartan restored the Ang-(1-7)-induced relaxation in aortic rings of CoA rats, which was blocked by the Mas antagonist A-779 and L-NAME. These data demonstrate that Mas is strongly involved in coronary vasodilation and that AT1 receptor (angiotensin II type 1 receptor) blockade potentiates the vasodilatory effects of Ang-(1-7) in the coronary beds of pressure-overloaded rat hearts through NO-related AT2- and Mas

  9. Heterogeneous blood flow distribution within single skeletal muscles in the rabbit: role of vasomotion, sympathetic nerve activity and effect of vasodilation.

    Science.gov (United States)

    Iversen, P O; Nicolaysen, G

    1989-09-01

    A major heterogeneous distribution of blood flow has been described on a non-microvascular level within single skeletal muscles at rest and during exercise hyperaemia both in the dog and in the rabbit. The heterogeneity in blood flow distribution could be composed of both a steady-state region-to-region variability (spatial) and a time-dependent variability (temporal) in blood flow to each region. In the present study we estimated their relative contributions to the variations in blood flow within the muscles. Furthermore, we determined whether sympathetic nerve activity contributed to and whether pharmacologically induced vasodilation affected the heterogeneous blood flow pattern. Regional blood flow measurements were based on microsphere infusions into anaesthetized rabbits. Blood flow was determined under both resting conditions and during exercise hyperaemia in regions weighing 0.25 g each within hind leg muscles. The coefficient of variation for the spatial variability was twice that of the temporal one: 0.32 and 0.16 (mean) respectively. Neither stimulation of the sympathetic nerves, sympathectomy nor vasodilation affected the heterogeneity in blood flow. When exercise hyperaemia was induced, blood flow increased in all regions so that a positive (P less than 0.05) correlation was present between resting and exercising blood flow values in the individual regions. Although regional variation in vascularization could explain the observations during exercise hyperaemia, we have at present no fully satisfying explanation for the observed regional heterogeneity in blood flow.

  10. Familial hypercholesterolemia impairs exercise-induced systemic vasodilation due to reduced NO bioavailability.

    Science.gov (United States)

    de Beer, Vincent J; Merkus, Daphne; Bender, Shawn B; Tharp, Darla L; Bowles, Douglas K; Duncker, Dirk J; Laughlin, M Harold

    2013-12-01

    Hypercholesterolemia impairs endothelial function [e.g., the nitric oxide (NO)-cyclic GMP-phosphodiesterase 5 (PDE5) pathway], limits shear stress-induced vasodilation, and is therefore expected to reduce exercise-induced vasodilation. To assess the actual effects of hypercholesterolemia on endothelial function and exercise-induced vasodilation, we compared the effects of endothelial NO synthase (eNOS) and PDE5 inhibition in chronically instrumented Yucatan (Control) and Rapacz familial hypercholesterolemic (FH) swine, at rest and during treadmill exercise. The increases in systemic vascular conductance produced by ATP (relative to nitroprusside) and exercise were blunted in FH compared with Control swine. The vasoconstrictor response to eNOS inhibition, with nitro-l-arginine (NLA), was attenuated in FH compared with Control swine, both at rest and during exercise. Furthermore, whereas the vasodilator response to nitroprusside was enhanced slightly, the vasodilator response to PDE5 inhibition, with EMD360527, was reduced in FH compared with Control swine. Finally, in the pulmonary circulation, FH resulted in attenuated vasodilator responses to ATP, while maintaining the responses to both NLA and EMD360527. In conclusion, hypercholesterolemia reduces exercise-induced vasodilation in the systemic but not the pulmonary circulation. This reduction appears to be the principal result of a decrease in NO bioavailability, which is mitigated by a lower PDE5 activity.

  11. Effects of ATP-induced leg vasodilation on VO2 peak and leg O2 extraction during maximal exercise in humans

    DEFF Research Database (Denmark)

    Calbet, J A L; Lundby, C; Sander, M

    2006-01-01

    During maximal whole body exercise VO2 peak is limited by O2 delivery. In turn, it is though that blood flow at near-maximal exercise must be restrained by the sympathetic nervous system to maintain mean arterial pressure. To determine whether enhancing vasodilation across the leg results in higher...... O2 delivery and leg VO2 during near-maximal and maximal exercise in humans, seven men performed two maximal incremental exercise tests on the cycle ergometer. In random order, one test was performed with and one without (control exercise) infusion of ATP (8 mg in 1 ml of isotonic saline solution......) into the right femoral artery at a rate of 80 microg.kg body mass-1.min-1. During near-maximal exercise (92% of VO2 peak), the infusion of ATP increased leg vascular conductance (+43%, P...

  12. Effects of hypercapnia on peripheral vascular reactivity in elderly patients with acute exacerbation of chronic obstructive pulmonary disease

    Science.gov (United States)

    de Matthaeis, Angela; Greco, Antonio; Dagostino, Mariangela Pia; Paroni, Giulia; Fontana, Andrea; Vinciguerra, Manlio; Mazzoccoli, Gianluigi; Seripa, Davide; Vendemiale, Gianluigi

    2014-01-01

    Blood acid-base imbalance has important effects on vascular reactivity, which can be related to nitric oxide (NO) concentration and increased during hypercapnia. Release of NO seems to be linked to H+ and CO2 concentration and to exacerbation of chronic obstructive pulmonary disease (COPD), a common medical condition in the elderly. Flow-mediated dilation (FMD), a valuable cardiovascular risk indicator, allows assessment of endothelial-dependent vasodilation, which is to a certain extent mediated by NO. We investigated the effects of hypercapnia and acid-base imbalance on endothelial-dependent vasodilation by measurement of FMD in 96 elderly patients with acute exacerbation of COPD. Patients underwent complete arterial blood gas analysis and FMD measurement before (phase 1) and after (phase 2) standard therapy for acute exacerbation of COPD and recovery. Significant differences between phase 1 and phase 2 were observed in the mean values of pH (7.38±0.03 versus 7.40±0.02, P<0.001), pO2 (59.6±4.9 mmHg versus 59.7±3.6 mmHg, P<0.001), pCO2 (59.3±8.63 mmHg versus 46.7±5.82 mmHg, P<0.001), FMD (10.0%±2.8% versus 8.28%±2.01%, P<0.001) and blood flow rate (1.5±0.3 m/s versus 1.5±0.3 m/s, P=0.001). FMD values were positively correlated with pCO2 values (r=0.294, P=0.004) at baseline. A significant correlation was also found between relative changes in FMD and pCO2 levels, passing from phase 1 to phase 2 (r=0.23, P=0.023). Patients with higher baseline endothelium-dependent vasodilation as evaluated by FMD showed greater modification with regard to pCO2 changes (2.6±1.39 versus 1.59±1.4, P=0.012). In conclusion, endothelium-dependent vasodilation as evaluated by FMD was elevated during hypercapnia, and varied significantly according to pCO2 changes in patients with higher baseline levels, suggesting that vascular reactivity in acute COPD exacerbations in the elderly depends on integrity of the vascular endothelium. PMID:24904207

  13. Derivatives of benzimidazole: vasodilator activity of 2-(p-chloro-alpha-hydroxybenzyl)-benzimidazole hydrochloride. Preliminary study.

    Science.gov (United States)

    Demenge, P; Carraz, G; Luu Duc, C; Silice, C

    1979-01-01

    The effects of 2-(p-chloro-alpha-hydroxybenzyl)-benzimidazole hydrochloride (HBBPC) have been studied in the rabbit and rat. Most of these studies were performed comparatively with reference vasodilators and papaverine. HBBPC vasodilator activity is nearly the same as that of papaverine in the isolated rabbit ear. The characteristic of the vasoactive action of HBBPC seems to reside in its duration. The mechanism of action of HBBPC seems of peripheral type, that is to say it acts on the vascular smooth muscle.

  14. 黄芩苷对离体大鼠胸主动脉的舒张作用及机制%Vasodilation Effect of Baicalin on Rat Isolated Thoracic Aorta and Its Related Mechanism

    Institute of Scientific and Technical Information of China (English)

    卞筱泓; 张映桥; 许激扬; 赵刚刚; 李兰娥; 王旻

    2013-01-01

    研究黄芩苷对大鼠离体胸主动脉环的舒张作用并探讨其可能的机制.记录去甲肾上腺素(NE)和KCl预收缩的大鼠离体主动脉环张力变化,观察黄芩苷的舒血管作用及不同工具药对其影响.实验发现黄芩苷对NE和KCl引起的去内皮和内皮完整大鼠胸主动脉环的收缩均有舒张作用;L-硝基精氨酸甲酯、亚甲蓝不能抑制黄芩苷对大鼠胸主动脉环的舒张作用,吲哚美辛能显著抑制;钾离子通道阻断剂4-氨基吡啶、四乙基胺、BaCl2不能抑制黄芩苷对胸主动脉环的舒张作用,格列苯脲能抑制黄芩苷的舒张作用;无钙环境下,黄芩苷预处理对NE收缩有明显抑制作用.因此,黄芩苷具有浓度依赖性血管舒张作用,此作用具有内皮依赖性和非内皮依赖性特点,内皮依赖性收缩可能与前列环素途径有关,非内皮依赖机制可能与KATP通道及钙离子通道有关.%To investigate the vasodilation effect of baicalin and its possible mechanism, isotonic tension of thoracic aortic rings precontracted with norepineprine and KC1 was recorded. The vasodilation of baicalin and the influence of various drugs were observed in the rings with endothelium intact or endothelium denuded. Baicalin caused concentration-dependent relaxation in thoracic aortas with or without endothelium. NG-nitro-L-argininemethylester and methylene blue had no effect on the vasodilation of baicalin while thoracic aortas were precontracted by NE,but indomethacin blocked the vascular effect of baicalin. Glibenclamide attenuated the vasodilation effect of baicalin, but 4-aminopyridine, tetraethylamonium and BaCl2 had no significant effect on it. In the absence of extracellular Ca2+ ,pre-incubation of the aortic rings with baicalin reduced significantly the contraction induced by NE. Baicalin induced a dose-dependent, endothelium-dependent and endothelium-independent relaxation on rat isolated aorta rings. Moreover, PGI2 pathway might be

  15. Pathomorphological effects of Alloxan induced acute hypoglycaemia ...

    African Journals Online (AJOL)

    Masood Saleem Mir

    2013-04-09

    Apr 9, 2013 ... humans and rodents under different glycemic conditions have shown that acute ..... sium (K+) leakage, all of which are indices of plasma membrane .... V. Nutritional and hypoglycemic effect of fruit pulp of Annona squamosa in ...

  16. Lipid Emulsions Enhance the Norepinephrine-Mediated Reversal of Local Anesthetic-Induced Vasodilation at Toxic Doses

    Science.gov (United States)

    Lee, Soo Hee; Sung, Hui-Jin; Ok, Seong-Ho; Yu, Jongsun; Choi, Mun-Jeoung; Lim, Jin Soo

    2013-01-01

    Purpose Intravenous lipid emulsions have been used to treat the systemic toxicity of local anesthetics. The goal of this in vitro study was to examine the effects of lipid emulsions on the norepinephrine-mediated reversal of vasodilation induced by high doses of levobupivacaine, ropivacaine, and mepivacaine in isolated endothelium-denuded rat aorta, and to determine whether such effects are associated with the lipid solubility of local anesthetics. Materials and Methods The effects of lipid emulsions (0.30, 0.49, 1.40, and 2.61%) on norepinephrine concentration-responses in high-dose local anesthetic (6×10-4 M levobupivacaine, 2×10-3 M ropivacaine, and 7×10-3 M mepivacaine)-induced vasodilation of isolated aorta precontracted with 60 mM KCl were assessed. The effects of lipid emulsions on local anesthetic- and diltiazem-induced vasodilation in isolated aorta precontracted with phenylephrine were also assessed. Results Lipid emulsions (0.30%) enhanced norepinephrine-induced contraction in levobupivacaine-induced vasodilation, whereas 1.40 and 2.61% lipid emulsions enhanced norepinephrine-induced contraction in both ropivacaine- and mepivacaine-induced vasodilation, respectively. Lipid emulsions (0.20, 0.49 and 1.40%) inhibited vasodilation induced by levobupivacaine and ropivacaine, whereas 1.40 and 2.61% lipid emulsions slightly attenuated mepivacaine (3×10-3 M)-induced vasodilation. In addition, lipid emulsions attenuated diltiazem-induced vasodilation. Lipid emulsions enhanced norepinephrine-induced contraction in endothelium-denuded aorta without pretreatment with local anesthetics. Conclusion Taken together, these results suggest that lipid emulsions enhance the norepinephrine-mediated reversal of local anesthetic-induced vasodilation at toxic anesthetic doses and inhibit local anesthetic-induced vasodilation in a manner correlated with the lipid solubility of a particular local anesthetic. PMID:24142661

  17. Medial prefrontal cortex acetylcholine injection-induced hypotension: the role of hindlimb vasodilation

    Science.gov (United States)

    Crippa, G. E.; Lewis, S. J.; Johnson, A. K.; Correa, F. M.

    2000-01-01

    The injection of acetylcholine (ACh) into the cingulate region of the medial prefrontal cortex (MPFC) causes a marked fall in arterial blood pressure which is not accompanied by changes in heart rate. The purpose of the present study was to investigate the hemodynamic basis for this stimulus-induced hypotension in Sprague-Dawley rats. The study was designed to determine whether a change in the vascular resistance of hindlimb, renal or mesenteric vascular beds contributes to the fall in arterial pressure in response to ACh injection into the cingulate cortex. Miniature pulsed-Doppler flow probes were used to measure changes in regional blood flow and vascular resistance. The results indicated that the hypotensive response was largely due to a consistent and marked vasodilation in the hindlimb vascular bed. On this basis, an additional experiment was then undertaken to determine the mechanisms that contribute to hindlimb vasodilation. The effect of interrupting the autonomic innervation of one leg on the hindlimb vasodilator response was tested. Unilateral transection of the lumbar sympathetic chain attenuated the cingulate ACh-induced vasodilation in the ipsilateral, but not in the contralateral hindlimb. These results suggest that the hypotensive response to cingulate cortex-ACh injection is caused by skeletal muscle vasodilation mediated by a sympathetic chain-related vasodilator system.

  18. Improved functional vasodilation in obese Zucker rats following exercise training

    OpenAIRE

    Sebai, Mohamad; Lu, Silu; Xiang, Lusha; Hester, Robert L.

    2011-01-01

    Obese individuals exhibit impaired functional vasodilation and exercise performance. We have demonstrated in obese Zucker rats (OZ), a model of morbid obesity, that insulin resistance impairs functional vasodilation via an increased thromboxane receptor (TP)-mediated vasoconstriction. Chronic treadmill exercise training improves functional vasodilation in the spinotrapezius muscle of the OZ, but the mechanisms responsible for the improvement in functional vasodilation are not clear. Based on ...

  19. Acute Effect of High-Intensity Eccentric Exercise on Vascular Endothelial Function in Young Men.

    Science.gov (United States)

    Choi, Youngju; Akazawa, Nobuhiko; Zempo-Miyaki, Asako; Ra, Song-Gyu; Shiraki, Hitoshi; Ajisaka, Ryuichi; Maeda, Seiji

    2016-08-01

    Choi, Y, Akazawa, N, Zempo-Miyaki, A, Ra, S-G, Shiraki, H, Ajisaka, R, and Maeda, S. Acute effect of high-intensity eccentric exercise on vascular endothelial function in young men. J Strength Cond Res 30(8): 2279-2285, 2016-Increased central arterial stiffness is as an independent risk factor for cardiovascular disease. Evidence regarding the effects of high-intensity resistance exercise on vascular endothelial function and central arterial stiffness is conflicting. The purpose of this study was to examine the effects of acute high-intensity eccentric exercise on vascular endothelial function and central arterial stiffness. We evaluated the acute changes in endothelium-dependent flow-mediated dilation (FMD), low-flow-mediated constriction (L-FMC), and arterial stiffness after high-intensity eccentric exercise. Seven healthy, sedentary men (age, 24 ± 1 year) performed maximal eccentric elbow flexor exercise using their nondominant arm. Before and 45 minutes after eccentric exercise, carotid arterial compliance and brachial artery FMD and L-FMC in the nonexercised arm were measured. Carotid arterial compliance was significantly decreased, and β-stiffness index significantly increased after eccentric exercise. Brachial FMD was significantly reduced after eccentric exercise, whereas there was no significant difference in brachial L-FMC before and after eccentric exercise. A positive correlation was detected between change in arterial compliance and change in FMD (r = 0.779; p ≤ 0.05), and a negative correlation was detected between change in β-stiffness index and change in FMD (r = -0.891; p eccentric exercise. In this study, acute high-intensity eccentric exercise increased central arterial stiffness; this increase was accompanied by a decrease in endothelial function caused by reduced endothelium-dependent vasodilation but not by a change in endothelium-dependent vasoconstriction.

  20. EFFECT OF LEFT VENTRICULAR SYSTOLIC DYSFUNCTION ON CEREBRAL HEMODYNAMICS IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION (THE RESULTS OF OBSERVATIONAL STUDIES

    Directory of Open Access Journals (Sweden)

    V. E. Kulikov

    2015-12-01

    Full Text Available Aim. To study the effect of left ventricular (LV systolic dysfunction on cerebral hemodynamic in patients with ST segment elevation myocardial infarction (STEMI during acute period. Material and methods. Cerebral hemodynamics ultrasound assessment was performed in the extra-and intracranial vessels in 118 patients with STEMI. Results. Significant changes in cerebral hemodynamics were found in LV systolic dysfunction with ejection fraction (LVEF ≤40% due to hemispheric blood flow asymmetry in the middle cerebral artery (MCA as large as 45.1±6.7% with correlation coefficient r=-0.87. Compensation of cerebral blood flow was manifested in vasoconstriction or vasodilation (resistive index 0.63-0.76 and 0.49-0.43 c.u., respectively. Conclusion. A strong relationship between LV systolic dysfunction and cerebral hemodynamic was found in patients with STEMI. It was manifested in significant contralateral hemispheric blood flow asymmetry in MCA in patients with LVEF ≤40%. Reduction in cerebral blood flow velocity activated autoregulation mechanism in the form of vasoconstriction or vasodilation.

  1. Mechanisms of rapid vasodilation after a brief contraction in human skeletal muscle.

    Science.gov (United States)

    Crecelius, Anne R; Kirby, Brett S; Luckasen, Gary J; Larson, Dennis G; Dinenno, Frank A

    2013-07-01

    A monophasic increase in skeletal muscle blood flow is observed after a brief single forearm contraction in humans, yet the underlying vascular signaling pathways remain largely undetermined. Evidence from experimental animals indicates an obligatory role of vasodilation via K⁺-mediated smooth muscle hyperpolarization, and human data suggest little to no independent role for nitric oxide (NO) or vasodilating prostaglandins (PGs). We tested the hypothesis that K⁺-mediated vascular hyperpolarization underlies the rapid vasodilation in humans and that combined inhibition of NO and PGs would have a minimal effect on this response. We measured forearm blood flow (Doppler ultrasound) and calculated vascular conductance 10 s before and for 30 s after a single 1-s dynamic forearm contraction at 10%, 20%, and 40% maximum voluntary contraction in 16 young adults. To inhibit K⁺-mediated vasodilation, BaCl₂ and ouabain were infused intra-arterially to inhibit inwardly rectifying K⁺ channels and Na⁺-K⁺-ATPase, respectively. Combined enzymatic inhibition of NO and PG synthesis occurred via NG-monomethyl-L-arginine (L-NMMA; NO synthase) and ketorolac (cyclooxygenase), respectively. In protocol 1 (n = 8), BaCl₂ + ouabain reduced peak vasodilation (range: 30-45%, P vasodilation (area under the curve, ~55-75% from control) at all intensities. Contrary to our hypothesis, L-NMMA + ketorolac had a further impact (peak: ~60% and area under the curve: ~80% from control). In protocol 2 (n = 8), the order of inhibitors was reversed, and the findings were remarkably similar. We conclude that K⁺-mediated hyperpolarization and NO and PGs, in combination, significantly contribute to contraction-induced rapid vasodilation and that inhibition of these signaling pathways nearly abolishes this phenomenon in humans.

  2. Involvement of endothelium-dependent and -independent mechanisms in midazolam-induced vasodilation.

    Science.gov (United States)

    Colussi, Gian Luca; Di Fabio, Alessandro; Catena, Cristiana; Chiuch, Alessandra; Sechi, Leonardo A

    2011-08-01

    Benzodiazepine (BDZ) infusion has been shown to reduce blood pressure in both humans and animals. Although the inhibitory effects of BDZ on the central nervous system have been well documented, less is known about the direct effects of BDZ on the vascular bed. The aims of this study were to assess the effects of the BDZ midazolam on the vascular system in C57/BL6 mouse aortic rings and to investigate the mechanisms of its direct vascular action. We found that midazolam induced reversible, dose-dependent vasodilation in potassium- and phenylephrine-precontracted rings. In rings that were precontracted with potassium or phenylephrine, treatment with 10 μmol l(-1) midazolam increased vasodilation by 15 and 60%, respectively, compared with baseline. Vasodilation increased by 80 and 87%, respectively, after treatment with 50 μmol l(-1) midazolam. Only the low concentration of midazolam (10 μmol l(-1)) induced endothelium-dependent vasodilation in phenylephrine-precontracted rings. Vasodilation increased by 60% in rings with endothelium and by 20% in rings without endothelium. Conversely, only the high concentration of midazolam (50 μmol l(-1)) reduced the CaCl(2)-induced vasoconstriction of aortic rings with EC(50) (the concentration giving 50% of the maximal effect) values of 1 and 6 mmol l(-1) for vehicle- and midazolam-treated rings, respectively. Furthermore, the incubation of phenylephrine-precontracted rings with an inhibitor of the nitric oxide synthase (NOS) NG-nitro-L-arginine methyl ester or the inhibitors of central or peripheral type BDZ receptors (flumazenil or PK 11195, respectively) produced no change in midazolam-induced vasodilation. Thus, low concentrations of midazolam induce vasodilation via an endothelium-dependent mechanism that does not involve NO production. In contrast, high concentrations of midazolam induce vasodilation via an endothelium-independent mechanism that implies reduced sensitivity of aortic rings to calcium ions. Additionally

  3. The cardiovascular pharmacology of ICI 170777 ((6RS)-6-methyl-5-(pyrid-4-yl)-3H,6H-1,3,4- thiadiazin-2-one) a novel compound with positive inotropic and vasodilator effects.

    Science.gov (United States)

    Collis, M. G.; Keddie, J. R.; Rouse, W.

    1989-01-01

    1. This paper describes the cardiovascular effects of ICI 170777, a novel compound which enhances cardiac contractility and causes arterial and venous dilatation. 2. The positive inotropic effects of ICI 170777 on the heart were demonstrated by an increase in left ventricular dP/dtmax in the anaesthetized and conscious dog, and by an increase in tension development in isolated papillary muscles from the cat. 3. In the anaesthetized dog, the positive inotropic effects of ICI 170777 and of isoprenaline were attenuated by atenolol (5 mg kg-1, i.v.). Atenolol displaced the dose-response curve to ICI 170777 to the right by 4 fold but displaced the isoprenaline dose-response curve to the right by 247 fold. In vitro, however, atenolol (10 microM) had no significant effect on the positive inotropic response to ICI 170777. In the ganglion-blocked anaesthetized dog, infusion of a low dose of ICI 170777 which had no effect on the basal left ventricular dP/dtmax, selectively potentiated the positive inotropic effects of isoprenaline. These results indicate that ICI 170777 has both a non-adrenoceptor-mediated positive inotropic effect on the heart and also facilitates the beta-adrenoceptor-mediated control of contractility. 4. In the denervated and perfused hind-limb of the dog, ICI 170777 reduced arterial perfusion pressure and increased limb circumference at a constant arterial flow and venous pressure. This indicates that ICI 170777 has direct dilator actions on both arterial and venous vessels. In this preparation, diazoxide exerted an arterial selective vasodilator effect and sodium nitroprusside was a relatively selective venous dilator.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2758224

  4. Muscle metaboreceptor modulation of cutaneous active vasodilation

    Science.gov (United States)

    Crandall, C. G.; Stephens, D. P.; Johnson, J. M.

    1998-01-01

    PURPOSE: Isometric handgrip exercise in hyperthermia has been shown to reduce cutaneous vascular conductance (CVC) by inhibiting the cutaneous active vasodilator system. METHODS: To identify whether this response was initiated by muscle metaboreceptors, in seven subjects two 3-min bouts of isometric handgrip exercise in hyperthermia were performed, followed by 2 min of postexercise ischemia (PEI). An index of forearm skin blood flow (laser-Doppler flowmetry) was measured on the contralateral arm at an unblocked site and at a site at which adrenergic vasoconstrictor function was blocked via bretylium iontophoresis to reveal active cutaneous vasodilator function unambiguously. Sweat rate was measured via capacitance hygrometry, CVC was indexed from the ratio of skin blood flow to mean arterial pressure and was expressed as a percentage of maximal CVC at that site. In normothermia, neither isometric exercise nor PEI affected CVC (P > 0.05). RESULTS: The first bout of isometric handgrip exercise in hyperthermia reduced CVC at control sites and this reduction persisted through PEI (pre-exercise: 59.8 +/- 5.4, exercise: 49.8 +/- 4.9, PEI: 49.7 +/- 5.3% of maximum; both P vasodilator system, is primarily mediated by muscle metaboreceptors, whereas central command or muscle mechanoreceptors have less influence.

  5. Acute marijuana effects on social conversation.

    Science.gov (United States)

    Higgins, S T; Stitzer, M L

    1986-01-01

    The present study assessed the acute effects of smoked marijuana on social conversation. Speech quantity was recorded continuously in seven moderate marijuana users during separate 1 h experimental sessions following the paced smoking of 0, 1.01, 1.84, and 2.84% THC marijuana cigarettes. Subjects engaged in conversation with undrugged partners who smoked placebo marijuana cigarettes. The active marijuana produced significant decreases in speech quantity, increases in heart rate, and increases in self-reports of "high" and sedation. Partners showed no effects in speech quantity or self-reports of drug effects that were systematically related to the doses administered to the subject pair members. The effects on speech quantity observed in the present study after acute dosing are similar to the effects on social conversation reported previously during chronic marijuana dosing. Marijuana appears to be an exception to the general rule that drugs of abuse increase verbal interaction.

  6. Protective Effect of Melatonin on Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    Jolanta Jaworek

    2012-01-01

    Full Text Available Melatonin, a product of the pineal gland, is released from the gut mucosa in response to food ingestion. Specific receptors for melatonin have been detected in many gastrointestinal tissues including the pancreas. Melatonin as well as its precursor, L-tryptophan, attenuates the severity of acute pancreatitis and protects the pancreatic tissue from the damage caused by acute inflammation. The beneficial effect of melatonin on acute pancreatitis, which has been reported in many experimental studies and supported by clinical observations, is related to: (1 enhancement of antioxidant defense of the pancreatic tissue, through direct scavenging of toxic radical oxygen (ROS and nitrogen (RNS species, (2 preservation of the activity of antioxidant enzymes; such as superoxide dismutase (SOD, catalase (CAT, or glutathione peroxidase (GPx, (3 the decline of pro-inflammatory cytokine tumor necrosis α (TNFα production, accompanied by stimulation of an anti-inflammatory IL-10, (4 improvement of pancreatic blood flow and decrease of neutrophil infiltration, (5 reduction of apoptosis and necrosis in the inflamed pancreatic tissue, (6 increased production of chaperon protein (HSP60, and (7 promotion of regenerative process in the pancreas. Conclusion. Endogenous melatonin produced from L-tryptophan could be one of the native mechanisms protecting the pancreas from acute damage and accelerating regeneration of this gland. The beneficial effects of melatonin shown in experimental studies suggest that melatonin ought to be employed in the clinical trials as a supportive therapy in acute pancreatitis and could be used in people at high risk for acute pancreatitis to prevent the development of pancreatic inflammation.

  7. Decongestion in acute heart failure

    NARCIS (Netherlands)

    Mentz, Robert J.; Kjeldsen, Keld; Rossi, Gian Paolo; Voors, Adriaan A.; Cleland, John G. F.; Anker, Stefan D.; Gheorghiade, Mihai; Fiuzat, Mona; Rossignol, Patrick; Zannad, Faiez; Pitt, Bertram; O'Connor, Christopher; Felker, G. Michael

    2014-01-01

    Congestion is a major reason for hospitalization in acute heart failure (HF). Therapeutic strategies to manage congestion include diuretics, vasodilators, ultrafiltration, vasopressin antagonists, mineralocorticoid receptor antagonists, and potentially also novel therapies such as gut sequesterants

  8. Acute Biphasic Effects of Ayahuasca.

    Directory of Open Access Journals (Sweden)

    Eduardo Ekman Schenberg

    Full Text Available Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8-13 Hz after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30-50 and 50-100 Hz, respectively between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca's chemical compounds, mostly N,N-dimethyltryptamine (DMT, harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered.

  9. Acute Biphasic Effects of Ayahuasca

    Science.gov (United States)

    Schenberg, Eduardo Ekman; Alexandre, João Felipe Morel; Filev, Renato; Cravo, Andre Mascioli; Sato, João Ricardo; Muthukumaraswamy, Suresh D.; Yonamine, Maurício; Waguespack, Marian; Lomnicka, Izabela; Barker, Steven A.; da Silveira, Dartiu Xavier

    2015-01-01

    Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG) recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8–13 Hz) after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30–50 and 50–100 Hz, respectively) between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca’s chemical compounds, mostly N,N-dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered. PMID:26421727

  10. Acute Biphasic Effects of Ayahuasca.

    Science.gov (United States)

    Schenberg, Eduardo Ekman; Alexandre, João Felipe Morel; Filev, Renato; Cravo, Andre Mascioli; Sato, João Ricardo; Muthukumaraswamy, Suresh D; Yonamine, Maurício; Waguespack, Marian; Lomnicka, Izabela; Barker, Steven A; da Silveira, Dartiu Xavier

    2015-01-01

    Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG) recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8-13 Hz) after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30-50 and 50-100 Hz, respectively) between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca's chemical compounds, mostly N,N-dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered.

  11. [Ascites and acute kidney injury].

    Science.gov (United States)

    Piano, Salvatore; Tonon, Marta; Angeli, Paolo

    2016-07-01

    Ascites is the most common complication of cirrhosis. Ascites develops as a consequence of an abnormal splanchnic vasodilation with reduction of effecting circulating volume and activation of endogenous vasoconstrictors system causing salt and water retention. Patients with ascites have a high risk to develop further complications of cirrhosis such as hyponatremia, spontaneous bacterial peritonitis and acute kidney injury resulting in a poor survival. In recent years, new studies helped a better understanding of the pathophysiology of ascites and acute kidney injury in cirrhosis. Furthermore, new diagnostic criteria have been proposed for acute kidney injury and hepatorenal syndrome and a new algorithm for their management has been recommended with the aim of an early diagnosis and treatment. Herein we will review the current knowledge on the pathophysiology, diagnosis and treatment of ascites and acute kidney injury in patients with cirrhosis and we will identify the unmet needs that should be clarified in the next years.

  12. [Acute myocardial infarction during tocolytic treatment with ritodrine].

    Science.gov (United States)

    Fornet, I; Calvo, M; Gimeno, M; Canser, E; Alonso, E; Gilsanz, F

    2006-05-01

    Ritodrine, a beta2-adrenergic agonist with a selective effect on the uterine muscle, is prescribed to prevent premature labor and to treat a hypertonic uterus. At therapeutic doses ritodrine has chronotropic and peripheral vasodilator effects. At high doses it has been related to sporadic cases of subendocardial necrosis, pulmonary edema, and death in pregnancy. We report the case of a pregnant woman who had a non-Q wave acute myocardial infarction after administration of ritodrine.

  13. Relaxin is a potent renal vasodilator in conscious rats

    OpenAIRE

    Danielson, Lee A.; Sherwood, O. David; Conrad, Kirk P.

    1999-01-01

    The kidneys and other nonreproductive organs vasodilate during early gestation; however, the “pregnancy hormones” responsible for the profound vasodilation of the renal circulation during pregnancy are unknown. We hypothesized that the ovarian hormone relaxin (RLX) contributes. Therefore, we tested whether the administration of RLX elicits renal vasodilation and hyperfiltration in conscious adult, intact female rats. After several days of treatment with either purified porcine RLX or recombin...

  14. Effect of Zinc supplementation on the Management of Acute ...

    African Journals Online (AJOL)

    Effect of Zinc supplementation on the Management of Acute Diarrhoea in Young ... Incidence and prevalence of diarrhea were compared between the groups. ... Supplementing the treatment of acute watery diarrhea with Zinc in just 2 cases ...

  15. ACUTE TOXICITY EFFECT OF THE AQUEOUS EXTRACT OF ...

    African Journals Online (AJOL)

    Administrator

    Acute And Toxicity Effect of The Aqueous Extract of Terminalia avicennioides. ACUTE TOXICITY ... that this valuable medicinal resources in plants are largely untapped because of .... Test of significance was done in rows. Same superscripts ...

  16. Effects of hypercapnia on peripheral vascular reactivity in elderly patients with acute exacerbation of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    de Matthaeis A

    2014-05-01

    Full Text Available Angela de Matthaeis,1 Antonio Greco,2,* Mariangela Pia Dagostino,2 Giulia Paroni,2 Andrea Fontana,3 Manlio Vinciguerra,1,4,5 Gianluigi Mazzoccoli,1,* Davide Seripa,2 Gianluigi Vendemiale61Division of Internal Medicine and Chronobiology Unit, 2Geriatrics Unit and Gerontology, Geriatrics Research Laboratory, Department of Medical Sciences, 3Unit of Biostatistics, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, 4Euro-Mediterranean Institute of Sciences and Technology, Palermo, Italy; 5University College London, Institute for Liver and Digestive Health, Division of Medicine, Royal Free Campus, London, UK; 6Geriatrics Unit, University of Foggia, Foggia, Italy*These authors contributed equally to this workAbstract: Blood acid-base imbalance has important effects on vascular reactivity, which can be related to nitric oxide (NO concentration and increased during hypercapnia. Release of NO seems to be linked to H+ and CO2 concentration and to exacerbation of chronic obstructive pulmonary disease (COPD, a common medical condition in the elderly. Flow-mediated dilation (FMD, a valuable cardiovascular risk indicator, allows assessment of endothelial-dependent vasodilation, which is to a certain extent mediated by NO. We investigated the effects of hypercapnia and acid-base imbalance on endothelial-dependent vasodilation by measurement of FMD in 96 elderly patients with acute exacerbation of COPD. Patients underwent complete arterial blood gas analysis and FMD measurement before (phase 1 and after (phase 2 standard therapy for acute exacerbation of COPD and recovery. Significant differences between phase 1 and phase 2 were observed in the mean values of pH (7.38±0.03 versus 7.40±0.02, P<0.001, pO2 (59.6±4.9 mmHg versus 59.7±3.6 mmHg, P<0.001, pCO2 (59.3±8.63 mmHg versus 46.7±5.82 mmHg, P<0.001, FMD (10.0%±2.8% versus 8.28%±2.01%, P<0.001 and blood flow rate (1.5±0.3 m/s versus 1.5±0.3 m/s, P=0.001. FMD values were

  17. Acute lorazepam effects on neurocognitive performance.

    Science.gov (United States)

    Loring, David W; Marino, Susan E; Parfitt, David; Finney, Glen R; Meador, Kimford J

    2012-11-01

    A double-blind, placebo-controlled, crossover design was employed to determine whether acute lorazepam (2 mg orally) cognitive side effects would emerge in a differential age-dependent fashion in 15 young (mean age=22 years) and 12 older (mean age=64 years) subjects. Acute use of lorazepam is frequently the initial treatment choice for convulsive status epilepticus or repetitive seizure clusters. Cognitive assessment was performed during drug and placebo conditions using a computerized battery of cognitive tests. With the exception of performance on the reasoning composite score, significant drug effects were present on all primary cognitive domain measures. However, the only significant drug-by-age interaction effect was seen for dual-task performance. The relationship between test performance and plasma lorazepam concentrations was generally modest and non-significant, suggesting that individual differences in pharmacokinetics are not a major factor contributing to the emergence of cognitive side effects. Despite robust lorazepam effects on multiple measures of neurocognitive function, differential age effects are largely restricted to dual-task performance. These results indicate that with the exception of dual-task performance, older individuals in the age range of this study do not appear to be at increased risk for the emergence of cognitive side effects following a single 2-mg dose of lorazepam.

  18. Vasodilating effect of capsaicin on rat mesenteric artery and its mechanism%辣椒素对大鼠肠系膜阻力血管的舒张作用及其机制

    Institute of Scientific and Technical Information of China (English)

    陈强; 朱欢欢; 张媛媛; 张媛; 王利宏; 郑良荣

    2013-01-01

    目的:观测辣椒素(capsaicin,CAP)对大鼠肠系膜阻力血管的舒张作用,探讨其可能机制.方法:雄性Sprague-Dawley大鼠,取肠系膜动脉三级分支约2 mm长血管环,置于DMT 610M系统,记录张力变化.结果:CAP(10-9~10-5 mol/L)对苯肾上腺素(PE)预收缩的内皮完整血管和去内皮血管产生浓度依赖性的舒张作用,其中内皮完整组的血管舒张作用比去内皮组更明显,两者相比CAP在10-7~1O-5 mol/L时,差异有统计学意义(P<0.01).该舒张作用可被一氧化氮合酶抑制剂L-NAME和CGRP竞争性阻滞剂CGRP8-37阻断.CGRP(10-10~3×10-8 mol/L)对PE预收缩的内皮完整血管和去内皮血管产生浓度依赖性的舒张作用,其中内皮完整组的血管舒张作用比去内皮组更明显,两者相比CGRP在3×10-9~3×10-8 mol/L时,差异有统计学意义(P<0.05).P物质对PE预收缩的内皮完整血管无舒张作用.结论:CAP对大鼠肠系膜阻力动脉具有部分内皮依赖性舒张作用,该作用机制与其促进内皮一氧化氮合酶(NOS)途径有关;CAP的非内皮依赖性舒张血管效应与CGRP释放有关.%Objective: To investigate the vasodilating effect of capsaicin ( CAP) on rat mesenteric artery and its mechanism. Methods: The third branch of the superior mesenteric artery in male Sprague-Dawley rat(250 -350 g) was excised,the periadventitial fat and connective tissue were removed and the mesenteric artery was dissected into 2 mm rings. Each ring was placed in a 5 ml organ bath of DMT 610M system and the tension was recorded. Results: CAP( 10 -9 - 10 -5 mol/L) relaxed endothelium-intact and endothelium-denuded mesenteric artery pre-constricted by phenylephrine ( 10-5 mol/L ) , and the vasodilation in endothelium-intact mesenteric artery was stronger than that in endothelium-denuded one. Pretreatment with either L-NAME (3×10-4mol/L) , an inhibitor of nitric oxide synthase ( NOS), or CGRP8-37(2×10-6 mol/L),an antagonist of calcitonin gene

  19. Acute marijuana effects on human risk taking.

    Science.gov (United States)

    Lane, Scott D; Cherek, Don R; Tcheremissine, Oleg V; Lieving, Lori M; Pietras, Cythia J

    2005-04-01

    Previous studies have established a relationship between marijuana use and risky behavior in natural settings. A limited number of laboratory investigations of marijuana effects on human risk taking have been conducted. The present study was designed to examine the acute effects of smoked marijuana on human risk taking, and to identify behavioral mechanisms that may be involved in drug-induced changes in the probability of risky behavior. Using a laboratory measure of risk taking designed to address acute drug effects, 10 adults were administered placebo cigarettes and three doses of active marijuana cigarettes (half placebo and half 1.77%; 1.77%; and 3.58% Delta9-THC) in a within-subject repeated-measures experimental design. The risk-taking task presented subjects with a choice between two response options operationally defined as risky and nonrisky. Data analyses examined cardiovascular and subjective effects, response rates, distribution of choices between the risky and nonrisky option, and first-order transition probabilities of trial-by-trial data. The 3.58% THC dose increased selection of the risky response option, and uniquely shifted response probabilities following both winning and losing outcomes following selection of the risky option. Acute marijuana administration thereby produced measurable changes in risky decision making under laboratory conditions. Consistent with previous risk-taking studies, shifts in trial-by-trial response probabilities at the highest dose suggested a change in sensitivity to both reinforced and losing risky outcomes. Altered sensitivity to consequences may be a mechanism in drug-induced changes in risk taking. Possible neurobiological sites of action related to THC are discussed.

  20. Regional cerebral blood flow and the effects of nicardipine, a new cerebral vasodilator, in patients with neuropsychiatric symptoms. A study of /sup 133/Xe inhalation method

    Energy Technology Data Exchange (ETDEWEB)

    Toyoda, Katsuhiro; Motomura, Naoyasu; Murata, Koen; Sakai, Toshiaki (Osaka Medical Coll., Takatsuki (Japan)); Yoshioka, Michio; Tsutsumi, Shigetoshi

    1984-02-01

    Regional cerebral blood flow (rCBF) was determined by /sup 133/Xe inhalation method in 22 neuropsychiatric patients with an average age of 65.8 years -- 14 patients having cerebrovascular disturbance (Group 1) and 8 patients having endogenous or organic psychosis or neurological lesions (Group 2). Furthermore, nicardipine was orally administered to the patients and its effects on rCBF and on neuropsychiatric symptoms were examined. Regarding the mean and abnormal decrease of rCBF in the bilateral hemispheres and the frequency of ischemic foci, there was no significant difference between the groups. However, regional ischemic focus was more frequently observed in Group 1 than in Group 2. Long-term serial administration of nicardipine increased the rCBF and improved psychiatric symptoms in some of the patients in Group 1.

  1. Estrogen and phytoestrogens: Effect on eNOS expression and in vitro vasodilation in cerebral arteries in ovariectomized Watanabe heritable hyperlipidemic rabbits

    DEFF Research Database (Denmark)

    Lund, Claus Otto; Mortensen, A; Nilas, Lisbeth

    2007-01-01

    -six female ovariectomized Watanabe heritable hyperlipidemic (WHHL) rabbits were randomised to treatment with 17beta-estradiol (17beta-E(2)), SoyLife 150 or control for 16 weeks. Ring segments of basilar artery (BA) and posterior cerebral artery (PCA) were mounted in myographs for isometric tension recordings......OBJECTIVES: To evaluate the effect of estrogen replacement therapy or soy isoflavones supplement on endothelium-dependent relaxation in vitro and gene expression of endothelial nitric oxide synthase (eNOS) in cerebral arteries in a rabbit model of human hypercholesterolemia. STUDY DESIGN: Thirty...... in any of the arteries. Correspondingly, eNOS mRNA was similarly expressed in all treatment groups in both arteries. CONCLUSIONS: Improvement of cerebral endothelial function by estrogen or soy isoflavones in ovariectomized WHHL rabbits is not supported by the present data. The findings may be unique...

  2. Estrogen and phytoestrogens: Effect on eNOS expression and in vitro vasodilation in cerebral arteries in ovariectomized Watanabe heritable hyperlipidemic rabbits

    DEFF Research Database (Denmark)

    Lund, Claus O.; Mortensen, Alicja; Nilas, Lisbeth

    2007-01-01

    -six female ovariectomized Watanabe heritable hyperlipidemic (WHHL) rabbits were randomised to treatment with 17 beta-estradiol (17 beta-E-2), SoyLife 150(R) or control for 16 weeks. Ring segments of basilar artery (BA) and posterior cerebral artery (PCA) were mounted in myographs for isometric tension......Objectives: To evaluate the effect of estrogen replacement therapy or soy isoflavones supplement on endothelium-dependent relaxation in vitro and gene expression of endothelial nitric oxide synthase (eNOS) in cerebral arteries in a rabbit model of human hypercholesterolemia. Study design: Thirty......-independent response to SNP in any of the arteries. Correspondingly, eNOS mRNA was similarly expressed in all treatment groups in both arteries. Conclusions: Improvement of cerebral endothelial function by estrogen or soy isoflavones in ovariectomized WHHL rabbits is not supported by the present data. The findings may...

  3. Estrogen and phytoestrogens: Effect on eNOS expression and in vitro vasodilation in cerebral arteries in ovariectomized Watanabe heritable hyperlipidemic rabbits

    DEFF Research Database (Denmark)

    Lund, Claus Otto; Mortensen, A; Nilas, Lisbeth

    2007-01-01

    OBJECTIVES: To evaluate the effect of estrogen replacement therapy or soy isoflavones supplement on endothelium-dependent relaxation in vitro and gene expression of endothelial nitric oxide synthase (eNOS) in cerebral arteries in a rabbit model of human hypercholesterolemia. STUDY DESIGN: Thirty......-six female ovariectomized Watanabe heritable hyperlipidemic (WHHL) rabbits were randomised to treatment with 17beta-estradiol (17beta-E(2)), SoyLife 150 or control for 16 weeks. Ring segments of basilar artery (BA) and posterior cerebral artery (PCA) were mounted in myographs for isometric tension recordings...... in any of the arteries. Correspondingly, eNOS mRNA was similarly expressed in all treatment groups in both arteries. CONCLUSIONS: Improvement of cerebral endothelial function by estrogen or soy isoflavones in ovariectomized WHHL rabbits is not supported by the present data. The findings may be unique...

  4. The Vasodilator Effect of a Cream Containing 10% Menthol and 15% Methyl Salicylate on Random-Pattern Skin Flaps in Rats

    Science.gov (United States)

    Dölen, Utku Can; Sungur, Nezih; Koca, Gökhan; Ertunç, Onur; Bağcı Bosi, Ayşe Tülay; Koçer, Uğur

    2015-01-01

    Background It is still difficult to prevent partial or full-thickness flap necrosis. In this study, the effects of a cream containing menthol and methyl salicylate on the viability of randompattern skin flaps were studied. Methods Forty female Sprague-Dawley rats were divided into two equal groups. Caudally based dorsal random-pattern skin flaps were elevated, including the panniculus carnosus. In the study group, 1.5 mL of a cream containing menthol and methyl salicylate was applied to the skin of the flap, and saline solution (0.9%) was used in the control group. Upon completion of the experiment, flap necrosis was analyzed with imaging software and radionuclide scintigraphy. Histopathological measurements were made of the percentage of viable flaps, the number of vessels, and the width of the panniculus carnosus muscle. Results According to the photographic analysis, the mean viable flap surface area in the study group was larger than that in the control group (P=0.004). According to the scintigrams, no change in radioactivity uptake was seen in the study group (P>0.05). However, a significant decrease was observed in the control group (P=0.006). No statistically significant differences were observed between the groups in terms of the percentage of viable flaps, the number of vessels, or the width of the panniculus carnosus muscle (P>0.05). Conclusions Based on these results, it is certain that the cream did not reduce the viability of the flaps. Due to its vasodilatory effect, it can be used as a component of the dressing in reconstructive operations where skin perfusion is compromised. PMID:26618115

  5. The Vasodilator Effect of a Cream Containing 10% Menthol and 15% Methyl Salicylate on Random-Pattern Skin Flaps in Rats.

    Science.gov (United States)

    Dölen, Utku Can; Sungur, Nezih; Koca, Gökhan; Ertunç, Onur; Bağcı Bosi, Ayşe Tülay; Koçer, Uğur; Korkmaz, Meliha

    2015-11-01

    It is still difficult to prevent partial or full-thickness flap necrosis. In this study, the effects of a cream containing menthol and methyl salicylate on the viability of randompattern skin flaps were studied. Forty female Sprague-Dawley rats were divided into two equal groups. Caudally based dorsal random-pattern skin flaps were elevated, including the panniculus carnosus. In the study group, 1.5 mL of a cream containing menthol and methyl salicylate was applied to the skin of the flap, and saline solution (0.9%) was used in the control group. Upon completion of the experiment, flap necrosis was analyzed with imaging software and radionuclide scintigraphy. Histopathological measurements were made of the percentage of viable flaps, the number of vessels, and the width of the panniculus carnosus muscle. According to the photographic analysis, the mean viable flap surface area in the study group was larger than that in the control group (P=0.004). According to the scintigrams, no change in radioactivity uptake was seen in the study group (P>0.05). However, a significant decrease was observed in the control group (P=0.006). No statistically significant differences were observed between the groups in terms of the percentage of viable flaps, the number of vessels, or the width of the panniculus carnosus muscle (P>0.05). Based on these results, it is certain that the cream did not reduce the viability of the flaps. Due to its vasodilatory effect, it can be used as a component of the dressing in reconstructive operations where skin perfusion is compromised.

  6. Current concepts of active vasodilation in human skin

    Science.gov (United States)

    Wong, Brett J.; Hollowed, Casey G.

    2017-01-01

    ABSTRACT In humans, an increase in internal core temperature elicits large increases in skin blood flow and sweating. The increase in skin blood flow serves to transfer heat via convection from the body core to the skin surface while sweating results in evaporative cooling of the skin. Cutaneous vasodilation and sudomotor activity are controlled by a sympathetic cholinergic active vasodilator system that is hypothesized to operate through a co-transmission mechanism. To date, mechanisms of cutaneous active vasodilation remain equivocal despite many years of research by several productive laboratory groups. The purpose of this review is to highlight recent advancements in the field of cutaneous active vasodilation framed in the context of some of the historical findings that laid the groundwork for our current understanding of cutaneous active vasodilation.

  7. Dihydralazine induces marked cerebral vasodilation in man

    DEFF Research Database (Denmark)

    Schroeder, T; Sillesen, H

    1987-01-01

    Dihydralazine is widely used for acute control of hypertension. In experimental studies it seems to dilate cerebral resistance vessels and increase intracranial pressure. However, the effect on cerebral blood flow (CBF) in man has been little studied. Measurements of CBF were performed with the i.......v. xenon-133 technique in seven young, normotensive volunteers before and 15, 60 and 180 min after 6.25 mg i.v. dihydralazine, corresponding approximately to 0.1 mg kg-1 body weight. For comparison the CBF reactivity to inhalation of 5% CO2 in air was investigated. Dihydralazine increased CBF throughout...

  8. Pycnogenol, French maritime pine bark extract, augments endothelium-dependent vasodilation in humans.

    Science.gov (United States)

    Nishioka, Kenji; Hidaka, Takayuki; Nakamura, Shuji; Umemura, Takashi; Jitsuiki, Daisuke; Soga, Junko; Goto, Chikara; Chayama, Kazuaki; Yoshizumi, Masao; Higashi, Yukihito

    2007-09-01

    Pycnogenol, an extract of bark from the French maritime pine, Pinus pinaster Ait., consists of a concentrate of water-soluble polyphenols. Pycnogenol contains the bioflavonoids catechin and taxifolin as well as phenolcarbonic acids. Antioxidants, such as bioflavonoids, enhance endothelial nitric oxide (NO) synthase expression and subsequent NO release from endothelial cells. The purpose of this study was to determine Pycnogenol's effects on endothelium-dependent vasodilation in humans. This was a double-blind, randomized, placebo and active drug study. We evaluated forearm blood flow (FBF) responses to acetylcholine (ACh), an endothelium-dependent vasodilator, and to sodium nitroprusside (SNP), an endothelium-independent vasodilator, in healthy young men before and after 2 weeks of daily oral administration of Pycnogenol (180 mg/day) (n=8) or placebo (n=8). FBF was measured by using strain-gauge plethysmography. Neither the placebo nor Pycnogenol altered forearm or systemic hemodynamics. Pycnogenol, but not placebo, augmented FBF response to ACh, from 13.1 +/- 7.0 to 18.5 +/- 4.0 mL/min per 100 mL tissue (pPycnogenol groups. The administration of N(G)-monomethyl-L-arginine, an NO synthase inhibitor, completely abolished Pycnogenol-induced augmentation of the FBF response to ACh. These findings suggest that Pycnogenol augments endothelium-dependent vasodilation by increasing in NO production. Pycnogenol would be useful for treating various diseases whose pathogeneses involve endothelial dysfunction.

  9. Diving response in rats: role of the subthalamic vasodilator area.

    Directory of Open Access Journals (Sweden)

    Eugene Golanov

    2016-09-01

    Full Text Available Diving response is a powerful integrative response targeted toward survival of the hypoxic/anoxic conditions. Being present in all animals and humans it allows to survive adverse conditions like diving. Earlier we discovered that forehead stimulation affords neuroprotective effect decreasing infarction volume triggered by permanent occlusion of the middle cerebral artery in rats. We hypothesized that cold stimulation of the forehead induces diving response in rats, which, in turn, exerts neuroprotection. We compared autonomic (AP, HR, CBF and EEG responses to the known diving response-triggering stimulus, ammonia stimulation of the nasal mucosa, cold stimulation of the forehead, and cold stimulation of the glabrous skin of the tail base in anesthetized rats. Responses in AP, HR, CBF and EEG to cold stimulation of the forehead and ammonia vapors instillation into the nasal cavity were comparable and differed significantly from responses to the cold stimulation of the tail base. Excitotoxic lesion of the subthalamic vasodilator area, which is known to participate in CBF regulation and to afford neuroprotection upon excitation, failed to affect autonomic components of the diving response evoked by forehead cold stimulation or nasal mucosa ammonia stimulation. We conclude that cold stimulation of the forehead triggers physiological response comparable to the response evoked by ammonia vapor instillation into the nasal cavity, which considered as stimulus triggering protective diving response. These observations may explain the neuroprotective effect of the forehead stimulation. Data demonstrate that subthalamic vasodilator area does not directly participate in the autonomic adjustments accompanying diving response, however, it is involved in diving-evoked modulation of EEG. We suggest that forehead stimulation can be employed as a stimulus capable of triggering oxygen-conserving diving response and can be used for neuroprotective therapy.

  10. [Comparison of the acute cardiovascular side effects of iopamidol, metrizamide and amidotrizoate after intracoronary and left ventricular injections].

    Science.gov (United States)

    Schräder, R; Wolpers, H G; Hoeft, A; Korb, H; Hellige, G

    1984-05-01

    The acute cardiovascular side effects of iopamidol (osmolality: 0.8 osmol/kg), metrizamide (0.6 osmol/kg), and amidotrizoate (2.1 osmol/kg) during coronary arteriography (n = 30) and left ventriculography (n = 9) have been compared in anesthetized closed-chest dogs (n = 5). The influences of these contrast media on hemodynamics, coronary circulation, ECG and physicochemical properties of coronary sinus blood were evaluated. Following intracoronary injection, iopamidol and metrizamide cause positive inotropism while amidotrizoate initially induces cardiodepression. All contrast solutions lead to marked increase of myocardial blood flow. Electrocardiographic changes are greater after amidotrizoate (P less than 0.05). A fall of cationic content in coronary sinus blood is seen after each contrast medium. Amidotrizoate leads to more decrease of potassium (P less than 0.01) and both ionized and total calcium (P less than 0.001). Increase of osmolality and hydrogen ionic content is greater after amidotrizoate than after iopamidol and metrizamide (P less than 0.01). Following left ventricular injection, marked peripheral vasodilation, as seen after amidotrizoate, does not occur after low osmolality compounds. There are no significant differences between iopamidol and metrizamide in spite of the slightly higher osmolality of the former. Thus, both contrast materials should be equivalent with respect to their acute cardiovascular side effects under clinical conditions. Advantages of low osmolality radiological contrast media are discussed.

  11. Role of BKCa channels in cephalic vasodilation induced by CGRP, NO and transcranial electrical stimulation in the rat

    DEFF Research Database (Denmark)

    Gozalov, A.; Jansen-Olesen, I.; Klærke, Dan Arne;

    2007-01-01

    by the NO donor glyceryltrinitrate (GTN) or by CGRP is partially mediated via large conductance calcium-activated potassium (BK(Ca)) channels. The effects of the BK(Ca) channel selective inhibitor iberiotoxin on dural and pial vasodilation induced by CGRP, GTN and endogenously released CGRP by transcranial...... electrical stimulation (TES) were examined. Iberiotoxin significantly attenuated GTN-induced dural and pial artery dilation in vivo and in vitro, but had no effect on vasodilation induced by CGRP and TES. Our results show that GTN- but not CGRP-induced dural and pial vasodilation involves opening of BK...

  12. Mechanisms of acetylcholine-mediated vasodilation in systemic arteries from mourning doves (Zenaida macroura).

    Science.gov (United States)

    Jarrett, Catherine; Lekic, Mateja; Smith, Christina L; Pusec, Carolina M; Sweazea, Karen L

    2013-10-01

    For mammals, acetylcholine (ACh) promotes endothelium-dependent vasodilation primarily through nitric oxide (NO) and prostaglandin-mediated pathways, with varying reliance on endothelial-derived hyperpolarizing factors. Currently, no studies have been conducted on small systemic arteries from wild birds. We hypothesized that ACh-mediated vasodilation of isolated small arteries from mourning doves (Zenaida macroura) would likewise depend on endothelial-derived factors. Small resistance mesenteric and cranial tibial (c. tibial) arteries (80-150 μm, inner diameter) were cannulated and pre-constricted to 50 % of resting inner diameter with phenylephrine then exposed to increasing concentrations of ACh (10(-9)-10(-5) M) or the NO donor, sodium nitroprusside (SNP; 10(-12)-10(-3) M). For mesenteric arteries, ACh-mediated vasodilation was significantly blunted with the potassium channel antagonist tetraethylammonium chloride (TEA, 10 mM); whereas responses were only moderately impaired with endothelial disruption or inhibition of prostaglandins (indomethacin, 10 μM). In contrast, endothelial disruption as well as exposure to TEA largely abolished vasodilatory responses to ACh in c. tibial arteries while no effect of prostaglandin inhibition was observed. For both vascular beds, responses to ACh were moderately dependent on the NO signaling pathway. Inhibition of NO synthase had no impact, despite complete reversal of phenylephrine-mediated tone with SNP, whereas inhibition of soluble guanylate cyclase (sGC) caused minor impairments. Endothelium-independent vasodilation also relied on potassium channels. In summary, ACh-mediated vasodilation of mesenteric and c. tibial arteries occurs through the activation of potassium channels to induce hyperpolarization with moderate reliance on sGC. Prostaglandins likewise play a small role in the vasodilatory response to ACh in mesenteric arteries.

  13. Captopril, but not nifedipine, improves endothelium-dependent vasodilation in hypertensive patients.

    Science.gov (United States)

    Millgård, J; Hägg, A; Sarabi, M; Lind, L

    1998-08-01

    The present study aimed to investigate the influence of the angiotensin-converting enzyme (ACE)-inhibitor captopril and the Ca-antagonist nifedipine on endothelium-dependent vasodilation (EDV) in the forearm of hypertensive patients. Twenty-three middle-aged untreated hypertensive patients underwent evaluation of EDV and endothelium-independent vasodilation (EIDV) in the forearm, by means of local intra-arterial infusions of methacholine (MCh, evaluating EDV) and sodium-nitroprusside (SNP, evaluating EIDV), before and 1 h after intake of either captopril (25 mg) or nifedipine (10 mg) in a randomised, double-blind fashion. A matched normotensive control group was investigated at baseline conditions only. Five of the hypertensives were also evaluated after 3 months of treatment with captopril 25 mg twice daily in an open pilot study. First, the vasodilation induced by methacholine (MCh), but not SNP, was significantly attenuated in the hypertensive patients compared to the normotensive controls (P micr og/min, P < 0.01) but not SNP, while nifedipine did not significantly alter the response to either MCh or SNP. The improvement in vasodilator response to MCh induced by captopril was closely related to the reduction in BP (r = 0.72, P < 0.01). Third, in the pilot study, 3 months of captopril treatment induced a significant potentiation of the vasodilator response to MCh (+34+/-17%, MCh 4 microg/min, P < 0.05) in parallel with a significant BP reduction (-22+/-24/13+/-13 mm Hg, P < 0.05), while the response to SNP was unchanged. In conclusion, the present study confirmed that essential hypertension is associated with a defect in EDV. Furthermore, an improvement in EDV was seen in hypertensive patients shortly after administration of captopril, but not nifedipine. In addition, a significant beneficial effect on EDV was seen in a small pilot study during long-term treatment with captopril.

  14. Beta-adrenoceptor-mediated vasodilation of retinal blood vessels is reduced in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Nakazawa, Taisuke; Sato, Ayumi; Mori, Asami; Saito, Maki; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2008-01-01

    We investigated the effects of epinephrine and dopamine on retinal blood vessels in streptozotocin (STZ, 80 mg/kg, i.p.)-treated rats and age-matched control rats to determine whether diabetes mellitus alters the retinal vascular responses to circulating catecholamines. Experiments were performed 6-8 weeks after treatment with STZ or the vehicle. The fundus images were captured with the digital fundus camera system for small animals we developed and diameters of retinal blood vessels contained in the digital images were measured. Epinephrine increased the diameters of retinal blood vessels, but the vasodilator responses were reduced in diabetic rats. Dopamine produced a biphasic retinal vascular response with an initial vasoconstriction followed by a vasodilation. The vasoconstrictor effects of dopamine on retinal arterioles were enhanced in diabetic rats, whereas the difference between the two groups was abolished by treatment with propranolol. The vasodilator effect of isoproterenol, but not of the activator of adenylyl cyclase colforsin, on retinal blood vessels was reduced in diabetic rats. No difference in vasoconstriction of retinal blood vessels to phenylephrine between non-diabetic and diabetic rats was observed. The vasodilator responses of retinal blood vessels to 1,1-dimethyl-4-phenylpiperazinium, a ganglionic nicotinic receptor agonist, were also attenuated in diabetic rats. These results suggest that diabetes mellitus alters the retinal vascular responses to circulating catecholamines and the impairment of vasodilator responses mediated by beta-adrenoceptors contributes to the alteration.

  15. NONINVASIVE ASSESSMENT OF ENDOTHELIUM-DEPENDENT VASODILATION IN HYPERTENSIVE PATIENTS

    Institute of Scientific and Technical Information of China (English)

    张延斌; 黄宗明; 吴兰芬; 陈清枝

    2002-01-01

    Endothelial dysfunction plays an important role in the pathogenesis of coronary artery disease and is considered as an early manifestation of atherosclerosis. In the conduit arteries, a vasodilator response

  16. Pharmacological Effects of Niacin on Acute Hyperlipemia.

    Science.gov (United States)

    la Paz, Sergio Montserrat-de; Bermudez, Beatriz; Naranjo, M Carmen; Lopez, Sergio; Abia, Rocio; Muriana, Francisco J G

    2016-01-01

    The well-known changes in modern lifestyle habits including over nutrition and physical inactivity have led to striking adverse effects on public health (e.g., obesity, diabetes, and metabolic syndrome) over recent decades. One noticeable consequence is exaggerated and prolonged state of postprandial hyperlipemia due to the ingestion of multiple fat-enriched meals during the course of a day. Postprandial (non-fasting) hyperlipemia is characterized by increased blood levels of exogenous triglycerides (TG) in the form of apolipoprotein (apo) B48-containing TG-rich lipoproteins (TRL), which have a causal role in the pathogenesis and progression of cardiovascular disease (CVD). The cardiovascular benefits of lifestyle modification (healthy diet and exercise) and conventional lipid-lowering therapies (e.g., statins, fibrates, and niacin) could involve their favourable effects on postprandial metabolism. Pharmacologically, niacin has been used as an athero-protective drug for five decades. Studies have since shown that niacin may decrease fasting levels of plasma verylow- density lipoproteins (VLDL), low-density lipoprotein cholesterol (LDL-C), and lipoprotein [a] (Lp[a]), while may increase high-density lipoprotein cholesterol (HDL-C). Herein, the purpose of this review was to provide an update on effects and mechanisms related to the pharmacological actions of niacin on acute hyperlipemia.

  17. Pharmacological evidence that 5-HT1D activation induces renal vasodilation by NO pathway in rats.

    Science.gov (United States)

    García-Pedraza, José-Ángel; García, Mónica; Martín, María-Luisa; Morán, Asunción

    2015-06-01

    5-HT is a powerful vasoconstrictor substance in renal vasculature (mainly by 5-HT₂ activation). Nevertheless, 5-HT is notable for its dual cardiovascular effects, producing both vasodilator and vasoconstrictor actions. This study aimed to investigate whether, behind the predominant serotonergic vasoconstrictor action, THE 5-HT system may exert renal vasodilator actions, and, if so, characterize the 5-HT receptors and possible indirect pathways. Renal perfusion pressure (PP), systemic blood pressure (SBP) and heart rate (HR) measurement in in situ autoperfused rat kidney was determined in phenylephrine infused rats. Intra arterial (i.a.) bolus administration of 5-HT (0.00000125-0.1 μg/kg) decreased renal PP in the presence of a phenylephrine continuous infusion (phenylephrine-infusion group), without modifying SBP or HR. These vasodilator responses were potentiated by 5-HT₂ antagonism (ritanserin, 1 mg/kg i.v.), whereas the responses were abolished by 5-HT₁ /₇ antagonist (methiothepin, 100 μg/kg i.v.) or 5-HT1D antagonist (LY310762, 1 mg/kg i.v.). The i.a. administration (0.00000125 to 0.1 μg/kg) of 5-CT or L-694,247 (5-HT1D agonist) mimicked 5-HT vasodilator effect, while other agonists (1-PBG, α-methyl-5-HT, AS-19 (5-HT₇), 8-OH-DPAT (5-HT1A) or CGS-12066B (5-HT1B)) did not alter baseline haemodynamic variables. L-694,247 vasodilation was abolished by i.v. bolus of antagonists LY310762 (5-HT1D, 1 mg/kg) or L-NAME (nitric oxide, 10 mg/kg), but not by i.v. bolus of indomethacin (cyclooxygenase, 2 mg/kg) or glibenclamide (ATP-dependent K(+) channel, 20 mg/kg). These outcomes suggest that 5-HT1D activation produces a vasodilator effect in the in situ autoperfused kidney of phenylephrine-infusion rats mediated by the NO pathway.

  18. 冠脉造影术评价麝香保心丸对冠状动脉的扩张作用%Effect of Shexiang Baoxin Pill on Coronary Vasodilation by Analysis of Coronary Angiography

    Institute of Scientific and Technical Information of China (English)

    张现朝; 侯亚敏; 欧知宏

    2014-01-01

    目的 通过冠脉造影术(coronary angiography,CAG)评价麝香保心丸(Shexiang Baoxin Pill,SBP)对冠状动脉的扩张作用.方法 300例均为2013年1-7月行CAG患者,术前随机分为对照组及SBP组,行CAG后对照组合服安慰剂,SBP组合服SBP,5 min后即刻重复CAG.采用定量血管造影分析法计算血管直径,对冠脉正常患者,测量冠状动脉前降支,对冠脉狭窄患者,测量最狭窄血管处.分别比较两组服药前、后心率,血压及冠状动脉血管直径的变化.结果 两组心率、收缩压和舒张压服药前与服药后比较,差异无统计学意义(均P >0.05).2组CAG正常患者64例,其中对照组30例,SBP组34例,CAG显示狭窄患者236例,其中对照组110例,SBP组126例.SBP组患者不论CAG正常或异常服药后冠状动脉血管直径均较本组服药前明显增大(均P<0.01),与对照组同期比较,冠状动脉血管直径亦增大明显(P< 0.05,P<0.01).结论 SBP对正常冠状动脉血管及病变冠状动脉血管的均有扩张作用,并未引起心率增快及血压降低.%Objective To evaluate the effect of Shexiang Baoxin Pill (SBP) on coronary vasodilation by analysis of coronary angiography (CAG).Methods A consecutive cohort of 300 patients who underwent CAG between January 2013 and July 2013 were recruited and randomly assigned to 2 groups before operation.Patients in the SBP group sublingually took SBP,while those in the control group sublingually took placebos.All patients repeatedly underwent CAG 5 min after administration.The vascular diameter was calculated by quantitative angiography analysis method.The diameter of the left anterior descending coronary artery was measured in patients whose coronary arteries had no stenosis.The narrowest vascular diameter was measured in patients whose coronary arteries had stenosis.The heart rate,blood pressure,and the vascular diameter were compared between before and after administration in the two groups.Results In the two

  19. Soluble guanylate cyclase is required for systemic vasodilation but not positive inotropy induced by nitroxyl in the mouse.

    Science.gov (United States)

    Zhu, Guangshuo; Groneberg, Dieter; Sikka, Gautam; Hori, Daijiro; Ranek, Mark J; Nakamura, Taishi; Takimoto, Eiki; Paolocci, Nazareno; Berkowitz, Dan E; Friebe, Andreas; Kass, David A

    2015-02-01

    Nitroxyl (HNO), the reduced and protonated form of nitric oxide (NO·), confers unique physiological effects including vasorelaxation and enhanced cardiac contractility. These features have spawned current pharmaceutical development of HNO donors as heart failure therapeutics. HNO interacts with selective redox sensitive cysteines to effect signaling but is also proposed to activate soluble guanylate cyclase (sGC) in vitro to induce vasodilation and potentially enhance contractility. Here, we tested whether sGC stimulation is required for these HNO effects in vivo and if HNO also modifies a redox-sensitive cysteine (C42) in protein kinase G-1α to control vasorelaxation. Intact mice and isolated arteries lacking the sGC-β subunit (sGCKO, results in full sGC deficiency) or expressing solely a redox-dead C42S mutant protein kinase G-1α were exposed to the pure HNO donor, CXL-1020. CXL-1020 induced dose-dependent systemic vasodilation while increasing contractility in controls; however, vasodilator effects were absent in sGCKO mice whereas contractility response remained. The CXL-1020 dose reversing 50% of preconstricted force in aortic rings was ≈400-fold greater in sGCKO than controls. Cyclic-GMP and cAMP levels were unaltered in myocardium exposed to CXL-1020, despite its inotropic-vasodilator activity. In protein kinase G-1α(C42S) mice, CXL-1020 induced identical vasorelaxation in vivo and in isolated aortic and mesenteric vessels as in littermate controls. In both groups, dilation was near fully blocked by pharmacologically inhibiting sGC. Thus, sGC and cGMP-dependent signaling are necessary and sufficient for HNO-induced vasodilation in vivo but are not required for positive inotropic action. Redox modulation of protein kinase G-1α is not a mechanism for HNO-mediated vasodilation.

  20. 5-Hydroxytryptamine-induced vasodilator responses in the hindquarters of the anaesthetized rat, involve beta2-adrenoceptors.

    Science.gov (United States)

    Calama, E; García, M; Jarque, M J; Morán, A; Martín, M L; San Román, L

    2003-10-01

    These studies were conducted to examine the role of the vasoactive mediators nitric oxide (NO) and adrenaline (epinephrine) in the serotonin (5-hydroxytryptamine; 5-HT)-induced vasodilator response in the hindquarter vascular bed of anaesthetized rats. Intra-arterial administration of doses of 5-HT in the range 0.12-25 ng kg(-1) produced a dose-independent vasodilator effect in the hindquarters. The selective 5-HT(1D/1B) receptor agonist, L-694,247 at intra-arterial doses of 0.0012-1000 ng kg(-1), as well as adrenaline (at doses of 0.05-50 ng kg(-1) i.a.), mimicked the dose-independent vasodilator effect induced by intra-arterial administration of 5-HT. Intravenous pre-treatment with the selective beta2-receptor antagonist ICI 118,551 (0.5 mg kg(-1)) blocked the vasodilator effect of 5-HT, adrenaline and L-694,247. Additionally, the inhibitor of NO synthase NG-nitro-L-arginine (L-NAME) (at a dose of 10 mg kg(-1) i.v.) blocked the vasodilator action of acetylcholine 300-3000 ng kg(-1)) but did not modify 5-HT-induced vasodilatation. The vasodilator effect produced by intra-arterial administration of 5-HT in the hindquarters was significantly inhibited both 30 min after denervation of the lumbar sympathetic chains and 1 h after bilateral adrenalectomy. Our data suggest that in the in-situ autoperfused hindquarters of the rat 5-HT-induced vasodilatation is mediated by a local 5-HT(1D) or 5-HT(1D/1B) activation, which in turn mediates the adrenal release of adrenaline, which then produces beta2-activation and vasodilatation.

  1. Antioxidant and Vasodilator Activity of Ugni molinae Turcz. (Murtilla) and Its Modulatory Mechanism in Hypotensive Response

    Science.gov (United States)

    Jofré, Ignacio; Pezoa, Cesar; Scheuermann, Erick; Rosalen, Pedro Luiz; Romero, Fernando

    2016-01-01

    Hypertension is a systemic condition with high morbidity and mortality rates worldwide, which poses an increased risk for cardiovascular diseases. In this study, we demonstrated the antioxidant and vasodilator activity of Ugni molinae Turcz. (Murtilla) fruit, a berry native to Chile and proposed models to explain its modulatory mechanism in hypotensive response. Murtilla fruits were cultivated in a germplasm bank and submitted to chemical and biological analyses. The phenolic compounds gallic acid, Catechin, Quercetin-3-β-D-glucoside, Myricetin, Quercetin, and Kaempferol were identified. Murtilla extract did not generate toxic effects on human endothelial cells and had significant antioxidant activity against ROS production, lipid peroxidation, and superoxide anion production. Furthermore, it showed dose-dependent vasodilator activity in aortic rings in the presence of endothelium, whose hypotensive mechanism is partially mediated by nitric oxide synthase/guanylate cyclase and large-conductance calcium-dependent potassium channels. Murtilla fruits might potentially have beneficial effects on the management of cardiovascular diseases. PMID:27688827

  2. Effects of Kangshen Oral Liquid on Gentamicin-induced Acute ...

    African Journals Online (AJOL)

    Purpose: To investigate the effects of Kangshen oral liquid (KSOL) on gentamicin sulfate (GS)-induced acute kidney injury ..... Upon GS administration, several physiological markers are .... Kara A, Bozkurt A. The protective effect of taurine.

  3. Acute effects of solar particle event radiation

    Science.gov (United States)

    Kennedy, Ann R.; Weissman, Drew; Sanzari, Jenine K.; Krigsfeld, Gabriel S.; Wan, X. Steven; Romero-Weaver, Ana L.; Diffenderfer, Eric S.; Lin, L.; Cengel, K.

    2014-01-01

    A major solar particle event (SPE) may place astronauts at significant risk for the acute radiation syndrome (ARS), which may be exacerbated when combined with other space flight stressors, such that the mission or crew health may be compromised. The National Space Biomedical Research Institute (NSBRI) Center of Acute Radiation Research (CARR) is focused on the assessment of risks of adverse biological effects related to the ARS in animals exposed to space flight stressors combined with the types of radiation expected during an SPE. The CARR studies are focused on the adverse biological effects resulting from exposure to the types of radiation, at the appropriate energies, doses and dose-rates, present during an SPE (and standard reference radiations: gamma rays or electrons). All animal studies described have been approved by the University of PA IACUC. Some conclusions from recent CARR investigations are as follows: (i) the relative biological effectiveness (RBE) values for SPE-like protons compared with standard reference radiations (gammas or electrons) for white blood cells (WBCs) vary greatly between mice, ferrets and pigs, with the RBE values being greater in ferrets than those in mice, and considerably greater in pigs compared with those in ferrets or mice [1, 2]. This trend for the data suggests that the RBE values for WBCs in humans could be considerably greater than those observed in small mammals, and SPE proton radiation may be far more hazardous to humans than previously estimated from small animal studies. (ii) Very low doses of SPE proton radiation (25 cGy) increase blood clotting times in ferrets, and the low SPE-like dose rate has more severe effects than high dose rate radiation [3]. (iii) Results from pig and ferret studies suggest that disseminated intravascular coagulation is a major cause of death at doses near the LD50 level for SPE-like proton and gamma radiation. (iv) Exposure to SPE-like proton or gamma radiation, in combination with

  4. Glucagon-like peptide-1 elicits vasodilation in adipose tissue and skeletal muscle in healthy men.

    Science.gov (United States)

    Asmar, Ali; Asmar, Meena; Simonsen, Lene; Madsbad, Sten; Holst, Jens J; Hartmann, Bolette; Sorensen, Charlotte M; Bülow, Jens

    2017-02-01

    In healthy subjects, we recently demonstrated that during acute administration of GLP-1, cardiac output increased significantly, whereas renal blood flow remained constant. We therefore hypothesize that GLP-1 induces vasodilation in other organs, for example, adipose tissue, skeletal muscle, and/or splanchnic tissues. Nine healthy men were examined twice in random order during a 2-hour infusion of either GLP-1 (1.5 pmol kg(-1) min(-1)) or saline. Cardiac output was continuously estimated noninvasively concomitantly with measurement of intra-arterial blood pressure. Subcutaneous, abdominal adipose tissue blood flow (ATBF) was measured by the (133)Xenon clearance technique. Leg and splanchnic blood flow were measured by Fick's Principle, using indocyanine green as indicator. In the GLP-1 study, cardiac output increased significantly together with a significant increase in arterial pulse pressure and heart rate compared with the saline study. Subcutaneous, abdominal ATBF and leg blood flow increased significantly during the GLP-1 infusion compared with saline, whereas splanchnic blood flow response did not differ between the studies. We conclude that in healthy subjects, GLP-1 increases cardiac output acutely due to a GLP-1-induced vasodilation in adipose tissue and skeletal muscle together with an increase in cardiac work.

  5. Lipid Emulsion Inhibits Vasodilation Induced by a Toxic Dose of Bupivacaine via Attenuated Dephosphorylation of Myosin Phosphatase Target Subunit 1 in Isolated Rat Aorta.

    Science.gov (United States)

    Ok, Seong-Ho; Byon, Hyo-Jin; Kwon, Seong-Chun; Park, Jungchul; Lee, Youngju; Hwang, Yeran; Baik, Jiseok; Choi, Mun-Jeoung; Sohn, Ju-Tae

    2015-01-01

    Lipid emulsions are widely used for the treatment of systemic toxicity that arises from local anesthetics. The goal of this in vitro study was to examine the cellular mechanism associated with the lipid emulsion-mediated attenuation of vasodilation induced by a toxic dose of bupivacaine in isolated endothelium-denuded rat aorta. The effects of lipid emulsion on vasodilation induced by bupivacaine, mepivacaine, and verapamil were assessed in isolated aorta precontracted with phenylephrine, the Rho kinase stimulant NaF, and the protein kinase C activator phorbol 12,13-dibutyrate (PDBu). The effects of Rho kinase inhibitor Y-27632 on contraction induced by phenylephrine or NaF were assessed. The effects of bupivacaine on intracellular calcium concentrations ([Ca(2+)]i) and tension induced by NaF were simultaneously measured. The effects of bupivacaine alone and lipid emulsion plus bupivacaine on myosin phosphatase target subunit 1 (MYPT1) phosphorylation induced by NaF were examined in rat aortic vascular smooth muscle cells. In precontracted aorta, the lipid emulsion attenuated bupivacaine-induced vasodilation but had no effect on mepivacaine-induced vasodilation. Y-27632 attenuated contraction induced by either phenylephrine or NaF. The lipid emulsion attenuated verapamil-induced vasodilation. Compared with phenylephrine-induced precontracted aorta, bupivacaine-induced vasodilation was slightly attenuated in NaF-induced precontracted aorta. The magnitude of the bupivacaine-induced vasodilation was higher than that of a bupivacaine-induced decrease in [Ca(2+)]i. Bupivacaine attenuated NaF-induced MYPT1 phosphorylation, whereas lipid emulsion pretreatment attenuated the bupivacaine-induced inhibition of MYPT1 phosphorylation induced by NaF. Taken together, these results suggest that lipid emulsions attenuate bupivacaine-induced vasodilation via the attenuation of inhibition of MYPT1 phosphorylation evoked by NaF.

  6. Single-walled carbon nanotubes (SWCNTs) induce vasodilation in isolated rat aortic rings.

    Science.gov (United States)

    Gutiérrez-Hernández, J M; Ramirez-Lee, M A; Rosas-Hernandez, H; Salazar-García, S; Maldonado-Ortega, D A; González, F J; Gonzalez, C

    2015-06-01

    Single-walled carbon nanotubes (SWCNTs) are used in biological systems with impact in biomedicine in order to improve diagnostics and treatment of diseases. However, their effects upon the vascular system, are not fully understood. Endothelium and smooth muscle cells (SMC) communicate through release of vasoactive factors as nitric oxide (NO) to maintain vascular tone. The aim of this study was to evaluate the effect of SWCNTs on vascular tone using isolated rat aortic rings, which were exposed to SWCNTs (0.1, 1 and 10 μg/mL) in presence and absence of endothelium. SWCNTs induced vasodilation in both conditions, indicating that this effect was independent on endothelium; moreover that vasodilation was NO-independent, since its blockage with L-NAME did not modify the observed effect. Together, these results indicate that SWCNTs induce vasodilation in the macrovasculature, may be through a direct interaction with SMC rather than endothelium independent of NO production. Further investigation is required to fully understand the mechanisms of action and mediators involved in the signaling pathway induced by SWCNTs on the vascular system.

  7. 血管扩张剂联合速尿治疗顽固性心力衰竭的临床效果研究%Vasodilator combined furosemide treatment of intractable heart failure clinical effectiveness research

    Institute of Scientific and Technical Information of China (English)

    张钰彬

    2013-01-01

    Objective:To study the analysis of vasodilator used in combination with furosemide refractory heart failure treatment.Methods:November 201 2 November 201 3 during my hospital to receive treatment 72 patients with refractory heart failure,according to the different treatment methods randomness wil be divided into two groups,one group received conventional therapy as control group,a while in the conventional treatment group vasodilator combination therapy with furosemide to the obG servation group.Result:The clinical response rate was significantly higher than the 94.44% 5 5 .5 6 %,respectively,P<0.05 considered statistical y significant.Conclusion:Vasodilator used in combination with furosemide treatment refractory heart failure and achieved satisfactory results,clinical application of higher value.%目的:研究分析血管扩张剂与速尿联合应用于顽固性心力衰竭的治疗效果.方法:选取2012年11月-2013年11月期间我院接收治疗的顽固性心力衰竭72例患者,根据治疗方法不同随机性将其分成两组,一组采取常规方法治疗设为对照组,一组在常规治疗的同时血管扩张剂与速尿联合治疗设为观察组.结果:观察组临床有效率是94.44%明显高于对照组的55.56%,差异 P<0.05统计学意义.结论:血管扩张剂与速尿联合用于顽固性心力衰竭的治疗取得了满意效果,临床推广应用价值较高.

  8. Role of nitric oxide in adenosine-induced vasodilation in humans

    Science.gov (United States)

    Costa, F.; Biaggioni, I.; Robertson, D. (Principal Investigator)

    1998-01-01

    Vasodilation is one of the most prominent effects of adenosine and one of the first to be recognized, but its mechanism of action is not completely understood. In particular, there is conflicting information about the potential contribution of endothelial factors. The purpose of this study was to explore the role of nitric oxide in the vasodilatory effect of adenosine. Forearm blood flow responses to intrabrachial adenosine infusion (125 microg/min) were assessed with venous occlusion plethysmography during intrabrachial infusion of saline or the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (L-NMMA) (12.5 mg/min). Intrabrachial infusions of acetylcholine (50 microg/min) and nitroprusside (3 microg/min) were used as a positive and negative control, respectively. These doses were chosen to produce comparable levels of vasodilation. In a separate study, a second saline infusion was administered instead of L-NMMA to rule out time-related effects. As expected, pretreatment with L-NMMA reduced acetylcholine-induced vasodilation; 50 microg/min acetylcholine increased forearm blood flow by 150+/-43% and 51+/-12% during saline and L-NMMA infusion, respectively (Pvasodilation is not mediated by nitric oxide in the human forearm.

  9. Differential time course of the vasodilator action of various calcium antagonists.

    Science.gov (United States)

    van der Lee, R; Kam, K L; Pfaffendorf, M; van Zwieten, P A

    1998-01-01

    It is rather the rate of the vasodilator effect than its magnitude which determines the triggering of reflex tachycardia associated with dihydropyridine calcium antagonists (DHP-CA). We therefore compared the rate of the vasodilator effects of a series of CA (both DHP and non-DHP) in rat isolated mesenteric artery preparations (size 256 +/- 3 microns, length 2 mm) from male Wistar rats (weighing 300-350 g) in an isolated wire myograph according to Mulvany and Halpern [12]. The mean force of the KCl-induced contraction amounted to 2.3 +/- 0.1 mN/mm. Potency (given as IC50-values), differential time course of action and recovery of the contractile response of the vessels after wash-out were established. These three parameters adhere to the following sequences: (1. potency) barnidipine [corrected] > (S)-lercanidipine > barnidipine racemate [corrected]> amlodipine > nifedipine, lacidipine > (R)-lercanidipine > verapamil, mibefradil; (2. differential time course) lacidipine, amlodipine > (S)- and (R)-lercanidipine, barnidipine [corrected], barnidipine racemate [corrected] > mibefradil, verapamil, nifedipine; (3. recovery) nifedipine > verapamil, barnidipine [corrected], amlodipine > barnidipine, lacidipine > mibefradil, (R)-lercanidipine > (S)-lercanidipine. In conclusion, barnidipine [corrected] proved to be the most potent vasodilator agent; interestingly, barnidipine was 20 times less potent when applied as a racemic mixture. A slow onset of action in DHP is a very important mechanism in preventing reflex tachycardia. For non-DHP (verapamil, mibefradil) reflex tachycardia probably is prevented by a direct effect on the conductive tissue in the myocardium.

  10. Local tetrahydrobiopterin administration augments reflex cutaneous vasodilation through nitric oxide-dependent mechanisms in aged human skin.

    Science.gov (United States)

    Stanhewicz, Anna E; Bruning, Rebecca S; Smith, Caroline J; Kenney, W Larry; Holowatz, Lacy A

    2012-03-01

    Functional constitutive nitric oxide synthase (NOS) is required for full expression of reflex cutaneous vasodilation that is attenuated in aged skin. Both the essential cofactor tetrahydrobiopterin (BH(4)) and adequate substrate concentrations are necessary for the functional synthesis of nitric oxide (NO) through NOS, both of which are reduced in aged vasculature through increased oxidant stress and upregulated arginase, respectively. We hypothesized that acute local BH(4) administration or arginase inhibition would similarly augment reflex vasodilation in aged skin during passive whole body heat stress. Four intradermal microdialysis fibers were placed in the forearm skin of 11 young (22 ± 1 yr) and 11 older (73 ± 2 yr) men and women for local infusion of 1) lactated Ringer, 2) 10 mM BH(4), 3) 5 mM (S)-(2-boronoethyl)-l-cysteine + 5 mM N(ω)-hydroxy-nor-l-arginine to inhibit arginase, and 4) 20 mM N(G)-nitro-l-arginine methyl ester (l-NAME) to inhibit NOS. Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasodilation was induced. After a 1.0°C rise in oral temperature (T(or)), mean body temperature was clamped and 20 mM l-NAME was perfused at each site. Cutaneous vascular conductance was calculated (CVC = LDF/mean arterial pressure) and expressed as a percentage of maximum (%CVC(max); 28 mM sodium nitroprusside and local heat, 43°C). Vasodilation was attenuated at the control site of the older subjects compared with young beginning at a 0.3°C rise in T(or). BH(4) and arginase inhibition both increased vasodilation in older (BH(4): 55 ± 5%; arginase-inhibited: 47 ± 5% vs. control: 37 ± 3%, both P 0.05) at a 1°C rise in T(or). With a 1°C rise in T(or), local BH(4) increased NO-dependent vasodilation in the older (BH(4): 31.8 ± 2.4%CVC(max) vs. control: 11.7 ± 2.0%CVC(max), P vasodilation in aged human skin and that BH(4) NOS coupling mechanisms may be a potential therapeutic target for increasing skin blood flow during

  11. An unusual adverse effect of sildenafil citrate: acute myocardial infarction in a nitrate-free patient.

    Science.gov (United States)

    Cakmak, Huseyin Altug; Ikitimur, Baris; Karadag, Bilgehan; Ongen, Zeki

    2012-10-19

    Myocardial infarction (MI) associated with sildenafil citrate is seen rarely in patients without any history of coronary artery disease. We report a nitrate-free patient with a history of cardiovascular risk factors who developed acute MI after taking sildenafil. A 44-year-old man diagnosed with acute anterior ST segment elevation MI 120 min after self-administration of 150 mg sildenafil was admitted before attempting any sexual intercourse. The coronary angiography revealed 99% occlusion of the left anterior descending artery (LAD) and a bare-metal stent was implanted. He was discharged after 5 days without any complication. Sildenafil may cause coronary steal or may lead to vasodilation causing hypotension in patient with pre-existing cardiovascular disease, especially in patients on nitrate therapy. Our patient was nitrate free, with normal blood pressure values. Emotional stimulation associated with anticipated sexual activity may have been a triggering factor for vulnerable coronary plaque rupture.

  12. Vasodilative effect and the underlying mechanism of gingerol on isolated thoracic aorta ring of rabbits%姜酚对家兔胸主动脉平滑肌的舒张作用及其机制

    Institute of Scientific and Technical Information of China (English)

    金燕; 赵文超; 王志举

    2015-01-01

    Objective To observe the effect of gingerol on the isolated thoracic aorta ring of rabbits and investigate its underlying mechanisms.Methods The thoracic aortic ring muscle strips with intact and denuded endothelium were prepared and placed in an organ chamber containing physiological salt solution (PSS).Every strip was connected to the tension transducer and the change of the vascular ring tension was recorded and analyzed by the biological signal collection and analysis computer system.Th isotonic tension of thoracic aortic tings with intact and denuded endothelium precontracted by norepinephrine (NE,1 × 10-5 mol/L) or KCl (20 mmol/L) was recorded before and after administrating gingerol.Meanwhile,we also observed the effects of N-nitro-L-arginine methyl ester (L-NAME,1 × 10-4 mol/L) and indomethacin (1 × 10-8 mol/L) on the action of gingerol in the rings.Results (1) Administration of 1 × 10-5 mol/L NE or 20 mmol/L KCl could produce the contraction effect in the thoracic aortic rings with intact endothelium.gingerol induced the muscle relaxation of aorta in both intact and denuded endothelium groups in a dose-dependant manner,meanwhile,the relaxation effect of gingerol was stronger in intact endothelium group than that in denuded endothelium group (P < 0.05).(2) L-NAME could inhibit the vasodilative role caused by gingerol in intact endothelium group (%,94.83 ±3.63 vs.96.83 ± 1.82,91.17 ± 2.89 vs.94.83 ± 2.68,83.83 ± 2.23 vs.94.67 ± 2.7,78.00 ± 3.54 vs.92.33 ± 2.91,67.83 ± 2.37 vs.90.83 ±3.77,62.83 ±3.42 vs.89.67 ±3.15 respectively in NE-treated group and 90.33 ± 8.33 vs.98.17±7.56,80.83 ±7.24 vs.96.83 ±7.28,70.83±7.57 vs.92.17±7.31,67.83 ±7.68 vs.89.83 ± 7.23,62.83 ± 7.49 vs.90.33 ± 8.87,57.33 ± 8.32 vs.87.67 ± 8.97 respectively in KCl-treated group,P < 0.05).(3) Indomethacin could inhibit the vasodilative role caused by gingerol in intact endothelium group (%,93.83 ± 7.61 vs.97.83 ± 7.45,92.50 ± 10.13 vs.95.33 ± 8

  13. Liposomal nanoparticles encapsulating iloprost exhibit enhanced vasodilation in pulmonary arteries.

    Science.gov (United States)

    Jain, Pritesh P; Leber, Regina; Nagaraj, Chandran; Leitinger, Gerd; Lehofer, Bernhard; Olschewski, Horst; Olschewski, Andrea; Prassl, Ruth; Marsh, Leigh M

    2014-01-01

    Prostacyclin analogues are standard therapeutic options for vasoconstrictive diseases, including pulmonary hypertension and Raynaud's phenomenon. Although effective, these treatment strategies are expensive and have several side effects. To improve drug efficiency, we tested liposomal nanoparticles as carrier systems. In this study, we synthesized liposomal nanoparticles tailored for the prostacyclin analogue iloprost and evaluated their pharmacologic efficacy on mouse intrapulmonary arteries, using a wire myograph. The use of cationic lipids, stearylamine, or 1,2-di-(9Z-octadecenoyl)-3-trimethylammonium-propane (DOTAP) in liposomes promoted iloprost encapsulation to at least 50%. The addition of cholesterol modestly reduced iloprost encapsulation. The liposomal nanoparticle formulations were tested for toxicity and pharmacologic efficacy in vivo and ex vivo, respectively. The liposomes did not affect the viability of human pulmonary artery smooth muscle cells. Compared with an equivalent concentration of free iloprost, four out of the six polymer-coated liposomal formulations exhibited significantly enhanced vasodilation of mouse pulmonary arteries. Iloprost that was encapsulated in liposomes containing the polymer polyethylene glycol exhibited concentration-dependent relaxation of arteries. Strikingly, half the concentration of iloprost in liposomes elicited similar pharmacologic efficacy as nonencapsulated iloprost. Cationic liposomes can encapsulate iloprost with high efficacy and can serve as potential iloprost carriers to improve its therapeutic efficacy.

  14. Polyunsaturated fatty acids are cerebral vasodilators via the TREK-1 potassium channel.

    Science.gov (United States)

    Blondeau, Nicolas; Pétrault, Olivier; Manta, Stella; Giordanengo, Valérie; Gounon, Pierre; Bordet, Régis; Lazdunski, Michel; Heurteaux, Catherine

    2007-07-20

    Vessel occlusion is the most frequent cause for impairment of local blood flow within the brain resulting in neuronal damage and is a leading cause of disability and death worldwide. Polyunsaturated fatty acids and especially alpha-linolenic acid improve brain resistance against cerebral ischemia. The purpose of the present study was to evaluate the effects of polyunsaturated fatty acids and particularly alpha-linolenic acid on the cerebral blood flow and on the tone of vessels that regulate brain perfusion. alpha-Linolenic acid injections increased cerebral blood flow and induced vasodilation of the basilar artery but not of the carotid artery. The saturated fatty acid palmitic acid did not produce vasodilation. This suggested that the target of the polyunsaturated fatty acids effect was the TREK-1 potassium channel. We demonstrate the presence of this channel in basilar but not in carotid arteries. We show that vasodilations induced by the polyunsaturated fatty acid in the basilar artery as well as the laser-Doppler flow increase are abolished in TREK-1(-/-) mice. Altogether these data indicate that TREK-1 activation elicits a robust dilation that probably accounts for the increase of cerebral blood flow induced by polyunsaturated fatty acids such as alpha-linolenic acid or docosahexanoic acid. They suggest that the selective expression and activation of TREK-1 in brain collaterals could play a significant role in the protective mechanisms of polyunsaturated fatty acids against stroke by providing residual circulation during ischemia.

  15. ADP is a vasodilator component from Lasiodora sp. mygalomorph spider venom.

    Science.gov (United States)

    Horta, C C; Rezende, B A; Oliveira-Mendes, B B R; Carmo, A O; Capettini, L S A; Silva, J F; Gomes, M T; Chávez-Olórtegui, C; Bravo, C E S; Lemos, V S; Kalapothakis, E

    2013-09-01

    Members of the spider genus Lasiodora are widely distributed in Brazil, where they are commonly known as caranguejeiras. Lasiodora spider venom is slightly harmful to humans. The bite of this spider causes local pain, edema and erythema. However, Lasiodora sp. spider venom may be a source of important pharmacological tools. Our research group has described previously that Lasiodora sp. venom produces bradycardia in the isolated rat heart. In the present work, we sought to evaluate the vascular effect of Lasiodora sp. venom and to isolate the vasoactive compounds from the venom. The results showed that Lasiodora spider venom induced a concentration-dependent vasodilation in rat aortic rings, which was dependent on the presence of a functional endothelium and abolished by the nitric oxide synthase (NOS) inhibitor L-NAME. Western blot experiments revealed that the venom also increased endothelial NOS function by increasing phosphorylation of the Ser¹¹⁷⁷ residue. Assay-directed fractionation isolated a vasoactive fraction from Lasiodora sp. venom. Mass spectrometry (MS) and nuclear magnetic resonance (NMR) assays identified a mixture of two compounds: adenosine diphosphate (ADP, approximately 90%) and adenosine monophosphate (AMP, approximately 10%). The vasodilator effects of Lasiodora sp. whole venom, as well as ADP, were significantly inhibited by suramin, which is a purinergic P2-receptor antagonist. Therefore, the results of the present work indicate that ADP is a main vasodilator component of Lasiodora sp. spider venom.

  16. Vasodilation and muscle pump contribution to immediate exercise hyperemia.

    Science.gov (United States)

    Tschakovsky, M E; Shoemaker, J K; Hughson, R L

    1996-10-01

    A rapid (within 0-5 s) increase in skeletal muscle blood flow has been demonstrated following muscle contraction, yet the mechanism remains unresolved. Recently, it was suggested that the entire rapid exercise hyperemia could be attributed to the mechanical muscle pump effect. Other evidence indicates that the muscle pump cannot increase arterial flow. We measured human forearm blood flow with the arm positioned above or below heart level during 1) simulation of rhythmic muscle pump function via repeated inflation/deflation of a forearm cuff to 100 mmHg to achieve mechanical emptying of forearm veins, and 2) 1-s single-cuff inflations, 1-s voluntary forearm contractions, and 1-s contractions performed within a cuff inflation. Rhythmic cuff inflation increased blood flow with the arm below heart level (P mechanical venous emptying (7.7 +/- 0.7 ml.100 ml(-1) min(-1)) could account for 60% of the peak flow increase due to muscle contraction (12.8 +/- 1.0 ml.100 ml(-1).min(-1)) with the arm below heart level, whereas above heart level mechanical venous emptying accounted for 46% of the flow increase due to contraction (3.0 +/- 0.4 vs. 6.5 +/- 0.6 ml.100 ml(-1).min(-1)). We conclude that a functional muscle pump does exist in the human forearm in vivo, but that a rapid vasodilation detectable within 2 s also contributes to the early exercise hyperemia.

  17. TRPC3 is involved in flow- and bradykinin-induced vasodilation in rat small mesenteric arteries

    Institute of Scientific and Technical Information of China (English)

    Cui-ling LIU; Yu HUANG; Ching-yuen NGAI; Yuk-ki LEUNG; Xiao-qiang YAO

    2006-01-01

    Aim: To test the possible involvement of TRPC3 in agonist-induced relaxation and flow-induced vasodilation in rat small mesenteric arteries. Methods: Male Sprague-Dawley rats were used in the present study. After 72 h-treatment of antisense oligo via tail vein injection, isometric tension and isobaric diameter measurement were carried out with isolated mesenteric artery segments by using either a Pressure Myograph or a Multi Myograph system. Endothelial [Ca2+]i changes were measured with a MetaFluor imaging system in response to flow or to 30 nmol/L bradykinin. Results: Immunohistochemical study showed that the 72 h-treatment of antisense oligo via tail vein injection markedly decreased the TRPC3 expression in mesenteric arteries, indicating the effectiveness of the antisense oligo. Isometric tension and isobaric diameter measurement showed that, although the antisense oligo treatment did not affect histamine-, ATP-, and CPA-induced relaxation, it did reduce the magnitude of flow-induced vasodilation by approximately 13% and decreased bradykinin-induced vascular relaxation with its EC50 value raised by nearly 3-fold. Endothelial [Ca2+]i measurement revealed that treatment of the arteries with antisense oligos significantly attenuated the magnitude of endothelial [Ca2+]i rise in response to flow and to 30 nmol/L bradykinin. Conclusion: The results suggest that TRPC3 is involved in flow- and bradykinin-induced vasodilation in rat small mesenteric arteries probably by mediating the Ca2+ influx into endothelial cells.

  18. Hemodynamic effects of acute digitalization several months after acute myocardial infarction.

    Science.gov (United States)

    Ressl, J; Jandová, R; Jebavý, P; Kasalický, J; Widimský, J

    1975-01-01

    Left ventricular function was investigated at rest and during exercise by heart catheterization in 15 patients 3-5 months after acute myocardial infarction. The effect of 1 mg digoxin i.v. in ten patients was correlated to placebo (saline solution) in five patients. A significant decrease of the left ventricular enddiastolic pressure, increase of left ventricular systolic ejection fraction and a shift of the left ventricular function curve to left upwards was found after digoxin with no changes in the placebo group. This beneficial effect of acute digitalization in patients convalescing from uncomplicated myocardial infarction without clinical signs of manifest heart failure could have therapeutic implication.

  19. Contribution of nitric oxide synthase isoforms to cholinergic vasodilation in murine retinal arterioles.

    Science.gov (United States)

    Gericke, Adrian; Goloborodko, Evgeny; Sniatecki, Jan J; Steege, Andreas; Wojnowski, Leszek; Pfeiffer, Norbert

    2013-04-01

    wild-type mice. Remarkably, in both genotypes, vasodilation to acetylcholine was negligible after incubation with l-NAME. In contrast, pharmacological inhibition of nNOS and iNOS had no effect on acetylcholine-induced vasodilation. These findings suggest that dilation of murine retinal arterioles to acetylcholine is mediated predominantly by eNOS.

  20. A critical role for astrocytes in hypercapnic vasodilation in brain

    DEFF Research Database (Denmark)

    Howarth, C; Sutherland, B A; Choi, H B

    2017-01-01

    increases in astrocyte calcium signaling which in turn stimulates COX-1 activity and generates downstream PgE2 production. We demonstrate that astrocyte calcium-evoked production of the vasodilator, PgE2, is critically dependent on brain levels of the antioxidant, glutathione. These data suggest a novel...

  1. NO donors, part 8 [1]: synthesis and vasodilating activities of substituted benzylnitrates compared to cyclohexylmethylnitrate and GTN.

    Science.gov (United States)

    Wessler, Christoph; Homann, Alexander; Fricke, Uwe; Lehmann, Jochen

    2003-06-01

    A series of substituted benzylnitrates (1) and the formally but not chemically similar cyclohexylmethylnitrate (CHMN) have been synthesised. Vasodilating activities were measured on endothelium-intact and N(G)-nitro-L-arginine (L-NNA)-blocked porcine right coronary arteries, precontracted with prostaglandin F(2alpha) (PGF(2alpha)). Glyceroltrinitrate (GTN) was used as reference. In intact coronary arteries the vasodilating activities of all benzylnitrates are lower compared with GTN, but higher compared with CHMN. However, blocking the function of the endothelium by L-NNA, the activity of all benzylnitrates increased, whereas that of CHMN and GTN remained nearly unaffected. Under these conditions, the mononitrates 4-nitro-benzylnitrate (1c) and 4-nitrooxymethyl-benzonitrile (1h) even showed higher vasodilator activities than the trinitrate GTN and in general, vasorelaxation by the benzylnitrates as defined by the concentrations for half maximal effects (EC(50) values) was found to be 2-3 orders of magnitude higher than that induced by CHMN. The study demonstrates that the in vitro activities of organic nitrates do not correlate with the number of nitrate groups within the molecule nor to the lipophilicity of the molecules. Instead, vasodilator activity is highly sensitive to the structure and the type of the substituents in the molecular carrier of the nitrate group.

  2. Effects of a high blood glucose fluctuation on endothelium-dependent vasodilation function in diabetic rats%血糖波动对糖尿病大鼠血管内皮依赖性舒张功能的影响

    Institute of Scientific and Technical Information of China (English)

    廖洁; 雷闽湘; 陈雄; 胡维; 王爱民

    2012-01-01

    Objective To investigate the effects of a blood glucose fluctuation on endothelium-dependent vasodilation function in diabetic rats. Method The 60 SD rats were assigened into normal control group, sustained high blood glucose group and blood glucose fluctuation group. Blood glucose fluctuations were induced by insulin subcutaneous injection twice daily. Three months after intervention, aorta was extracted for endothelium- dependent vasodilation function measurement, and NO was measured by Griess reactioa The protein of PI3K, Akt and eNOS were measured by Western blot Result An endothelium-dependent vasodilation function and NO production were significantly decreased in high blood glucose fluctuation group versus sustained high blood glucose group(P<0. 05). PI3K-P85, phosphorylation of eNOS-Serll77 and AktSer473 in intermittent high glucose group were significantly lower than in constant high glucose group(P<0. 05) Conclusion These findings suggest that variability in glycemic control could attenuated endothelium-dependent vasodilation function by inhibiting PI3K/Akt/eNOS pathway.%目的 观察比较血糖波动对糖尿病大鼠血管内皮依赖舒张功能的影响及其初步机制.方法 60只SD大鼠随机分成正常组、持续组和血糖波动组.血糖波动组每日2次皮下注射胰岛素的方法诱导血糖波动.干预12周后处死大鼠,取各组大鼠主动脉测离体舒张功能、NO浓度及Western blot方法检测PI3K、蛋白激酶B(PKB/Akt)、内皮型一氧化氮合酶(eNOS)蛋白表达水平. 结果 波动组和持续组大鼠胸主动脉内皮依赖性血管舒张功能低于正常组(P<0.01),波动组又明显低于持续组(P<0.05);波动组及持续高血糖组的NO浓度、PI3K及磷酸化Akt、eNOS蛋白表达水平均较正常组显著下调(P<0.01),而波动组又显著低于持续组(P<0.05). 结论 长期血糖波动可以明显引起糖尿病大鼠血管内皮依赖性舒张功能下降,可能与抑制PI3K/Akt/eNOS

  3. Liposomal nanoparticles encapsulating iloprost exhibit enhanced vasodilation in pulmonary arteries

    Directory of Open Access Journals (Sweden)

    Jain PP

    2014-07-01

    Full Text Available Pritesh P Jain,1 Regina Leber,1,2 Chandran Nagaraj,1 Gerd Leitinger,3 Bernhard Lehofer,4 Horst Olschewski,1,5 Andrea Olschewski,1,6 Ruth Prassl,1,4 Leigh M Marsh11Ludwig Boltzmann Institute for Lung Vascular Research, 2Biophysics Division, Institute of Molecular Biosciences, University of Graz, 3Research Unit Electron Microscopic Techniques, Institute of Cell Biology, Histology, and Embryology, 4Institute of Biophysics, 5Division of Pulmonology, Department of Internal Medicine, 6Department of Anesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, AustriaAbstract: Prostacyclin analogues are standard therapeutic options for vasoconstrictive diseases, including pulmonary hypertension and Raynaud’s phenomenon. Although effective, these treatment strategies are expensive and have several side effects. To improve drug efficiency, we tested liposomal nanoparticles as carrier systems. In this study, we synthesized liposomal nanoparticles tailored for the prostacyclin analogue iloprost and evaluated their pharmacologic efficacy on mouse intrapulmonary arteries, using a wire myograph. The use of cationic lipids, stearylamine, or 1,2-di-(9Z-octadecenoyl-3-trimethylammonium-propane (DOTAP in liposomes promoted iloprost encapsulation to at least 50%. The addition of cholesterol modestly reduced iloprost encapsulation. The liposomal nanoparticle formulations were tested for toxicity and pharmacologic efficacy in vivo and ex vivo, respectively. The liposomes did not affect the viability of human pulmonary artery smooth muscle cells. Compared with an equivalent concentration of free iloprost, four out of the six polymer-coated liposomal formulations exhibited significantly enhanced vasodilation of mouse pulmonary arteries. Iloprost that was encapsulated in liposomes containing the polymer polyethylene glycol exhibited concentration-dependent relaxation of arteries. Strikingly, half the concentration of iloprost in liposomes elicited

  4. Peroxynitrite mediates testosterone-induced vasodilation of microvascular resistance vessels.

    Science.gov (United States)

    Puttabyatappa, Yashoda; Stallone, John N; Ergul, Adviye; El-Remessy, Azza B; Kumar, Sanjiv; Black, Stephen; Johnson, Maribeth; Owen, Mary P; White, Richard E

    2013-04-01

    Our knowledge of how androgens influence the cardiovascular system is far from complete, and this lack of understanding is especially true of how androgens affect resistance vessels. Our aim was to identify the signaling mechanisms stimulated by testosterone (TES) in microvascular arteries and to understand how these mechanisms mediate TES-induced vasodilation. Mesenteric microvessels were isolated from male Sprague-Dawley rats. Tension studies demonstrated a rapid, concentration-dependent, vasodilatory response to TES that did not involve protein synthesis or aromatization to 17β-estradiol. Dichlorofluorescein fluorescence and nitrotyrosine immunoblot experiments indicated that TES stimulated peroxynitrite formation in microvessels, and functional studies demonstrated that TES-induced vasodilation was inhibited by scavenging peroxynitrite. As predicted, TES enhanced the production of both peroxynitrite precursors (i.e., superoxide and nitic oxide), and xanthine oxidase was identified as the likely source of TES-stimulated superoxide production. Functional and biochemical studies indicated that TES signaling involved activity of the phosphoinositide 3 (PI3) kinase-protein kinase B (Akt) cascade initiated by activation of the androgen receptor and culminated in enhanced production of cGMP and microvascular vasodilation. These findings, derived from a variety of analytical and functional approaches, provide evidence for a novel nongenomic signaling mechanism for androgen action in the microvasculature: TES-stimulated vasodilation mediated primarily by peroxynitrite formed from xanthine oxidase-generated superoxide and NO. This response was associated with activation of the PI3 kinase-Akt signaling cascade initiated by activation of the androgen receptor. We propose this mechanism could account for TES-stimulated cGMP production in microvessels and, ultimately, vasodilation.

  5. Nitric oxide and Kir6.1 potassium channel mediate isoquercitrin-induced endothelium-dependent and independent vasodilation in the mesenteric arterial bed of rats.

    Science.gov (United States)

    Gasparotto Junior, Arquimedes; Dos Reis Piornedo, Renê; Assreuy, Jamil; Da Silva-Santos, José Eduardo

    2016-10-05

    The vascular effect of flavonoid isoquercitrin was investigated in the perfused mesenteric vascular bed of rats. In preparations with functional endothelium isoquercitrin (100, 300 and 1000nmol) dose-dependently reduced the perfusion pressure by 13±2.2, 33±3.9, and 58±3.7mm Hg, respectively. Endothelium removal or inhibition of the nitric oxide synthase enzymes by l-NAME did not change the effects of 100 and 300 nmol isoquercitrin, but reduced by 30-40% the vasodilation induced by 1000 nmol isoquercitrin. Perfusion with nutritive solution containing 40mM KCl abolished the vasodilatory effect of all isoquercitrin doses. Treatment with glibenclamide, a Kir6.1 (ATP-sensitive) potassium channel blocker, inhibited vasodilation induced by 100 and 300 nmol isoquercitrin, but only partially reduced the effect of 1000 nmol isoquercitrin. The non-selective KCa (calcium-activated) potassium channel blocker tetraethylammonium, but not the selective KCa1.1 channel blocker iberiotoxin, reduced by around 60% vasodilation induced by all isoquercitrin doses. In addition, association of tetraethylammonium and glibenclamide, or l-NAME and glibenclamide, fully inhibited isoquercitrin-induced vasodilation. Our study shows that isoquercitrin induces vasodilation in resistance arteries, an effect mediated by K(+) channel opening and endothelial nitric oxide production.

  6. Glucagon-like peptide-1 elicits vasodilation in adipose tissue and skeletal muscle in healthy men

    DEFF Research Database (Denmark)

    Asmar, Ali; Asmar, Meena; Simonsen, Lene

    2017-01-01

    In healthy subjects, we recently demonstrated that during acute administration of GLP-1, cardiac output increased significantly, whereas renal blood flow remained constant. We therefore hypothesize that GLP-1 induces vasodilation in other organs, for example, adipose tissue, skeletal muscle, and....../or splanchnic tissues. Nine healthy men were examined twice in random order during a 2-hour infusion of either GLP-1 (1.5 pmol kg(-1) min(-1)) or saline. Cardiac output was continuously estimated noninvasively concomitantly with measurement of intra-arterial blood pressure. Subcutaneous, abdominal adipose...... and heart rate compared with the saline study. Subcutaneous, abdominal ATBF and leg blood flow increased significantly during the GLP-1 infusion compared with saline, whereas splanchnic blood flow response did not differ between the studies. We conclude that in healthy subjects, GLP-1 increases cardiac...

  7. Vasodilators and regression of left ventricular hypertrophy. Hydralazine versus prazosin in hypertensive humans.

    Science.gov (United States)

    Leenen, F H; Smith, D L; Farkas, R M; Reeves, R A; Marquez-Julio, A

    1987-05-01

    Long-term treatment of hypertensive rats with arterial vasodilators may further increase left ventricular hypertrophy. Since left ventricular hypertrophy may be an important determinant of outcome in hypertension, the long-term effects of arterial vasodilation with hydralazine on left ventricular mass and function were compared with those of an alternative third-line drug, the alpha1 blocker prazosin, in patients still hypertensive despite combined diuretic and beta blocker therapy. A single-blind, randomized, two-group parallel design was employed. Both treatments induced a sustained antihypertensive effect, with hydralazine showing more effect on supine blood pressure, and prazosin having more effect on standing pressure. Heart rate, cardiac output, and volume status showed only minor changes. Plasma norepinephrine showed a sustained increase when measured in both the supine and standing positions, but the increases were similar for the two treatments. Supine and standing plasma renin activity increased only during long-term treatment with hydralazine. Prazosin induced a progressive decrease in left ventricular mass over time (-34 +/- 15 g/m2 at 12 months), but hydralazine did not (-9 +/- 10 g/m2 after 12 months). Stepwise regression indicated that a decrease in systolic blood pressure was associated with a decrease in left ventricular mass with both treatments, but an increase in plasma norepinephrine was associated with an increase in left ventricular mass only with hydralazine, suggesting that increased sympathetic activity may affect left ventricular mass via cardiac alpha1 receptors. Thus, if regression of left ventricular hypertrophy is a worthwhile therapeutic goal, hydralazine and analogous arterial vasodilators are not drugs of choice.

  8. Cost-Effectiveness of Decision Support Strategies in Acute Bronchitis.

    Science.gov (United States)

    Michaelidis, Constantinos I; Kern, Melissa S; Smith, Kenneth J

    2015-10-01

    A recent clinical trial suggests that printed (PDS) and computer decision support (CDS) interventions are safe and effective in reducing antibiotic use in acute bronchitis relative to usual care (UC). Our aim was to evaluate the cost-effectiveness of decision support interventions in reducing antibiotic use in acute bronchitis. We conducted a clinical trial-based cost-effectiveness analysis comparing UC, PDS and CDS for management of acute bronchitis. We assumed a societal perspective, 5-year program duration and 30-day time horizon. The U.S. population aged 13-64 years presenting with acute bronchitis in the ambulatory setting. Printed and computer decision support interventions relative to usual care. Cost per antibiotic prescription safely avoided. In the base case, PDS dominated UC and CDS, with lesser total costs (PDS: $2,574, UC: $2,768, CDS: $2,805) and fewer antibiotic prescriptions (PDS: 3.79, UC: 4.60, CDS: 3.95) per patient over 5 years. In one-way sensitivity analyses, PDS dominated UC across all parameter values, except when antibiotics reduced work loss by ≥ 1.9 days or the probability of hospitalization within 30 days was ≥ 0.9 % in PDS (base case: 0.2 %) or ≤ 0.4 % in UC (base case: 1.0 %). The dominance of PDS over CDS was sensitive both to probability of hospitalization and plausible variation in the adjusted odds of antibiotic use in both strategies. A PDS strategy to reduce antibiotic use in acute bronchitis is less costly and more effective than both UC and CDS strategies, although results were sensitive to variation in probability of hospitalization and the adjusted odds of antibiotic use. This simple, low-cost, safe, and effective intervention would be an economically reasonable component of a multi-component approach to address antibiotic overuse in acute bronchitis.

  9. Acute Stressor Effects on Goal-Directed Action in Rats

    Science.gov (United States)

    Braun, Stephanie; Hauber, Wolfgang

    2013-01-01

    Here we examined effects of acute stressors that involve either systemic coadministration of corticosterone/yohimbine (3 mg/kg each) to increase glucocorticoid/noradrenaline activity (denoted as "pharmacological" stressor) or one or several distinct restraint stressors (denoted as "single" vs. "multiple" stressor) on…

  10. Acute effects of winter air pollution on respiratory health

    NARCIS (Netherlands)

    Zee, van der S.

    1999-01-01

    In this thesis, acute respiratory health effects of exposure to winter air pollution are investigated in panels of children (7-11 yr) and adults (50-70 yr) with and without chronic respiratory symptoms, living in urban and non-urban areas in the Netherlands. The study was performed during three cons

  11. Acute Stressor Effects on Goal-Directed Action in Rats

    Science.gov (United States)

    Braun, Stephanie; Hauber, Wolfgang

    2013-01-01

    Here we examined effects of acute stressors that involve either systemic coadministration of corticosterone/yohimbine (3 mg/kg each) to increase glucocorticoid/noradrenaline activity (denoted as "pharmacological" stressor) or one or several distinct restraint stressors (denoted as "single" vs. "multiple" stressor) on…

  12. The effects of acute exercise bouts on hepcidin in women.

    NARCIS (Netherlands)

    Newlin, M.K.; Williams, S.; McNamara, T.; Tjalsma, H.; Swinkels, D.W.; Haymes, E.M.

    2012-01-01

    PURPOSE: To investigate the effects of acute exercise on serum hepcidin and iron (sFe) in active women. Changes in interleukin-6 (IL-6), hepcidin, ferritin, and sFe in response to 2 different exercise durations were compared. METHODS: Twelve women age 19-32 yr performed 2 treadmill runs (60 and 120

  13. Effect of carbon dioxide in acute mountain sickness

    DEFF Research Database (Denmark)

    Harvey, T C; Raichle, M E; Winterborn, M H

    1988-01-01

    of the respiratory alkalosis normally seen at high altitude. Symptoms of acute mountain sickness were rapidly relieved. In three subjects cerebral blood flow increased by 17-39%, so that oxygen delivery to the brain would have been considerably improved. This study confirms earlier suggestions of the beneficial...... effect of CO2 inhalation at high altitude....

  14. Effects of Acute Exercise on Long-Term Memory

    Science.gov (United States)

    Labban, Jeffrey D.; Etnier, Jennifer L.

    2011-01-01

    In this study, we tested the effect of acute exercise on long-term memory, specifically the timing of exercise relative to the memory challenge. We assessed memory via paragraph recall, in which participants listened to two paragraphs (exposure) and recounted them following a 35-min delay. Participants (n = 48) were randomly assigned to one of…

  15. The effects of acute exercise bouts on hepcidin in women.

    NARCIS (Netherlands)

    Newlin, M.K.; Williams, S.; McNamara, T.; Tjalsma, H.; Swinkels, D.W.; Haymes, E.M.

    2012-01-01

    PURPOSE: To investigate the effects of acute exercise on serum hepcidin and iron (sFe) in active women. Changes in interleukin-6 (IL-6), hepcidin, ferritin, and sFe in response to 2 different exercise durations were compared. METHODS: Twelve women age 19-32 yr performed 2 treadmill runs (60 and 120

  16. Effects of Acute Exercise on Long-Term Memory

    Science.gov (United States)

    Labban, Jeffrey D.; Etnier, Jennifer L.

    2011-01-01

    In this study, we tested the effect of acute exercise on long-term memory, specifically the timing of exercise relative to the memory challenge. We assessed memory via paragraph recall, in which participants listened to two paragraphs (exposure) and recounted them following a 35-min delay. Participants (n = 48) were randomly assigned to one of…

  17. Acute effect of substance P in immunologic vasculitis in the rat colon.

    Science.gov (United States)

    Murthy, S N; DePace, D M; Shah, R S; Podell, R

    1991-01-01

    Substance P has been implicated as a neuronal mediator of inflammation in various inflammatory conditions. However, the exact role played by substance P in inflammatory bowel diseases or in experimental colonic vasculitis has not been clearly understood. In this study, we examined the effect of close superior mesenteric artery injection of substance P under prevailing inflammatory conditions induced by intravenous human albumin antialbumin immune complex followed by intracolonic perfusion of 2.5% formaldehyde in rats or intracolonic perfusion of 5% alcohol alone. The immune complex- and formaldehyde-treated rats showed severe microvascular changes such as microvascular plugging by red blood cells, endothelial breakage and extravasation of plasma proteins and red blood cells. The bolus injection of 10(-8) M substance P reduced extravasation of Evans blue dye by 50% and the tissue wet to dry ratio by 20% in immune complex- and formaldehyde-perfused rats. Myeloperoxidase activity was not changed. Substance P also significantly inhibited (44%) the extravasation in alcohol-perfused rats. Pretreatment of immune complex- and formaldehyde-treated rats with substance P antagonist reversed the effect of substance P. These findings suggest that the most immediate effect of substance P may be vasodilation and clearing of vascular plugs induced by immune complex and formaldehyde. This effect of substance P differs from its chronic effect, which causes vasodilation and extravasation.

  18. Metabolic forearm vasodilation is enhanced following Bier block with phentolamine.

    Science.gov (United States)

    Moradkhan, Raman; McQuillan, Patrick; Hogeman, Cynthia; Leuenberger, Andrea; Linton-Frazier, Latoya; Leuenberger, Urs A

    2007-10-01

    The extent to which sympathetic nerve activity restrains metabolic vasodilation in skeletal muscle remains unclear. We determined forearm blood flow (FBF; ultrasound/Doppler) and vascular conductance (FVC) responses to 10 min of ischemia [reactive hyperemic blood flow (RHBF)] and 10 min of systemic hypoxia (inspired O(2) fraction = 0.1) before and after regional sympathetic blockade with the alpha-receptor antagonist phentolamine via Bier block in healthy humans. In a control group, we performed sham Bier block with saline. Consistent with alpha- receptor inhibition, post-phentolamine, basal FVC (FBF/mean arterial pressure) increased (pre vs. post: 0.42 +/- 0.05 vs. 1.03 +/- 0.21 units; P phentolamine, total RHBF (over 3 min) increased substantially (pre vs. post: 628 +/- 75 vs. 826 +/- 92 ml/min; P phentolamine (pre vs. post: 0.43 +/- 0.06 vs. 1.16 +/- 0.17 units; P < 0.01; n = 8) but not post-saline (pre vs. post: 0.93 +/- 0.16 vs. 0.87 +/- 0.19 ml/min; P = not significant; n = 5), the FVC response to hypoxia (arterial O(2) saturation = 77 +/- 1%) was markedly enhanced. These data suggest that sympathetic vasoconstrictor nerve activity markedly restrains skeletal muscle vasodilation induced by local (forearm ischemia) and systemic (hypoxia) vasodilator stimuli.

  19. The effects of citicoline on acute ischemic stroke

    DEFF Research Database (Denmark)

    Overgaard, Karsten

    2014-01-01

    therapy. Also there is no established effective acute treatment of spontaneous intracerebral bleeding. Therefore, an effective therapy applicable to all stroke victims is needed. The neuroprotective drug citicoline has been extensively studied in clinical trials with volunteers and more than 11......,000 patients with various neurologic disorders, including acute ischemic stroke (AIS). The conclusion is that citicoline is safe to use and may have a beneficial effect in AIS patients and most beneficial in less severe stroke in older patients not treated with recombinant tissue plasminogen activator....... No other neuroprotective agent had any beneficial effect in confirmative clinical trials or had any positive effect in the subgroup analysis. Citicoline is the only drug that in a number of different clinical stroke trials continuously had some neuroprotective benefit....

  20. Asymmetrical dimethylarginine plasma concentrations are related to basal nitric oxide release but not endothelium-dependent vasodilation of resistance arteries in peritoneal dialysis patients.

    Science.gov (United States)

    Mittermayer, Friedrich; Schaller, Georg; Pleiner, Johannes; Vychytil, Andreas; Sunder-Plassmann, Gere; Hörl, Walter H; Wolzt, Michael

    2005-06-01

    Vascular dysfunction in chronic renal failure may be linked to reduced nitric oxide (NO) bioactivity and increased circulating concentrations of the endogenous NO synthase inhibitor asymmetrical dimethyl L-arginine (ADMA). The association between ADMA and basal endothelial NO release and endothelium-dependent vasodilation in resistance arteries of chronic renal failure patients is unknown. Forearm blood flow responses to the endothelium-dependent vasodilator acetylcholine, the endothelium-independent vasodilator nitroglycerine, and the endothelium-dependent vasoconstrictor N(G)-monomethyl-L-arginine (L-NMMA) were assessed in 37 peritoneal dialysis patients. L-arginine and ADMA plasma concentrations were measured by HPLC. ADMA (mean +/- SEM: 0.68 +/- 0.02 micromol/L) was associated with basal forearm blood flow (r = -0.33; P < 0.05) and L-NMMA induced vasoconstriction (r = -0.55; P < 0.0005), but not with dilator effects of acetylcholine or nitroglycerine. L-arginine (68 +/- 3 micromol/L) tended to correlate with acetylcholine-induced vasodilation (r = 0.32; P = 0.05) but was not associated with other parameters. ADMA is related to basal but not to acetylcholine-stimulated NO bioactivity in patients on peritoneal dialysis. Impaired endothelium-dependent vasodilation found in chronic renal failure is not explained by elevated circulating NO synthase inhibitors in renal failure.

  1. Nebivolol: vasodilator properties and evidence for relevance in treatment of cardiovascular disease.

    Science.gov (United States)

    Howlett, Jonathan G

    2014-05-01

    β-adrenergic blocking agents, a pharmacologically diverse class of cardiovascular medications, are recommended as first-line treatment for patients with hypertension and concomitant structural heart disease, and for angina and heart failure. Many within-class differences exist, from pharmacokinetics and pharmacodynamics to ancillary effects, such as intrinsic sympathomimetic activity, antiarrhythmic activity, α-1 adrenergic receptor blockade affinity, and direct vasodilation. Nebivolol is a third-generation, β1 selective, long acting β-blocker, which causes direct vasodilation via endothelium-dependent nitric oxide stimulation. The vasodilatory actions of nebivolol might result in clinical effects with some distinct properties. Differences from other β-blockers might include improvement of endothelial function, enhancement of forward flow in muscular resistance arteries, maintenance of exercise tolerance, and overall improved tolerability, side effect profile, and adherence. Nebivolol has been shown to be a clinically effective β-blocker for treatment as initial or add-on therapy for systemic hypertension, as an antianginal agent, and as therapy for patients with heart failure. These properties position nebivolol as a treatment option for patients with hypertension and/or structural heart disease, although its precise role in the therapeutic armamentarium remains to be clarified. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  2. Cardiovascular Effects of Acute Organophosphate Poisoning

    Directory of Open Access Journals (Sweden)

    Shankar Laudari

    2014-06-01

    Conclusion:Cardiac effects of OP poisoning can be life-threatening. Prompt diagnosis, early supportive and definitive therapies with atropine and oximes along with vigilant monitoring of the patients for prominent cardiac effects such as QT prolongation, VT or VF during hospital stay can definitely save lives of the victims.

  3. Efecto vasodilatador mediado por óxido nítrico del extracto hidroalcohólico de Zea mays L. (maíz morado en anillos aórticos de rata Vasodilator effect mediated by nitric oxide of the Zea mays L (andean purple corn hydroalcoholic extract in aortic rings of rat

    Directory of Open Access Journals (Sweden)

    Oscar Moreno-Loaiza

    2010-12-01

    with an isometric tension transducer. Basal contraction was produced with 120 mM KCl and then, we proceeded to determinate the vasodilator effect of 3 doses of the extract: 0.1, 0.5, and 1.0 mg/mL. We used L-NG-Nitroarginin methyl ester (L-NAME to verify that the vasodilation depends on nitric oxide sinteasa (NOs. Then we compared the inhibition of vascular contraction after incubation for 30 minutes, with purple corn extract and captopril 10-5 M. Results: We observed a reduction in maximum contraction (100% to 85.25 ± 2.60%, 77.76 ± 3.23%, and 73.3 ± 4.87% for doses of 0.1, 0.5 and 1,0 mg/mL respectively. The vasodilation was inhibited by prior incubation with L-NAME. Andean purple corn extract did not inhibit vascular contraction as captopril did (reduction to 75.27 ± 8.61%. Conclusion. The hydroalcoholic extract of Zea mays L produces NO dependent vasodilation.

  4. The effects of citicoline on acute ischemic stroke: a review.

    Science.gov (United States)

    Overgaard, Karsten

    2014-08-01

    Early reopening of the occluded artery is, thus, important in ischemic stroke, and it has been calculated that 2 million neurons die every minute in an ischemic stroke if no effective therapy is given; therefore, "Time is Brain." In massive hemispheric infarction and edema, surgical decompression lowers the risk of death or severe disability defined as a modified Rankin Scale score greater than 4 in selected patients. The majority, around 80%-85% of all ischemic stroke victims, does not fulfill the criteria for revascularization therapy, and also for these patients, there is no effective acute therapy. Also there is no established effective acute treatment of spontaneous intracerebral bleeding. Therefore, an effective therapy applicable to all stroke victims is needed. The neuroprotective drug citicoline has been extensively studied in clinical trials with volunteers and more than 11,000 patients with various neurologic disorders, including acute ischemic stroke (AIS). The conclusion is that citicoline is safe to use and may have a beneficial effect in AIS patients and most beneficial in less severe stroke in older patients not treated with recombinant tissue plasminogen activator. No other neuroprotective agent had any beneficial effect in confirmative clinical trials or had any positive effect in the subgroup analysis. Citicoline is the only drug that in a number of different clinical stroke trials continuously had some neuroprotective benefit.

  5. Acute effects of tea consumption on attention and mood.

    Science.gov (United States)

    Einöther, Suzanne J; Martens, Vanessa E

    2013-12-01

    Tea has historically been associated with mood and performance benefits, such as relaxation and concentration. This review summarizes the research on the acute effects of tea, and its ingredients theanine and caffeine, on attention and mood. Consistent with abundant research on the benefits of caffeine, the performance benefits of tea were identified in a number of studies, with particularly consistent evidence for improved attention. Tea consumption also consistently improved self-reported alertness and arousal, whereas effects on pleasure or relaxation were less consistent. In addition to the research on caffeine in real-life performance, 2 recent studies have provided a broader perspective on tea's effects on psychological function in that they showed beneficial effects in related areas such as work performance and creativity. These studies showed the validity of laboratory findings by supporting the idea that tea consumption has acute benefits on both mood and performance in real-life situations.

  6. [Acute and long-term effects of ecstasy

    OpenAIRE

    Salzmann, Julie; Marie-Claire, Cynthia; Noble, Florence

    2004-01-01

    International audience; Side effects in the short term Recreational use of Ecstasy (3,4-methylenedioxymethamphetamine or MDMA), a synthetic drug, has considerably increased over the last decade. Since its appearance it is associated with the rave culture, but its use has spread to other social settings. The drug produces euphoria and empathy, but can lead to side effects, notably acute, potentially lethal, toxicity (malignant hyperthermia and/or hepatitis). Neurotoxicity in the long-term More...

  7. Sprouty-Related Ena/Vasodilator-Stimulated Phosphoprotein Homology 1-Domain-Containing Protein-2 Critically Regulates Influenza A Virus-Induced Pneumonia.

    Science.gov (United States)

    Ito, Toshihiro; Itakura, Junya; Takahashi, Sakuma; Sato, Miwa; Mino, Megumi; Fushimi, Soichiro; Yamada, Masao; Morishima, Tuneo; Kunkel, Steven L; Matsukawa, Akihiro

    2016-07-01

    Influenza A virus causes acute respiratory infections that induce annual epidemics and occasional pandemics. Although a number of studies indicated that the virus-induced intracellular signaling events are important in combating influenza virus infection, the mechanism how specific molecule plays a critical role among various intracellular signaling events remains unknown. Raf/MEK/extracellular signal-regulated kinase cascade is one of the key signaling pathways during influenza virus infection, and the Sprouty-related Ena/vasodilator-stimulated phosphoprotein homology 1-domain-containing protein has recently been identified as a negative regulator of Raf-dependent extracellular signal-regulated kinase activation. Here, we examined the role of Raf/MEK/extracellular signal-regulated kinase cascade through sprouty-related Ena/vasodilator-stimulated phosphoprotein homology 1-domain-containing protein in influenza A viral infection because the expression of sprouty-related Ena/vasodilator-stimulated phosphoprotein homology 1-domain-containing protein was significantly enhanced in human influenza viral-induced pneumonia autopsy samples. Prospective animal trial. Research laboratory. Wild-type and sprouty-related Ena/vasodilator-stimulated phosphoprotein homology 1-domain-containing protein-2 knockout mice inoculated with influenza A. Wild-type or sprouty-related Ena/vasodilator-stimulated phosphoprotein homology 1-domain-containing protein-2 knockout mice were infected by intranasal inoculation of influenza A (A/PR/8). An equal volume of phosphate-buffered saline was inoculated intranasally into mock-infected mice. Influenza A infection of sprouty-related Ena/vasodilator-stimulated phosphoprotein homology 1-domain-containing protein-2 knockout mice led to higher mortality with greater viral load, excessive inflammation, and enhanced cytokine production than wild-type mice. Administration of MEK inhibitor, U0126, improved mortality and reduced both viral load and

  8. Neuromuscular Effects of Acute Organophosphate Poisoning

    Directory of Open Access Journals (Sweden)

    Taylan Pekoz

    2014-08-01

    Conclusion: There is no evoked potential studies performed in organophosphate poisoning althoung electroneurography repetitive and P300 studies exist in literature. More further studies are needed to evaluate the cardiac and neuromuscular effects of organophosphate poisoning. [Cukurova Med J 2014; 39(4.000: 795-800

  9. Alcohol acutely increases vascular reactivity together with insulin sensitivity in type 2 diabetic men.

    Science.gov (United States)

    Schaller, G; Kretschmer, S; Gouya, G; Haider, D G; Mittermayer, F; Riedl, M; Wagner, O; Pacini, G; Wolzt, M; Ludvik, B

    2010-01-01

    Moderate alcohol consumption is associated with increased insulin sensitivity and reduced cardiovascular risk. We hypothesized that this relates to a direct effect of alcohol and therefore investigated whether acute alcohol intake altered insulin sensitivity or endothelial function in patients with type 2 diabetes. In an open-label two period design, the effect of a single oral dose of 40 g of alcohol (168 ml 40% vodka) on an insulin-modified frequently sampled intravenous glucose tolerance test (FSIGT) and on endothelium-dependent (flow mediated, FMD) or endothelium-independent (glyceroltrinitrate (GTN)-induced) vasodilation of the brachial artery measured by ultrasound was studied. Experiments were carried out in twelve male patients with type 2 diabetes mellitus (64+/-6 years, body mass index 28.4+/-5.7 kg/m (2)). Baseline insulin sensitivity index (S (I)) was 1.10+/-0.34 min (-1).microU (-1).ml, baseline FMD was +4.1+/-3.0%, and GTN-induced vasodilation +7.4+/-2.3% from resting brachial artery diameter. Acute alcohol intake increased alcohol plasma levels to 0.33+/-0.04 per thousand, S (I) to 1.86+/-0.45 min (-1).microU (-1).ml (p<0.05), and FMD to +8.2+/-2.8% (p<0.05), while GTN-induced dilation remained unchanged. No relationship was detectable between the observed changes. We conclude that alcohol intake acutely increases endothelium-dependent brachial artery vasodilation in patients with type 2 diabetes together with insulin sensitivity. This acute effect might explain some beneficial effects of low alcohol consumption in epidemiological observations.

  10. Effect of riluzole on acute pain and hyperalgesia in humans

    DEFF Research Database (Denmark)

    Hammer, N A; Lillesø, J; Pedersen, J L;

    1999-01-01

    Riluzole modulates several transmitter systems which may be involved in nociception. Antinociceptive effects have been shown in animal studies, but there are no human data. Therefore, we have examined the acute analgesic effect of riluzole in a human model of inflammatory pain induced by a thermal...... injury on the distal leg (47 degrees C, 7 min, 12.5 cm2) in 20 healthy volunteers. Hyperalgesia to mechanical and heat stimuli were examined by von Frey hairs and thermodes. We used a randomized, double-blind, placebo-controlled design, and subjects received riluzole 100 mg or placebo for 2 days...... with a 14-day interval. The burns produced significant hyperalgesia, but riluzole had no acute analgesic effects in normal or hyperalgesic skin....

  11. Antioxidant and Vasodilator Activity of Ugni molinae Turcz. (Murtilla and Its Modulatory Mechanism in Hypotensive Response

    Directory of Open Access Journals (Sweden)

    Ignacio Jofré

    2016-01-01

    Full Text Available Hypertension is a systemic condition with high morbidity and mortality rates worldwide, which poses an increased risk for cardiovascular diseases. In this study, we demonstrated the antioxidant and vasodilator activity of Ugni molinae Turcz. (Murtilla fruit, a berry native to Chile and proposed models to explain its modulatory mechanism in hypotensive response. Murtilla fruits were cultivated in a germplasm bank and submitted to chemical and biological analyses. The phenolic compounds gallic acid, Catechin, Quercetin-3-β-D-glucoside, Myricetin, Quercetin, and Kaempferol were identified. Murtilla extract did not generate toxic effects on human endothelial cells and had significant antioxidant activity against ROS production, lipid peroxidation, and superoxide anion production. Furthermore, it showed dose-dependent vasodilator activity in aortic rings in the presence of endothelium, whose hypotensive mechanism is partially mediated by nitric oxide synthase/guanylate cyclase and large-conductance calcium-dependent potassium channels. Murtilla fruits might potentially have beneficial effects on the management of cardiovascular diseases.

  12. Acute effects of aerobic exercise promote learning

    OpenAIRE

    Renza Perini; Marta Bortoletto; Michela Capogrosso; Anna Fertonani; Carlo Miniussi

    2016-01-01

    The benefits that physical exercise confers on cardiovascular health are well known, whereas the notion that physical exercise can also improve cognitive performance has only recently begun to be explored and has thus far yielded only controversial results. In the present study, we used a sample of young male subjects to test the effects that a single bout of aerobic exercise has on learning. Two tasks were run: the first was an orientation discrimination task involving the primary visual cor...

  13. Acute effects of synthetic cannabinoids: Update 2015.

    Science.gov (United States)

    Tournebize, Juliana; Gibaja, Valérie; Kahn, Jean-Pierre

    2017-01-01

    Cannabis is the most widely used illicit drug in the United States and Europe. In recent years, a range of new substances with cannabis-like effects-known as synthetic cannabinoids (SCs)-have suddenly burst on the drug scene. However, there is limited information about the clinical hazards linked to the use of these emerging substances. This review summarizes the literature to date relating the health effects of SCs. A systematic literature review of original case studies was performed using PubMed and Web of Science (January 1980-July 2015). Only articles in which a drug screening was reported were included in this review. Forty-six articles meeting the inclusion criteria were included in this review, reporting data on 114 patients who went to hospital emergency departments after exposure to SCs. The majority of patients were adolescent or young adult males (14-25 years; 24.5 ± 10.1 years). The most common route of administration was smoking. The SCs most involved were John William Huffman (JWH) derivatives, followed by XRL-11, ADB-PINACA, AM-2201, MAM-2201, and 5F-PB-22. This analysis showed that the use of these substances may cause minor and moderate side effects similar to those of cannabis intoxication, including tachycardia, nausea, somnolence, hallucinations, paranoia, xerostomia, and injected conjunctivae among others. However, atypical cannabis intoxication effects and worse complications (such as renal injuries, aggressiveness, cerebral ischemia, myocardial infarction, etc.) were also observed, which led to a significant morbidity were also observed. Some SCs were highlighted as being involved in 24 cases of deaths. In this review, the nature and frequency of the signs and symptoms of SC poisoning were estimated in order to inform health professionals about the health risks of these new and emerging substances.

  14. Effect of Acute and Fractionated Irradiation on Hippocampal Neurogenesis

    Directory of Open Access Journals (Sweden)

    Jin Kyu Kim

    2012-08-01

    Full Text Available Ionizing radiation has become an inevitable health concern emanating from natural sources like space travel and from artificial sources like medical therapies. In general, exposure to ionizing radiation such as γ-rays is one of the methods currently used to stress specific model systems. In this study, we elucidated the long-term effect of acute and fractionated irradiation on DCX-positive cells in hippocampal neurogenesis. Groups of two-month-old C57BL/6 female mice were exposed to whole-body irradiation at acute dose (5 Gy or fractional doses (1 Gy × 5 times and 0.5 Gy × 10 times. Six months after exposure to γ-irradiation, the hippocampus was analyzed. Doublecortin (DCX immunohistochemistry was used to measure changes of neurogenesis in the subgranular zone (SGZ of the hippocampal dentate gyrus (DG. The number of DCX-positive cells was significantly decreased in all acute and fractionally irradiation groups. The long-term changes in DCX-positive cells triggered by radiation exposure showed a very different pattern to the short-term changes which tended to return to the control level in previous studies. Furthermore, the number of DCX-positive cells was relatively lower in the acute irradiation group than the fractional irradiation groups (approximately 3.6-fold, suggesting the biological change on hippocampal neurogenesis was more susceptible to being damaged by acute than fractional irradiation. These results suggest that the exposure to γ-irradiation as a long-term effect can trigger biological responses resulting in the inhibition of hippocampal neurogenesis.

  15. Acute health effects common during graffiti removal.

    Science.gov (United States)

    Langworth, S; Anundi, H; Friis, L; Johanson, G; Lind, M L; Söderman, E; Akesson, B A

    2001-04-01

    The aim of this study was to identify possible health effects caused by different cleaning agents used in graffiti removal. In 38 graffiti removers working 8-h shifts in the Stockholm underground system, the exposure to organic solvents was assessed by active air sampling, biological monitoring, and by interviews and a questionnaire. Health effects were registered, by physical examinations, porta7ble spirometers and self-administered questionnaires. The prevalence of symptoms was compared with 49 controls working at the underground depots, and with 177 population controls. The 8-h time-weighted average exposures (TWA) were low, below 20% of the Swedish permissible exposure limit value (PEL) for all solvents. The short-term exposures occasionally exceeded the Swedish short-term exposure limit values (STEL), especially during work in poorly ventilated spaces, e.g. in elevators. The graffiti removers reported significantly higher prevalence of tiredness and upper airway symptoms compared with the depot controls, and significantly more tiredness, headaches and symptoms affecting airways, eyes and skin than the population controls. Among the graffiti removers, some of the symptoms increased during the working day. On a group basis, the lung function registrations showed normal values. However, seven workers displayed a clear reduction of peak expiratory flow (PEF) over the working shift. Though their average exposure to organic solvents was low, the graffiti removers reported significantly higher prevalence of unspecific symptoms such as fatigue and headache as well as irritative symptoms from the eyes and respiratory tract, compared with the controls. To prevent adverse health effects it is important to inform the workers about the health risks, and to restrict use of the most hazardous chemicals. Furthermore, it is important to develop good working practices and to encourage the use of personal protective equipment.

  16. Acute effects of aerobic exercise promote learning.

    Science.gov (United States)

    Perini, Renza; Bortoletto, Marta; Capogrosso, Michela; Fertonani, Anna; Miniussi, Carlo

    2016-05-05

    The benefits that physical exercise confers on cardiovascular health are well known, whereas the notion that physical exercise can also improve cognitive performance has only recently begun to be explored and has thus far yielded only controversial results. In the present study, we used a sample of young male subjects to test the effects that a single bout of aerobic exercise has on learning. Two tasks were run: the first was an orientation discrimination task involving the primary visual cortex, and the second was a simple thumb abduction motor task that relies on the primary motor cortex. Forty-four and forty volunteers participated in the first and second experiments, respectively. We found that a single bout of aerobic exercise can significantly facilitate learning mechanisms within visual and motor domains and that these positive effects can persist for at least 30 minutes following exercise. This finding suggests that physical activity, at least of moderate intensity, might promote brain plasticity. By combining physical activity-induced plasticity with specific cognitive training-induced plasticity, we favour a gradual up-regulation of a functional network due to a steady increase in synaptic strength, promoting associative Hebbian-like plasticity.

  17. Acute effects of cannabis on breath-holding duration.

    Science.gov (United States)

    Farris, Samantha G; Metrik, Jane

    2016-08-01

    Distress intolerance (an individual's perceived or actual inability to tolerate distressing psychological or physiological states) is associated with cannabis use. It is unknown whether a biobehavioral index of distress intolerance, breath-holding duration, is acutely influenced (increased or decreased) by cannabis. Such information may further inform understanding of the expression of psychological or physiological distress postcannabis use. This within-subjects study examined whether smoked marijuana with 2.7%-3.0% delta-9-tetrahydrocannabinol (THC), relative to placebo, acutely changed duration of breath holding. Participants (n = 88; 65.9% male) were nontreatment-seeking frequent cannabis users who smoked placebo or active THC cigarette on two separate study days and completed a breath-holding task postsmoking. Controlling for baseline breath-holding duration and participant sex, THC produced significantly shorter breath-holding durations relative to placebo. There was a significant interaction of drug administration × frequency of cannabis use, such that THC decreased breath-holding time among less frequent but not among more frequent users. Findings indicate that cannabis may exacerbate distress intolerance (via shorter breath-holding durations). As compared to less frequent cannabis users, frequent users display tolerance to cannabis' acute effects including increased ability to tolerate respiratory distress when holding breath. Objective measures of distress intolerance are sensitive to contextual factors such as acute drug intoxication, and may inform the link between cannabis use and the expression of psychological distress. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  18. 2-methoxyestradiol induces vasodilation by stimulating NO release via PPARγ/PI3K/Akt pathway.

    Science.gov (United States)

    Chen, Weiyu; Cui, Yuhong; Zheng, Shuhui; Huang, Jinghe; Li, Ping; Simoncini, Tommaso; Zhang, Yongfu; Fu, Xiaodong

    2015-01-01

    The endogenous estradiol metabolite 2-methoxyestradiol (2-ME) reduces atherosclerotic lesion formation, while the underlying mechanisms remain obscure. In this work, we investigated the vasodilatory effect of 2-ME and the role of nitric oxide (NO) involved. In vivo studies using noninvasive tail-cuff methods showed that 2-ME decreased blood pressure in Sprague Dawley rats. Furthermore, in vitro studies showed that cumulative addition of 2-ME to the aorta caused a dose- and endothelium-dependent vasodilation. This effect was unaffected by the pretreatment with the pure estrogen receptor antagonist ICI 182,780, but was largely impaired by endothelial nitric oxide synthase (eNOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME) or by phosphoinositide 3-kinase (PI3K) inhibitor wortmannin (WM). Moreover, 2-ME(10-7 ∼10-5 M)enhanced phosphorylation of Akt and eNOS and promoted NO release from cultured human umbilical endothelial cells (HUVECs). These effects were blocked by PI3K inhibitor WM, or by the transfection with Akt specific siRNA, indicating that endothelial Akt/eNOS/NO cascade plays a crucial role in 2-ME-induced vasodilation. The peroxisome proliferator-activated receptor γ (PPARγ) mRNA and protein expression were detected in HUVECs and the antagonist GW9662 or the transfection with specific PPARγ siRNA inhibited 2-ME-induced eNOS and Akt phosphorylation, leading to the impairment of NO production and vasodilation. In conclusion, 2-ME induces vasodilation by stimulating NO release. These actions may be mediated by PPARγ and the subsequent activation of Akt/eNOS cascade in vascular endothelial cells.

  19. Effect of solcoseryl on antitumour action and acute toxicity of some antineoplastic drugs.

    Science.gov (United States)

    Danysz, A; Sołtysiak-Pawluczuk, D; Czyzewska-Szafran, H; Jedrych, A; Jastrzebski, Z

    1991-01-01

    The in vivo effect of Solcoseryl on the antitumour activity and acute toxicity of some antineoplastic drugs was examined. It was found that Solcoseryl does not inhibit the antineoplastic effectiveness of the drugs against transplantable P 388 leukaemia in mice. Studies of the effect of Solcoseryl on acute toxicity of selected antineoplastic drugs in mice revealed that the biostimulator could exert a modifying influence. The prior administration of Solcoseryl significantly decreases the acute toxicity of methotrexate but has no effect on acute toxicity of 5-fluorouracil, increases the acute toxicity of bleomycin and vinblastine and has no effect on acute toxicity of methotrexate and mitoxantron. On the other hand, Solcoseryl administered simultaneously with the antineoplastic drugs increases acute toxicity of 5-fluorouracil, bleomycin and mitoxantron. The protective effect of the biostimulator noted exclusively against acute toxicity of 5-fluorouracil was also observed after multiple administration of this anticancer drug.

  20. The Protective Effects of Buzui on Acute Alcoholism in Mice

    Directory of Open Access Journals (Sweden)

    Chen Chen

    2016-01-01

    Full Text Available This study was designed to investigate the role of a traditional buzui recipe in anti-inebriation treatment. Buzui consists of Fructus Schisandrae Chinensis, Fructus Chebulae, Fructus Mume, Fructus Crataegi, Endothelium Corneum Gigeriae Galli, and Excrementum Bombycis. The buzui mixture was delivered by gavage, and ethanol was delivered subsequent to the final treatment. The effects of buzui on the righting reflex, inebriation rates, and the survival curve are depicted. Blood alcohol concentrations, alanine aminotransferase (ALT levels, aspartate aminotransferase (AST levels, and alkaline phosphatase (ALP levels were recorded. The activities of alcohol dehydrogenase (ADH, aldehyde dehydrogenase (ALDH, and superoxide dismutase (SOD, as well as malonaldehyde (MDA levels, were also measured. Our results demonstrated that a traditional buzui recipe showed significant effects on promoting wakefulness and the prevention of acute alcohol intoxication, accelerating the metabolism of alcohol in the liver and reducing the oxidative damage caused by acute alcoholism.

  1. SAFETY AND EFFECTIVENESS OF PIDOTIMOD IN ACUTE AND CHRONIC BRONCHITIS

    Directory of Open Access Journals (Sweden)

    A.V. Karaulov

    2010-01-01

    Full Text Available One of effective and safe immunomodulators for prophylaxis and treatment of frequently ailing children is pidotimod (Imunorix. Efficacy of the drug in pediatric practice was studied in more than 3200 patients with acute and recurrent respiratory infections. The article shows reasonability of pidotimod administration in children with acute and chronic bronchitis. This fact was confirmed with doubleblinded placebo-controlled studies. Treatment with pidotimod results in decreased terms of recovery of chronic bronchitis exacerbation, shortening of exacerbation. Realization of stable effect is related to recovery of key functions of inborn and adaptive immunity, it begins in 15 days after intake of the drug in therapeutic dose. Prophylactic doses of pidotimod should be used during next 30–60 days.Key words: children, bronchitis, pidotimod, immunity, treatment.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2010;9(6:139-143

  2. The Protective Effects of Buzui on Acute Alcoholism in Mice

    Science.gov (United States)

    Wen, Da-Chao; Gao, Shu-di; Hu, Xiao-yu; Yi, Cheng

    2016-01-01

    This study was designed to investigate the role of a traditional buzui recipe in anti-inebriation treatment. Buzui consists of Fructus Schisandrae Chinensis, Fructus Chebulae, Fructus Mume, Fructus Crataegi, Endothelium Corneum Gigeriae Galli, and Excrementum Bombycis. The buzui mixture was delivered by gavage, and ethanol was delivered subsequent to the final treatment. The effects of buzui on the righting reflex, inebriation rates, and the survival curve are depicted. Blood alcohol concentrations, alanine aminotransferase (ALT) levels, aspartate aminotransferase (AST) levels, and alkaline phosphatase (ALP) levels were recorded. The activities of alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), and superoxide dismutase (SOD), as well as malonaldehyde (MDA) levels, were also measured. Our results demonstrated that a traditional buzui recipe showed significant effects on promoting wakefulness and the prevention of acute alcohol intoxication, accelerating the metabolism of alcohol in the liver and reducing the oxidative damage caused by acute alcoholism. PMID:26884793

  3. Effects of gabapentin in acute inflammatory pain in humans

    DEFF Research Database (Denmark)

    Werner, M U; Perkins, F M; Holte, Kathrine;

    2001-01-01

    BACKGROUND AND OBJECTIVES: The aim of the study was to examine the analgesic effects of the anticonvulsant, gabapentin, in a validated model of acute inflammatory pain. METHODS: Twenty-two volunteers were investigated in a double-blind, randomized, placebo-controlled cross-over study. Gabapentin 1...... not significantly changed by gabapentin (P study indicates that gabapentin has no analgesic effect in normal skin, but may reduce primary mechanical allodynia in acute......,200 mg or placebo was given on 2 separate study days. Three hours after drug administration, a first-degree burn injury was produced on the medial aspect of the nondominant calf (12.5 cm(2), 47 degrees C for 7 minutes). Quantitative sensory testing (QST) included pain ratings to thermal and mechanical...

  4. Affinin (Spilanthol, Isolated from Heliopsis longipes, Induces Vasodilation via Activation of Gasotransmitters and Prostacyclin Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Jesús Eduardo Castro-Ruiz

    2017-01-01

    Full Text Available Heliopsis longipes roots have been widely used in Mexican traditional medicine to relieve pain, mainly, toothaches. Previous studies have shown that affinin, the major alkamide of these roots, induces potent antinociceptive and anti-inflammatory activities. However, the effect of H. longipes root extracts and affinin on the cardiovascular system have not been investigated so far. In the present study, we demonstrated that the dichloromethane and ethanolic extracts of H. longipes roots, and affinin, isolated from these roots, produce a concentration-dependent vasodilation of rat aorta. Affinin-induced vasorelaxation was partly dependent on the presence of endothelium and was significantly blocked in the presence of inhibitors of NO, H2S, and CO synthesis (NG-nitro-l-arginine methyl ester (l-NAME, dl-propargylglycine (PAG, and chromium mesoporphyrin (CrMP, respectively; K+ channel blockers (glibenclamide (Gli and tetraethyl ammonium (TEA, and guanylate cyclase and cyclooxygenase inhibitors (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ and indomethacin (INDO, respectively. Our results demonstrate, for the first time, that affinin induces vasodilation by mechanisms that involve gasotransmitters, and prostacyclin signaling pathways. These findings indicate that this natural alkamide has therapeutic potential in the treatment of cardiovascular diseases.

  5. Affinin (Spilanthol), Isolated from Heliopsis longipes, Induces Vasodilation via Activation of Gasotransmitters and Prostacyclin Signaling Pathways

    Science.gov (United States)

    Castro-Ruiz, Jesús Eduardo; Rojas-Molina, Alejandra; Luna-Vázquez, Francisco J.; Rivero-Cruz, Fausto; García-Gasca, Teresa; Ibarra-Alvarado, César

    2017-01-01

    Heliopsis longipes roots have been widely used in Mexican traditional medicine to relieve pain, mainly, toothaches. Previous studies have shown that affinin, the major alkamide of these roots, induces potent antinociceptive and anti-inflammatory activities. However, the effect of H. longipes root extracts and affinin on the cardiovascular system have not been investigated so far. In the present study, we demonstrated that the dichloromethane and ethanolic extracts of H. longipes roots, and affinin, isolated from these roots, produce a concentration-dependent vasodilation of rat aorta. Affinin-induced vasorelaxation was partly dependent on the presence of endothelium and was significantly blocked in the presence of inhibitors of NO, H2S, and CO synthesis (NG-nitro-l-arginine methyl ester (l-NAME), dl-propargylglycine (PAG), and chromium mesoporphyrin (CrMP), respectively); K+ channel blockers (glibenclamide (Gli) and tetraethyl ammonium (TEA)), and guanylate cyclase and cyclooxygenase inhibitors (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and indomethacin (INDO), respectively). Our results demonstrate, for the first time, that affinin induces vasodilation by mechanisms that involve gasotransmitters, and prostacyclin signaling pathways. These findings indicate that this natural alkamide has therapeutic potential in the treatment of cardiovascular diseases. PMID:28117739

  6. Prolonged local forearm hyperinsulinemia induces sustained enhancement of nitric oxide-dependent vasodilation in healthy subjects

    DEFF Research Database (Denmark)

    Hermann, Thomas S; Ihlemann, Nikolaj; Dominguez, Helena;

    2005-01-01

    -dependent and -independent vasodilation.N(G)-monomethyl-L-arginine (L-NMMA) was coinfused to test the degree of nitric oxide (NO)-mediated vasodilation. Insulin infusion for 60 min enhanced serotonin-induced vasodilation by 37% compared to vehicle, p = .016. This increase was maintained for 4 h and was blocked by L......-NMMA. The SNP response was increased by insulin but the increment was inhibited by L-NMMA. Four hours of local forearm hyperinsulinemia causes a sustained increase in endothelium dependent vasodilation in resistance vessels, which is mediated by NO....

  7. Acute effect of different stretching methods on isometric muscle strength

    OpenAIRE

    Gabriel Vasconcellos de Lima Costa e Silva; Anderson Luiz Bezerra da Silveira; Fabrízio Di Masi; Cláudio Melibeu Bentes; Maria do Socorro Cirilo de Sousa; Jefferson da Silva Novaes

    2014-01-01

    http://dx.doi.org/10.4025/actascihealthsci.v36i1.15581 This study investigated the acute effect of static stretching methods (SS) and proprioceptive neuromuscular facilitation (PNF) on the static muscle strength (SMS). Eleven young male subjects with strength training experience, performed 3 tests with a 48h interval between them, randomly selected, where each one subject carried out all procedures: a) hand grip without stretching; b) hand grip preceded by static stretching of wrist flexor...

  8. Acute effect of a single bout of aerobic exercise on vascular and baroreflex function of young males with a family history of hypertension.

    Science.gov (United States)

    Boutcher, Y N; Hopp, J P; Boutcher, S H

    2011-05-01

    The effect of one single bout of aerobic exercise on the vascular and baroreceptor function of individuals with a family history of hypertension was investigated. Forty young males, mean age 21 years, comprising offspring with (FH(+); n=20) and without (FH(-); n=20) a family history of hypertension participated in this study. Acute exercise was performed on a stationary bike for 20 min at 60% of maximal oxygen uptake. Peak forearm blood flow (FBF) was assessed using plethysmography and was determined as the highest blood flow after 5 min of reactive hyperaemia. Cardiopulmonary baroreceptor (CPBR) sensitivity was measured using lower-body negative pressure (LBNP) for 5 min at -20 mm Hg. CPBR was determined by calculating change of stroke volume and forearm vascular resistance (FVR) at baseline and during LBNP. Carotid baroreceptor (CBR) sensitivity was assessed using neck suction at -20, -40, -60 and -80 mm Hg pressures and was determined from RR interval divided by systolic blood pressure. Augmentation index (AIx), a measure of wave reflection, was assessed using applanation tonometry, and was calculated as the ratio of augmented pressure and pulse pressure. The peak FBF at pre-exercise was lower in FH(+) than in FH(-) subjects. Twenty minutes of acute cycle exercise resulted in significantly increased peak FBF by 22% in FH(+) and by 11% in FH(-) subjects, whereas peak FVR of both groups decreased by 17% and 11%, respectively. No change occurred in CPBR, CBR or AIx. It is concluded that 20 min of acute cycle exercise normalised baseline FBF and forearm vasodilation during hyperaemia in FH(+) subjects.

  9. Hormonal therapy with estradiol and drospirenone improves endothelium-dependent vasodilation in the coronary bed of ovariectomized spontaneously hypertensive rats.

    Science.gov (United States)

    Borgo, M V; Claudio, E R G; Silva, F B; Romero, W G; Gouvea, S A; Moysés, M R; Santos, R L; Almeida, S A; Podratz, P L; Graceli, J B; Abreu, G R

    2016-01-01

    Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces blood pressure in hypertensive women. However, the effects of DRSP on endothelium-dependent coronary vasodilation have not been evaluated. This study investigated the effects of combined therapy with estrogen (E2) and DRSP on endothelium-dependent vasodilation of the coronary bed of ovariectomized (OVX) spontaneously hypertensive rats. Female spontaneously hypertensive rats (n=87) at 12 weeks of age were randomly divided into sham operated (Sham), OVX, OVX treated with E2 (E2), and OVX treated with E2 and DRSP (E2+DRSP) groups. Hemodynamic parameters were directly evaluated by catheter insertion into the femoral artery. Endothelium-dependent vasodilation in response to bradykinin in the coronary arterial bed was assessed using isolated hearts according to a modified Langendorff method. Coronary protein expression of endothelial nitric oxide synthase and estrogen receptor alpha (ER-α) was assessed by Western blotting. Histological slices of coronary arteries were stained with hematoxylin and eosin, and morphometric parameters were analyzed. Oxidative stress was assessed in situ by dihydroethidium fluorescence. Ovariectomy increased systolic blood pressure, which was only prevented by E2+DRSP treatment. Estrogen deficiency caused endothelial dysfunction, which was prevented by both treatments. However, the vasodilator response in the E2+DRSP group was significantly higher at the three highest concentrations compared with the OVX group. Reduced ER-α expression in OVX rats was restored by both treatments. Morphometric parameters and oxidative stress were augmented by OVX and reduced by E2 and E2+DRSP treatments. Hormonal therapy with E2 and DRSP may be an important therapeutic option in the prevention of coronary heart disease in hypertensive post-menopausal women.

  10. Hormonal therapy with estradiol and drospirenone improves endothelium-dependent vasodilation in the coronary bed of ovariectomized spontaneously hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Borgo, M.V.; Claudio, E.R.G.; Silva, F.B.; Romero, W.G.; Gouvea, S.A.; Moysés, M.R.; Santos, R.L.; Almeida, S.A. [Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES (Brazil); Podratz, P.L.; Graceli, J.B. [Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Abreu, G.R. [Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES (Brazil)

    2015-11-17

    Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces blood pressure in hypertensive women. However, the effects of DRSP on endothelium-dependent coronary vasodilation have not been evaluated. This study investigated the effects of combined therapy with estrogen (E2) and DRSP on endothelium-dependent vasodilation of the coronary bed of ovariectomized (OVX) spontaneously hypertensive rats. Female spontaneously hypertensive rats (n=87) at 12 weeks of age were randomly divided into sham operated (Sham), OVX, OVX treated with E2 (E2), and OVX treated with E2 and DRSP (E2+DRSP) groups. Hemodynamic parameters were directly evaluated by catheter insertion into the femoral artery. Endothelium-dependent vasodilation in response to bradykinin in the coronary arterial bed was assessed using isolated hearts according to a modified Langendorff method. Coronary protein expression of endothelial nitric oxide synthase and estrogen receptor alpha (ER-α) was assessed by Western blotting. Histological slices of coronary arteries were stained with hematoxylin and eosin, and morphometric parameters were analyzed. Oxidative stress was assessed in situ by dihydroethidium fluorescence. Ovariectomy increased systolic blood pressure, which was only prevented by E2+DRSP treatment. Estrogen deficiency caused endothelial dysfunction, which was prevented by both treatments. However, the vasodilator response in the E2+DRSP group was significantly higher at the three highest concentrations compared with the OVX group. Reduced ER-α expression in OVX rats was restored by both treatments. Morphometric parameters and oxidative stress were augmented by OVX and reduced by E2 and E2+DRSP treatments. Hormonal therapy with E2 and DRSP may be an important therapeutic option in the prevention of coronary heart disease in hypertensive post-menopausal women.

  11. Glucocorticoid therapy-induced memory deficits: acute versus chronic effects.

    Science.gov (United States)

    Coluccia, Daniel; Wolf, Oliver T; Kollias, Spyros; Roozendaal, Benno; Forster, Adrian; de Quervain, Dominique J-F

    2008-03-26

    Conditions with chronically elevated glucocorticoid levels are usually associated with declarative memory deficits. Considerable evidence suggests that long-term glucocorticoid exposure may cause cognitive impairment via cumulative and long-lasting influences on hippocampal function and morphology. However, because elevated glucocorticoid levels at the time of retention testing are also known to have direct impairing effects on memory retrieval, it is possible that such acute hormonal influences on retrieval processes contribute to the memory deficits found with chronic glucocorticoid exposure. To investigate this issue, we examined memory functions and hippocampal volume in 24 patients with rheumatoid arthritis who were treated either chronically (5.3 +/- 1.0 years, mean +/- SE) with low to moderate doses of prednisone (7.5 +/- 0.8 mg, mean +/- SE) or without glucocorticoids. In both groups, delayed recall of words learned 24 h earlier was assessed under conditions of either elevated or basal glucocorticoid levels in a double-blind, placebo-controlled crossover design. Although the findings in this patient population did not provide evidence for harmful effects of a history of chronic prednisone treatment on memory performance or hippocampal volume per se, acute prednisone administration 1 h before retention testing to either the steroid or nonsteroid group impaired word recall. Thus, these findings indicate that memory deficits observed under chronically elevated glucocorticoid levels result, at least in part, from acute and reversible glucocorticoid effects on memory retrieval.

  12. A Critical Role for Astrocytes in Hypercapnic Vasodilation in Brain

    Science.gov (United States)

    Lind, Barbara Lykke; LeDue, Jeffrey M.; Ellis-Davies, Graham; Sibson, Nicola R.

    2017-01-01

    Cerebral blood flow (CBF) is controlled by arterial blood pressure, arterial CO2, arterial O2, and brain activity and is largely constant in the awake state. Although small changes in arterial CO2 are particularly potent to change CBF (1 mmHg variation in arterial CO2 changes CBF by 3%–4%), the coupling mechanism is incompletely understood. We tested the hypothesis that astrocytic prostaglandin E2 (PgE2) plays a key role for cerebrovascular CO2 reactivity, and that preserved synthesis of glutathione is essential for the full development of this response. We combined two-photon imaging microscopy in brain slices with in vivo work in rats and C57BL/6J mice to examine the hemodynamic responses to CO2 and somatosensory stimulation before and after inhibition of astrocytic glutathione and PgE2 synthesis. We demonstrate that hypercapnia (increased CO2) evokes an increase in astrocyte [Ca2+]i and stimulates COX-1 activity. The enzyme downstream of COX-1 that synthesizes PgE2 (microsomal prostaglandin E synthase-1) depends critically for its vasodilator activity on the level of glutathione in the brain. We show that, when glutathione levels are reduced, astrocyte calcium-evoked release of PgE2 is decreased and vasodilation triggered by increased astrocyte [Ca2+]i in vitro and by hypercapnia in vivo is inhibited. Astrocyte synthetic pathways, dependent on glutathione, are involved in cerebrovascular reactivity to CO2. Reductions in glutathione levels in aging, stroke, or schizophrenia could lead to dysfunctional regulation of CBF and subsequent neuronal damage. SIGNIFICANCE STATEMENT Neuronal activity leads to the generation of CO2, which has previously been shown to evoke cerebral blood flow (CBF) increases via the release of the vasodilator PgE2. We demonstrate that hypercapnia (increased CO2) evokes increases in astrocyte calcium signaling, which in turn stimulates COX-1 activity and generates downstream PgE2 production. We demonstrate that astrocyte calcium

  13. Effects of octreotide on acute necrotizing pancreatitis in rabbits

    Institute of Scientific and Technical Information of China (English)

    László Czakó; Péter Hegyi; Tamás Takács; Csaba Góg; András Farkas; Yvette Mándy; Ilona Sz. Varga; László Tiszlavicz; János Lonovics

    2004-01-01

    AIM: To assess the role of oxygen-derived free radicals and cytokines in the pathogenesis of taurocholic acid-induced acute pancreatitiS, and to evaluate the preventive effects of octreotide towards the development of acute pancreatitis.METHODS: Acute pancreatitis was induced in male New Zealand 50 g/L sodium taurocholate (NaTC) in the pancreatic duct. Shamwas administered subcutaneously before the induction of pancreatitis. Blood was taken from the jugular vein before and at 1, 3, 6, 12 and 24 h after pancreatitis induction.Serum activities of amylase, IL-6 and TNF-α and levels of malonyl dialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), catalase and superoxide dismutase (Mn-,Cu-, and Zn-SOD) in pancreatic tissue were measured.RESULTS: Serum TNF-α and IL-6 levels increased significantly 3 h after the onset of pancreatitis, and then returned to control level. The tissue concentration of MDA was significantly elevated at 24 h, while the GSH level and GP-x, catalase, Mn-SOD, Cu-, Zn-SOD activities were all significantly decreased in animals with pancreatitis as compared to the control. Octreotide pretreatment significantly reversed the changes in cytokines and reactive oxygen metabolites. Octreotide treatment did not alter the serum amylase activity and did not have any beneficial effects on the development of histopathological changes.CONCLUSION: Oxygen-derived free radicals and proinflammatory cytokines are generated at an early stage of NaTc-induced acute pancreatitis in rabbits. Prophylactic octreotide treatment can prevent release of cytokines and generation of reactive oxygen metabolites, but does not have any beneficial effects on the development of necrotizing pancreatitis.

  14. Effect of acute exercise on prostate cancer cell growth.

    Science.gov (United States)

    Rundqvist, Helene; Augsten, Martin; Strömberg, Anna; Rullman, Eric; Mijwel, Sara; Kharaziha, Pedram; Panaretakis, Theocharis; Gustafsson, Thomas; Östman, Arne

    2013-01-01

    Physical activity is associated with reduced risk of several cancers, including aggressive prostate cancer. The mechanisms mediating the effects are not yet understood; among the candidates are modifications of endogenous hormone levels. Long-term exercise is known to reduce serum levels of growth stimulating hormones. In contrast, the endocrine effects of acute endurance exercise include increased levels of mitogenic factors such as GH and IGF-1. It can be speculated that the elevation of serum growth factors may be detrimental to prostate cancer progression into malignancy. The incentive of the current study is to evaluate the effect of acute exercise serum on prostate cancer cell growth. We designed an exercise intervention where 10 male individuals performed 60 minutes of bicycle exercise at increasing intensity. Serum samples were obtained before (rest serum) and after completed exercise (exercise serum). The established prostate cancer cell line LNCaP was exposed to exercise or rest serum. Exercise serum from 9 out of 10 individuals had a growth inhibitory effect on LNCaP cells. Incubation with pooled exercise serum resulted in a 31% inhibition of LNCaP growth and pre-incubation before subcutaneous injection into SCID mice caused a delay in tumor formation. Serum analyses indicated two possible candidates for the effect; increased levels of IGFBP-1 and reduced levels of EGF. In conclusion, despite the fear of possible detrimental effects of acute exercise serum on tumor cell growth, we show that even the short-term effects seem to add to the overall beneficial influence of exercise on neoplasia.

  15. Effect of acute exercise on prostate cancer cell growth.

    Directory of Open Access Journals (Sweden)

    Helene Rundqvist

    Full Text Available Physical activity is associated with reduced risk of several cancers, including aggressive prostate cancer. The mechanisms mediating the effects are not yet understood; among the candidates are modifications of endogenous hormone levels. Long-term exercise is known to reduce serum levels of growth stimulating hormones. In contrast, the endocrine effects of acute endurance exercise include increased levels of mitogenic factors such as GH and IGF-1. It can be speculated that the elevation of serum growth factors may be detrimental to prostate cancer progression into malignancy. The incentive of the current study is to evaluate the effect of acute exercise serum on prostate cancer cell growth. We designed an exercise intervention where 10 male individuals performed 60 minutes of bicycle exercise at increasing intensity. Serum samples were obtained before (rest serum and after completed exercise (exercise serum. The established prostate cancer cell line LNCaP was exposed to exercise or rest serum. Exercise serum from 9 out of 10 individuals had a growth inhibitory effect on LNCaP cells. Incubation with pooled exercise serum resulted in a 31% inhibition of LNCaP growth and pre-incubation before subcutaneous injection into SCID mice caused a delay in tumor formation. Serum analyses indicated two possible candidates for the effect; increased levels of IGFBP-1 and reduced levels of EGF. In conclusion, despite the fear of possible detrimental effects of acute exercise serum on tumor cell growth, we show that even the short-term effects seem to add to the overall beneficial influence of exercise on neoplasia.

  16. Effect of Taurine on Febrile Episodes in Acute Lymphoblastic Leukemia

    Directory of Open Access Journals (Sweden)

    Mina Islambulchilar

    2015-03-01

    Full Text Available Purpose: The purpose of our study was to evaluate the effect of oral taurine on the incidence of febrile episodes during chemotherapy in young adults with acute lymphoblastic leukemia. Methods: Forty young adults with acute lymphoblastic leukemia, at the beginning of maintenance course of their chemotherapy, were eligible for this study. The study population was randomized in a double blind manner to receive either taurine or placebo (2 gram per day orally. Life quality and side effects including febrile episodes were assessed using questionnaire. Data were analyzed using Pearson’s Chi square test. Results: Of total forty participants, 43.8% were female and 56.3 % were male. The mean age was 19.16±1.95 years (ranges: 16-23 years. The results indicated that the levels of white blood cells are significantly (P<0.05 increased in taurine treated group. There was no elevation in blasts count. A total of 70 febrile episodes were observed during study, febrile episodes were significantly (P<0.05 lower in taurine patients in comparison to the control ones. Conclusion: The overall incidence of febrile episodes and infectious complications in acute lymphoblastic leukemia patients receiving taurine was lower than placebo group. Taurine’s ability to increase leukocyte count may result in lower febrile episodes.

  17. Vasodilator and vasoconstrictor responses induced by 5-hydroxytryptamine in the in situ blood autoperfused hindquarters of the anaesthetized rat.

    Science.gov (United States)

    Calama, E; Fernández, M M; Morán, A; Martín, M L; San Román, L

    2002-08-01

    In the present study we attempted to characterise the responses and receptors involved in the effects of 5-hydroxytryptamine (5-HT, serotonin) in in situ autoperfused rat hindquarters. Intra-arterial administration of the lowest doses of 5-HT used (0.12-12.5 ng/kg) induced vasodilator responses, whereas the highest doses (25-1000 ng/kg) produced vasoconstriction. The vasodilator effect was inhibited by methiothepin (a non-specific 5-HT(1,2,5,6,7) receptor antagonist) and by a 5-HT(1D/1B) receptor antagonist, i.e., 3-[4-(4-chlorophenyl)piperazin-1-yl]-1,1-diphenyl-2-propanolol (BRL 15572), but not by ritanserin (a selective 5-HT(2) receptor antagonist), 5-methyl-1-(3-pyridylcarbamoyl)-1,2,3,5-tetrahydropyrrolo[2,3-f] indole (SB 206553, a selective 5-HT(2B/2C) receptor antagonist) or mesulergine (a non-specific serotonergic antagonist that shows affinity to the 5-HT(7) receptor). This vasodilator effect was mimicked by administration of a selective 5-HT(1) receptor agonist - 5-carboxamidotryptamine (5-CT) - and by 2-[5-[3-(4-methylsulphonylamino)benzyl-1,2,4-1 H-indol-3-yl]ethanamine (L-694,247, a selective 5-HT(1D/1B) receptor agonist). Methiothepin, but not mesulergine, inhibited 5-CT-induced vasodilatation and the selective 5-HT(1D/1B) receptor antagonist (BRL 15572) inhibited the vasodilator action induced by L-694,247. The vasoconstrictor effect of 5-HT was significantly decreased by methiothepin, ritanserin and SB 206553, and was mimicked by alpha-methyl-5-HT (a selective 5-HT(2) receptor agonist) but not by administration of BW 723C86, a selective 5HT(2B) receptor agonist. Ritanserin, SB 206553 and spiperone (a non-specific 5-HT(1/2A) receptor antagonist) inhibited the alpha-methyl-5HT-induced vasoconstriction.Our data suggest that the vasodilator response induced by 5-HT in autoperfused rat hindquarters is mainly mediated by 5-HT(1D/1B) receptors, whereas the vasoconstrictor effect is mainly due to the activation of 5-HT(2A) receptors.

  18. Does PGE₁ vasodilator prevent orthopaedic implant-related infection in diabetes? Preliminary results in a mouse model.

    Directory of Open Access Journals (Sweden)

    Arianna B Lovati

    Full Text Available BACKGROUND: Implant-related infections are characterized by bacterial colonization and biofilm formation on the prosthesis. Diabetes represents one of the risk factors that increase the chances of prosthetic infections because of related severe peripheral vascular disease. Vasodilatation can be a therapeutic option to overcome diabetic vascular damages and increase the local blood supply. In this study, the effect of a PGE₁ vasodilator on the incidence of surgical infections in diabetic mice was investigated. METHODOLOGY: A S. aureus implant-related infection was induced in femurs of diabetic mice, then differently treated with a third generation cephalosporin alone or associated with a PGE₁ vasodilator. Variations in mouse body weight were evaluated as index of animal welfare. The femurs were harvested after 28 days and underwent both qualitative and quantitative analysis as micro-CT, histological and microbiological analyses. RESULTS: The analysis performed in this study demonstrated the increased host response to implant-related infection in diabetic mice treated with the combination of a PGE₁ and antibiotic. In this group, restrained signs of infections were identified by micro-CT and histological analysis. On the other hand, the diabetic mice treated with the antibiotic alone showed a severe infection and inability to successfully respond to the standard antimicrobial treatment. CONCLUSIONS: The present study revealed interesting preliminary results in the use of a drug combination of antibiotic and vasodilator to prevent implant-related Staphylococcus aureus infections in a diabetic mouse model.

  19. Cyclooxygenase-derived vasoconstriction restrains hypoxia-mediated cerebral vasodilation in young adults with metabolic syndrome.

    Science.gov (United States)

    Harrell, John W; Schrage, William G

    2014-01-15

    Poor cerebrovascular function in metabolic syndrome (MetSyn) likely contributes to elevated risk of cerebrovascular disease in this growing clinical population. Younger MetSyn adults without clinical evidence of cerebrovascular disease exhibit preserved hypercapnic vasodilation yet markedly impaired hypoxic vasodilation, but the mechanisms behind reduced hypoxic vasodilation are unknown. Based on data from rats, we tested the hypothesis that younger adults with MetSyn exhibit reduced cerebral hypoxic vasodilation due to loss of vasodilating prostaglandins. Middle cerebral artery velocity (MCAv) was measured with transcranial Doppler ultrasound in adults with MetSyn (n = 13, 33 ± 3 yr) and healthy controls (n = 15, 31 ± 2 yr). Isocapnic hypoxia was induced by titrating inspired oxygen to lower arterial saturation to 90% and 80% for 5 min each. Separately, hypercapnia was induced by increasing end-tidal CO2 10 mmHg above baseline levels. Cyclooxygenase inhibition (100 mg indomethacin) was conducted in a randomized double-blind, placebo controlled design. MCAv was normalized for group differences in blood pressure (healthy: 89 ± 2 mmHg vs. MetSyn: 102 ± 2 mmHg) as cerebrovascular conductance index (CVCi), and used to assess cerebral vasodilation. Hypoxia increased CVCi in both groups; however, vasodilation was ∼55% lower in MetSyn at SpO2 = 80% (P vasodilation in healthy controls, and unexpectedly increased dilation in MetSyn (P vasodilation was similar between groups, as was the decrease in vasodilation with indomethacin. These data indicate increased production of vasoconstrictor prostaglandins restrains hypoxic cerebral vasodilation in MetSyn, preventing them from responding appropriately to this important physiological stressor.

  20. Levosimendan beyond inotropy and acute heart failure

    DEFF Research Database (Denmark)

    Farmakis, Dimitrios; Alvarez, Julian; Gal, Tuvia Ben

    2016-01-01

    Levosimendan is a positive inotrope with vasodilating properties (inodilator) indicated for decompensated heart failure (HF) patients with low cardiac output. Accumulated evidence supports several pleiotropic effects of levosimendan beyond inotropy, the heart and decompensated HF. Those effects a...

  1. Effects of acute bouts of exercise on cognition.

    Science.gov (United States)

    Tomporowski, Phillip D

    2003-03-01

    A review was conducted of studies that assessed the effects of acute bouts of physical activity on adults' cognitive performance. Three groups of studies were constituted on the basis of the type of exercise protocol employed. Each group was then evaluated in terms of information-processing theory. It was concluded that submaximal aerobic exercise performed for periods up to 60 min facilitate specific aspects of information processing; however, extended exercise that leads to dehydration compromises both information processing and memory functions. The selective effects of exercise on cognitive performance are explained in terms of Sanders' [Acta Psychol. 53 (1983) 61] cognitive-energetic model.

  2. Influence of dehydration on locally mediated hindlimb vasodilation in baboons.

    Science.gov (United States)

    Thornton, R M; Proppe, D W

    1988-08-01

    Previous studies indicate that the heat stress-induced cutaneous vasodilation in baboons is attenuated during dehydration by mechanisms other than the well-known neurohumoral vasoconstrictor mechanisms. Therefore, this study sought to determine whether dehydration also attenuates locally mediated maximum hindlimb blood flow and vascular conductance in baboons. Five baboons were chronically instrumented to measure arterial blood pressure and mean external iliac artery blood flow (MIBF). Hindlimb vasodilation was induced by occlusions of the external iliac artery for 2.5, 5.0, 7.5, and 10.0 min and by close-arterial injections of acetylcholine (ACh) and sodium nitroprusside (NP) in graded doses. These vasodilatory stimuli were applied in euhydrated and dehydrated states, the latter being produced by water deprivation for 64-68 h. Maximum MIBF and iliac vascular conductance (IVC) after arterial occlusion were reduced by 67-70% during dehydration. Also, maximum MIBF and IVC produced by ACh in the dehydrated state were 46-52% lower than in the euhydrated state. A similar reduction in the responses to NP occurred during dehydration. It is concluded that the maximum hindlimb blood flow and vascular conductance produced by local, nonneurohumoral mechanisms are attenuated in the baboon during dehydration.

  3. Vasodilation increases pulse pressure variation, mimicking hypovolemic status in rabbits

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    Glauco A Westphal

    2010-01-01

    Full Text Available OBJECTIVE: To test the hypothesis that pulse pressure respiratory variation (PPV amplification, observed in hypovolemia, can also be observed during sodium nitroprusside (SNP-induced vasodilation. INTRODUCTION: PPV is largely used for early identification of cardiac responsiveness, especially when hypovolemia is suspected. PPV results from respiratory variation in transpulmonary blood flow and reflects the left ventricular preload variations during respiratory cycles. Any factor that decreases left ventricular preload can be associated with PPV amplification, as seen in hypovolemia. METHODS: Ten anesthetized and mechanically ventilated rabbits underwent progressive hypotension by either controlled hemorrhage (Group 1 or intravenous SNP infusion (Group 2. Animals in Group 1 (n = 5 had graded hemorrhage induced at 10% steps until 50% of the total volume was bled. Mean arterial pressure (MAP steps were registered and assumed as pressure targets to be reached in Group 2. Group 2 (n = 5 was subjected to a progressive SNP infusion to reach similar pressure targets as those defined in Group 1. Heart rate (HR, systolic pressure variation (SPV and PPV were measured at each MAP step, and the values were compared between the groups. RESULTS: SPV and PPV were similar between the experimental models in all steps (p > 0.16. SPV increased earlier in Group 2. CONCLUSION: Both pharmacologic vasodilation and graded hemorrhage induced PPV amplification similar to that observed in hypovolemia, reinforcing the idea that amplified arterial pressure variation does not necessarily represent hypovolemic status but rather potential cardiovascular responsiveness to fluid infusion.

  4. Placental growth factor is a potent vasodilator of rat and human resistance arteries.

    Science.gov (United States)

    Osol, George; Celia, Gerard; Gokina, Natalia; Barron, Carolyn; Chien, Edward; Mandala, Maurizio; Luksha, Leonid; Kublickiene, Karolina

    2008-03-01

    The objectives of this study were to determine whether placental growth factor (PlGF) exerts a vasodilatory effect on rat uterine vessels (arcuate arteries and veins) and to examine regional differences in reactivity by comparing these responses to those of comparably sized mesenteric vessels. We also sought to examine and compare its effects on human uterine and subcutaneous vessels. All vessels were studied in vitro, under pressurized (rat) or isometric wire-mounted (human) conditions, and exposed to a range of PlGF concentrations. Inhibitors of nitric oxide and prostaglandin synthesis were included in an effort to understand the causal mechanism(s). In rat uterine arteries, the effects of receptor inhibition and activation using selective ligands for VEGFR-1 (PlGF) vs. VEGFR-2 (VEGF-E) were determined, and real-time RT-PCR was performed to evaluate the effect of pregnancy on relative abundance of VEGFR-1 and VEGFR-2 message in the vascular wall. PlGF was a potent vasodilator of all vessels studied, with greatest sensitivity observed in rat uterine arteries. Pregnancy significantly augmented dilator sensitivity to PlGF, and this effect was associated with selective upregulation of VEGFR-1 message in the pregnant state. The contribution of nitric oxide was appreciable in rat and human uterine arteries, with lesser effects in rat uterine veins and mesenteric arteries, and with no observable effect in human subcutaneous vessels. Based on these results, we conclude that PlGF is a potent vasodilator of several vessel types in both humans and rats. Its potency and mechanism vary with physiological state and vessel location and are mediated solely by the VEGFR-1 receptor subtype. Gestational changes in the uterine circulation suggest that this factor may play a role in modulating uterine vascular remodeling and blood flow during the pregnant state.

  5. PLACENTAL GROWTH FACTOR (PlGF) IS A POTENT VASODILATOR OF RAT AND HUMAN RESISTANCE ARTERIES

    Science.gov (United States)

    Osol, George; Celia, Gerard; Gokina, Natalia; Barron, Carolyn; Chien, Edward; Mandala, Maurizio; Luksha, Leonid; Kublickiene, Karolina

    2010-01-01

    The objectives of this study were to determine whether PlGF exerts a vasodilatory effect on rat uterine vessels (arcuate arteries and veins) and to examine regional differences in reactivity by comparing these responses to those of comparably-sized mesenteric vessels. We also sought to examine and compare its effects on human uterine and subcutaneous vessels. All vessels were studied in vitro, under pressurized (rat) or isometric wire-mounted (human) conditions, and exposed to a range of PlGF concentrations. Inhibitors of nitric oxide and prostaglandin synthesis were included in an effort to understand the causal mechanism(s). In rat uterine arteries, the effects of receptor inhibition and activation using selective ligands for VEGFR-1 (PlGF) vs. VEGFR-2 (VEGF-E) were determined, and real-time RT-PCR was performed to evaluate the effect of pregnancy on relative abundance of VEGFR-1 and VEGFR-2 message in the vascular wall. PlGF was a potent vasodilator of all vessels studied, with greatest sensitivity observed in rat uterine arteries. Pregnancy significantly augmented dilator sensitivity to PlGF, and this effect was associated with selective upregulation of VEGFR-1 message in the pregnant state. The contribution of nitric oxide was appreciable in rat and human uterine arteries, with lesser effects in rat uterine veins and mesenteric arteries, and with no observable effect in human subcutaneous vessels. Based on these results, we conclude that PlGF is a potent vasodilator of several vessel types in both humans and rats. Its potency and mechanism varies with physiological state and vessel location, and is mediated solely by the VEGFR-1 receptor subtype. Gestational changes in the uterine circulation suggest that this factor may play a role in modulating uterine vascular remodeling and blood flow during the pregnant state. PMID:18192215

  6. Bronchodilator, vasodilator and spasmolytic activities of methanolic extract of Myrtus communis L.

    Science.gov (United States)

    Janbaz, K H; Nisa, M; Saqib, F; Imran, I; Zia-Ul-Haq, M; De Feo, V

    2013-08-01

    The present study was undertaken to validate some of the folkloric claims about the effectiveness of the use of a Myrtus communis L. crude methanol extract (Mc.Cr) in gastrointestinal, respiratory and vascular diseases. Mc.Cr caused complete relaxation of spontaneous and K⁺ (80 mM)-induced contractions in isolated rabbit jejunum. It caused right ward parallel shift of calcium concentration response curves. Mc.Cr exhibited relaxant effect on CCh- and K⁺ (80 mM)-induced contractions in isolated rabbit tracheal preparations. Furthermore, Mc.Cr caused relaxation of phenylephrine (1 μM)- and K⁺ (80 mM)-induced contractions in isolated rabbit aorta preparations. These effects were similar to verapamil, a standard calcium channel blocker. These findings could be the basis for explaining the spasmolytic, bronchodilator and vasodilator activities of the extract, through a possible calcium channel blocking activity.

  7. Evaluation of the antidepressant-like effects of acute and sub-acute administration of crocin and crocetin in mice

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    Bahareh Amin

    2015-08-01

    Full Text Available Objective: The present study was designed to investigate the putative antidepressant effects of crocin and crocetin, two major active ingredients of Crocus sativus L. (saffron using mice in two different regimens of acute and sub-acute administration. Material and Methods: In acute treatment, antidepressant-like activities of crocin and crocetin (10, 20 and 40 mg/kg, i.p. were evaluated using forced swim test (FST. In sub-acute study (21 times with 24-h intervals, antidepressant-like effects of oral administration of drugs were examined using FST and tail suspension test (TST. Locomotor activity and motor coordination were studied using open field and rotarod tests, respectively. Results: Acute treatment with crocin (40 mg/kg and crocetin (20 and 40 mg/kg produced antidepressant-like effect in FST without affecting the baseline locomotion in mice. Sub-acute oral administration of crocin significantly decreased immobility time only at the highest dose (100 mg/kg. Crocetin (12.5, 25 and 50 mg/kg was able to decrease immobility time in FST and TST. Locomotor activity and coordination of mice were not affected by crocin or crocetin. Conclusion: Since higher doses of crocin was required to show antidepressant effects, more efficacy of crocetin may be concluded. This observation provides further support for metabolism of crocin to crocetin following oral administration.

  8. A Lipid Emulsion Reverses Toxic-Dose Bupivacaine-Induced Vasodilation during Tyrosine Phosphorylation-Evoked Contraction in Isolated Rat Aortae

    Science.gov (United States)

    Ok, Seong-Ho; Lee, Soo Hee; Kwon, Seong-Chun; Choi, Mun Hwan; Shin, Il-Woo; Kang, Sebin; Park, Miyeong; Hong, Jeong-Min; Sohn, Ju-Tae

    2017-01-01

    The goal of this in vitro study was to examine the effect of a lipid emulsion on toxic-dose bupivacaine-induced vasodilation in a model of tyrosine phosphatase inhibitor sodium orthovanadate-induced contraction in endothelium-denuded rat aortae and to elucidate the associated cellular mechanism. The effect of a lipid emulsion on vasodilation induced by a toxic dose of a local anesthetic during sodium orthovanadate-induced contraction was examined. In addition, the effects of various inhibitors, either bupivacaine alone or a lipid emulsion plus bupivacaine, on protein kinase phosphorylation induced by sodium orthovanadate in rat aortic vascular smooth muscle cells was examined. A lipid emulsion reversed the vasodilation induced by bupivacaine during sodium orthovanadate-induced contraction. The lipid emulsion attenuated the bupivacaine-mediated inhibition of the sodium orthovanadate-induced phosphorylation of protein tyrosine, c-Jun NH2-terminal kinase (JNK), myosin phosphatase target subunit 1 (MYPT1), phospholipase C (PLC) γ-1 and extracellular signal-regulated kinase (ERK). These results suggest that a lipid emulsion reverses toxic-dose bupivacaine-induced vasodilation during sodium orthovanadate-induced contraction via the activation of a pathway involving either tyrosine kinase, JNK, Rho-kinase and MYPT1 or tyrosine kinase, PLC γ-1 and ERK, and this reversal is associated with the lipid solubility of the local anesthetic and the induction of calcium sensitization. PMID:28208809

  9. A Lipid Emulsion Reverses Toxic-Dose Bupivacaine-Induced Vasodilation during Tyrosine Phosphorylation-Evoked Contraction in Isolated Rat Aortae

    Directory of Open Access Journals (Sweden)

    Seong-Ho Ok

    2017-02-01

    Full Text Available The goal of this in vitro study was to examine the effect of a lipid emulsion on toxic-dose bupivacaine-induced vasodilation in a model of tyrosine phosphatase inhibitor sodium orthovanadate-induced contraction in endothelium-denuded rat aortae and to elucidate the associated cellular mechanism. The effect of a lipid emulsion on vasodilation induced by a toxic dose of a local anesthetic during sodium orthovanadate-induced contraction was examined. In addition, the effects of various inhibitors, either bupivacaine alone or a lipid emulsion plus bupivacaine, on protein kinase phosphorylation induced by sodium orthovanadate in rat aortic vascular smooth muscle cells was examined. A lipid emulsion reversed the vasodilation induced by bupivacaine during sodium orthovanadate-induced contraction. The lipid emulsion attenuated the bupivacaine-mediated inhibition of the sodium orthovanadate-induced phosphorylation of protein tyrosine, c-Jun NH2-terminal kinase (JNK, myosin phosphatase target subunit 1 (MYPT1, phospholipase C (PLC γ-1 and extracellular signal-regulated kinase (ERK. These results suggest that a lipid emulsion reverses toxic-dose bupivacaine-induced vasodilation during sodium orthovanadate-induced contraction via the activation of a pathway involving either tyrosine kinase, JNK, Rho-kinase and MYPT1 or tyrosine kinase, PLC γ-1 and ERK, and this reversal is associated with the lipid solubility of the local anesthetic and the induction of calcium sensitization.

  10. Contribution of Kv7 channels to natriuretic peptide mediated vasodilation in normal and hypertensive rats

    DEFF Research Database (Denmark)

    Stott, Jennifer B; Barrese, Vincenzo; Jepps, Thomas Andrew;

    2015-01-01

    -cAMP-linked vasodilator pathways has not been investigated. Natriuretic peptides are potent vasodilators, which operate primarily through the activation of a cGMP-dependent signaling pathway. This study investigated the putative role of Kv7 channels in natriuretic peptide-dependent relaxations in the vasculature...

  11. Contribution of different local vascular responses to mid-gestational vasodilation

    NARCIS (Netherlands)

    Drongelen, J. van; Pertijs, J.C.L.M.; Wouterse, A.C.; Hermsen, R.; Sweep, F.C.; Lotgering, F.K.; Smits, P.; Spaanderman, M.E.A.

    2011-01-01

    OBJECTIVE: At-term pregnancy-induced vasodilation is the resultant of endothelium-dependent vasodilation, decreased myogenic reactivity, increased compliance, and reduced sensitivity to vasoconstrictor agents. We hypothesized that these vascular changes are already present at mid-gestation. STUDY

  12. Role of non-nitric oxide non-prostaglandin endothelium-derived relaxing factor(s in bradykinin vasodilation

    Directory of Open Access Journals (Sweden)

    A.C. Resende

    1998-09-01

    Full Text Available The most conspicuous effect of bradykinin following its administration into the systemic circulation is a transient hypotension due to vasodilation. In the present study most of the available evidence regarding the mechanisms involved in bradykinin-induced arterial vasodilation is reviewed. It has become firmly established that in most species vasodilation in response to bradykinin is mediated by the release of endothelial relaxing factors following the activation of B2-receptors. Although in some cases the action of bradykinin is entirely mediated by the endothelial release of nitric oxide (NO and/or prostacyclin (PGI2, a large amount of evidence has been accumulated during the last 10 years indicating that a non-NO/PGI2 factor accounts for bradykinin-induced vasodilation in a wide variety of perfused vascular beds and isolated small arteries from several species including humans. Since the effect of the non-NO/PGI2 endothelium-derived relaxing factor is practically abolished by disrupting the K+ electrochemical gradient together with the fact that bradykinin causes endothelium-dependent hyperpolarization of vascular smooth muscle cells, the action of such factor has been attributed to the opening of K+ channels in these cells. The pharmacological characteristics of these channels are not uniform among the different blood vessels in which they have been examined. Although there is some evidence indicating a role for KCa or KV channels, our findings in the mesenteric bed together with other reports indicate that the K+ channels involved do not correspond exactly to any of those already described. In addition, the chemical identity of such hyperpolarizing factor is still a matter of controversy. The postulated main contenders are epoxyeicosatrienoic acids or endocannabinoid agonists for the CB1-receptors. Based on the available reports and on data from our laboratory in the rat mesenteric bed, we conclude that the NO/PGI2-independent endothelium

  13. Non-endothelial endothelin counteracts hypoxic vasodilation in porcine large coronary arteries

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    Fröbert Ole

    2011-05-01

    Full Text Available Abstract Background The systemic vascular response to hypoxia is vasodilation. However, reports suggest that the potent vasoconstrictor endothelin-1 (ET-1 is released from the vasculature during hypoxia. ET-1 is reported to augment superoxide anion generation and may counteract nitric oxide (NO vasodilation. Moreover, ET-1 was proposed to contribute to increased vascular resistance in heart failure by increasing the production of asymmetric dimethylarginine (ADMA. We investigated the role of ET-1, the NO pathway, the potassium channels and radical oxygen species in hypoxia-induced vasodilation of large coronary arteries. Results In prostaglandin F2α (PGF2α, 10 μM-contracted segments with endothelium, gradual lowering of oxygen tension from 95 to 1% O2 resulted in vasodilation. The vasodilation to O2 lowering was rightward shifted in segments without endothelium at all O2 concentrations except at 1% O2. The endothelin receptor antagonist SB217242 (10 μM markedly increased hypoxic dilation despite the free tissue ET-1 concentration in the arterial wall was unchanged in 1% O2 versus 95% O2. Exogenous ET-1 reversed hypoxic dilation in segments with and without endothelium, and the hypoxic arteries showed an increased sensitivity towards ET-1 compared to the normoxic controls. Without affecting basal NO, hypoxia increased NO concentration in PGF2α-contracted arteries, and an NO synthase inhibitor, L-NOARG,(300 μM, NG-nitro-L-Arginine reduced hypoxic vasodilation. NO-induced vasodilation was reduced in endothelin-contracted preparations. Arterial wall ADMA concentrations were unchanged by hypoxia. Blocking of potassium channels with TEA (tetraethylammounium chloride(10 μM inhibited vasodilation to O2 lowering as well as to NO. The superoxide scavenger tiron (10 μM and the putative NADPH oxidase inhibitor apocynin (10 μM leftward shifted concentration-response curves for O2 lowering without changing vasodilation to 1% O2. PEG (polyethylene

  14. Endothelium-derived hyperpolarizing factor contributes to hypoxia-induced skeletal muscle vasodilation in humans.

    Science.gov (United States)

    Spilk, Samson; Herr, Michael D; Sinoway, Lawrence I; Leuenberger, Urs A

    2013-12-01

    Systemic hypoxia causes skeletal muscle vasodilation, thereby preserving O2 delivery to active tissues. Nitric oxide (NO), adenosine, and prostaglandins contribute to this vasodilation, but other factors may also play a role. We tested the hypothesis that regional inhibition of endothelium-derived hyperpolarizing factor with the cytochrome P-450 2C9 antagonist fluconazole, alone or combined with the NO synthase antagonist N(G)-monomethyl-L-arginine (L-NMMA), attenuates hypoxia-induced vasodilation. We compared forearm blood flow (FBF) and skin blood flow before and during brachial artery infusion of fluconazole (0.3 mg/min; trial 1) or fluconazole + L-NMMA (50 mg over 10 min; trial 2) and during systemic hypoxia (10 min, arterial Po2 ~37 mmHg) in infused (experimental) and control forearms of 12 healthy humans. During normoxia, fluconazole and fluconazole + L-NMMA reduced (P vasodilation and could be particularly relevant when other vasodilator systems are impaired.

  15. Effect of Probiotic Administration on Acute Inflammatory Pain

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    Shadnoush

    2016-11-01

    Full Text Available Background Acute inflammatory pain causes by direct stimulation of nociceptors and release of inflammatory mediators and cytokines. Probiotics are capable to modulate the immune system, down regulate the inflammatory mediators, and increase regulatory and anti-inflammatory cytokines. Objectives The aim of this study was to examine the effect of oral administration of probiotics on behavioral, cellular and molecular aspects of acute inflammatory pain in male rats. Methods Adult male Wistar rats (200 - 220 g were selected and randomly divided into 7 experimental groups (CFA, CFA control, CFA + vehicle (distilled water, CFA + 3 doses of probiotics, CFA + indomethacin and each group was divided into 3 subgroups based on different time points (days 0, 3, and 7 (n = 6 rats, each group. Complete Freund’s adjuvant (CFA-induced arthritis (AA was caused by a single subcutaneous injection of CFA into the rats’ left hind paw on day 0. Different doses of probiotics (1/250, 1/500 and 1/1000 (109 CFU/g was administered daily (gavage after the CFA injection. Blood samples were taken from the vessel retro-orbital corners of rat’s eyes. After behavioral and inflammatory tests, the lumbar segments of rat’s spinal cord (L1 - L5 were removed. Hyperalgesia, edema, serum TNF-α and IL-1β levels and NF-κB expression were assessed on days 0, 3, and 7 of the study. Results The results of this study showed the role of effective dose of probiotics (1/500 in reducing edema (P = 0.0009, hyperalgesia (P = 0.0002, serum levels of TNF-α (P = 0.0004 and IL-1β (P = 0.0004 and NF-κB expression (P = 0.0007 during the acute phase of inflammatory pain caused by CFA. Conclusions It seems that an effective dose of probiotics due to its direct effects on inhibition of intracellular signaling pathways and pro-inflammatory cytokines can alleviate inflammatory symptoms and pain in the acute phase.

  16. Acute mucocutaneous and systemic adverse effects of Etretinate

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    "Mortazavi H

    2003-06-01

    Full Text Available This cross sectional study was carried out between 1993 to 1998 at Razi Skin Hospital, the affiliated Dermatology Department of Tehran University of Medical Sciences. Eight hundred patients receiving etretinate for various skin diseases took part in this study. Among them, 457 patients with first admission to dermatologic clinic who had at least four regular sequential visits and responding to our questionnaire were selected to enter the study for evaluating acute toxicity of etretinate. Cheilitis with a frequency of 88 percent was the most frequent side effect. Hair loss (22.97%, dry mouth with thirst (15.09%, dryness of mucous membranes (13.12%, xerosis with pruritus (11.15%, nose bleeding (8.31%, paronychia (5.47%, facial dermatitis (3.06%, conjunctivitis (2.84% and in addition to mucocutaneous ones, chills (2.63%, headache (2.19%, mental depression (2.19%, urinary frequency (1.53% and papilledema (0.44% were among the other observed toxicities, The relationship between mucocutaneous side effect with dosage of etretinate, sex and, age of the patients was evaluated. The association between mucoctaneous toxicities and sex was significant, sex and, age of the patients was evaluated. The association between mucocutaneous toxicities and sex was significant (P<0.05. We observed four rare side effect in the patients including hair color lightening appering as whitening or blondness, hair waving, dyspareunia and gynecomastia. In conclusion, females were more to acute mucocutaneous toxicities of etretinate.

  17. Insulin in Acute Coronary Syndrome: a Narrative Review with Contemporary Perspectives.

    Science.gov (United States)

    Nam, Michael C Y; Byrne, Christopher D; Kaski, Juan Carlos; Greaves, Kim

    2016-10-01

    The role of insulin in the treatment of acute coronary syndrome (ACS) has been widely studied over the past 100 years. The current indication for its use in this context is the treatment of hyperglycemia, irrespective of diabetes, which is associated with adverse outcome. Initial theories proposed that glucose was beneficial in the context of myocardial ischemia and insulin was required to enable glucose cell uptake. However, studies testing this hypothesis with routine insulin administration during ACS have produced disappointing results and research interest has therefore declined. We propose that the less well known but important vasodilator effect of insulin has been overlooked by some of these studies and warrants further consideration. Previous reports have shown that hyperinsulinemic euglycaemia improves myocardial blood flow reserve. With this in mind, this review considers the role of insulin in the context of ACS from the perspective of a vasodilator rather than a metabolic modulator. We discuss the importance of time to treatment, dosage of insulin administered, problems with hypoglycaemia and insulin resistance, and how they may have affected the outcomes of the major trials. Finally, we propose new study designs that allow determination of the optimal vasodilator conditions for the use of insulin as adjunctive pharmacotherapy during myocardial ischaemia.

  18. The effects of acute nicotine on contextual safety discrimination.

    Science.gov (United States)

    Kutlu, Munir G; Oliver, Chicora; Gould, Thomas J

    2014-11-01

    Anxiety disorders, such as post-traumatic stress disorder (PTSD), may be related to an inability to distinguish safe versus threatening environments and to extinguish fear memories. Given the high rate of cigarette smoking in patients with PTSD, as well as the recent finding that an acute dose of nicotine impairs extinction of contextual fear memory, we conducted a series of experiments to investigate the effect of acute nicotine in an animal model of contextual safety discrimination. Following saline or nicotine (at 0.0275, 0.045, 0.09 and 0.18 mg/kg) administration, C57BL/6J mice were trained in a contextual discrimination paradigm, in which the subjects received presentations of conditioned stimuli (CS) that co-terminated with a foot-shock in one context (context A (CXA)) and only CS presentations without foot-shock in a different context (context B (CXB)). Therefore, CXA was designated as the 'dangerous context', whereas CXB was designated as the 'safe context'. Our results suggested that saline-treated animals showed a strong discrimination between dangerous and safe contexts, while acute nicotine dose-dependently impaired contextual safety discrimination (Experiment 1). Furthermore, our results demonstrate that nicotine-induced impairment of contextual safety discrimination learning was not a result of increased generalized freezing (Experiment 2) or contingent on the common CS presentations in both contexts (Experiment 3). Finally, our results show that increasing the temporal gap between CXA and CXB during training abolished the impairing effects of nicotine (Experiment 4). The findings of this study may help link nicotine exposure to the safety learning deficits seen in anxiety disorder and PTSD patients. © The Author(s) 2014.

  19. Role of protein sulfation in vasodilation induced by minoxidil sulfate, a K+ channel opener

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    Meisheri, K.D.; Oleynek, J.J.; Puddington, L. (Cardiovascular Diseases Research, Upjohn Laboratories, Upjohn Company, Kalamazoo, MI (United States))

    1991-09-01

    Evidence from contractile, radioisotope ion flux and electrophysiological studies suggest that minoxidil sulfate (MNXS) acts as a K+ channel opener in vascular smooth muscle. This study was designed to examine possible biochemical mechanisms by which MNXS exerts such an effect. Experiments performed in the isolated rabbit mesenteric artery (RMA) showed that MNXS, 5 microM, but not the parent compound minoxidil, was a potent vasodilator. Whereas the relaxant effects of an another K+ channel opener vasodilator, BRL-34915 (cromakalim), were removed by washing with physiological saline solution, the effects of MNXS persisted after repeated washout attempts. Furthermore, after an initial exposure of segments of intact RMA to (35S) MNXS, greater than 30% of the radiolabel was retained 2 hr after removal of the drug. In contrast, retention of radiolabel was not detected with either (3H)MNXS (label on the piperidine ring of MNXS) or (3H)minoxidil (each less than 3% after a 2-hr washout). These data suggested that the sulfate moiety from MNXS was closely associated with the vascular tissue. To determine if proteins were the acceptors of sulfate from MNXS, intact RMAs were incubated with (35S)MNXS, and then 35S-labeled proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analyzed by fluorography. Preferential labeling of a 116 kD protein was detected by 2 and 5 min of treatment. A 43 kD protein (resembling actin) also showed significant labeling. A similar profile of 35S-labeled proteins was observed in (35S) MNXS-treated A7r5 rat aortic smooth muscle cells, suggesting that the majority of proteins labeled by (35S)MNXS in intact RMA were components of smooth muscle cells.

  20. Evidence for a role of nitric oxide in hindlimb vasodilation induced by hypothalamic stimulation in anesthetized rats

    OpenAIRE

    Ferreira-Neto Marcos L.; Possas Olga S.; Lopes Oswaldo U.; Cravo Sérgio L.

    2005-01-01

    Electrical stimulation of the hypothalamus produces cardiovascular adjustments consisting of hypertension, tachycardia, visceral vasoconstriction and hindlimb vasodilation. Previous studies have demonstrated that hindlimb vasodilation is due a reduction of sympathetic vasoconstrictor tone and to activation of beta2-adrenergic receptors by catecholamine release. However, the existence of a yet unidentified vasodilator mechanism has also been proposed. Recent studies have suggested that nitric ...

  1. Vasodilator-stimulated phosphoprotein-phosphorylation assay in patients on clopidogrel: does standardisation matter?

    Science.gov (United States)

    Freynhofer, Matthias K; Bruno, Veronika; Willheim, Martin; Hübl, Wolfgang; Wojta, Johann; Huber, Kurt

    2012-03-01

    The vasodilator-stimulated phosphoprotein-phosphorylation (VASP-P) flow-cytometric assay is mainly used in clinical trials to measure thienopyridine effects. However, there are remarkable differences in the reported optimal cut-offs, ranging from 48-61% platelet reactivity index (PRI). We therefore investigated whether a lack of standardisation might explain the differences in the cut-offs. We measured VASP-P in 62 individuals. PRI was calculated using the mean, geometric mean and median fluorescence intensities (FI). Stability of the blood-samples (time-to-assay, 0-2 days) and stability of the processed samples (0-120 minutes) within the recommended time-span were tested. Time-to-assay significantly influenced the PRI (pprecise standardisation is inevitable, as the PRI significantly depends on the method of calculation, the time-to-assay as well as on the lag time after processing. Tolerably stable results were obtained for the PRI from the median FI.

  2. [Acute and long-term effects of ecstasy].

    Science.gov (United States)

    Salzmann, Julie; Marie-Claire, Cynthia; Noble, Florence

    2004-10-23

    Side effects in the short term Recreational use of Ecstasy (3,4-methylenedioxymethamphetamine or MDMA), a synthetic drug, has considerably increased over the last decade. Since its appearance it is associated with the rave culture, but its use has spread to other social settings. The drug produces euphoria and empathy, but can lead to side effects, notably acute, potentially lethal, toxicity (malignant hyperthermia and/or hepatitis). Neurotoxicity in the long-term Moreover, MDMA has been shown to induce long-term deleterious effects and provoke neurotoxic affecting the serotoninergic system. However, the psychopathological consequences of such neurotoxicity are still controversial, particularly since many ecstasy consumers are multi-drug users. A complex pharmacological profile The mechanism of action of MDMA involves various neurobiological systems (serotonin, dopamine, noradrenalin), that may all interact.

  3. Calycosin and Formononetin Induce Endothelium-Dependent Vasodilation by the Activation of Large-Conductance Ca2+-Activated K+ Channels (BKCa

    Directory of Open Access Journals (Sweden)

    Hisa Hui Ling Tseng

    2016-01-01

    Full Text Available Calycosin and formononetin are two structurally similar isoflavonoids that have been shown to induce vasodilation in aorta and conduit arteries, but study of their actions on endothelial functions is lacking. Here, we demonstrated that both isoflavonoids relaxed rat mesenteric resistance arteries in a concentration-dependent manner, which was reduced by endothelial disruption and nitric oxide synthase (NOS inhibition, indicating the involvement of both endothelium and vascular smooth muscle. In addition, the endothelium-dependent vasodilation, but not the endothelium-independent vasodilation, was blocked by BKCa inhibitor iberiotoxin (IbTX. Using human umbilical vein endothelial cells (HUVECs as a model, we showed calycosin and formononetin induced dose-dependent outwardly rectifying K+ currents using whole cell patch clamp. These currents were blocked by tetraethylammonium chloride (TEACl, charybdotoxin (ChTX, or IbTX, but not apamin. We further demonstrated that both isoflavonoids significantly increased nitric oxide (NO production and upregulated the activities and expressions of endothelial NOS (eNOS and neuronal NOS (nNOS. These results suggested that calycosin and formononetin act as endothelial BKCa activators for mediating endothelium-dependent vasodilation through enhancing endothelium hyperpolarization and NO production. Since activation of BKCa plays a role in improving behavioral and cognitive disorders, we suggested that these two isoflavonoids could provide beneficial effects to cognitive disorders through vascular regulation.

  4. Mustard gas toxicity: the acute and chronic pathological effects.

    Science.gov (United States)

    Ghabili, Kamyar; Agutter, Paul S; Ghanei, Mostafa; Ansarin, Khalil; Shoja, Mohammadali M

    2010-10-01

    Ever since it was first used in armed conflict, mustard gas (sulfur mustard, MG) has been known to cause a wide range of acute and chronic injuries to exposure victims. The earliest descriptions of these injuries were published during and in the immediate aftermath of the First World War, and a further series of accounts followed the Second World War. More recently, MG has been deployed in warfare in the Middle East and this resulted in large numbers of victims, whose conditions have been studied in detail at hospitals in the region. In this review, we bring together the older and more recent clinical studies on MG toxicity and summarize what is now known about the acute and chronic effects of the agent on the eyes, skin, respiratory tract and other physiological systems. In the majority of patients, the most clinically serious long-term consequences of MG poisoning are on the respiratory system, but the effects on the skin and other systems also have a significant impact on quality of life. Aspects of the management of these patients are discussed.

  5. Effects of antiarrhythmic peptide 10 on acute ventricular arrhythmia

    Institute of Scientific and Technical Information of China (English)

    Bing Sun; Jin-Fa Jiang; Cui-Mei Zhao; Chao-Hui Hu

    2015-01-01

    Objective:To observe the effects antiarrhythmic peptide 10 (AAP10) aon acute ventricular arrhythmia and the phosphorylation state of ischemic myocardium connexin.Methods:Acute total ischemia and partial ischemia models were established by ceasing perfusion and ligating the left anterior descending coronary artery in SD rats. The effects of AAP10 (1 mg/L) on the incidence rate of ischemia-induced ventricular arrhythmia were observed. The ischemic myocardium was sampled to detect total-Cx43 and NP-Cx43 by immunofluorescent staining and western blotting. the total-Cx43 expression was detected through image analysis system by semi-quantitative analysis.Results: AAP10 could significantly decrease the incidence of ischemia-induced ventricular tachycardia and ventricular fibrillation. During ischemic stage, total ischemia (TI) and AAP10 total ischemia (ATI) groups were compared with partial ischemia (PI) and AAP10 partial ischemia (API) groups. The rates of incidence for arrhythmia in the ATI and API groups (10% and 0%) were lower than those in the TI and PI groups (60% and 45%). The difference between the two groups was statistically significant (P=0.019, P=0.020). The semi-quantitative analysis results of the ischemic myocardium showed that the total-Cx43 protein expression distribution areas for TI, ATI, PI and API groups were significantly decreased compared with the control group. On the other hand, the NP-Cx43 distribution areas of TI, ATI, PI and API groups were significantly increased compared with the control group (P>0.05). AAP10 could increase the total-Cx43 expression in the ischemic area and decrease the NP-Cx43 expression. Western blot results were consistent with the results of immunofluorescence staining.Conclusions:AAP10 can significantly decrease the rate of incidence of acute ischemia-induced ventricular tachycardia and ventricular fibrillation. Acute ischemic ventricular arrhythmias may have a relationship with the decreased phosphorylation of Cx43

  6. EFFECTS OF ACUTE HYPOGLYCEMIA ON THE OREXIN SYSTEM IN RAT

    Institute of Scientific and Technical Information of China (English)

    Yu-yan Zhao; Lei Guo; Jian Du; Guo-liang Liu

    2005-01-01

    Objective To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells.Methods Thirty adult male Wistar rats were randomly divided into three equal groups (n= 10). The acute hypoglycemia rat model was induced by a single subcutaneous injection of insulin. Twenty acute hypoglycemia rats were divided into group B and group C. Group B was allowed to eat freely, while group C was food-deprived. Control rats were injected the same volume of saline. The effect of glucose levels (2.8 mmol/L and 8.3 mmol/L) on pancreatic islet cell orexin system was detected in pancreas islet cell cultured in vitro. The expression of prepro-orexin and OXR mRNA was examined in rat hypothalamus tissue and pancreatic islets cell cultured in vitro using reverse transcription-polymerase chain reaction (RTPCR).Results Expression of orexin mRNA increased about 150% for the food-deprived hypoglycemia rats in comparison with control group (P < 0.01), whereas expression of OX1R mRNA decreased up to 30% (P < 0.01). However, expression of OX2R mRNA was unchanged in comparison with control group. In vitro, after incubation with 2.8 mmol/L glucose for 6hours, the expression of prepro-orexin mRNA increased 2 times in rat pancreas islet cells in comparison with 8.3 mmol/Lglucose group (P < 0.01). But the expression of OX1R mRNA was not sensitive to acute glucose fluctuation.Conclusions Orexin in rat hypothalamus is stimulated by decline in blood glucose and inhibited by signals related to feeding. Moreover, glucose plays a role in modulating the gene expression of prepro-orexin in rat pancreatic islet cells.

  7. Alpha-adrenergic receptor blockade by phentolamine increases the efficacy of vasodilators in penile corpus cavernosum.

    Science.gov (United States)

    Kim, N N; Goldstein, I; Moreland, R B; Traish, A M

    2000-03-01

    Penile trabecular smooth muscle tone, a major determinant of erectile function, is highly regulated by numerous inter- and intracellular pathways. The interaction between pathways mediating contraction and relaxation has not been studied in detail. To this end, we investigated the functional effects of alpha adrenergic receptor blockade with phentolamine and its interaction with vasodilators (sildenafil, vasoactive intestinal polypeptide (VIP) and PGE1) that elevate cyclic nucleotides on penile cavernosal smooth muscle contractility. In organ bath preparations of cavernosal tissue strips contracted with phenylephrine, phentolamine significantly enhanced relaxation induced by sildenafil, VIP and PGE1. Sildenafil, VIP or PGE1 also significantly enhanced relaxation induced by phentolamine in cavernosal tissue strips contracted with phenylephrine. To study the effects of alpha adrenergic receptor blockade and modification of cyclic nucleotide metabolism during active neurogenic input, cavernosal tissue strips in organ bath preparations were contracted with the non-adrenergic agonist endothelin-1 and subjected to electrical field stimulation (EFS) in the absence or presence of phentolamine and/or sildenafil. EFS (5-40Hz) typically caused biphasic relaxation and contraction responses. Phentolamine alone enhanced relaxation and reduced or prevented contraction to EFS. Sildenafil enhanced relaxation to EFS at lower frequencies (phentolamine and sildenafil enhanced EFS-induced relaxation at all frequencies tested. EFS, in the presence of 10 nM phentolamine and 30 nM sildenafil, produced enhanced relaxation responses which were quantitatively similar to those obtained in the presence of 50 nM sildenafil alone. Thus, blockade of alpha-adrenergic receptors with phentolamine increases the efficacy of cyclic nucleotide-dependent vasodilators. Furthermore, phentolamine potentiates relaxation and attenuates contraction in response to endogenous neurotransmitters which are released

  8. The effects of specific preconditioning activities on acute sprint performance.

    Science.gov (United States)

    Guggenheimer, Joshua D; Dickin, D Clark; Reyes, Gabriel F; Dolny, Dennis G

    2009-07-01

    Previous research suggests that specific preconditioning activities such as whole-body vibration (WBV) and resistance training may play an important role in ensuing dynamic activities. The purpose of this study was to examine the effects of 2 preconditioning activities, WBV and power cleans (PC), on acute sprint performance. Two studies were conducted in which 14 (WBV) and 9 (PC) male track and field athletes were subjects. The WBV treatment consisted of 4 bouts of 5 seconds of high-knee running on a vibrating platform at 0, 30, 40, or 50 Hz. The PC treatment consisted of 3 PC reps at 90% 1RM. In both cases, acute sprint performance was the dependent variable of interest. For WBV, split times were recorded at 10, 20, and 40 m. Reaction times (RXN) as well as 5-, 10-, and 40-m split times were recorded for the PC study. Results indicated no significant differences between treatment and nontreatment groups for both studies. However, significant correlations were present between RXN and 5-m splits (r = 0.65) and RXN and 10-m splits (r = 0.63), although they decreased as a function of sprint distance to r = 0.43 at 40 m. These results suggest little efficacy for the use of WBV and PC as a means of augmenting acute sprint performance. However, a trend within the 30-Hz protocol may suggest that WBV as part of a warm-up for sprinting activities greater than 40 m (i.e., 100 m) could potentially result in a decreased sprint time of nearly 1/10th of a second, which is worth future consideration.

  9. Acute hyperglycemia-induced endothelial dysfunction in retinal arterioles in cats.

    Science.gov (United States)

    Sogawa, Kenji; Nagaoka, Taiji; Izumi, Naohiro; Nakabayashi, Seigo; Yoshida, Akitoshi

    2010-05-01

    To investigate the effects of acute hyperglycemia on retinal microcirculation and endothelial function in cats and removal of superoxide to prevent retinal endothelial dysfunction from hyperglycemia. Hyperglycemia was induced by intravenous injection of 25% glucose to maintain the plasma glucose concentration at 30 mM. Laser Doppler velocimetry was used to measure the vessel diameter (D) and blood velocity (V) simultaneously and calculated retinal blood flow (RBF) in second-order retinal arterioles in cats. Intravitreous, endothelial-dependent vasodilator bradykinin (BK) and endothelium-independent vasodilator sodium nitroprusside (SNP) were administered into the vitreous cavity to evaluate endothelial function in the retinal arterioles. To control osmolality, 25% mannitol was administered the same way. Systemic hyperoxia was induced to noninvasively examine endothelial function during hyperglycemia. To determine the effect of the superoxide on the hyperglycemia-induced changes in the retinal circulation, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) was administered in drinking water for 14 days before the experiment. The D, V, and RBF increased with acute hyperglycemia and mannitol compared with baseline. BK-induced increases in D, V, and RBF significantly declined, whereas SNP-induced increases were unattenuated during acute hyperglycemia. Return of the decreased RBF to baseline after cessation of systemic hyperoxia was significantly (P oxidative stress. Systemic hyperoxia can be used to noninvasively evaluate retinal endothelial function during hyperglycemia.

  10. Acute and neuropathic orofacial antinociceptive effect of eucalyptol.

    Science.gov (United States)

    Melo Júnior, José de Maria de Albuquerque de; Damasceno, Marina de Barros Mamede Vidal; Santos, Sacha Aubrey Alves Rodrigues; Barbosa, Talita Matias; Araújo, João Ronielly Campêlo; Vieira-Neto, Antonio Eufrásio; Wong, Deysi Viviana Tenazoa; Lima-Júnior, Roberto César Pereira; Campos, Adriana Rolim

    2017-02-16

    Terpenes have a wide range of pharmacological properties, including antinociceptive action. The anti-inflammatory and antinociceptive effects of eucalyptol are well established. The purpose of this study was to evaluate the antinociceptive effect of eucalyptol on acute and neuropathic orofacial pain in rodent models. Acute orofacial and corneal nociception was induced with formalin, capsaicin, glutamate and hypertonic saline in mice. In another series, animals were pretreated with capsazepine or ruthenium red to evaluate the involvement of TRPV1 receptors in the effect of eucalyptol. In a separate experiment, perinasal tissue levels of IL-1β, TNF-α and IFN-γ were measured. Rats were pretreated with eucalyptol before induction of temporomandibular joint pain with formalin or mustard oil. In another experiment, rats were submitted to infraorbital nerve transection (IONX) to induce chronic pain, followed by induction of mechanical hypersensitivity using Von Frey hairs. Locomotor performance was evaluated with the open-field test, and molecular docking was conducted on the TRPV1 channel. Pretreatment with eucalyptol significantly reduced formalin-induced nociceptive behaviors in all mouse strains, but response was more homogenous in the Swiss strain. Eucalyptol produced antinociceptive effects in all tests. The effect was sensitive to capsazepine but not to ruthenium red. Moreover, eucalyptol significantly reduced IFN-γ levels. Matching the results of the experiment in vivo, the docking study indicated an interaction between eucalyptol and TRPV1. No locomotor activity changes were observed. Our study shows that eucalyptol may be a clinically relevant aid in the treatment of orofacial pain, possibly by acting as a TRPV1 channel antagonist.

  11. Side effects of using nitrates to treat heart failure and the acute coronary syndromes, unstable angina and acute myocardial infarction.

    Science.gov (United States)

    Thadani, Udho; Ripley, Toni L

    2007-07-01

    Nitrates are potent venous dilators and anti-ischemic agents. They are widely used for the relief of chest pain and pulmonary congestion in patients with acute coronary syndromes and heart failure. Nitrates, however, do not reduce mortality in patients with acute coronary syndromes. Combination of nitrates and hydralazine when given in addition to beta-blockers and angiotensin-converting enzyme (ACE) inhibitors reduce mortality and heart failure hospitalizations in patients with heart failure due to left ventricular systolic dysfunction who are of African-American origin. Side effects during nitrate therapy are common but are less well described in the literature compared with the reported side effects in patients with stable angina pectoris. The reported incidence of side effects varies highly among different studies and among various disease states. Headache is the most commonly reported side effect with an incidence of 12% in acute heart failure, 41-73% in chronic heart failure, 3-19% in unstable angina and 2-26% in acute myocardial infarction. The reported incidence of hypotension also differs: 5-10% in acute heart failure, 20% in chronic heart failure, 9% in unstable angina and < 1-48% in acute myocardial infarction, with the incidence being much higher with concomitant nitrate therapy plus angiotensin-converting enzyme inhibitors. Reported incidence of dizziness is as low as 1% in patients with acute myocardial infarction to as high as 29% in patients with heart failure. Severe headaches and/or symptomatic hypotension may necessitate discontinuation of nitrate therapy. Severe life threatening hypotension or even death may occur when nitrates are used in patients with acute inferior myocardial infarction associated with right ventricular dysfunction or infarction, or with concomitant use of phosphodiesterase-5 inhibitors or N-acetylcysteine. Despite the disturbing observational reports in the literature that continuous and prolonged use of nitrates may lead to

  12. Impact of local endothelial challenge with cytomegalovirus or glycoprotein B on vasodilation in intact pressurized arteries from nonpregnant and pregnant mice.

    Science.gov (United States)

    Gombos, Randi B; Teefy, Jana; Lee, Albert; Hemmings, Denise G

    2012-10-01

    Cytomegalovirus (CMV) infections are associated with vascular diseases in the human population. We have previously shown vascular dysfunction in systemic and uterine arteries dissected from nonpregnant (NP) mouse CMV (mCMV)-infected mice that was further impaired during late pregnancy (LP). CMV attachment alone through glycoprotein B (GB) can generate signals that impact vascular tone regulation. However, the contribution of direct virus interactions with endothelium to the vascular dysfunction we previously observed after in vivo mCMV infection is not known. We used a pressure myograph system to infuse GB or whole intact mCMV inside arteries dissected from uninfected mice and assessed vasodilation to methacholine infused inside pressurized arteries rather than applied abluminally. These results were compared to those observed after methacholine infusion into untreated arteries dissected from mCMV-infected mice. In mesenteric arteries, vasodilation to infused methacholine did not differ among treatments in NP or LP groups in contrast to previously published studies. However, increased vasoconstrictor activity was unmasked after blocking thromboxane receptors or prostaglandin production. Vasodilation in uterine arteries from uninfected NP mice to infused methacholine was increased by both GB and whole intact mCMV pretreatment. Untreated uterine arteries from mCMV-infected NP mice showed even greater vasodilation. There was no effect of GB or whole intact mCMV pretreatment in uterine arteries from uninfected LP mice, whereas vasodilation to infused methacholine was reduced in untreated uterine arteries from mCMV-infected LP mice. CMV exerts direct effects on vascular function which should be considered during viral reactivation leading to viremia and during GB-based vaccine administration.

  13. Acute effect of different stretching methods on isometric muscle strength

    Directory of Open Access Journals (Sweden)

    Gabriel Vasconcellos de Lima Costa e Silva

    2014-03-01

    This study investigated the acute effect of static stretching methods (SS and proprioceptive neuromuscular facilitation (PNF on the static muscle strength (SMS. Eleven young male subjects with strength training experience, performed 3 tests with a 48h interval between them, randomly selected, where each one subject carried out all procedures: a hand grip without stretching; b hand grip preceded by static stretching of wrist flexors muscles; c hand grip preceded by PNF stretching of wrist flexors muscles. The Shapiro-Wilk test verified the normality of data, and a one-way ANOVA with repeated measures, followed by Tukey’s post hoc test, evaluated the differences between the groups. The significance was set at p 0.05. In conclusion, both stretching methods had caused negative effects on isometric strength, reducing its levels.

  14. Red Wine Prevents the Acute Negative Vascular Effects of Smoking.

    Science.gov (United States)

    Schwarz, Viktoria; Bachelier, Katrin; Schirmer, Stephan H; Werner, Christian; Laufs, Ulrich; Böhm, Michael

    2017-01-01

    Moderate consumption of red wine is associated with fewer cardiovascular events. We investigated whether red wine consumption counteracts the adverse vascular effects of cigarette smoking. Participants smoked 3 cigarettes alone or after drinking a titrated volume of red wine. Clinical chemistry, blood counts, plasma cytokine enzyme-linked immunosorbent assays, immunomagnetic separation of CD14(+) monocytes for gene expression analysis, fluorescence-activated cell sorting for microparticles, and isolation of circulating mononuclear cells to measure telomerase activity were performed, and urine cotinine levels were quantified. Compared with baseline, leukocytosis (P = .019), neutrophilia (P wine consumption. Cigarette smoke results in acute endothelial damage, vascular and systemic inflammation, and indicators of the cellular aging processes in otherwise healthy nonsmokers. Pretreatment with red wine was preventive. The findings underscore the magnitude of acute damage exerted by cigarette smoking in "occasional lifestyle smokers" and demonstrate the potential of red wine as a protective strategy to avert markers of vascular injury. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Acute effect of smoking on plasma Obestatin levels

    Directory of Open Access Journals (Sweden)

    Saroglou Maria

    2010-01-01

    Full Text Available Abstract Background Smoking and smoking cessation are considered to be associated with weight changes. We have recently shown that smoking acutely increases plasma levels of ghrelin, a known orexigenic hormone. Obestatin is a peptide encoded by the ghrelin gene, which opposes ghrelin effects on food intake. We conducted a study in adult volunteers measuring plasma levels of obestatin immediately after initiation of smoking. Methods 31 volunteers (mean age 32.2 ± 9.2 years and mean BMI 25.7 ± 4.1, 17 smokers and 14 non-smokers, were enrolled in our study. The 2 groups were matched in age and BMI. Plasma obestatin concentrations were determined at baseline (T0, 2 (T2, 5 (T5, 15 (T15, and 60 (T60 minutes after the initiation of smoking. Results In all 31 subjects, no significant difference in the mean values of plasma obestatin levels was observed from baseline at T2, T5, T15 and T60 after initiation of smoking (overall p = 0.15. However, a trend for higher obestatin levels was noted in smokers vs non-smokers (overall p = 0.069, which was not related to the pack-years. Conclusion On the contrary with ghrelin's response after smoking initiation, there is no such an acute response of plasma obestatin levels.

  16. Integrins mediate mechanical compression-induced endothelium-dependent vasodilation through endothelial nitric oxide pathway.

    Science.gov (United States)

    Lu, Xiao; Kassab, Ghassan S

    2015-09-01

    Cardiac and skeletal muscle contraction lead to compression of intramuscular arterioles, which, in turn, leads to their vasodilation (a process that may enhance blood flow during muscle activity). Although endothelium-derived nitric oxide (NO) has been implicated in compression-induced vasodilation, the mechanism whereby arterial compression elicits NO production is unclear. We cannulated isolated swine (n = 39) myocardial (n = 69) and skeletal muscle (n = 60) arteriole segments and exposed them to cyclic transmural pressure generated by either intraluminal or extraluminal pressure pulses to simulate compression in contracting muscle. We found that the vasodilation elicited by internal or external pressure pulses was equivalent; moreover, vasodilation in response to pressure depended on changes in arteriole diameter. Agonist-induced endothelium-dependent and -independent vasodilation was used to verify endothelial and vascular smooth muscle cell viability. Vasodilation in response to cyclic changes in transmural pressure was smaller than that elicited by pharmacological activation of the NO signaling pathway. It was attenuated by inhibition of NO synthase and by mechanical removal of the endothelium. Stemming from previous observations that endothelial integrin is implicated in vasodilation in response to shear stress, we found that function-blocking integrin α5β1 or αvβ3 antibodies attenuated cyclic compression-induced vasodilation and NOx (NO(-)2 and NO(-)3) production, as did an RGD peptide that competitively inhibits ligand binding to some integrins. We therefore conclude that integrin plays a role in cyclic compression-induced endothelial NO production and thereby in the vasodilation of small arteries during cyclic transmural pressure loading.

  17. The effect of long-term homocysteine-lowering on carotid intima-media thickness and flow-mediated vasodilation in stroke patients: a randomized controlled trial and meta-analysis

    Directory of Open Access Journals (Sweden)

    Green Daniel J

    2008-09-01

    Full Text Available Abstract Background Experimental and epidemiological evidence suggests that homocysteine (tHcy may be a causal risk factor for atherosclerosis. B-vitamin supplements reduce tHcy and improve endothelial function in short term trials, but the long-term effects of the treatment on vascular structure and function are unknown. Methods We conducted a sub-study of VITATOPS, a randomised, double-blind, placebo-controlled intervention trial designed to test the efficacy of long term B-vitamin supplementation (folic acid 2 mg, vitamin B6 25 mg and vitamin B12 0.5 mg in the prevention of vascular events in patients with a history of stroke. We measured carotid intima-medial thickness (CIMT and flow-mediated dilation (FMD at least two years after randomisation in 162 VITATOPS participants. We also conducted a systematic review and meta-analysis of studies designed to test the effect of B-vitamin treatment on CIMT and FMD. Results After a mean treatment period of 3.9 ± 0.9 years, the vitamin-treated group had a significantly lower mean plasma homocysteine concentration than the placebo-treated group (7.9 μmol/L, 95% CI 7.5 to 8.4 versus 11.8 μmol/L, 95% CI 10.9 to 12.8, p Conclusion Although short-term treatment with B-vitamins is associated with increased FMD, long-term homocysteine-lowering did not significantly improve FMD or CIMT in people with a history of stroke. Trial Registration Clinical Trial Registration URL: http://www.actr.org.au/ Trial Registration number: 12605000005651

  18. Protective effects of erythropoietin against acute lung injury in a rat model of acute necrotizing pancreatitis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate the effect of exogenous erythropoietin (EPO) administration on acute lung injury (ALI) in an experimental model of sodium taurodeoxycholateinduced acute necrotizing pancreatitis (ANP).METHODS: Forty-seven male Wistar albino rats were randomly divided into 7 groups: sham group (n = 5),3 ANP groups (n = 7 each) and 3 EPO groups (n = 7each). ANP was induced by retrograde infusion of 5% sodium taurodeoxycholate into the common bile duct.Rats in EPO groups received 1000 U/kg intramuscular EPO immediately after induction of ANP. Rats in ANP groups were given 1 mL normal saline instead. All animals were sacrificed at postoperative 24 h, 48 h and 72 h. Serum amilase, IL-2, IL-6 and lung tissue malondialdehyde (MDA) were measured. Pleural effusion volume and lung/body weight (LW/BW) ratios were calculated. Tissue levels of TNF-α, IL-2 and IL-6 were screened immunohistochemically. Additionally, ox-LDL accumulation was assessed with immune-fluorescent staining. Histopathological alterations in the lungs were also scored.RESULTS: The mean pleural effusion volume, calculated LW/BW ratio, serum IL-6 and lung tissue MDA levels were significantly lower in EPO groups than in ANP groups. No statistically significant difference was observed in either serum or tissue values of IL-2 among the groups. The level of tumor necrosis factor-α (TNF-α)and IL-6 and accumulation of ox-LDL were evident in the lung tissues of ANP groups when compared to EPO groups, particularly at 72 h. Histopathological evaluation confirmed the improvement in lung injury parameters after exogenous EPO administration, particularly at 48 h and 72 h.CONCLUSION: EPO administration leads to a significant decrease in ALI parameters by inhibiting polymorphonuclear leukocyte (PMNL) accumulation,decreasing the levels of proinflammatory cytokines in circulation, preserving microvascular endothelial cell integrity and reducing oxidative stress-associated lipid peroxidation and therefore, can be

  19. Acute effects of cigarette smoke on inflammation and oxidative stress : a review

    NARCIS (Netherlands)

    van der Vaart, H; Postma, DS; Timens, W; Ten Hacken, NHT

    2004-01-01

    Compared with the effects of chronic smoke exposure on lung function and airway inflammation, there are few data on the acute effects of smoking. A review of the literature identified 123 studies investigating the acute effects of cigarette smoking on inflammation and oxidative stress in human, anim

  20. Protective effects of rhubarb on experimental severe acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Yu-Qing Zhao; Xiao-Hong Liu; Tetsuhide Ito; Jia-Ming Qian

    2004-01-01

    AIM: To investigate the effects of rhubarb on severe acute pancreatitis (SAP) in rats.METHODS: Severe acute pancreatitis was induced by two intraperitoneal injections of cerulein (40 μg/kg body weight) plus 5-h restraint water-immersion stress. Rhubarb (75-150 mg/kg) was orally fed before the first cerulein injection.The degree of pancreatic edema, serum amylase level,local pancreatic blood flow (PBF), and histological alterations were investigated. The effects of rhubarb on pancreatic exocrine secretion in this model were evaluated by comparing with those of somatostatin.RESULTS: In the Cerulein+Stress group, severe edema and diffuse hemorrhage in the pancreas were observed,the pancreatic wet weight (11.60±0.61 g/Kg) and serum amylase (458 490±43 100 U/L) were markedly increased (P<0.01 vs control). In the rhubarb (150 mg/kg) treated rats, necrosis and polymorphonuclear neutrophil (PMN) infiltration in the pancreas were significantly reduced (P<0.01), and a marked decrease (50%) in serum amylase levels was also observed (P<0.01). PBF dropped to 38%(93±5 Ml/min per 100 g) of the control in the Cerulein+Stressgroup and partly recovered in the Cerulein+Stress+Rhubarb 150 mg group (135±12 Ml/min per 100 g) (P<0.01). The pancreatic exocrine function was impaired in the SAP rats.The amylase levels of pancreatic juice were reduced in the rats treated with rhubarb or somatostatin, comparing with that of untreated SAP group. The bicarbonate concentration of pancreatic juice was markedly elevated only in the rhubarb treated group (P<0.01).CONCLUSION: Rhubarb can exert protective effects on SAP, probably by inhibiting the inflammation of pancreas,improving pancreatic microcirculation, and altering exocrine secretion.

  1. Effect of Antiepileptic Drugs for Acute and Chronic Seizures in Children with Encephalitis

    OpenAIRE

    Kuang-Lin Lin; Jainn-Jim Lin; Shao-Hsuan Hsia; Min-Liang Chou; Po-Cheng Hung; Huei-Shyong Wang

    2015-01-01

    Background Encephalitis presents with seizures in the acute phase and increases the risk of late unprovoked seizures and epilepsy. This study aimed to evaluate the effect of antiepileptic drugs in pediatric patients with acute seizures due to encephalitis and epilepsy. Patients and Methods Cases of acute pediatric encephalitis between January 2000 and December 2010 were reviewed. Clinical data, including onset at age, seizure type, seizure frequency, effects of antiepileptic drugs, and progno...

  2. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    Directory of Open Access Journals (Sweden)

    Lindsay B. Baker

    2015-07-01

    Full Text Available Intermittent sports (e.g., team sports are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h. Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1 potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2 the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3 what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports. Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before

  3. Acute effects of energy drinks in medical students.

    Science.gov (United States)

    García, Andrés; Romero, César; Arroyave, Cristhian; Giraldo, Fabián; Sánchez, Leidy; Sánchez, Julio

    2016-06-16

    To determine the acute effects of a variety of recognized energy drinks on medical students, based on the hypothesis that these beverages may affect negatively cardiovascular parameters, stress levels and working memory. Eighty young healthy medical students were included in the study. 62.5 % of the participants were male, and the age mean was 21.45 years. Each person was evaluated via measurement of systolic and diastolic blood pressure, electrocardiogram (ECG), heart rate, oxygen saturation, breath rate, temperature, STAI score (to assess anxiety state), salivary cortisol and N-back task score (to determine cognitive enhancement). These evaluations were performed before and following the intake of either carbonated water or one of three energy drinks containing caffeine in similar concentrations and an undetermined energy blend; A contained less sugar and no taurine. Thirty-minute SBP increased significantly in the A and C groups. The B group exhibited a diminution of the percentage of the 1-h SBP increase, an increase of 1-h DBP and QTc shortening. HR showed an increase in the percent change in the A and C groups. Cortisol salivary levels increased in the B group. The STAI test score decreased in the C group. The percent change in N-back scores increased in the A group. The data reinforce the need for further research on the acute and chronic effects of energy drinks to determine the actual risks and benefits. Consumers need to be more informed about the safety of these energy drinks, especially the young student population.

  4. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    Science.gov (United States)

    Baker, Lindsay B.; Rollo, Ian; Stein, Kimberly W.; Jeukendrup, Asker E.

    2015-01-01

    Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a

  5. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance.

    Science.gov (United States)

    Baker, Lindsay B; Rollo, Ian; Stein, Kimberly W; Jeukendrup, Asker E

    2015-07-14

    Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1-2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30-60 g/h in the form of a 6%-7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a game

  6. Brain natriuretic peptide is a potent vasodilator in aged human microcirculation and shows a blunted response in heart failure patients

    DEFF Research Database (Denmark)

    Edvinsson, Marie-Louise; Uddman, Erik; Edvinsson, Lars;

    2014-01-01

    BACKGROUND: Brain natriuretic peptide (BNP) is normally present in low levels in the circulation, but it is elevated in parallel with the degree of congestion in heart failure subjects (CHF). BNP has natriuretic effects and is a potent vasodilator. It is suggested that BNP could be a therapeutic...... in the forearm was measured by laser Doppler Flowmetry. Local heating (+44°C, 10 min) was used to evoke a maximum local dilator response. RESULTS: Non-invasive iontophoretic administration of either BNP or acetylcholine (ACh), a known endothelium-dependent dilator, elicited an increase in local flow. The nitric...

  7. Vasodilator activity of 2-(p-chloro-alpha-hydroxybenzyl)benzimidazole (HBBPC) on femoral vascular bed of the rabbit.

    Science.gov (United States)

    Demenge, P; Silice, C; Luu Duc, C; Carraz, G

    1979-01-01

    The effects of 2-(p-chloro-alpha-hydroxybenzyl) benzimidazole HCl (HBBPC) have been studied on the femoral peripheral resistance (i.v. route) and only femoral blood flow (local i.a. injection), in comparison with other vasodilators, i.e., sodium nitroprusside, dihydralazine and piribedil. The vasomotor activity of HBBPC, namely, decreased peripheral resistance and increased femoral blood flow, seems interesting because it begins after pressure has returned to normal. This substance is likely to induce a vasoconstriction in other areas (increased femoral blood flow with decreased peripheral resistance without a fall of blood pressure).

  8. Comparison of the vasodilator responses of isolated human and rat middle meningeal arteries to migraine related compounds

    DEFF Research Database (Denmark)

    Grände, Gustaf; Labruijere, Sieneke; Haanes, Kristian Agmund

    2014-01-01

    , telcagepant) were applied to the isolated arteries, and both induced a significant decrease of the effect of exogenously administrated CGRP. In experiments on rat middle meningeal arteries, pre-contracted with PGF2α, similar tendencies were seen. When the pre-contraction was switched to K+ in a separate...... series of experiments, CGRP and sildenafil significantly relaxed the arteries. CONCLUSIONS: Still no definite answer can be given as to why pain is experienced during an attack of migraine. No clear correlation was found between the efficacy of a substance as a meningeal artery vasodilator in human...

  9. Vasoconstrictor and vasodilator effects of adenosine in the kidney

    DEFF Research Database (Denmark)

    Hansen, Pernille B; Schnermann, Jurgen

    2003-01-01

    Adenosine is an ATP breakdown product that in most vessels causes vasodilatation and that contributes to the metabolic control of organ perfusion, i.e., to the match between oxygen demand and oxygen delivery. In the renal vasculature, in contrast, adenosine can produce vasoconstriction, a respons...... activation from changes in vascular adenosine concentration, a characteristic that is ideally suited for the role of renal adenosine as a paracrine factor in the control of glomerular function.......Adenosine is an ATP breakdown product that in most vessels causes vasodilatation and that contributes to the metabolic control of organ perfusion, i.e., to the match between oxygen demand and oxygen delivery. In the renal vasculature, in contrast, adenosine can produce vasoconstriction, a response...... that has been suggested to be an organ-specific version of metabolic control designed to restrict organ perfusion when transport work increases. However, the vasoconstriction elicited by an intravenous infusion of adenosine is only short lasting, being replaced within 1-2 min by vasodilatation. It appears...

  10. Effects of vasodilator and esmolol-induced hemodynamic stability on ...

    African Journals Online (AJOL)

    Class twelve Grade two, The Middle School Attached to Liaoning Normal University, ... esmolol on the occurrence of early post-operative cognitive dysfunction (POCD) in elderly patients. ... er age, which has been identified as an independent risk ..... With the growth in the elderly popu- .... eral anesthesia in older adults.

  11. Non-endothelial endothelin counteracts hypoxic vasodilation in porcine large coronary arteries

    DEFF Research Database (Denmark)

    Hedegaard, Elise Røge; Stankevicius, Edgaras; Simonsen, Ulf

    2011-01-01

    of large coronary arteries. RESULTS: In prostaglandin F2α (PGF2α, 10 μM)-contracted segments with endothelium, gradual lowering of oxygen tension from 95 to 1% O2 resulted in vasodilation. The vasodilation to O2 lowering was rightward shifted in segments without endothelium at all O2 concentrations except...... at 1% O2. The endothelin receptor antagonist SB217242 (10 μM) markedly increased hypoxic dilation despite the free tissue ET-1 concentration in the arterial wall was unchanged in 1% O2 versus 95% O2. Exogenous ET-1 reversed hypoxic dilation in segments with and without endothelium, and the hypoxic...... arteries showed an increased sensitivity towards ET-1 compared to the normoxic controls. Without affecting basal NO, hypoxia increased NO concentration in PGF2α-contracted arteries, and an NO synthase inhibitor, L-NOARG,(300 μM, NG-nitro-L-Arginine) reduced hypoxic vasodilation. NO-induced vasodilation...

  12. Hemodynamic properties of bucindolol, a beta-adrenoreceptor blocking drug with vasodilator activity.

    Science.gov (United States)

    Bett, N; Dryburgh, L; Boyle, C; Hawley, C

    1986-03-01

    Bucindolol is a new nonselective beta-adrenergic blocking agent with direct vasodilator, partial agonist and alpha-adrenergic blocking properties. Its hemodynamic effects were evaluated in 13 healthy young men. In an open study, the effects of increasing single oral doses (50 to 200 mg) were examined. Two hours after each dose there was little effect at rest, but the responses of heart rate and systolic blood pressure to cycle exercise (50 to 150 W) were significantly reduced. There was no greater effect with larger doses. The second phase was a 3-way double-blind study comparing the effects of placebo with 50 and 200 mg of bucindolol. Left ventricular (LV) ejection phase indexes derived from digitized M-mode echocardiograms (% fractional shortening, mean and peak velocity of circumferential fiber shortening, stroke volume) increased more than 10% 2 and 4 hours after bucindolol was administered, whereas systemic vascular resistance and the ratio preejection period/LV ejection time decreased to the same extent. Although there was little effect on measurements at rest, the response to cycle exercise of heart rate and systolic blood pressure were significantly attenuated. These results show that the effects of bucindolol on LV systolic function are related at least in part to reduction of afterload, but do not indicate whether the drug has an additional direct inotropic effect.

  13. A critical role for astrocytes in hypercapnic vasodilation in brain

    DEFF Research Database (Denmark)

    Howarth, C; Sutherland, B A; Choi, H B

    2017-01-01

    Cerebral blood flow (CBF) is controlled by arterial blood pressure, arterial CO2, arterial O2, and brain activity and is largely constant in the awake state. Although small changes in arterial CO2 are particularly potent to change CBF (1 mmHg variation in arterial CO2 changes CBF by 3-4%), the co......Cerebral blood flow (CBF) is controlled by arterial blood pressure, arterial CO2, arterial O2, and brain activity and is largely constant in the awake state. Although small changes in arterial CO2 are particularly potent to change CBF (1 mmHg variation in arterial CO2 changes CBF by 3...... in brain slices with in vivo work in rats and C57Bl/6J mice to examine the hemodynamic responses to CO2 and somatosensory stimulation before and after inhibition of astrocytic glutathione and PgE2 synthesis. We demonstrate that hypercapnia (increased CO2) evokes an increase in astrocyte [Ca(2+)]i...... and stimulates COX-1 activity. The enzyme downstream of COX-1 that synthesizes PgE2 (microsomal prostaglandin E synthase-1) depends critically for its vasodilator activity on the level of glutathione in the brain. We show that when glutathione levels are reduced, astrocyte calcium-evoked release of PgE2...

  14. The effect of indacaterol during an acute exacerbation of COPD.

    Science.gov (United States)

    Segreti, Andrea; Fiori, Enrica; Calzetta, Luigino; Sabatini, Marco; Segreti, Vincenzo; Rogliani, Paola; Cazzola, Mario

    2013-12-01

    Some clinical trials have suggested that the inhaled long-acting β2-agonists (LABAs) may be effective in the treatment of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Since indacaterol, the first once-daily LABA to be developed for the regular treatment of COPD, exhibits fast onset of action and 24-h duration of bronchodilation, we have investigated its effects in patients with AECOPD managed in the emergency department. In a randomised controlled pilot trial, we have enrolled 29 consecutive patients with a recent (i.e., within ≤ 4 d) history of AECOPD and requiring hospitalization. All patients received a standard protocol consisting of ipratropium bromide aerosol 500 μg three times a day, intravenous methylprednisolone 20 mg twice-daily and, if indicated, oral levofloxacin 500 mg once-daily. Moreover, they were randomly allocated to one of the two 5-day treatment groups (indacaterol maleate 300 μg once-daily or salbutamol nebulizer 1250 μg three times a day). The administration of indacaterol 300 μg to patients admitted to emergency department for an AECOPD resulted in a greater improvement of pulmonary function compared with traditional therapy, without cardiovascular side effects. Our results suggest that indacaterol could be a useful option in the treatment of AECOPD. However, further larger double-blinded randomized clinical trials are needed to validate the intriguing results obtained in this setting. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Selective venous vasodilator properties of the analgesic metamizole (dipyrone) in a human ex vivo model-implications for postoperative pain management.

    Science.gov (United States)

    Hoenicka, Markus; Gorki, Hagen; Traeger, Karl; Liebold, Andreas

    2017-05-01

    Metamizole (dipyrone) is a first-line, non-opioid analgesic used for postoperative pain management. Clinical data and animal experiments indicate a possible vasodilator action of this drug. We investigated the effects of metamizole on human artery and vein tone in an ex vivo model to assess potential contributions to venous pooling. Excess segments of bypass grafts were harvested during coronary artery bypass grafting procedures. Tensions were measured in an organ bath for 120 min after adding metamizole to the preconstricted vessels. Contribution of endothelium was assessed in endothelium-denuded vessels, and indometacin was used to identify cyclooxygenase-mediated effects. Internal mammary arteries (n = 6) constricted after addition of 1, 3, and 10 μM metamizole and remained constricted at the lower doses. Transient constrictions also occurred in saphenous veins (n = 20), but veins relaxed below solvent controls after 20 min at all concentrations. Endothelium removal (n = 12) and cyclooxygenase inhibition (n = 12) suppressed the vasoconstrictor effect but not the vasodilator effect. Metamizole and its metabolites display counteracting effects on blood vessel tone ex vivo. The vasoconstrictor effect is mediated by cyclooxygenase-derived products. The net effect is site-specific, resulting in a selective venous vasodilator action. This may exacerbate unwanted venous pooling during postoperative pain therapy.

  16. Effects of acute restraint stress on set-shifting and reversal learning in male rats.

    Science.gov (United States)

    Thai, Chester A; Zhang, Ying; Howland, John G

    2013-03-01

    Exposure to acute stress alters cognition; however, few studies have examined the effects of acute stress on executive functions such as behavioral flexibility. The goal of the present experiments was to determine the effects of acute periods of stress on two distinct forms of behavioral flexibility: set-shifting and reversal learning. Male Sprague-Dawley rats were trained and tested in an operant-chamber-based task. Some of the rats were exposed to acute restraint stress (30 min) immediately before either the set-shifting test day or the reversal learning test day. Acute stress had no effect on set-shifting, but it significantly facilitated reversal learning, as assessed by both trials to criterion and total errors. In a second experiment, the roles of glucocorticoid (GR) and mineralocorticoid receptors (MR) in the acute-stress-induced facilitation of reversal learning were examined. Systemic administration of the GR-selective antagonist RU38486 (10 mg/kg) or the MR-selective antagonist spironolactone (50 mg/kg) 30 min prior to acute stress failed to block the facilitation on reversal learning. The present results demonstrate a dissociable effect of acute stress on set-shifting and reversal learning and suggest that the facilitation of reversal learning by acute stress may be mediated by factors other than corticosterone.

  17. Histoprotective effect of antihypoxant olifen during experimental acute pancreatitis.

    Science.gov (United States)

    Tolstoi, A D; Dzhurko, B I; Vashetko, R V; Medvedev, Y V; Gol'tsov, V R; Dvoinov, V G; Zakharova, E V

    2001-04-01

    We evaluated the efficiency of perfusion with olifen in preventing oxidative stress at the early stage of acute pancreatitis. Transaortic perfusion with olifen prevented clinical and biochemical symptoms of acute pancreatitis, attenuated oxidative stress, reduced peritoneal exudation, and restricts the area of pancreatic necrosis to 6% tissue.

  18. Minimal effects of acute liver injury/acute liver failure on hemostasis as assessed by thromboelastography

    NARCIS (Netherlands)

    Stravitz, R. Todd; Lisman, Ton; Luketic, Velimir A.; Sterling, Richard K.; Puri, Puneet; Fuchs, Michael; Ibrahim, Ashraf; Lee, William M.; Sanyal, Arun J.

    2012-01-01

    Background & Aims: Patients with acute liver injury/failure (ALI/ALF) are assumed to have a bleeding diathesis on the basis of elevated INR; however, clinically significant bleeding is rare. We hypothesized that patients with ALI/ALF have normal hemostasis despite elevated INR. Methods: Fifty-one pa

  19. Acute effects of stochastic resonance whole body vibration.

    Science.gov (United States)

    Elfering, Achim; Zahno, Jasmine; Taeymans, Jan; Blasimann, Angela; Radlinger, Lorenz

    2013-01-01

    To investigate the acute effects of stochastic resonance whole body vibration (SR-WBV) training to identify possible explanations for preventive effects against musculoskeletal disorders. Twenty-three healthy, female students participated in this quasi-experimental pilot study. Acute physiological and psychological effects of SR-WBV training were examined using electromyography of descending trapezius (TD) muscle, heart rate variability (HRV), different skin parameters (temperature, redness and blood flow) and self-report questionnaires. All subjects conducted a sham SR-WBV training at a low intensity (2 Hz with noise level 0) and a verum SR-WBV training at a higher intensity (6 Hz with noise level 4). They were tested before, during and after the training. Conclusions were drawn on the basis of analysis of variance. Twenty-three healthy, female students participated in this study (age = 22.4 ± 2.1 years; body mass index = 21.6 ± 2.2 kg/m(2)). Muscular activity of the TD and energy expenditure rose during verum SR-WBV compared to baseline and sham SR-WBV (all P HRV were similar to those observed during sham SR-WBV. The same applies for most of the skin characteristics, while microcirculation of the skin of the middle back was higher during verum compared to sham SR-WBV (P changes over the three measurement points only in the middle back area (P = 0.022). There was a significant rise from baseline to verum SR-WBV (0.86 ± 0.25 perfusion units; P = 0.008). The self-reported chronic pain grade indicators of pain, stiffness, well-being, and muscle relaxation showed a mixed pattern across conditions. Muscle and joint stiffness (P = 0.018) and muscular relaxation did significantly change from baseline to different conditions of SR-WBV (P < 0.001). Moreover, muscle relaxation after verum SR-WBV was higher than after sham SR-WBV (P < 0.05). Verum SR-WBV stimulated musculoskeletal activity in young healthy individuals while cardiovascular activation was low. Training of

  20. Inhibitory effect of Patrinia scabiosaefolia on acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Sang-Wan Seo; Hyung-Min Kim; Sung-Joo Park; Cheung-Seog Park; Seung-Heon Hong; Kang-Beom Kwon; Hyoung-Chul Moon; Bong-keun Song; Kyung-Yo Kim; Young-Min Park; Ho-Joon Song

    2006-01-01

    AIM: To investigate the effect of Patrinia scabiosaefolia (PS) on the cholecystokinin (CCK) octapeptide- induced acute pancreatitis (AP) in rats.METHODS: Wistar rats weighing 240-260 g were divided into three groups: (1) Normal saline-treated group;(2) treatment with PS at 100 mg/kg group, in which PS was administered orally, followed by subcutaneous administration of 75 μg/kg CCK octapeptide three times after 1, 3 and 5 h, and this whole procedure was repeated for 5 d; (3) treatment with saline group,in which the protocols were the same as in treatment group with PS. We determined the pancreatic weight/body weight ratio, the levels of pancreatic HSP60,HSP72 and the secretion of pro-inflammatory cytokines.Repeated CCK octapeptide treatment resulted in the typical laboratory findings of experimentally induced pancreatitis.RESULTS: PS reduced the pancreatic weight/body weight ratio, the levels of serum amylase and lipase,and inhibited expressions of pro-inflammatory cytokines in the CCK octapeptide-induced AP. Furthermore, PS pretreatment increased the pancreatic levels of HSP60and HSP72.CONCLUSION: Pretreatment with PS has an antiinflammatory effect on CCK octapeptide-induced AP.

  1. The vasodilator mechanisms of sodium metabisulfite on precontracted isolated aortic rings in rats: signal transduction pathways and ion channels.

    Science.gov (United States)

    Yang, Zhenhua; Zhang, Yuexia; Meng, Ziqiang

    2012-09-01

    Sodium metabisulfite (SMB) is most commonly used as a food additives, however few study was performed on the vasodilator effect of SMB. In the present paper, the vasodilator effects of SMB and roles of Ca(2+) and K(+) channels as well as the cGMP pathway on isolated rat aortic rings were studied. The results show that: (1) SMB could relax isolated aortic rings precontracted by norepinephrine in a concentration-dependent manner. The maximal endothelium-dependent vasorelaxation was approximately 20% whereas that not depending on the presence of the endothelium was more than 90%. (2) The vasorelaxant effects induced by 50 or 200 μM SMB were partially inhibited by iberiotoxin, NS-2028 or l-NNA. The vasorelaxation of 1000 μM SMB was partially inhibited by nifedipine or glibenclamide. The SMB induced vasorelaxation was partially inhibited by tetraethylammonium. These results led to the conclusions that the vasorelaxation of SMB at low concentrations (500 μM) was endothelium-independent and mediated by K(ATP) channel and L-type Ca(2+) channel. The maximal allowable concentration from China and the acceptable daily intake level from WHO of SMB as a food additive should be revised. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Neurological Effects of Acute Carbon Monoxide Poisoning in Children

    Directory of Open Access Journals (Sweden)

    Coskun YARAR

    2009-11-01

    Full Text Available Carbon monoxide poisoning (COP is one of the most common causes of mortality and morbidity due to poisoning in all over the world. Although the incidence of COP has not been known exactly in the childhood, almost one-third of CO exposures occurred in children. The data regarding COP in children are inconclusive. Children may be more vulnerable to CO exposure than adults as a result of their high respiration and metabolic rates, high oxygen metabolism, and immature central nervous system. Recent researches proposed new theories about neurological effects of CO toxicity. The clinical presentations associated acute COP may be various and nonspecific. Unrecognized CO exposure may lead to significant morbidity and mortality. CO exposed children often become symptomatic earlier, and recover more rapidly, than similarly CO exposed adults. Mild clinical signs and symptoms associated with COP are headache, dizziness, weakness, lethargy, and myalgia; however, severe signs and symptoms such as blurred vision, syncope, convulsion, coma, cardiopulmonary arrest and death can also accompany with COP. Neurologic manifestations can include altered mental status at different degrees, neck stiffness, tremor, ataxia, and positive Babinski's sign. Delayed neurologic sequels (DNS of COP might be seen in children like adults. DNS symptoms and signs in children include memory problems, mental retardation, mutism, fecal and urinary incontinence, motor deficits, facial palsy, psychosis, chronic headache, seizures, and epilepsy. After CO exposure children must be cared to detect and treat DNS. Although hyperbaric oxygen therapy (HBOT is reported to prevent development of DNS, its indications, application duration and procedures are controversial in both of the children and adults. Although their predictive values are limited, exposing to CO more than eight hours and suffering from CO-induced coma, cardiac arrest, lactic acidosis, high COHb levels, and pathologic findings

  3. Effects of asphalt fume condensate exposure on acute pulmonary responses

    Energy Technology Data Exchange (ETDEWEB)

    Ma, J.Y.C.; Barger, M.W.; Castranova, V. [Health Effects Lab. Div., National Inst. for Occupational Safety and Health, Morgantown, WV (United States); Kriech, A.J. [Heritage Research Group, Indianapolis, IN (United States)

    2000-10-01

    The present study was carried out to characterize the effects of in vitro exposure to paving asphalt fume condensate (AFC) on alveolar macrophage (AM) functions and to monitor acute pulmonary responses to in vivo AFC exposure in rats. Methods: For in vitro studies, rat primary AM cultures were incubated with various concentrations of AFC for 24 h at 37 C. AM-conditioned medium was collected and assayed for lactate dehydrogenase (LDH) as a marker of cytotoxicity. Tumor necrosis factor-{alpha} (TNF-{alpha}) and interleukin-1 (IL-1) production were assayed in AM-conditioned medium to monitor AM function. The effect of AFC on chemiluminescence (CL) generated by resting AM or AM in response to zymosan or PMA stimulation was also determined as a marker of AM activity. For in vivo studies, rats received either (1) a single intratracheal (IT) instillation of saline, or 0.1 mg or 0.5 mg AFC and were killed 1 or 3 days later; or (2) IT instillation of saline, or 0.1, 0.5, or 2 mg AFC for three consecutive days and were killed the following day. Differential counts of cells harvested by bronchoalveolar lavage were measured to monitor inflammation. Acellular LDH and protein content in the first lavage fluid were measured to monitor damage. CL generation, TNF-{alpha} and IL-1 production by AM were assayed to monitor AM function. Results: In vitro AFC exposure at <200 {mu}g/ml did not induce cytotoxicity, oxidant generation, or IL-1 production by AM, but it did cause a small but significant increase in TNF-{alpha} release from AM. In vitro exposure of AM to AFC resulted in a significant decline of CL in response to zymosan or PMA stimulation. The in vivo studies showed that AFC exposure did not induce significant neutrophil infiltration or alter LDH or protein content in acellular lavage samples. Macrophages obtained from AFC-exposed rats did not show significant differences in oxidant production or cytokine secretion at rest or in response to LPS in comparison with control

  4. Effect of hyperthermia on prognosis after acute ischemic stroke.

    Science.gov (United States)

    Saini, Monica; Saqqur, Maher; Kamruzzaman, Anmmd; Lees, Kennedy R; Shuaib, Ashfaq

    2009-09-01

    Experimental studies have shown that hyperthermia is a determinant of poor outcome after ischemic stroke. Clinical studies evaluating the effect of temperature on poststroke outcome have, however, been limited by small sample sizes. We sought to evaluate the effect of temperature and timing of hyperthermia on outcome after ischemic stroke. Data of 5305 patients in acute stroke trials from the Virtual International Stroke Trials Archive (VISTA) data set were analyzed. Data for temperatures at baseline, eighth, 24th, 48th, and 72nd hours, and seventh day were assessed in relation to outcome (poor versus good) based on the modified Rankin Scale at 3 months. Hyperthermia was defined as temperature >37.2 degrees C and poor outcome as 90-day modified Rankin Scale >2. Hazard ratios with 95% CIs were reported for hyperthermia in relation to the outcome. Logistic regression models, in relation to hyperthermia, were fitted for a set of preselected covariates at different time points to identify predictors/determinants of hyperthermia. The average age of patients was 68.0+/-11.9 years, 2380 (44.9%) were females, and 42.3% (2233) received thrombolysis using recombinant tissue plasminogen activator. After adjustment, hyperthermia was a statistically significant predictor of poor outcome. The hazard ratios (95% CI) for poor outcome in relation to hyperthermia at different time points were: baseline 1.2 (1.0 to 1.4), eighth hour 1.7 (1.2 to 2.2), 24th hour 1.5 (1.2 to 1.9), 48th hour 2.0 (1.5 to 2.6), 72nd hour 2.2 (1.7 to 2.9), and seventh day 2.7 (2.0 to 3.8). Gender, stroke severity (National Institutes of Health Stroke Scale score >16), white blood cell count, and antibiotic use were significantly associated with hyperthermia (Pacute ischemic stroke, is associated with a poor clinical outcome. The later the hyperthermia occurs within the first week, the worse the prognosis. Severity of stroke and inflammation are important determinants of hyperthermia after ischemic stroke

  5. Cost effectiveness of pneumococcal conjugate vaccination against acute otitis media in children: a review.

    NARCIS (Netherlands)

    Boonacker, C.W.; Broos, P.H.; Sanders, E.A.; Schilder, A.G.M.; Rovers, M.M.

    2011-01-01

    While pneumococcal conjugate vaccines have shown to be highly effective against invasive pneumococcal disease, their potential effectiveness against acute otitis media (AOM) might become a major economic driver for implementing these vaccines in national immunization programmes. However, the

  6. alpha-adrenergic Blockade Unmasks a Greater Compensatory Vasodilation in Hypoperfused Contracting Muscle

    Directory of Open Access Journals (Sweden)

    Darren P. Casey

    2012-07-01

    Full Text Available We previously demonstrated that acute hypoperfusion in exercising human muscle causes an immediate increase in vascular resistance that is followed by a partial restoration (less than 100% recovery of flow. In the current study we examined the contribution of alpha-adrenergic vasoconstriction in the initial changes in vascular resistance at the onset of hypoperfusion as well as in the recovery of flow over time. Nine healthy male subjects (29 ± 2 performed rhythmic forearm exercise (20% of maximum during hypoperfusion evoked by intra-arterial balloon inflation. Each trial included; baseline, exercise prior to inflation, exercise with inflation, and exercise after deflation (3 min each. Forearm blood flow (FBF; ultrasound, local (brachial artery, and systemic arterial pressure (MAP; Finometer were measured. The trial was repeated during phentolamine infusion (alpha-adrenergic receptor blockade. Forearm vascular conductance (FVC; ml min-1 100 mmHg-1 and resistance (mmHg ml min-1 was calculated from BF (ml min-1 and local MAP (mmHg. Recovery of FBF and FVC (steady state inflation plus exercise value – nadir/ [steady state exercise (control value-nadir] with phentolamine was enhanced compared with the respective control (no drug trial (FBF = 97 ± 5% vs. 81 ± 6%, P < 0.05; FVC = 126 ± 9% vs. 91 ± 5%, P < 0.01. However, the absolute (0.05 ± 0.01 vs. 0.06 ± 0.01 mmHg ml min-1; P = 0.17 and relative (35 ± 5% vs. 31 ± 2%; P = 0.41 increase in vascular resistance at the onset of balloon inflation was not different between the alpha-adrenergic receptor inhibition and control (no drug trials. Therefore, our data indicate that alpha-adrenergic mediated vasoconstriction restricts compensatory vasodilation during forearm exercise with hypoperfusion, but is not responsible for the initial increase in vascular resistance at the onset of hypoperfusion.

  7. Dose-rate dependent effects of ionizing radiation on vascular reactivity.

    Science.gov (United States)

    Suvorava, T; Luksha, L; Bulanova, K Ya; Lobanok, L M

    2006-01-01

    This study was designed to investigate the dose-rate dependent effects of ionising radiation on endothelium- and NO-mediated reactivity of aorta and coronary vessels. Rats were exposed to acute ((137)Cs, 9 x 10(-4) Gy s(-1), 18 min) and chronic ((137)Cs, 2.8 x 10(-7) Gy s(-1), 41 days) radiation in 1 Gy dose. Acute irradiation transiently increased coronary flow in eNOS-activity-dependent manner on day 3 after exposure. In striking contrast, chronic irradiation caused a significant depression of coronary flow even on day 90 after irradiation and abolished the effects of NO-synthase inhibitor N-nitro-L-arginine methyl ester (10 micromol l(-1)). Furthermore, low intensity radiation strongly diminished the vasodilator properties of NO-donor sodium nitroprusside (5 micromol l(-1)). A similar pattern was observed in aortic rings. Endothelium-dependent vasodilation was increased on days 3 and 10 after acute irradiation, but strongly inhibited following chronic exposure for the entire post-radiation period. This was accompanied by a diminished vasodilator response to NO-donor on days 3, 10 and 30 of post-radiation but not on day 90. The data suggest that ionising radiation in 1 Gy induces changes of aortic and coronary vessels reactivity depending on the dose-rate and the interval after exposure.

  8. Strain-dependent Effects of Acute, Chronic, and Withdrawal from Chronic Nicotine on Fear Conditioning

    OpenAIRE

    Portugal, George S.; Wilkinson, Derek S.; Kenney, Justin W.; Sullivan, Colleen; Gould, Thomas J.

    2011-01-01

    The effects of nicotine on cognitive processes such as learning and memory may play an important role in the addictive liability of tobacco. However, it remains unknown whether genetic variability modulates the effects of nicotine on learning and memory. The present study characterized the effects of acute, chronic, and withdrawal from chronic nicotine administration on fear conditioning, somatic signs, and the elevated plus maze in 8 strains of inbred mice. Strain-dependent effects of acute ...

  9. [Use of enoximone in patients with acute and subacute heart failure in the intensive care unit].

    Science.gov (United States)

    Holubarsch, C; Pieske, B; Hasenfuss, G; Just, H

    1994-01-01

    The phosphodiesterase inhibitor enoximone has both vasodilating and positive inotropic pharmacological properties. The balance between vasodilation and positive inotropism may be different between the various types of heart failure as well as the various stages of heart failure. Therefore, we investigated the effect of intravenous application of enoximone (1 mg/kg body weight) in a cohort of patients (n = 10) suffering from acute or subacute heart failure mainly due to ischemia or hypoxia. All patients had high left ventricular filling pressure, low cardiac output and were pretreated with intravenous dobutamine. Enoximone increased cardiac output from 3.2 +/- 1.2 to 5.5 +/- 2.2 l/min, increased heart rate from 94 +/- 20 to 100 +/- 18 beats/min, decreased systemic peripheral resistance from 1770 +/- 861 to 931 +/- 340 dyn.sec.cm-5 and decreased pulmonary wedge pressure from 24 +/- 5 to 20 +/- 6 mmHg, significantly. However, systolic aortic pressure, systolic pulmonary pressure and right atrial pressure were not significantly altered. We conclude that in a selected group of patients enoximone-given intravenously and acutely in the intensive care unity-can induce beneficial effects on central hemodynamics without critical falls in perfusion pressure.

  10. Protective Effects of Hydrogen Gas on Experimental Acute Pancreatitis.

    Directory of Open Access Journals (Sweden)

    Hao-Xin Zhou

    Full Text Available Acute pancreatitis (AP is an inflammatory disease mediated by damage to acinar cells and pancreatic inflammation. In patients with AP, subsequent systemic inflammatory responses and multiple organs dysfunction commonly occur. Interactions between cytokines and oxidative stress greatly contribute to the amplification of uncontrolled inflammatory responses. Molecular hydrogen (H2 is a potent free radical scavenger that not only ameliorates oxidative stress but also lowers cytokine levels. The aim of the present study was to investigate the protective effects of H2 gas on AP both in vitro and in vivo. For the in vitro assessment, AR42J cells were treated with cerulein and then incubated in H2-rich or normal medium for 24 h, and for the in vivo experiment, AP was induced through a retrograde infusion of 5% sodium taurocholate into the pancreatobiliary duct (0.1 mL/100 g body weight. Wistar rats were treated with inhaled air or 2% H2 gas and sacrificed 12 h following the induction of pancreatitis. Specimens were collected and processed to measure the amylase and lipase activity levels; the myeloperoxidase activity and production levels; the cytokine mRNA expression levels; the 8-hydroxydeoxyguanosine, malondialdehyde, and glutathione levels; and the cell survival rate. Histological examinations and immunohistochemical analyses were then conducted. The results revealed significant reductions in inflammation and oxidative stress both in vitro and in vivo. Furthermore, the beneficial effects of H2 gas were associated with reductions in AR42J cell and pancreatic tissue damage. In conclusion, our results suggest that H2 gas is capable of ameliorating damage to the pancreas and AR42J cells and that H2 exerts protective effects both in vitro and in vivo on subjects with AP. Thus, the results obtained indicate that this gas may represent a novel therapy agent in the management of AP.

  11. Effects of chronic kidney disease on platelet response to antiplatelet therapy in acute myocardial infarction patients

    Institute of Scientific and Technical Information of China (English)

    邓捷

    2012-01-01

    Objective To elucidate the effects of dual antiplatelet therapy on platelet response in acute myocardial infarction patients with chronic kidney disease. Methods From September 2011 to June 2012,a total of 195 acute myocardial infarction patients with drug eluting stent implanting were enrolled. Among them,133 cases had normal

  12. Acute effects of ambient air pollution episodes on respiratory health of children.

    NARCIS (Netherlands)

    Hoek, G.

    1992-01-01

    In this thesis the acute effects of air pollution episodes on respiratory health of seven to eleven year old children living in non-urban communities in the Netherlands are discussed. Repeated measurements of pulmonary function (spirometry) and the occurrence of acute respiratory symptoms using a da

  13. Oral glutamate intake reduces acute and chronic effects of ethanol in ...

    African Journals Online (AJOL)

    Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights ... Oral treatment with 2.5 g/kg of glutamate reversed the acute motor effects of .... error of means (SEM). For the acute .... a clinical review.

  14. Effect of age and body weight on toxicity and survival in pediatric acute myeloid leukemia

    DEFF Research Database (Denmark)

    Løhmann, Ditte J A; Abrahamsson, Jonas; Ha, Shau-Yin

    2016-01-01

    Treatment for pediatric acute myeloid leukemia is very toxic and the association between outcome and age and Body Mass Index is unclear. We investigated effect of age and Body Mass Index on toxicity and survival in pediatric acute myeloid leukemia. We studied all patients who completed first indu...

  15. Effects of lysine-induced acute renal failure in dogs.

    Science.gov (United States)

    Asanuma, Kentaro; Adachi, Kenji; Sugimoto, Tetsuro; Chiba, Shuichi

    2006-05-01

    This study investigates the effects of lysine-induced acute renal failure. Female dogs received a lysine hydrochloride (lysine) of 4500 mg/kg/day (3.75 ml/kg/hr) for 3 consecutive days. The dogs were observed for clinical signs. Body weights were recorded, food consumption and water consumption calculated, and urinalysis and blood biochemistry were performed daily. Plasma samples for amino acid determinations were obtained from all dogs, which were necropsied on Day 3. Histopathological examinations were done on all test animals. Compound-related findings include the following. Blood biochemistry results showed increases in ammonia, blood urea nitrogen, blood urea nitrogen/creatinine ratio, and creatinine. Urinary changes consisted of increases in urine volume, total protein, albumin, gamma-glutamyl transpeptidase, and N-acetyl-beta-D-glucosaminidase. In addition, macroscopic findings consisted of pale, congested capsule; microscopic findings consisted of hypertrophy of proximal convoluted tubule (mainly S1 segment), and degeneration/desquamation of urinary tubule (mainly S3 segment with hyaline casts) in the kidney. From these findings, it can be concluded that lysine is nephrotoxic in dogs. Nephrotoxicity of lysine may relate to direct tubular toxicity and to tubular obstruction.

  16. Acute effects of resistance training with local vibration.

    Science.gov (United States)

    Couto, B P; Silva, H R; Filho, A G; da Silveira Neves, S R; Ramos, M G; Szmuchrowski, L A; Barbosa, M P

    2013-09-01

    The aim of this study was to verify the acute effects of the application of local vibration on upper limbs during resistance training on the number of maximum repetitions, metabolic and hormonal responses. 32 volunteers performed a maximum voluntary contraction test during a lat pulldown exercise. After the test, all volunteers underwent one conventional resistance training session and one resistance training session with local vibration. In both interventions, volunteers performed 4 sets with the highest possible number of repetitions of the lat pulldown exercise at 55% of maximum voluntary contraction. During the vibratory resistance training intervention, vibration was locally applied (20-Hz and 12-mm). During the conventional resistance training, volunteers performed the same procedures without vibration. Blood samples were taken at each experimental session before and 5 min after the end of each intervention. No significant differences were observed in number of maximum repetitions between the series of vibratory and conventional training. Serum testosterone, cortisol and lactate were significantly increased after 2 interventions. Vibratory resistance training induced greater increases in testosterone and lactate concentrations. No significant changes were found in creatine kinase, creatinine or urea concentration. These data indicate that local vibration increases the metabolic and anabolic response to the resistance training, without changing the training volume. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Hepatic effect of NAC on sevear acute pancteatise of rats

    Institute of Scientific and Technical Information of China (English)

    Fang Chen; Ye-Jiang Zhou

    2014-01-01

    Objective:To analyze the hepatic protection of n-acetyl cysteine(NAC) on severe acute pancreatitis(SAP).Methods:SD rats were randomly divided into control group,SAP group and NAC group.SAPAHO method was adopted to establish the model,2 h after modeling, rats inNAC group had intraperitoneal injection ofNAC(200 mg/kg).Ten rats from each group were sacrificed in every6 and12 h at different time points respectively.Liver damage, liver function and serum amylase,AST,ALT and malondialdehyde(MDA) were determined.Results:Serum amylase,AST, ALT andMDA content inSAP,NAC group at each time point were significantly higher in the control group(P<0.05), serum amylase,AST,ALT andMDA content inNAC group rats were lower in theSAP group significantly(P<0.05);Microscopic examination showed that the liver injury in rats and theNAC group significantly reduced in theSAP group.Conclusions:NAC provides effective protection against liver damage toSAP, protective fromSAP liver injury.

  18. Acute effects of cigarette smoking on pattern electroretinogram.

    Science.gov (United States)

    Gundogan, Fatih C; Durukan, A Hakan; Mumcuoglu, Tarkan; Sobaci, Gungor; Bayraktar, M Zeki

    2006-09-01

    In this study, acute effects of cigarette smoking on the pattern electroretinogram (PERG) were investigated. First, variability of the PERG was studied in a group of young male smokers (26 right eyes of 26 subjects). Then PERGs were investigated in a group of habitual smokers (17 right eyes of 17 subjects) in separate real smoking and sham smoking sessions. On each session PERGs were recorded pre-smoking (PS), immediately after smoking (IAS) and 5 min after smoking (5th) conditions. Real smoking significantly increased P50 amplitudes and decreased N95 latencies. Regarding P50 amplitudes in the real smoking sessions, the differences were significant between PS and IAS (PS: 3.3 +/- 0.5 muV, IAS: 3.7 +/- 0.7microV, P = 0.015) and between PS-5th (PS: 3.3 +/- 0.5microV, 5th: 4.1 +/- 0.9microV, P = 0.039). There was significant difference (P = 0.024) between N95 latencies of PS (98.5 +/- 6.9 ms) and IAS (94.7 +/- 5.1 ms) in the real smoking sessions. No statistically significant difference was observed in sham smoking sessions. Our results indicated, for the first time, that cigarette smoking may influence PERG amplitude and latency significantly in habitual smokers.

  19. Sepsis-induced acute kidney injury in patients with cirrhosis.

    Science.gov (United States)

    Angeli, Paolo; Tonon, Marta; Pilutti, Chiara; Morando, Filippo; Piano, Salvatore

    2016-01-01

    Acute kidney injury (AKI) is a common and life-threatening complication in patients with cirrhosis. Recently, new criteria for the diagnosis of AKI have been proposed in patients with cirrhosis by the International Club of Ascites. Almost all types of bacterial infections can induce AKI in patients with cirrhosis representing its most common precipitating event. The bacterial infection-induced AKI usually meets the diagnostic criteria of hepatorenal syndrome (HRS). Well in keeping with the "splanchnic arterial vasodilation hypothesis", it has been stated that HRS develops as a consequence of a severe reduction of effective circulating volume related to splanchnic arterial vasodilation and to an inadequate cardiac output. Nevertheless, the role of bacterial infections in precipitating organ failures, including renal failure, is enhanced when their course is characterized by the development of a systemic inflammatory response syndrome (SIRS), thus, when sepsis occurs. Sepsis has been shown to be capable to induce "per se" AKI in animals as well as in patients conditioning also the features of renal damage. This observation suggests that when precipitated by sepsis, the pathogenesis and the clinical course of AKI also in patients with cirrhosis may differentiate to a certain extent from AKI with another or no precipitating factor. The purpose of this review is to describe the features of AKI precipitated by bacterial infections and to highlight whether infection and/or the development of SIRS may influence its clinical course, and, in particular, the response to treatment.

  20. Hyperosmolality-mediated peritoneal microvascular vasodilation is linked to aquaporin function.

    Science.gov (United States)

    Zakaria, El Rasheid; Althani, Asma; Fawzi, Ashraf A; Fituri, Omar M

    2014-01-01

    Glucose-based peritoneal dialysis (PD) solutions dilate the parietal and visceral peritoneal microvasculature by endothelium-dependent mechanisms that primarily involve hyperosmolality. This PD-mediated dilation occurs by active intracellular glucose uptake and adenosine Al receptor activation, and by hyperosmolality-stimulated glibenclamide-sensitive potassium channels. Both pathways invoke NO as a second messenger for vasodilation. We hypothesized that during crystalloid-induced osmosis, the osmotic water flux through the transendothelial water-exclusive aquaporin 1 (AQP1) channels is the primary mechanism whereby the endothelium is being stimulated to instigate hyperosmolality-driven vasodilation. Four microvascular levels (diameters in the range 6 - 100 microm) were visualized by intravital videomicroscopy of the terminal ileum in anesthetized rats. Microvascular diameters and flow were measured after topical exposure to a 5% hypertonic mannitol or 2.5% glucose-based PD solution, at baseline and after brief tissue pre-treatment (with 0.1% glutaraldehyde for 10 seconds) or after combined tissue pre-treatment and pharmacologic blockade of AQP1 with HgCl2 (100 micromol/L). Vascular endothelial integrity was verified by the response to acetylcholine (10(-4) mol/L) and sodium nitroprusside (10(-4) mol/L). The hyperosmolar solutions both caused rapid and sustained vasodilation at all microvascular levels, which was not altered by tissue pre-treatment. Inhibition of AQP1 completely abolished the mannitol-induced vasodilation and markedly attenuated the PD fluid-mediated vasodilation. Neither glutaraldehyde pre-treatment nor HgCl2 affected tissue integrity or endothelial cell function. We conclude that the peritoneal microvascular vasodilation caused by hyperosmolar PD fluid is instigated by the osmotic water flux through AQP1. Clinical PD solutions have components other than hyperosmolality that can induce endothelium-dependent peritoneal microvascular vasodilation

  1. 复方夏枯草活性部位对离体大鼠胸主动脉的舒张作用及机制研究%Vasodilation Effect and Underlying Mechanism of Active Fraction from Compound Prunella Vulgaris L. in I-solated Thoracic Aorta of Rats

    Institute of Scientific and Technical Information of China (English)

    雀苏云; 楼一层; 侯靖

    2015-01-01

    Objective:To investigate the vasorelaxant effect of active fraction from compound Prunella vulgaris L. ( AFCP) on the i-solated thoracic aorta of rats and underlying mechanism. Methods:The study was performed with the tension experiment of the isolate rat thoracic aorta. The changes of vascular ring tension were measured by biological signal acquisition and analysis system, and the vasodila-tor effect of AFCP was observed. Results:AFCP(100-500μg·ml-1)could induce significant relaxation in aorta rings pre-contracted by phenylephrine (PE,1 μmol·L-1), and the relaxation effect was significant(75% ±8%) in endothelium-intact aortic and endothelium-denuded aortic. The vasodilatation effect of AFCP was not significantly affected by nitric oxide synthase ( NOS) inhibitor NG-nitro-L-argi-nine( L-NNA) , guanylate cyclase inhibitor MB,potassium channel blocker TEA and glibenclamide. In Ca2+-free bath solutions, AFCP (300 μg·ml-1 ) could shift downward dose-response curve of CaCl2 and significantly reduce the maximum contraction amplitude of PE. Conclusion:AFCP can relax rat aorta rings in a dose-dependent manner, which is endothelium-independent. The mechanism may be re-lated to the inhibition of intracellular calcium release and extracellular calcium flow, and has nothing to do with NO pathway, prostacyclin generation and calcium-activated potassium channels.%目的::探讨复方夏枯草活性部位( AFCP)对大鼠离体胸主动脉的作用及其可能的机制。方法:采用离体大鼠胸主动脉张力实验,经生物信号采集与分析系统测定血管环张力的变化,观察AFCP的舒张血管作用。结果:AFCP(100~500μg·ml-1)能显著降低苯肾上腺素(PE,1μmol·L-1)引起的血管收缩,对内皮完整和去内皮血管均有(75%±8%)舒张作用。 AFCP的舒血管作用不受一氧化氮合酶抑制药L-NNA、岛苷酸环化酶抑制药MB、钾通道阻滞药TEA和格列苯脲的影响。在无钙K-H 液中AFCP(300μg·ml-1)可使CaCl2

  2. Angiotensin-(1-7)-induced renal vasodilation in hypertensive humans is attenuated by low sodium intake and angiotensin II co-infusion.

    Science.gov (United States)

    van Twist, Daan J L; Houben, Alfons J H M; de Haan, Michiel W; Mostard, Guy J M; Kroon, Abraham A; de Leeuw, Peter W

    2013-10-01

    Current evidence suggests that angiotensin-(1-7) plays an important role in the regulation of tissue blood flow. This evidence, however, is restricted to studies in animals and human forearm. Therefore, we studied the effects of intrarenal angiotensin-(1-7) infusion on renal blood flow in hypertensive humans. To assess the influence of renin-angiotensin system activity, sodium intake was varied and co-infusion with angiotensin II was performed in a subgroup. In 57 hypertensive patients who were scheduled for renal angiography, renal blood flow was measured ((133)Xenon washout method) before and during intrarenal infusion of angiotensin-(1-7) (3 incremental doses: 0.27, 0.9, and 2.7 ng/kg per minute). Patients were randomized into low or high sodium intake. These 2 groups of patients received angiotensin-(1-7), with or without intrarenal co-infusion of angiotensin II (0.3 ng/kg per minute). Angiotensin-(1-7) infusion resulted in intrarenal vasodilation in patients adhering to a sodium-rich diet. This vasodilatory effect of angiotensin-(1-7) was clearly attenuated by low sodium intake, angiotensin II co-infusion, or both. Regression analyses showed that the prevailing renin concentration was the only independent predictor of angiotensin-(1-7)-induced renal vasodilation. In conclusion, angiotensin-(1-7) induces renal vasodilation in hypertensive humans, but the effect of angiotensin-(1-7) is clearly attenuated by low sodium intake and co-infusion of angiotensin II. This supports the hypothesis that angiotensin-(1-7) induced renal vasodilation depends on the degree of renin-angiotensin-system activation.

  3. The effectiveness of heliox in acute respiratory distress syndrome.

    Science.gov (United States)

    Yilmaz, Sema; Daglioglu, Kenan; Yildizdas, Dincer; Bayram, Ibrahim; Gumurdulu, Derya; Polat, Sait

    2013-01-01

    The management of acute respiratory distress syndrome (ARDS) was investigated with the use of heliox in an experimental model. To investigate whether heliox can be considered a new therapeutic approach in ARDS. ARDS was designed in Wistar albino male rats, 250-300 g in weight, by intratracheal instillation of physiological saline solution. Anesthezied and tracheotomized rats with ARDS were pressure-controlled ventilated. At the end of 210 min, helium gas was tried. All rats were assigned to two groups: Group 1 (n = 10) was the control group, and was given no treatment; group 2 (n = 7) was given heliox (He: O(2) = 50:50). The heliox group received heliox for 1 h continously. Rats were continued to be kept on a ventilator through the experiment. Two hours after the last inhalation, both lungs of the rats were excised for both histopathological examination and immunohistochemical evaluation. Histopathological grading were expressed as median interquartile range. Mann-Whitney U-test was used to assess the relationships between the variables. The infiltation of neutrophils were decreased in rats treated with heliox. Edema in the interstitial and intraalveolar areas was less than that of the control rats. Also, the diminishing of perivascular and/or intraalveolar hemorrhage was apperant. Hyaline membrane (HM) formation decreased in the heliox group compared with the control group. Decreased inducible nitric oxide synthase expression was shown via immunohistochemical examination in the heliox group. The present study histopathologically indicated the effectiveness of heliox in the decreasing of neutrophil infiltation, interstitial/intraalveolar edema, perivascular and/or intraalveolar hemorrhage and HM formation in ARDS. Besides the known effect of heliox in obstructive lung disease, inhaled heliox therapy could be associated with the improvement of inflamation in ARDS.

  4. Effect of fluid ingestion on orthostatic responses following acute exercise

    Science.gov (United States)

    Davis, J. E.; Fortney, S. M.

    1997-01-01

    Orthostatic tolerance is impaired following an acute bout of exercise. This study examined the effect of fluid ingestion following treadmill exercise in restoring the cardiovascular responses to an orthostatic stress. Five men (age, 29.6 +/- 3.4 yrs) were exposed to a graded lower body negative (LBNP) pressure protocol (0 to -50 mmHg) during euhydration without exercise (C), 20 minutes after exercise dehydration (D), 20 minutes after exercise and fluid ingestion (FI20), and 60 minutes after exercise and fluid ingestion (FI60). Fluid ingestion (mean +/- SE) consisted of water-ingestion equivalent to 50% of the body weight lost during exercise (520 +/- 15 ml). Exercise dehydration resulted in significantly higher heart rates (119 +/- 8 vs 82 +/- 7 bpm), lower systolic blood pressures (95 +/- 1.7 vs 108 +/- 2.3 mmHg), a smaller increase in leg circumference (3.7 +/- 4 vs 6.9 +/- 1.0 mm), and an attenuated increase in total peripheral resistance (2.58 +/- 1.2 vs 4.28 +/- 0.9 mmHg/L/min) at -50 mmHg LBNP compared to the C condition. Fluid ingestion (both 20 and 60), partially restored the heart rate, systolic blood pressure, and total peripheral resistance responses to LBNP, but did not influence the change in leg circumference during LBNP (4 +/- 0.3 for R20 and 2.8 +/- 0.4 mm for R60). These data illustrate the effectiveness of fluid ingestion on improving orthostatic responses following exercise, and suggest that dehydration is a contributing factor to orthostatic intolerance following exercise.

  5. Improvement of vascular function by acute and chronic treatment with the GPR30 agonist G1 in experimental diabetes mellitus.

    Directory of Open Access Journals (Sweden)

    Zi-lin Li

    Full Text Available The G-protein coupled estrogen receptor 30 (GPR30 is a seven-transmembrane domain receptor that mediates rapid estrogen responses in a wide variety of cell types. This receptor is highly expressed in the cardiovascular system, and exerts vasodilatory effects. The objective of the present study was to investigate the effects of GPR30 on vascular responsiveness in diabetic ovariectomized (OVX rats and elucidate the possible mechanism involved. The roles of GPR30 were evaluated in the thoracic aorta and cultured endothelial cells. The GPR30 agonist G1 induced a dose-dependent vasodilation in the thoracic aorta of the diabetic OVX rats, which was partially attenuated by the nitric oxide synthase (NOS inhibitor, nitro-L-arginine methylester (L-NAME and the GPR30-selective antagonist G15. Dose-dependent vasoconstrictive responses to phenylephrine were attenuated significantly in the rings of the thoracic aorta following the acute G1 administration in the diabetic OVX rats. This effect of G1 was abolished partially by L-NAME and G15. The acute administration of G1 increased significantly the eNOS activity and the concentration of NO in the endothelial cells exposed to high glucose. G1 treatment induced an enhanced endothelium-dependent relaxation to acetylcholine (Ach in the diabetic OVX rats. Further examination revealed that G1 induced vasodilation in the diabetic OVX rats by increasing the phosphorylation of eNOS. These findings provide preliminary evidence that GPR30 activation leads to eNOS activation, as well as vasodilation, to a certain degree and has beneficial effects on vascular function in diabetic OVX rats.

  6. Central nitric oxide modulates hindquarter vasodilation elicited by AMPA receptor stimulation in the NTS of conscious rats.

    Science.gov (United States)

    Dias, Ana Carolina Rodrigues; Colombari, Eduardo

    2006-05-01

    Microinjection of S-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) in the nucleus of the solitary tract (NTS) of conscious rats causes hypertension, bradycardia, and vasoconstriction in the renal, mesenteric, and hindquarter vascular beds. In the hindquarter, the initial vasoconstriction is followed by vasodilation with AMPA doses >5 pmol/100 nl. To test the hypothesis that this vasodilation is caused by activation of a nitroxidergic pathway in the NTS, we examined the effect of pretreatment with the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 10 nmol/100 nl, microinjected into the NTS) on changes in mean arterial pressure, heart rate, and regional vascular conductance (VC) induced by microinjection of AMPA (10 pmol/100 nl in the NTS) in conscious rats. AMPA increased hindquarter VC by 18 +/- 4%, but after pretreatment with L-NAME, AMPA reduced hindquarter VC by 16 +/- 7% and 17 +/- 9% (5 and 15 min after pretreatment, P NTS activates both vasodilatatory and vasoconstrictor mechanisms and that the vasodilatatory mechanism depends on production of nitric oxide in the NTS.

  7. Low K⁺ current in arterial myocytes with impaired K⁺-vasodilation and its recovery by exercise in hypertensive rats.

    Science.gov (United States)

    Seo, Eun Yeong; Kim, Hae Jin; Zhao, Zai Hao; Jang, Ji Hyun; Jin, Chun Zi; Yoo, Hae Young; Zhang, Yin-Hua; Kim, Sung Joon

    2014-11-01

    K(+) channels determine the plasma membrane potential of vascular myocytes, influencing arterial tone. In many types of arteries, a moderate increase in [K(+)]e induces vasorelaxation by augmenting the inwardly rectifying K(+) channel current (I Kir). K(+)-vasodilation matches regional tissue activity and O2 supply. In chronic hypertension (HT), small arteries and arterioles undergo various changes; however, ion channel remodeling is poorly understood. Here, we investigated whether K(+) channels and K(+)-induced vasodilation are affected in deep femoral (DFA) and cerebral artery (CA) myocytes of angiotensin II-induced hypertensive rats (Ang-HT). Additionally, we tested whether regular exercise training (ET) restores HT-associated changes in K(+) channel activity. In Ang-HT, both the voltage-gated K(+) channel current (I Kv) and I Kir were decreased in DFA and CA myocytes, and were effectively restored and further increased by combined ET for 2 weeks (HT-ET). Consistently, K(+)-vasodilation of the DFA was impaired in Ang-HT, and recovered in HT-ET. Interestingly, ET did not reverse the decreased K(+)-vasodilation of CA. CA myocytes from the Ang-HT and HT-ET groups demonstrated, apart from K(+) channel changes, an increase in nonselective cationic current (I NSC). In contrast, DFA myocytes exhibited decreased I NSC in both the Ang-HT and HT-ET groups. Taken together, the decreased K(+) conductance in Ang-HT rats and its recovery by ET suggest increased peripheral arterial resistance in HT and the anti-hypertensive effects of ET, respectively. In addition, the common upregulation of I NSC in the CA in the Ang-HT and HT-ET groups might imply a protective adaptation preventing excessive cerebral blood flow under HT and strenuous exercise.

  8. Effects of acute hypercapnia with and without acidosis on lung inflammation and apoptosis in experimental acute lung injury.

    Science.gov (United States)

    Nardelli, L M; Rzezinski, A; Silva, J D; Maron-Gutierrez, T; Ornellas, D S; Henriques, I; Capelozzi, V L; Teodoro, W; Morales, M M; Silva, P L; Pelosi, P; Garcia, C S N B; Rocco, P R M

    2015-01-01

    We investigated the effects of acute hypercapnic acidosis and buffered hypercapnia on lung inflammation and apoptosis in experimental acute lung injury (ALI). Twenty-four hours after paraquat injection, 28 Wistar rats were randomized into four groups (n=7/group): (1) normocapnia (NC, PaCO2=35-45 mmHg), ventilated with 0.03%CO2+21%O2+balancedN2; (2) hypercapnic acidosis (HC, PaCO2=60-70 mmHg), ventilated with 5%CO2+21%O2+balancedN2; and (3) buffered hypercapnic acidosis (BHC), ventilated with 5%CO2+21%O2+balancedN2 and treated with sodium bicarbonate (8.4%). The remaining seven animals were not mechanically ventilated (NV). The mRNA expression of interleukin (IL)-6 (p=0.003), IL-1β (pacidosis, reduced lung inflammation and lung and kidney cell apoptosis.

  9. Use-dependent loss of active sympathetic neurogenic vasodilation after nitric oxide synthase inhibition in conscious rats. Evidence for the presence of preformed stores of nitric oxide-containing factors

    Science.gov (United States)

    Davisson, R. L.; Shaffer, R. A.; Johnson, A. K.; Lewis, S. J.

    1996-01-01

    In this study, we examined whether air-jet stress-induced active sympathetic hindlimb vasodilation in conscious rats involves the release of preformed stores of nitric oxide-containing factors. We determined the effects of repeated episodes of air-jet stress (six episodes given 5 minutes apart) on mean arterial pressure and vascular resistances in the mesenteric bed and intact and sympathetically denervated hindlimb beds of conscious rats treated with saline or the nitric oxide synthesis inhibitor N omega-nitro-L-arginine methyl ester (L-NAME, 25 mumol/kg IV). In saline-treated rats, air-jet stress produced alerting behavior, minor changes in blood pressure, pronounced mesenteric vaso-constriction, and immediate and marked vasodilation in the sympathetically intact hindlimb but a minor vasodilation in the sympathetically denervated hindlimb. Each air-jet stress produced virtually identical responses. In L-NAME-treated rats, the first air-jet stress produced vasodilator responses in the sympathetically intact and sympathetically denervated hindlimbs that were similar to those in the saline-treated rats. However, each subsequent air-jet stress produced progressively smaller vasodilator responses in the sympathetically intact but not the sympathetically denervated hindlimb. There was no loss of air-jet stress-induced alerting behavior or mesenteric vasoconstriction, suggesting that L-NAME did not interfere with the central processing of the air-jet or the resultant changes in autonomic nerve activity. The progressive diminution of air-jet stress-induced vasodilation in the intact hindlimb of L-NAME-treated rats may be due to the use-dependent depletion of preformed stores of nitric oxide-containing factors that cannot be replenished in the absence of nitric oxide synthesis.

  10. Acute stress does not affect the impairing effect of chronic stress on memory retrieval

    Directory of Open Access Journals (Sweden)

    Jamile Ozbaki

    2016-07-01

    Full Text Available Objective(s: Due to the prevalence and pervasiveness of stress in modern life and exposure to both chronic and acute stresses, it is not clear whether prior exposure to chronic stress can influence the impairing effects of acute stress on memory retrieval. This issue was tested in this study. Materials and Methods: Adult male Wistar rats were randomly assigned to the following groups: control, acute, chronic, and chronic + acute stress groups. The rats were trained with six trials per day for 6 consecutive days in the water maze. Following training, the rats were either kept in control conditions or exposed to chronic stress in a restrainer 6 hr/day for 21 days. On day 22, a probe test was done to measure memory retention. Time spent in target and opposite areas, platform location latency, and proximity were used as indices of memory retention. To induce acute stress, 30 min before the probe test, animals received a mild footshock. Results: Stressed animals spent significantly less time in the target quadrant and more time in the opposite quadrant than control animals. Moreover, the stressed animals showed significantly increased platform location latency and proximity as compared with control animals. No significant differences were found in these measures among stress exposure groups. Finally, both chronic and acute stress significantly increased corticosterone levels. Conclusion: Our results indicate that both chronic and acute stress impair memory retrieval similarly. Additionally, the impairing effects of chronic stress on memory retrieval were not influenced by acute stress.

  11. Acute stress does not affect the impairing effect of chronic stress on memory retrieval

    Science.gov (United States)

    Ozbaki, Jamile; Goudarzi, Iran; Salmani, Mahmoud Elahdadi; Rashidy-Pour, Ali

    2016-01-01

    Objective(s): Due to the prevalence and pervasiveness of stress in modern life and exposure to both chronic and acute stresses, it is not clear whether prior exposure to chronic stress can influence the impairing effects of acute stress on memory retrieval. This issue was tested in this study. Materials and Methods: Adult male Wistar rats were randomly assigned to the following groups: control, acute, chronic, and chronic + acute stress groups. The rats were trained with six trials per day for 6 consecutive days in the water maze. Following training, the rats were either kept in control conditions or exposed to chronic stress in a restrainer 6 hr/day for 21 days. On day 22, a probe test was done to measure memory retention. Time spent in target and opposite areas, platform location latency, and proximity were used as indices of memory retention. To induce acute stress, 30 min before the probe test, animals received a mild footshock. Results: Stressed animals spent significantly less time in the target quadrant and more time in the opposite quadrant than control animals. Moreover, the stressed animals showed significantly increased platform location latency and proximity as compared with control animals. No significant differences were found in these measures among stress exposure groups. Finally, both chronic and acute stress significantly increased corticosterone levels. Conclusion: Our results indicate that both chronic and acute stress impair memory retrieval similarly. Additionally, the impairing effects of chronic stress on memory retrieval were not influenced by acute stress. PMID:27635201

  12. Role of nitric oxide and adenosine in the onset of vasodilation during dynamic forearm exercise.

    Science.gov (United States)

    Casey, Darren P; Mohamed, Essa A; Joyner, Michael J

    2013-02-01

    We tested the hypothesis that nitric oxide (NO) and adenosine contribute to the onset of vasodilation during dynamic forearm exercise. Twenty-two subjects performed rhythmic forearm exercise (20 % of maximum) during control and NO synthase (NOS) inhibition (N (G)-monomethyl-L-arginine; L-NMMA) trials. A subset of subjects performed a third trial of forearm exercise during combined inhibition of NOS and adenosine (aminophylline; n = 9). Additionally, a separate group of subjects (n = 7) performed rhythmic forearm exercise during control, inhibition of adenosine alone and combined inhibition of adenosine and NOS. Forearm vascular conductance (FVC; ml min(-1) · 100 mmHg(-1)) was calculated from blood flow and mean arterial pressure (mmHg). The onset of vasodilation was assessed by calculating the slope of the FVC response for every duty cycle between baseline and steady state, and the number of duty cycles (1-s contraction/2-s relaxation) to reach steady state. NOS inhibition blunted vasodilation at the onset of exercise (11.1 ± 0.8 vs. 8.5 ± 0.6 FVC units/duty cycle; P Vasodilation was blunted further with combined inhibition of NOS and adenosine (7.5 ± 0.6 vs. 6.2 ± 0.8 FVC units/duty cycle; P vasodilation during dynamic forearm exercise.

  13. β-Adrenergic-mediated vasodilation in young men and women: cyclooxygenase restrains nitric oxide synthase.

    Science.gov (United States)

    Limberg, Jacqueline K; Johansson, Rebecca E; Peltonen, Garrett L; Harrell, John W; Kellawan, J Mikhail; Eldridge, Marlowe W; Sebranek, Joshua J; Schrage, William G

    2016-03-15

    We tested the hypothesis that women exhibit greater vasodilator responses to β-adrenoceptor stimulation compared with men. We further hypothesized women exhibit a greater contribution of nitric oxide synthase and cyclooxygenase to β-adrenergic-mediated vasodilation compared with men. Forearm blood flow (Doppler ultrasound) was measured in young men (n = 29, 26 ± 1 yr) and women (n = 33, 25 ± 1 yr) during intra-arterial infusion of isoproterenol (β-adrenergic agonist). In subset of subjects, isoproterenol responses were examined before and after local inhibition of nitric oxide synthase [N(G)-monomethyl-l-arginine (l-NMMA); 6 male/10 female] and/or cyclooxygenase (ketorolac; 5 male/5 female). Vascular conductance (blood flow ÷ mean arterial pressure) was calculated to assess vasodilation. Vascular conductance increased with isoproterenol infusion (P 0.99) or women (P = 0.21). In contrast, ketorolac infusion markedly increased isoproterenol-mediated responses in both men (P vasodilation is not different between men and women and sex differences in the independent contribution of nitric oxide synthase and cyclooxygenase to β-mediated vasodilation are not present. However, these data are the first to demonstrate β-adrenoceptor activation of cyclooxygenase suppresses nitric oxide synthase signaling in human forearm microcirculation and may have important implications for neurovascular control in both health and disease.

  14. Cardiac output and vasodilation in the vasovagal response: An analysis of the classic papers.

    Science.gov (United States)

    Wieling, Wouter; Jardine, David L; de Lange, Frederik J; Brignole, Michele; Nielsen, Henning B; Stewart, Julian; Sutton, Richard

    2016-03-01

    The simple faint is secondary to hypotension and bradycardia resulting in transient loss of consciousness. According to Ohm's law applied to the circulation, BP = SVR × CO, hypotension can result from a decrease in systemic vascular resistance (SVR), cardiac output (CO), or both. It is important to understand that when blood pressure (BP) is falling, SVR and CO do not change reciprocally as they do in the steady state. In 1932, Lewis, assuming that decreased SVR alone accounted for hypotension, defined "the vasovagal response" along pathophysiologic lines to denote the association of vasodilation with vagal-induced bradycardia in simple faint. Studies performed by Barcroft and Sharpey-Schafer between 1940 and 1950 used volume-based plethysmography to demonstrate major forearm vasodilation during extreme hypotension and concluded that the main mechanism for hypotension was vasodilation. Plethysmographic measurements were intermittent and not frequent enough to capture rapid changes in blood flow during progressive hypotension. However, later investigations by Weissler, Murray, and Stevens performed between 1950 and 1970 used invasive beat-to-beat BP measurements and more frequent measurements of CO using the Fick principle. They demonstrated that CO significantly fell before syncope, and little vasodilation occurred until very late in the vasovagal reaction Thus, since the 1970s, decreasing cardiac output rather than vasodilation has been regarded as the principal mechanism for the hypotension of vasovagal syncope.

  15. The Gatekeepers in the Mouse Ophthalmic Artery: Endothelium-Dependent Mechanisms of Cholinergic Vasodilation.

    Science.gov (United States)

    Manicam, Caroline; Staubitz, Julia; Brochhausen, Christoph; Grus, Franz H; Pfeiffer, Norbert; Gericke, Adrian

    2016-02-02

    Cholinergic regulation of arterial luminal diameter involves intricate network of intercellular communication between the endothelial and smooth muscle cells that is highly dependent on the molecular mediators released by the endothelium. Albeit the well-recognized contribution of nitric oxide (NO) towards vasodilation, the identity of compensatory mechanisms that maintain vasomotor tone when NO synthesis is deranged remain largely unknown in the ophthalmic artery. This is the first study to identify the vasodilatory signalling mechanisms of the ophthalmic artery employing wild type mice. Acetylcholine (ACh)-induced vasodilation was only partially attenuated when NO synthesis was inhibited. Intriguingly, the combined blocking of cytochrome P450 oxygenase (CYP450) and lipoxygenase (LOX), as well as CYP450 and gap junctions, abolished vasodilation; demonstrating that the key compensatory mechanisms comprise arachidonic acid metabolites which, work in concert with gap junctions for downstream signal transmission. Furthermore, the voltage-gated potassium ion channel, Kv1.6, was functionally relevant in mediating vasodilation. Its localization was found exclusively in the smooth muscle. In conclusion, ACh-induced vasodilation of mouse ophthalmic artery is mediated in part by NO and predominantly via arachidonic acid metabolites, with active involvement of gap junctions. Particularly, the Kv1.6 channel represents an attractive therapeutic target in ophthalmopathologies when NO synthesis is compromised.

  16. Influence of habitual high dietary fat intake on endothelium-dependent vasodilation.

    Science.gov (United States)

    Dow, Caitlin A; Stauffer, Brian L; Greiner, Jared J; DeSouza, Christopher A

    2015-07-01

    High-fat diets are associated with an increased risk of cardiovascular disease. A potential underlying mechanism for the increased cardiovascular risk is endothelial dysfunction. Nitric oxide (NO)-mediated endothelium-dependent vasodilation is critical in the regulation of vascular tone and overall vascular health. The aim of this study was to determine the influence of dietary fat intake on endothelium-dependent vasodilation. Forty-four middle-aged and older sedentary, healthy adults were studied: 24 consumed a lower fat diet (LFD; 29% ± 1% calories from fat) and 20 consumed a high-fat diet (HFD; 41% ± 1% calories from fat). Four-day diet records were used to assess fat intake, and classifications were based on American Heart Association guidelines (vasodilator response to sodium nitroprusside. These data indicate that a high-fat diet is associated with endothelium-dependent vasodilator dysfunction due, in part, to diminished NO bioavailability. Impaired NO-mediated endothelium-dependent vasodilation may contribute to the increased cardiovascular risk with high dietary fat intake.

  17. Acetylcholine released from cholinergic nerves contributes to cutaneous vasodilation during heat stress

    Science.gov (United States)

    Shibasaki, Manabu; Wilson, Thad E.; Cui, Jian; Crandall, Craig G.

    2002-01-01

    Nitric oxide (NO) contributes to active cutaneous vasodilation during a heat stress in humans. Given that acetylcholine is released from cholinergic nerves during whole body heating, coupled with evidence that acetylcholine causes vasodilation via NO mechanisms, it is possible that release of acetylcholine in the dermal space contributes to cutaneous vasodilation during a heat stress. To test this hypothesis, in seven subjects skin blood flow (SkBF) and sweat rate were simultaneously monitored over three microdialysis membranes placed in the dermal space of dorsal forearm skin. One membrane was perfused with the acetylcholinesterase inhibitor neostigmine (10 microM), the second membrane was perfused with the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME; 10 mM) dissolved in the aforementioned neostigmine solution (l-NAME(Neo)), and the third membrane was perfused with Ringer solution as a control site. Each subject was exposed to approximately 20 min of whole body heating via a water-perfused suit, which increased mean body temperature from 36.4 +/- 0.1 to 37.5 +/- 0.1 degrees C (P acetylcholine released from cholinergic nerves is capable of modulating cutaneous vasodilation via NO synthase mechanisms early in the heat stress but not after substantial cutaneous vasodilation.

  18. Peripheral vasodilators and the management of peripheral vascular disease and Raynaud's syndrome in general practice.

    Science.gov (United States)

    Connolly, J P; McGavock, H; Wilson-Davis, K

    1998-05-01

    There is no convincing evidence that peripheral vasodilators produce any significant improvement in exercise tolerance in patients with peripheral vascular disease, and these drugs may do more harm than good. In the treatment of severe Raynaud's syndrome, however, thymoxamine, prazosin or nifedipine is recommended. A descriptive study was carried out, firstly, to determine why these drugs are prescribed in general practice, and secondly, to describe the drug choices in the treatment of both Raynaud's syndrome and peripheral vascular disease in a representative sample of 22 practices in Northern Ireland. Of those patients prescribed peripheral vasodilators 69.6% were diagnosed as peripheral vascular disease, claudication or atherosclerosis. Over three-quarters of peripheral vasodilators prescribed were repeat prescriptions. Of those with Raynaud's syndrome only half were treated appropriately, and certainty of diagnosis did not guarantee appropriate treatment. Peripheral vasodilators accounted for the majority (51.5%) of items prescribed for peripheral vascular disease. A minority of patients with peripheral vascular disease (20.3%) were prescribed aspirin, and a smaller minority (4.4%) had undergone amputation. Peripheral vasodilators were prescribed unnecessarily and inappropriately. Measures to promote evidence-based treatment of both Raynaud's syndrome and peripheral vascular disease in general practice need to be taken. Copyright 1998 John Wiley & Sons, Ltd.

  19. Acute effects of flexible pole exercise on heart rate dynamics.

    Science.gov (United States)

    de Oliveira, Letícia Santana; Moreira, Patrícia S; Antonio, Ana M; Cardoso, Marco A; de Abreu, Luiz Carlos; Navega, Marcelo T; Raimundo, Rodrigo D; Valenti, Vitor E

    2015-01-01

    Exercise with flexible poles provides fast eccentric and concentric muscle contractions. Although the literature reports significant muscle chain activity during this exercise, it is not clear if a single bout of exercise induces cardiac changes. In this study we assessed the acute effects of flexible pole exercise on cardiac autonomic regulation. The study was performed on 22 women between 18 and 26 years old. We assessed heart rate variability (HRV) in the time (SDNN, RMSSD and pNN50) and frequency (HF, LF and LF/HF ratio) domains and geometric indices of HRV (RRTri, TINN, SD1, SD2 and SD1/SD2 ratio). The subjects remained at rest for 10 min and then performed the exercises with the flexible poles. Immediately after the exercise protocol, the volunteers remained seated at rest for 60 min and HRV was analyzed. We observed no significant changes in time domain (SDNN: p=0.72; RMSSD: p=0.94 and pNN50: p=0.92) or frequency domain indices (LF [nu]: p=0.98; LF [ms(2)]: p=0.72; HF [nu]: p=0.98; HF [ms(2)]: p=0.82 and LF/HF ratio: p=0.7) or in geometric indices (RRTri: p=0.54; TINN: p=0.77; SD1: p=0.94; SD2: p=0.67 and SD/SD2: p=0.42) before and after a single bout of flexible pole exercise. A single bout of flexible pole exercise did not induce significant changes in cardiac autonomic regulation in healthy women. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  20. Inhibition factors of arsenic trioxide therapeutic effects in patients with acute promyelocytic leukemia

    Institute of Scientific and Technical Information of China (English)

    Sui Meijuan; Zhang Zhuo; Zhou Jin

    2014-01-01

    Objective To summarize limitations involved in arsenic trioxide therapeutic effects in acute promyelocytic leukemia,because current studies show that some individuals of acute promyelocytic leukemia have relatively poor outcomes during treatment with arsenic trioxide.Data sources Most relevant articles were included in the PubMed database between 2000 and 2013 with the keywords "acute promyelocytic leukemia","arsenic trioxide","thiol" or "methylation".In addition,a few older articles were also reviewed.Study selection Data and articles related to arsenic trioxide effect in acute promyelocytic leukemia treatment were selected and reviewed.We developed an overview of limitations associated with arsenic trioxide therapeutic effect.Results This review focuses on the researches about the arsenic trioxide therapeutic effect in acute promyelocytic leukemia and summarizes three mainly limitations which can influence the arsenic trioxide therapeutic effect to different degrees.First,with the combination of arsenic and glutathione the therapeutic effect and cytotoxicity decrease when glutathione concentration increases; second,arsenic methylation,stable arsenic methylation products weaken the apoptosis effect of arsenic trioxide in leukemia cells; third,gene mutations affect the sensitivity of tumor cells to arsenic trioxide and increase the resistance of leukemia cells to arsenic trioxide.Conclusions The chief limitations are listed in the review.If we can exclude all of them,we can obtain a better therapeutic effect of arsenic trioxide in patients with acute promyelocytic leukemia.

  1. Effects of Losartan on acute atrial electrical remodeling

    Institute of Scientific and Technical Information of China (English)

    李悦; 李为民; 薛竟宜; 韩薇; 杨树森; 谷宏越

    2004-01-01

    Background Atrial electrical remodeling (AER) contributes to the maintainance of atrial fibrillation (AF). This study was to compare the effects of Losartan with those of Diltiazem on tachycardia-induced acute AER in rabbits.Methods Twenty-one rabbits paced with maximal atrial capture rate for 3 hours in the right atrium (RA) were randomly divided into saline group, Diltiazem group and Losartan group. After autonomic blockage, we measured atrial effective refractory period (AERP), AERP rate adapting feature, AERP dispersion and RA conduction time at basic cycle lengths (BCLs) of 200 ms and 150 ms at baseline, 0.5 hour, 1 hour, 2 and 3 hours after rapid atrial pacing. Results In the saline group, there was a prompt decrease in AERP as a result of rapid atrial pacing, and AERP200 and AERP150 were shortened sharply within 0.5 hour of pacing (30.2±10.5 ms and 24.1±9.1 ms, respectively). The AERP did not change dramatically in the Diltiazem and Losartan groups. In the saline group, the value of (AERP200-AERP150)/50 ms in high RA was 0.17±0.08 at baseline and became significantly smaller at 0.5 hour (0.08±0.06), 1 hour (0.09±0.06), 2 hours (0.08±0.04) and 3 hours (0.09±0.05) (all P<0.05), suggesting a reduction of rate adaptation of AERP. The value of (AERP200-AERP150)/50 ms in high RA did not change during the 3 hours of pacing in both Diltiazem and Losartan groups. In the saline group, AERP dispersion increased significantly at 2 and 3 hours (P<0.05). However, Diltiazem could not prevent the increase of AERP dispersion at 3 hours (P<0.05). During Losartan infusion, the AERP dispersion was no longer increased after rapid atrial pacing. There was no significant difference in RA conduction time among the three groups.Conclusion Like calcium antagonist Diltiazem, Losartan could prevent AERP shortening and preserve rate adaptation of AERP after rapid atrial pacing. Losartan is more effective than Diltiazem in inhibiting the increase of AERP dispersion.

  2. Adaptive changes in the acute haemodynamic effects of cilazapril during chronic treatment. Comparison with long-term clinical effect

    DEFF Research Database (Denmark)

    Larsen, J; Sykulski, R; Jensen, G;

    1996-01-01

    OBJECTIVE: To study the adaptive changes in the acute haemodynamic response to ACE inhibition during chronic treatment in CHF. METHODS: The acute and chronic effects of oral cilazapril (CLZ) treatment, an ACE-inhibitor with prolonged duration on haemodynamic measures (PCWP, PAP, RAP, CI and SVR) ...

  3. Effect of metoprolol on chest pain in acute myocardial infarction.

    OpenAIRE

    Herlitz, J; Hjalmarson, A.; Holmberg, S.; Pennert, K; Swedberg, K; Vedin, A; Waagstein, F; Waldenström, A; Wedel, H.; Wilhelmsen, L

    1984-01-01

    A total of 1395 patients aged 40 to 74 years were included in a double blind trial with the beta 1 selective blocker metoprolol in suspected acute myocardial infarction. Metoprolol was given intravenously (15 mg) as soon as possible after admission to hospital followed by 200 mg daily for three months. A placebo was given in the same manner. The severity of chest pain in the acute phase was calculated by recording the number of injections of analgesics given and the time from the start of bli...

  4. Effect of acute adrenalectomy on rat liver glucocorticoid receptor

    Directory of Open Access Journals (Sweden)

    Isenović Esma R.

    2006-01-01

    Full Text Available In order to improve current clinical treatment of human hypocortisolism, it is necessary to understand molecular aspects of this pathophysiology. In this study liver tissues from male Wistar rats were used as an experimental model to study structural and functional properties of glucocorticoid receptor (GR in the absence of glucocorticoid hormones (GC. Results show that acute adrenalectomy (ADX significantly increases the number of GR binding sites and GR protein content. In addition, acute ADX stimulates increase in stability of the GR, decrease in stability of the glucocorticoid- receptor complex (G-R, and changes in accumulation of the G-R complex in nuclei and its cellular distribution. .

  5. Acute Effects of Fine Particulate Air Pollution on ST Segment Height: A Longitudinal Study

    Science.gov (United States)

    Background: The mechanisms for the relationship between particulate air pollution and cardiac disease are not fully understood. Air pollution-induced myocardial ischemia is one of the potentially important mechanisms. Methods: We investigate the acute effects and the time cours...

  6. Acute toxicity and effect of some petroleum hydrocarbon on the metabolic index in Etroplus suratensis

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Farshchi, P.

    Acute toxicity (LC sub(50)) and effect of some petroleum hydrocarbons (Toluene, Quinoline, Pyridine and Naphthalene) on the metabolic index (oxygen consumption rate) of an estuarine fish. Etroplus suratensis is reported. The LC sub(50) values were...

  7. Respiratory Effects and Systemic Stress Response Following Acute Acrolein Inhalation in Rats

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data set is an Excel file pertaining to the study that examined nasal, pulmonary, and systemic effects of acrolein in rats acutely exposed to a range of...

  8. Consensus definitions of 14 severe acute toxic effects for childhood lymphoblastic leukaemia treatment

    DEFF Research Database (Denmark)

    Schmiegelow, Kjeld; Attarbaschi, Andishe; Barzilai, Shlomit

    2016-01-01

    Although there are high survival rates for children with acute lymphoblastic leukaemia, their outcome is often counterbalanced by the burden of toxic effects. This is because reported frequencies vary widely across studies, partly because of diverse definitions of toxic effects. Using the Delphi...... method, 15 international childhood acute lymphoblastic leukaemia study groups assessed acute lymphoblastic leukaemia protocols to address toxic effects that were to be considered by the Ponte di Legno working group. 14 acute toxic effects (hypersensitivity to asparaginase, hyperlipidaemia, osteonecrosis......, thromboembolism, and Pneumocystis jirovecii pneumonia) that are serious but too rare to be addressed comprehensively within any single group, or are deemed to need consensus definitions for reliable incidence comparisons, were selected for assessment. Our results showed that none of the protocols addressed all 14...

  9. Protective effect of grifolin against brain injury in an acute cerebral ...

    African Journals Online (AJOL)

    Protective effect of grifolin against brain injury in an acute ... Sent for review: 24 January 2017 ... levels in tissue homogenates of the cerebral ischemic rats compared with those in the negative ... Stroke is a major cause of death worldwide [1].

  10. Cystathionine γ-lyase, a H2S-generating enzyme, is a GPBAR1-regulated gene and contributes to vasodilation caused by secondary bile acids.

    Science.gov (United States)

    Renga, Barbara; Bucci, Mariarosaria; Cipriani, Sabrina; Carino, Adriana; Monti, Maria Chiara; Zampella, Angela; Gargiulo, Antonella; d'Emmanuele di Villa Bianca, Roberta; Distrutti, Eleonora; Fiorucci, Stefano

    2015-07-01

    GPBAR1 is a bile acid-activated receptor (BAR) for secondary bile acids, lithocholic (LCA) and deoxycholic acid (DCA), expressed in the enterohepatic tissues and in the vasculature by endothelial and smooth muscle cells. Despite that bile acids cause vasodilation, it is unclear why these effects involve GPBAR1, and the vascular phenotype of GPBAR1 deficient mice remains poorly defined. Previous studies have suggested a role for nitric oxide (NO) in regulatory activity exerted by GPBAR1 in liver endothelial cells. Hydrogen sulfide (H2S) is a vasodilatory agent generated in endothelial cells by cystathionine-γ-lyase (CSE). Here we demonstrate that GPBAR1 null mice had increased levels of primary and secondary bile acids and impaired vasoconstriction to phenylephrine. In aortic ring preparations, vasodilation caused by chenodeoxycholic acid (CDCA), a weak GPBAR1 ligand and farnesoid-x-receptor agonist (FXR), was iberiotoxin-dependent and GPBAR1-independent. In contrast, vasodilation caused by LCA was GPBAR1 dependent and abrogated by propargyl-glycine, a CSE inhibitor, and by 5β-cholanic acid, a GPBAR1 antagonist, but not by N(5)-(1-iminoethyl)-l-ornithine (l-NIO), an endothelial NO synthase inhibitor, or iberiotoxin, a large-conductance calcium-activated potassium (BKCa) channels antagonist. In venular and aortic endothelial (HUVEC and HAEC) cells GPBAR1 activation increases CSE expression/activity and H2S production. Two cAMP response element binding protein (CREB) sites (CREs) were identified in the CSE promoter. In addition, TLCA stimulates CSE phosphorylation on serine residues. In conclusion we demonstrate that GPBAR1 mediates the vasodilatory activity of LCA and regulates the expression/activity of CSE. Vasodilation caused by CDCA involves BKCa channels. The GPBAR1/CSE pathway might contribute to endothelial dysfunction and hyperdynamic circulation in liver cirrhosis.

  11. Effect of sesame oil against acetaminophen-induced acute oxidative hepatic damage in rats.

    Science.gov (United States)

    Chandrasekaran, Victor Raj Mohan; Wan, Chang-Hsin; Liu, Li-Lian; Hsu, Dur-Zong; Liu, Ming-Yie

    2008-08-01

    Acetaminophen (APAP) overdose causes acute liver injury or even death in both humans and experimental animals. We investigated the effect of sesame oil on APAP-induced acute liver injury. Male Wistar rats were given APAP (1,000 mg/kg; orally) to induce acute liver injury. Acetaminophen significantly increased aspartate transaminase, alanine transaminase, lipid peroxidation, and superoxide anion and hydroxyl radical generation levels; it also induced glutathione depletion. Sesame oil (8 mL/kg; orally) did not alter the gastric absorption of APAP, but it inhibited all the parameters altered by APAP and protected the rats against APAP-induced acute liver injury. We hypothesize that sesame oil maintained the intracellular glutathione levels, reduced reactive oxygen species levels, and inhibited lipid peroxidation in rats with APAP-induced acute liver injury.

  12. Pharmacodynamic and pharmacokinetic effects of flumazenil and theophylline application in rats acutely intoxicated by diazepam

    OpenAIRE

    2009-01-01

    Background/Aim. The majority of symptoms and signs of acute diazepam poisoning are the consequence of its sedative effect on the CNS affecting selectively polisynaptic routes by stimulating inhibitory action of GABA. The aim of the present study was to examine the effects of combined application of theophylline and flumazenil on sedation and impaired motor function activity in acute diazepam poisoning in rats. Methods. Male Wistar rats were divided in four main groups and treated as follows: ...

  13. [The use of arteriography in the pharmacological study of a vasodilator substance].

    Science.gov (United States)

    Bonnin, A; d'Izarn, J J; Collard, M; Viallet, J F; Viallet, P; Cluzan, R; Ledoux-Lebard, G

    1977-03-01

    The administration of a vasodilator substance is followed by the development of a higher contrast gradient in a given film in comparison with a reference X-ray carried out in the same subject under comparable technical conditions. Comparative densitometric measurement of the contrast gradient in the two successive arteriographic series, one with and one without the injection, arterial or venous, of a vasodilator substance (Couramine-Rutine) represents a valuable method for the study in man of the action of the substance in a visceral territory. The present study was limited to the kedney (79 cases), ans the territory of the superior mesenteric (46 cases). The absence of any densitometric difference between the two renal series at too low doses of vasodilator substance leads to the supposition of the possibility of a threshold dose of pharmacological activity.

  14. Contribution of endothelium-derived hyperpolarizing factor to exercise-induced vasodilation in health and hypercholesterolemia.

    Science.gov (United States)

    Ozkor, Muhiddin A; Hayek, Salim S; Rahman, Ayaz M; Murrow, Jonathan R; Kavtaradze, Nino; Lin, Ji; Manatunga, Amita; Quyyumi, Arshed A

    2015-02-01

    The role of endothelium-derived hyperpolarizing factor (EDHF) in either the healthy circulation or in those with hypercholesterolemia is unknown. In healthy and hypercholesterolemic subjects, we measured forearm blood flow (FBF) using strain-gauge plethysmography at rest, during graded handgrip exercise, and after sodium nitroprusside infusion. Measurements were repeated after l-NMMA, tetraethylammonium (TEA), and combined infusions. At rest, l-NMMA infusion reduced FBF in healthy but not hypercholesterolemic subjects. At peak exercise, vasodilation was lower in hypercholesterolemic compared to healthy subjects (274% vs 438% increase in FBF, p=0.017). TEA infusion reduced exercise-induced vasodilation in both healthy and hypercholesterolemic subjects (27%, pvasodilation in hypercholesterolemia. In conclusion, exercise-induced vasodilation is impaired and predominantly mediated by EDHF in hypercholesterolemic subjects. CLINICAL TRIAL REGISTRATION IDENTIFIER NCT00166166:

  15. Insulin and non-insulin mediated vasodilation and glucose uptake in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Scheede-Bergdahl, Celena; Olsen, David Benee; Reving, Danny;

    2009-01-01

    AIMS: The objective was to re-examine endothelial function, insulin mediated vasodilation and glucose extraction in the forearm of patients with type 2 diabetes (T2DM) and matched control subjects (CON) to investigate whether blood flow impairments result from diabetes per se or from concurrent...... disease. METHODS: 18 subjects (10 with T2DM, 8 CON) had graded brachial artery infusions of endothelial dependent (acetylcholine: 15, 30, 60mug/min), endothelial independent (sodium nitroprusside: 1, 3, 10mug/min) and partially endothelial mediated (adenosine: 50, 150, 500mug/min) vasodilators....... The protocol was repeated during a hyperinsulinemic clamp. Forearm blood flow and glucose extraction were measured at each dose of vasodilator (with/without insulin). Measurements were also taken in the control arm, reflecting systemic insulin infusion only. RESULTS: Non-insulin mediated increases in bulk...

  16. Semicarbazide-sensitive amine oxidase: role in the vasculature and vasodilation after in situ inhibition.

    Science.gov (United States)

    Vidrio, H

    2003-01-01

    1. The characteristics of semicarbazide-sensitive amine oxidase (SSAO) are reviewed and the unknown physiological or pathological role of this enzyme emphasized. 2. The various mechanisms of action proposed for the vasodilator drug hydralazine are considered. In particular, the inhibitory action on various enzymes, related or not to cardiovascular function, are discussed. 3. Studies linking inhibition of SSAO to hydralazine hypotension are reviewed and a general hypothesis relating both actions is presented. The hypothesis postulates that (a). vascular SSAO is involved in the regulation of vascular tone, and (b). hydralazine vasodilation is the consequence of vascular SSAO inhibition. 4. Evidence supporting these postulates is presented and vascular SSAO inhibition is proposed as a novel mechanism of vasodilation.

  17. NO-donor phenols: a new class of products endowed with antioxidant and vasodilator properties.

    Science.gov (United States)

    Boschi, Donatella; Tron, Gian Cesare; Lazzarato, Loretta; Chegaev, Konstantin; Cena, Clara; Di Stilo, Antonella; Giorgis, Marta; Bertinaria, Massimo; Fruttero, Roberta; Gasco, Alberto

    2006-05-18

    The synthesis and study of the antioxidant and vasodilator properties of a new class of phenols able to release nitric oxide are described. The products were designed through a symbiotic approach using selected phenols and selected nitrooxy and furoxan NO-donors as reference models. The antioxidant activities of the hybrid products were assessed by detecting the 2-thiobarbituric acid reactive substances (TBARS) produced in the ferrous salt/ascorbate-induced autoxidation of lipids present in microsomial membranes of rat hepatocytes. The vasodilator activity was assessed on rat aortic strips precontracted with phenylephrine. Some of the products (13, 35, 37, 60-62, 64) behave principally as vasodilators and others as antioxidants (24, 32, 72), and the two properties are relatively balanced in 19, 41, and 68. Further in vivo studies should clarify whether some of these products may become preclinical candidates for the treatment of cardiovascular disease underpinned by atheroma.

  18. Comparison of the effects of acute and chronic psychological stress on metabolic features in rats

    Institute of Scientific and Technical Information of China (English)

    Fatemeh ROSTAMKHANI; Homeira ZARDOOZ; Saleh ZAHEDIASL; Babak FARROKHI

    2012-01-01

    This study was aimed to compare the effects of acute and chronic psychological stress on metabolic factors.Forty-two male Wistar rats were divided into control and stressed groups.Stress was applied by a communication box acutely (1 d) and chronically (15 and 30 d).Blood sampling was carried out by retro-orbital-puncture method.The plasma levels of glucose,cholesterol,triglyceride,insulin,and corticosterone were measured.In addition,feed and water intake,latency to eat and drink,adrenal and body weights were determined.Acute and chronic psychological stress did not significantly change basal plasma corticosterone levels.However,immediately (1 min) after acute exposure to stress,plasma corticosterone level increased compared to that before stress exposure.Acute stress increased plasma insulin levels significantly.Fifteen days of stress exposure resulted in plasma glucose increase.Chronic stress significantly increased feed intake,latency to eat,and adrenal weight compared to acute stress.The body weights of both control and stressed groups increased markedly during the experiment.Homeostasis model assessment of insulin resistance (HOMA-IR) index did not change significantly in the stressed group.In conclusion,application of acute and chronic psychological stress leads to different metabolic and/or behavioral changes but the metabolic changes resulting from acute exposure to stress seem to be more pronounced.

  19. EFFECTS OF ACUTE PYRETHROID EXPOSURE ON THERMOREGULATION IN RATS.

    Science.gov (United States)

    Pyrethroid insecticides produce acute neurotoxicity in mammals. According to the FQPA mandate, the USEPA is required to consider the risk of cumulative toxicity posed to humans through exposure to pyrethroid mixtures. Thermoregulatory response (TR) is being used to determine if t...

  20. Specific Effects of Acute Moderate Exercise on Cognitive Control

    Science.gov (United States)

    Davranche, Karen; McMorris, Terry

    2009-01-01

    The main issue of this study was to determine whether cognitive control is affected by acute moderate exercise. Twelve participants [4 females (VO[subscript 2 max]=42 ml/kg/min) and 8 males (VO[subscript 2 max]=48 ml/kg/min)] performed a Simon task while cycling at a carefully controlled workload intensity corresponding to their individual…

  1. Acetylcholine released from cholinergic nerves contributes to cutaneous vasodilation during heat stress

    Science.gov (United States)

    Shibasaki, Manabu; Wilson, Thad E.; Cui, Jian; Crandall, Craig G.

    2002-01-01

    Nitric oxide (NO) contributes to active cutaneous vasodilation during a heat stress in humans. Given that acetylcholine is released from cholinergic nerves during whole body heating, coupled with evidence that acetylcholine causes vasodilation via NO mechanisms, it is possible that release of acetylcholine in the dermal space contributes to cutaneous vasodilation during a heat stress. To test this hypothesis, in seven subjects skin blood flow (SkBF) and sweat rate were simultaneously monitored over three microdialysis membranes placed in the dermal space of dorsal forearm skin. One membrane was perfused with the acetylcholinesterase inhibitor neostigmine (10 microM), the second membrane was perfused with the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME; 10 mM) dissolved in the aforementioned neostigmine solution (l-NAME(Neo)), and the third membrane was perfused with Ringer solution as a control site. Each subject was exposed to approximately 20 min of whole body heating via a water-perfused suit, which increased mean body temperature from 36.4 +/- 0.1 to 37.5 +/- 0.1 degrees C (P vasodilation was significantly lower at the neostigmine-treated site relative to the other sites (neostigmine: 36.6 +/- 0.1 degrees C, l-NAME(Neo): 37.1 +/- 0.1 degrees C, control: 36.9 +/- 0.1 degrees C), whereas no significant threshold difference was observed between the l-NAME(Neo)-treated and control sites. At the end of the heat stress, SkBF was not different between the neostigmine-treated and control sites, whereas SkBF at the l-NAME(Neo)-treated site was significantly lower than the other sites. These results suggest that acetylcholine released from cholinergic nerves is capable of modulating cutaneous vasodilation via NO synthase mechanisms early in the heat stress but not after substantial cutaneous vasodilation.

  2. PROCOAGULANT EFFECTS OF THROMBOLYTIC THERAPY IN ACUTE MYOCARDIAL INFARCTION

    Institute of Scientific and Technical Information of China (English)

    王燕妮; 刘茜茜; 祝家庆; 袁祖贻; 马西

    2002-01-01

    Objective.To examine the procoagulant effects of thrombolytic agent on hemostasis and study the role of hemostatic markers as predictors of clinical outcomes.Methods.In the present study,eighteen patients with acute myocardial infarction(AMI) received 1.5 or 2.0 million U nonspecific urokinase(UK),or 70~80 mg fibrin specific recombinant tissue plasminogen activator(rt PA)and did not use heparin until 8 hours after intravenous injection of the above agents.Eight patients with AMI and without thrombolytic therapy were enrolled as controls.Coagulant and thrombolytic activity markers included thrombin antithrombin Ⅲ complex (TAT),D dimer,fibrinogen (Fg),FMPV/Amax.All markers were determined before,immediately,1,2,4 and 8 hours after the administration of thrombolytic agents respectively. Results.Molecular marker of thrombin generation- - TAT showed an activated coagulant state immediately after thrombolytic therapy.Level of TAT showed no significant changes between every two observed phases in controls.However,level of TAT increased significantly from 4.95± 1.75μ g/L ( 4.63± 1.37μ g/L) to 14.71± 3.31μ g/L ( 14.25± 2.53μ g/L) before and immediately after administration of thrombolytic agents UK(or rt PA).There was significant difference between level of serum TAT of patients with and without thrombolytic therapy (P< 0.05).Patients achieving clinical reperfusion had lower TAT level than those failing in thrombolytic therapy,and higher FMPV/Amax level than controls.D dimer,a surrogate of thrombolytic activity increased markedly and Fg significantly declined after thrombolytic therapy(P< 0.05). Conclusions.Thrombin generation occurred in plasma in response to excess fibrinolysis induced by thrombolytic therapy.Both urokinase and rt PA had procoagulant action.This transient activation of the coagulant system might contribute to early reocclusion.These data provided the theoretical support for simultaneous administration of anticoagulant therapy with thrombolytic

  3. Is management of acute traumatic brain injury effective?

    OpenAIRE

    Lei, Jin; Gao, Guo-Yi; Jiang, Ji-Yao

    2012-01-01

    【Abstract】 Objective: To evaluate all the possible therapeutic measures concerning the acute management of traumatic brain injury (TBI) mentioned in Cochrane System-atic Reviews published in the Cochrane Database of Sys-tematic Reviews (CDSR). Methods: An exhausted literature search for all pub-lished Cochrane Systematic Reviews discussing therapeu-tic rather than prevention or rehabilitative interventions of TBI was conducted. We retrieved such databases as CDSR and Coch...

  4. Paradoxical Effect of Hyperoncotic Albumin in Acutely Burned Children

    Science.gov (United States)

    1981-01-01

    lob (gnil respiratory acidosis : but within a few hours, she suffered a I 12 2.880 1,8) 1(0.0 cardiac arrest and (tied. Acute tubular necrosis and...only minimally, and the acidosis er- stitial pulmonary edema were found at autopsy. sisted. Thirty-six hours postburn, the patient suffered the first...urea fluids and protein as fluid infusion proceeds (1). .4 nitrogen 48 mg/di. The hyperkalemia was treated with glucose, Certainly, the most

  5. [Effects of the effective components group of xiaoshuantongluo formula on rat acute blood stasis model].

    Science.gov (United States)

    Zhao, Yan; Yu, Xin; Shi, Li-Li; Chen, Bai-Nian; Wang, Shao-Hua; Du, Guan-Hua

    2012-05-01

    Effects of the effective components group of Xiaoshuantongluo formula (XECG) on rat acute blood stasis model were studied under the guidance of the concept of effective components group. Rat acute blood stasis model was induced by subcutaneous injection of epinephrine combined with ice water bath. Hemorheology indices such as whole blood viscosity, plasma viscosity, erythrocyte aggregation index and platelet aggregation rate; coagulation parameters including PT, APTT, TT and FIB; 6-keto-PGF1alpha, TXB2 and D-dimer levels were determined to evaluate the effects of XECG. The results showed that XECG significantly reduced ADP-induced platelet aggregation, but showed little influence on the whole blood viscosity, plasma viscosity and erythrocyte aggregation rate. XECG extended PT and TT slightly, but had no effects on APTT and FIB content. D-dimer levels significantly decreased after administration of XECG with a little decrease of TXB2, but the content of 6-keto-PGF1alpha did not change significantly. The results suggest that the role of XECG of anti-aggregation is more prominent.

  6. Effect of gomisin A in an immunologically-induced acute hepatic failure model.

    Science.gov (United States)

    Mizoguchi, Y; Shin, T; Kobayashi, K; Morisawa, S

    1991-02-01

    Guinea pigs were sensitized with trinitrophenylated liver macromolecular protein fraction (TNP-LP1) prepared by using sodium trinitrobenzenesulfonate of strong immunogenicity as the hapten and LP1 as the carrier protein. The administration of trinitrophenylated hepatocytes and lipopolysaccharide to these TNP-LP1-sensitized guinea pigs through the mesenteric vein 2 weeks later resulted in the induction of acute hepatic failure accompanied by massive hepatic cell necrosis in almost all of the guinea pigs. Using this experimental model, the effect of Gomisin A on the induction of immunological acute hepatic failure was examined. As a result, the administration of gomisin A remarkably improved the survival rate and serum transaminase levels of the immunologically-induced acute hepatic failure guinea pigs. Gomisin A also improved the histological changes of the liver in these guinea pigs. These results suggested that gomisin A is effective for the improvement of immunologically-induced acute hepatic failure in our experimental model.

  7. The Effects of Inhaled Steroids on Recurrent Wheeze After Acute Bronchiolitis

    Directory of Open Access Journals (Sweden)

    Patricia Green MD

    2015-07-01

    Full Text Available Background. Acute bronchiolitis infection during infancy is associated with an increased risk of asthma later in life. The objective of this study was to determine if inhaled steroids are effective in preventing the development of recurrent wheeze or asthma following acute bronchiolitis. Methods. Multiple databases and bibliographies of selected references were searched. Inclusion required (a a randomized controlled trial of inhaled steroids and control group, (b at least 2 weeks duration of therapy started during the acute phase of disease, and (c identification of the rate of recurrent wheeze or asthma at least 6 months after therapy. Results. Of 1410 studies reviewed, 8 reports were included in this meta-analysis (748 patients. The overall odds ratio for developing recurrent wheeze or asthma with treatment versus without treatment was 1.02 (95% confidence interval = 0.58-1.81. Conclusions. A course of inhaled steroids after acute bronchiolitis is not effective in preventing recurrent wheeze or asthma.

  8. Tea consumption enhances endothelial-dependent vasodilation; a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Rouyanne T Ras

    Full Text Available BACKGROUND: Tea consumption is associated with a lower risk of cardiovascular disease including stroke. Direct effects of tea components on the vasculature, particularly the endothelium, may partly explain this association. OBJECTIVE: We performed a meta-analysis of controlled human intervention studies on the effect of tea on flow-mediated dilation (FMD of the brachial artery, a measurement of endothelial function, which is suggested to be associated with cardiovascular risk. METHODS: Human intervention studies were identified by systematic search of the databases Medline, Embase, Chemical Abstracts and Biosis through March 2009 and by hand-searching related articles. Studies were selected based on predefined criteria: intervention with tea as the sole experimental variable, placebo-controlled design, and no missing data on FMD outcome or its variability. A random effects model was used to calculate the pooled overall effect on FMD due to the intake of tea. The impact of various subject and treatment characteristics was investigated in the presence of heterogeneity. RESULTS: In total, 9 studies from different research groups were included with 15 relevant study arms. The overall absolute increase in FMD of tea vs. placebo was 2.6% of the arterial diameter (95% CI: 1.8-3.3%; P-value <0.001 for a median daily dose of 500 mL of tea (2-3 cups. This is a relative increase of approximately 40% compared to the average FMD of 6.3% measured under placebo or baseline conditions. There was significant heterogeneity between studies (P-value <0.001 that might partly be explained by the cuff position either distal or proximal to the area of FMD measurement. No indication for publication bias was found. CONCLUSION: Moderate consumption of tea substantially enhances endothelial-dependent vasodilation. This may provide a mechanistic explanation for the reduced risk of cardiovascular events and stroke observed among tea drinkers.

  9. Effects of Acute Tryptophan Depletion on Three Different Types of Behavioral Impulsivity

    OpenAIRE

    2010-01-01

    Introduction: While central nervous system serotonin has been implicated in a variety of problematic impulsive behaviors, biological manipulation of brain serotonin using acute tryptophan depletion for studying changes in impulsive behavior has received little attention. Methods: Using identical treatment conditions, we examined the effects of reduced serotonin synthesis for each of three matched groups using acute tryptophan depletion. Thirty healthy men and women (ages 18–45) were assigned ...

  10. Estrogen Effects after a Crush Muscle Injury and Acute Exposure to Hypobaric Hypoxia

    Science.gov (United States)

    2015-03-01

    et al. Intermittent hypobaric hypoxia increases the ability of neutrophils to generate superoxide anion in humans. Clin Exp Pharmacol Physiol. 2003...AFRL-SA-WP-TR-2015-0007 Estrogen Effects after a Crush Muscle Injury and Acute Exposure to Hypobaric Hypoxia Dr. Barbara St...after a Crush Muscle Injury and Acute Exposure to Hypobaric Hypoxia 5a. CONTRACT NUMBER FA7014-10-2-0001 5b. GRANT NUMBER 5c. PROGRAM

  11. Dietary phosphorus acutely impairs endothelial function.

    Science.gov (United States)

    Shuto, Emi; Taketani, Yutaka; Tanaka, Rieko; Harada, Nagakatsu; Isshiki, Masashi; Sato, Minako; Nashiki, Kunitaka; Amo, Kikuko; Yamamoto, Hironori; Higashi, Yukihito; Nakaya, Yutaka; Takeda, Eiji

    2009-07-01

    Excessive dietary phosphorus may increase cardiovascular risk in healthy individuals as well as in patients with chronic kidney disease, but the mechanisms underlying this risk are not completely understood. To determine whether postprandial hyperphosphatemia may promote endothelial dysfunction, we investigated the acute effect of phosphorus loading on endothelial function in vitro and in vivo. Exposing bovine aortic endothelial cells to a phosphorus load increased production of reactive oxygen species, which depended on phosphorus influx via sodium-dependent phosphate transporters, and decreased nitric oxide production via inhibitory phosphorylation of endothelial nitric oxide synthase. Phosphorus loading inhibited endothelium-dependent vasodilation of rat aortic rings. In 11 healthy men, we alternately served meals containing 400 mg or 1200 mg of phosphorus in a double-blind crossover study and measured flow-mediated dilation of the brachial artery before and 2 h after the meals. The high dietary phosphorus load increased serum phosphorus at 2 h and significantly decreased flow-mediated dilation. Flow-mediated dilation correlated inversely with serum phosphorus. Taken together, these findings suggest that endothelial dysfunction mediated by acute postprandial hyperphosphatemia may contribute to the relationship between serum phosphorus level and the risk for cardiovascular morbidity and mortality.

  12. THE EFFECT OF ACUTE MYOCARDIUM ISCHEMIC ON HEART FUNCTION OF PREGNANCY RAT

    Institute of Scientific and Technical Information of China (English)

    Zheng Xiaopu; Ma Aiqun; Niu Changmin; Dong Anping; Han Ke; Liu Yu; Zhang Wei; Geng Tao

    2006-01-01

    Objective To investigate the effect of acute myocardium ischemic on heart function of pregnancy rat.Methods 13 female SD rats and 6 early pregnancy rats were divided into normal group, unpregnant group with acute myocardial infarction and early pregnant group with acute myocardial infarction. The anterior branch of the left coronary artery was ligated. 3 weeks later, Image 1.31 software was used to measure areas of myocardial infarction,and to evaluate hemodynamics of heart with powerLAB4.12, and cardiac tissues were stained with Massion. Results Compared with unpregnant group with acute myocardial infarction , the early pregnant group with acute myocardial infarction had less myocardial infarction area (28. 86% vs. 36. 8%), and had a higher left ventricle end systolic pressure, ±dp/dt max, and lower left ventricle end diastolic pressure. Massion stain showed the amount of collagen of the lesion was less in the early pregnant group with acute myocardial infarction than that in unpregnant group.Conclusion The early pregnant group with acute myocardial infarction had better heart contractive and diastolic function.

  13. Sex- and limb-specific differences in the nitric oxide-dependent cutaneous vasodilation in response to local heating.

    Science.gov (United States)

    Stanhewicz, Anna E; Greaney, Jody L; Kenney, W Larry; Alexander, Lacy M

    2014-10-01

    Local heating of the skin is commonly used to assess cutaneous microvasculature function. Controversy exists as to whether there are limb or sex differences in the nitric oxide (NO)-dependent contribution to this vasodilation, as well as the NO synthase (NOS) isoform mediating the responses. We tested the hypotheses that 1) NO-dependent vasodilation would be greater in the calf compared with the forearm; 2) total NO-dependent dilation would not be different between sexes within limb; and 3) women would exhibit greater neuronal NOS (nNOS)-dependent vasodilation in the calf. Two microdialysis fibers were placed in the skin of the ventral forearm and the calf of 19 (10 male and 9 female) young (23 ± 1 yr) adults for the local delivery of Ringer solution (control) or 5 mM N(ω)-propyl-l-arginine (NPLA; nNOS inhibition). Vasodilation was induced by local heating (42°C) at each site, after which 20 mM N(G)-nitro-l-arginine methyl ester (l-NAME) was perfused for within-site assessment of NO-dependent vasodilation. Cutaneous vascular conductance (CVC) was calculated as laser-Doppler flux/mean arterial pressure and normalized to maximum (28 mM sodium nitroprusside, 43°C). Total NO-dependent vasodilation in the calf was lower compared with the forearm in both sexes (Ringer: 42 ± 5 vs. 62 ± 4%; P vasodilation was lower in the forearm for women (Ringer: 52 ± 6 vs. 71 ± 4%; P vasodilation across limbs in either sex (P > 0.05). These data suggest that the NO-dependent component of local heating-induced cutaneous vasodilation is lower in the calf compared with the forearm. Contrary to our original hypothesis, there was no contribution of nNOS to NO-dependent vasodilation in either limb during local heating.

  14. Effects of Acute Exposures to Carbon Dioxide upon Cognitive Functions

    Science.gov (United States)

    Ryder, V. E.; Scully, R. R.; Alexander, D. J.; Lam, C. W.; Young, M.; Satish, U.; Basner, M.

    2017-01-01

    Carbon dioxide (CO2) originates from human metabolism and typically remains about 10-fold higher in concentration on the International Space Station (ISS) than at the earth's surface. There have been recurring complaints by crew members of episodes of "mental viscosity" adversely affecting their performance, and there is evidence from the ISS that associates CO2 levels with reports of headaches by crewmembers. Consequently, flight rules have been employed to control CO2 below 3 mm Hg, which is well below the existing Spacecraft Maximum Allowable Concentration (SMAC) of 10 mm Hg for 24-hour exposures, and 5.3 mm Hg for exposures of 7 to 180 days. Headaches, while sometime debilitating themselves, are also symptoms that can provide evidence that physiological defense mechanisms have been breached, and there is evidence that CO2 has effects at levels below the threshold for headaches. This concern appears to be substantiated in reports that CO2 at concentrations below 2 mm Hg substantially reduced some cognitive functions that are associated with the ability to make complex decisions in conditions that are characterized by volatility, uncertainty, complexity, ambiguity, and delayed feedback. These are conditions that could be encountered by crews in off-nominal situations or during the first missions beyond low earth orbit. Therefore, we set out to determine if decision-making under volatile, uncertain, confusing and ambiguous circumstances, where feedback is delayed or absent, is correlated with low levels of CO2 during acute exposures (several hours) in crew-like subjects and to determine if additional cognitive domains are sensitive to concentrations of CO2 at, or below, current ISS levels by using a test battery that is currently available onboard ISS. We enrolled 22 volunteers (8 females, 14 males) between the ages of 30-55 (38.8 +/- 7.0) years whose training and professional experience reflect that of the astronaut corps. Subjects were divided among 4 study

  15. Plasma endothelin in patients with endotoxernia and dynamic comparison between vasoconstrictor and vasodilator in cirrhotic patients

    Institute of Scientific and Technical Information of China (English)

    Feng Liu; Ji Xin Li; Chun Mei Li; Xi Sheng Leng

    2001-01-01

    @@ INTRODUCTIONPortal hypertension is a common clinical syndromecharacterized by an abnormal increase in portalblood to the systemic circulation, bypassing theliver. Recent studies have reported that humoralsubstances play an important role in thepathogenesis of portal hypertension, either byincreasing vascular resistance at both theintrahepatic and porto-collateral sites or affectingsplanchnic vasodilation with a concomitant increasein parto-collateral blood flow[1-6

  16. Intracoronary Blood Flow Velocity and Transstenotic Pressure Drop in an Awake Human Being During Coronary Vasodilation

    NARCIS (Netherlands)

    F. Zijlstra (Felix); P.W.J.C. Serruys (Patrick)

    1988-01-01

    textabstractThe pressure drop over a coronary stenosis and the intracoronary Doppler blood flow velocity were measured at rest and during coronary vasodilation. We report the first observation that confirms the validity of fluid dynamic equations to describe the hemodynamics of a coronary stenosis b

  17. Impaired acetylcholine-induced cutaneous vasodilation in young smokers: roles of nitric oxide and prostanoids.

    Science.gov (United States)

    Fujii, Naoto; Reinke, Maggie C; Brunt, Vienna E; Minson, Christopher T

    2013-03-01

    Cigarette smoking attenuates acetylcholine (ACh)-induced cutaneous vasodilation in humans, but the underlying mechanisms are unknown. We tested the hypothesis that smokers have impaired nitric oxide (NO)- and cyclooxygenase (COX)-dependent cutaneous vasodilation to ACh infusion. Twelve young smokers, who have smoked more than 5.2 ± 0.7 yr with an average daily consumption of 11.4 ± 1.2 cigarettes, and 12 nonsmokers were tested. Age, body mass index, and resting mean arterial pressure were similar between the groups. Cutaneous vascular conductance (CVC) was evaluated as laser-Doppler flux divided by mean arterial pressure, normalized to maximal CVC (local heating to 43.0°C plus sodium nitroprusside administration). We evaluated the increase in CVC from baseline to peak (CVCΔpeak) and area under the curve of CVC (CVCAUC) during a bolus infusion (1 min) of 137.5 μM ACh at four intradermal microdialysis sites: 1) Ringer (control), 2) 10 mM N(G)-nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor), 3) 10 mM ketorolac (COX inhibitor), and 4) combination of l-NAME + ketorolac. CVCΔpeak and CVCAUC at the Ringer site in nonsmokers were greater than in smokers (CVCΔpeak, 42.9 ± 5.1 vs. 22.3 ± 3.5%max, P vasodilation in young smokers is related to diminished NO- and COX-dependent vasodilation.

  18. Contribution of nitric oxide in the contraction-induced rapid vasodilation in young and older adults.

    Science.gov (United States)

    Casey, Darren P; Walker, Branton G; Ranadive, Sushant M; Taylor, Jennifer L; Joyner, Michael J

    2013-08-15

    We tested the hypothesis that reduced nitric oxide (NO) bioavailability contributes to the attenuated peak and total vasodilation following single-muscle contractions in older adults. Young (n = 10; 24 ± 2 yr) and older (n = 10; 67 ± 2 yr) adults performed single forearm contractions at 10, 20, and 40% of maximum during saline infusion (control) and NO synthase (NOS) inhibition via N(G)-monomethyl-l-arginine. Brachial artery diameters and velocities were measured using Doppler ultrasound and forearm vascular conductance (FVC; in ml·min(-1)·100 mmHg(-1)) was calculated from blood flow (ml/min) and blood pressure (mmHg). Peak and total vasodilator responses [change (Δ) in FVC from baseline] were attenuated in older adults at all intensities (P vasodilator response (area under the curve) with NOS inhibition was also greater in young vs. older adults at all intensities. Our data suggest that contraction-induced rapid vasodilation is mediated in part by NO, and that the contribution of NO is greater in young adults.

  19. Reproducibility of axon reflex-related vasodilation assessed by dynamic thermal imaging in healthy subjects

    NARCIS (Netherlands)

    M.D. Nieuwenhoff (Mariska D.); Y. Wu; F.J.P.M. Huygen (Frank); A.C. Schouten (A.); F.C.T. van der Helm (Frans); S.P. Niehof (Sjoerd)

    2016-01-01

    textabstractIntroduction Small nerve fiber dysfunction is an early feature of diabetic neuropathy. There is a strong clinical need for a non-invasive method to assess small nerve fiber function. Small nerve fibers mediate axon reflex-related vasodilation and play an important role in thermoregulati

  20. Reproducibility of axon reflex-related vasodilation assessed by dynamic thermal imaging in healthy subjects

    NARCIS (Netherlands)

    M.D. Nieuwenhoff (Mariska D.); Wu, Y.; F.J.P.M. Huygen (Frank); A.C. Schouten (A.); F.C.T. van der Helm (Frans C.); S.P. Niehof (Sjoerd)

    2016-01-01

    textabstractIntroduction: Small nerve fiber dysfunction is an early feature of diabetic neuropathy. There is a strong clinical need for a non-invasive method to assess small nerve fiber function. Small nerve fibers mediate axon reflex-related vasodilation and play an important role in thermoregulati

  1. Familial hypercholesterolemia impairs exercise-induced systemic vasodilation due to reduced NO bioavailability

    NARCIS (Netherlands)

    V.J. de Beer (Vincent Jacob); D. Merkus (Daphne); S.B. Bender (Shawn ); D.L. Tharp (Darla); D.K. Bowles; D.J.G.M. Duncker (Dirk); H. Laughlin (Harold)

    2013-01-01

    textabstractFamilial hypercholesterolemia impairs exercise-induced systemic vasodilation due to reduced NO bioavailability. J Appl Physiol 115: 17671776, 2013. First published October 24, 2013; doi:10.1152/japplphysiol.00619.2013. Hypercholesterolemia impairs endothelial function [e.g., the nitric o

  2. CORONARY VASODILATION INDUCED BY CAPTOPRIL AND ZOFENOPRILAT - EVIDENCE FOR A PROSTAGLANDIN-INDEPENDENT MECHANISM

    NARCIS (Netherlands)

    VANWIJNGAARDEN, J; TIO, RA; VANGILST, WH; DEGRAEFF, PA; DELANGEN, CDJ; WESSELING, H

    In this study, the vasodilating properties of captopril and zofenoprilat, two angiotensin-converting enzyme (ACE) inhibitors containing the sulfhydryl group, are investigated in the isolated rat heart. It is demonstrated that both compounds increase coronary flow in a dose-dependent manner. However,

  3. Repeated increases in blood flow, independent of exercise, enhance conduit artery vasodilator function in humans

    NARCIS (Netherlands)

    Naylor, L.H.; Carter, H.; Fitzsimons, M.G.; Cable, N.T.; Thijssen, D.H.J.; Green, D.J.

    2011-01-01

    This study aimed to determine the importance of repeated increases in blood flow to conduit artery adaptation, using an exercise-independent repeated episodic stimulus. Recent studies suggest that exercise training improves vasodilator function of conduit arteries via shear stress-mediated

  4. Phosphorylated vasodilator-stimulated phosphoprotein is localized on mitotic spindles of the gastric cancer cell line SGC-7901

    Institute of Scientific and Technical Information of China (English)

    Yan Tao; Yong-Chang Chen; Ying Wang; Zhi-Jian Zhang; Wen-Rong Xu

    2006-01-01

    AIM: To elucidate the localization of vasodilator stimulated phosphoprotein (VASP), a cytoskeletal organizing protein and a substrate of protein kinases A and G in mitotic gastric cancer cells.METHODS: Tmmunofluorescence microscopy was used to observe the localization of α-tubulin, VASP and Ser157 phosphorylated VASP (p-VASP) in interphase of mitotic gastric cancer of the cell line SGC-7901.RESULTS: Immunofluorescence staining showed that p-VASP but not VASP was co-localized with α-tubulin on spindle poles and fibers in prophase, metaphase and anaphase of the mitotic process of the gastric cancer cell line SGC-7901. H89, an inhibitor of protein kinases A and G, had no effect on the localization of p-VASP on the spindles.CONCLUSION: VASP may play a role in assembling and stabilizing the mitotic spindle of cells, and phosphorylation of the protein is the precondition for it to exert this function.

  5. Mechanisms of systemic vasodilation by lysozyme-c in septic shock.

    Science.gov (United States)

    Gotes, Jose; Kasian, Krika; Jacobs, Hans; Cheng, Zhao-Qin; Mink, Steven N

    2012-02-01

    In septic shock (SS), cardiovascular collapse is caused by the release of inflammatory mediators. We previously found that lysozyme-c (Lzm-S), released from leukocytes, contributed to systemic vasodilation in a canine model of SS. We then delineated the pathway by which this occurs in a canine carotid artery organ bath preparation (CAP). We showed that Lzm-S could intrinsically generate hydrogen peroxide (H(2)O(2)) and that H(2)O(2) subsequently reacted with endogenous catalase to form compound I, an oxidized form of catalase. In turn, compound I led to an increase in cyclic guanosine 3',5'-monophosphate to produce vasodilation. However, it was not clear from previous studies whether it is necessary for Lzm-S to bind to the vasculature to cause vasodilation or, alternatively, whether the generation of H(2)O(2) by Lzm-S in the surrounding medium is all that is required. We examined this question in the present study in which we used multiple preparations. In a partitioned CAP, we found that when we added Lzm-S to a partitioned space in which a semipermeable membrane prevented diffusion of Lzm-S to the carotid artery tissue, vasodilation still occurred because of diffusion of H(2)O(2). On the other hand, we found that Lzm-S could accumulate within the vascular smooth muscle layer (VSML) after 7 h of SS in a canine model. We also determined that when Lzm-S was located in close proximity to vascular smooth muscle cells, it could generate H(2)O(2) to produce lengthening in a human cell culture preparation. We conclude that there are two mechanisms by which Lzm-S can cause vasodilation in SS. In one instance, H(2)O(2) generated by Lzm-S in plasma diffuses to the VSML to cause vasodilation. In a second mechanism, Lzm-S directly binds to the VSML, where it generates H(2)O(2) to produce vasodilation.

  6. Impaired peripheral vasodilation during graded systemic hypoxia in healthy older adults: role of the sympathoadrenal system.

    Science.gov (United States)

    Richards, Jennifer C; Crecelius, Anne R; Larson, Dennis G; Luckasen, Gary J; Dinenno, Frank A

    2017-04-01

    Systemic hypoxia is a physiological and pathophysiological stress that activates the sympathoadrenal system and, in young adults, leads to peripheral vasodilation. We tested the hypothesis that peripheral vasodilation to graded systemic hypoxia is impaired in older healthy adults and that this age-associated impairment is due to attenuated β-adrenergic mediated vasodilation and elevated α-adrenergic vasoconstriction. Forearm blood flow was measured (Doppler ultrasound), and vascular conductance (FVC) was calculated in 12 young (24 ± 1 yr) and 10 older (63 ± 2 yr) adults to determine the local dilatory responses to graded hypoxia (90, 85, and 80% O2 saturations) in control conditions, following local intra-arterial blockade of β-receptors (propranolol), and combined blockade of α- and β-receptors (phentolamine + propranolol). Under control conditions, older adults exhibited impaired vasodilation to hypoxia compared with young participants at all levels of hypoxia (peak ΔFVC at 80% [Formula: see text] = 4 ± 6 vs. 35 ± 8%; P adults actively constricted at 85 and 80% [Formula: see text] (peak ΔFVC at 80% [Formula: see text] = -13 ± 6%; P adults; however, older adults failed to significantly vasodilate (peak ΔFVC at 80% [Formula: see text]= 12 ± 11% vs. 58 ± 11%; P adults, which cannot be fully explained by altered sympathoadrenal control of vascular tone. Thus, the impairment in hypoxic vasodilation is likely due to attenuated local vasodilatory and/or augmented vasoconstrictor signaling with age.NEW & NOTEWORTHY We found that the lack of peripheral vasodilation during graded systemic hypoxia with aging is not mediated by the sympathoadrenal system, strongly implicating local vascular control mechanisms in this impairment. Understanding these mechanisms may lead to therapeutic advances for improving tissue blood flow and oxygen delivery in aging and disease. Copyright © 2017 the American Physiological Society.

  7. Therapeutic effect of ghrelin in the course of cerulein-induced acute pancreatitis in rats.

    Science.gov (United States)

    Warzecha, Z; Ceranowicz, P; Dembinski, A; Cieszkowski, J; Kusnierz-Cabala, B; Tomaszewska, R; Kuwahara, A; Kato, I

    2010-08-01

    Recent studies have shown that pretreatment with ghrelin exhibits protective effect in the gut. Administration of ghrelin reduces gastric mucosal damage, as well as inhibits the development of experimental pancreatitis. However, this protective effect requires administration of ghrelin before gastric or pancreatic damage and thus has a limited clinical value. The aim of present study was to assess the influence of ghrelin administered after development of acute pancreatitis on the course of this disease. Acute pancreatitis was induced by cerulein. Ghrelin was administered twice a day for 1, 2, 4, 6 or 9 days at the dose of 4, 8 or 16 nmol/kg/dose. The first dose of ghrelin was given 24 hours after last injection of cerulein. The severity of acute pancreatitis was assessed between 0 h and 10 days after cessation of cerulein administration. Administration of caerulein led to the development of acute edematous pancreatitis and maximal severity of this disease was observed 24 hours after induction of pancreatitis. Treatment with ghrelin reduced morphological signs of pancreatic damage such as pancreatic edema, leukocyte infiltration and vacuolization of acinar cells, and led to earlier regeneration of the pancreas. Also biochemical indexes of the severity of acute pancreatitis, serum activity of lipase and amylase were significantly reduced in animals treated with ghrelin. These effects were accompanied by an increase in the pancreatic DNA synthesis and a decrease in serum level of pro-inflammatory interleukin-1b. Administration of ghrelin improved pancreatic blood flow in rats with acute pancreatitis. We conclude that: (1) treatment with ghrelin exhibits therapeutic effect in caerulein-induced experimental acute pancreatitis; (2) this effect is related, at least in part, to the improvement of pancreatic blood flow, reduction in proinflammatory interleukin-1beta and stimulation of pancreatic cell proliferation.

  8. [Effect of opioid receptors on acute stress-induced changes in recognition memory].

    Science.gov (United States)

    Liu, Ying; Wu, Yu-Wei; Qian, Zhao-Qiang; Yan, Cai-Fang; Fan, Ka-Min; Xu, Jin-Hui; Li, Xiao; Liu, Zhi-Qiang

    2016-12-25

    Although ample evidence has shown that acute stress impairs memory, the influences of acute stress on different phases of memory, such as acquisition, consolidation and retrieval, are different. Experimental data from both human and animals support that endogenous opioid system plays a role in stress, as endogenous opioid release is increased and opioid receptors are activated during stress experience. On the other hand, endogenous opioid system mediates learning and memory. The aim of the present study was to investigate the effect of acute forced swimming stress on recognition memory of C57 mice and the role of opioid receptors in this process by using a three-day pattern of new object recognition task. The results showed that 15-min acute forced swimming damaged the retrieval of recognition memory, but had no effect on acquisition and consolidation of recognition memory. No significant change of object recognition memory was found in mice that were given naloxone, an opioid receptor antagonist, by intraperitoneal injection. But intraperitoneal injection of naloxone before forced swimming stress could inhibit the impairment of recognition memory retrieval caused by forced swimming stress. The results of real-time PCR showed that acute forced swimming decreased the μ opioid receptor mRNA levels in whole brain and hippocampus, while the injection of naloxone before stress could reverse this change. These results suggest that acute stress may impair recognition memory retrieval via opioid receptors.

  9. About choosing a vasodilator for vasoreactivity tests in heart transplant candidates

    Directory of Open Access Journals (Sweden)

    А. Е. Баутин

    2015-10-01

    Full Text Available The purpose of our prospective, consistent, non-randomized study was to analyze the results of vasoreactivity tests (VRT performed with nitric oxide (NO or inhaled Iloprost in heart transplant candidates. 72 VRTs were done in 58 candidates for heart transplantation. All patients had heart failure III-IV NYHA and pulmonary hypertension (PH with pulmonary vascular resistance (PVR over 2.5 WU. 43 patients received NO, 80 ppm for 20 min. 29 patients inhaled 20 g of Iloprost (Ventavis, Bayer. Hemodynamic parameters were measured at baseline, 20 min after NO inhalation and 15 min following the completion of Iloprost inhalation. There were no between-group differences in the severity of patient's condition and baseline hemodynamic indicators. Both vasodilators caused statistically significant reduction in mean PAP: in the NO group it dropped (p = 0.002, in the Iloprost group the mean PAP decreased (p<0.0001. A more than 20% decrease in PAP was recorded in 13 cases (30.2% in the NO group and in 16 cases (55.2% in the Iloprost group (p = 0.03. A more than 20% decrease in PVR was noted in 24 cases (55.8% in the NO group and in 24 cases (82.8% in the Iloprost group (p<0.02. We found some differences in the effect of NO and Iloprost on LV efficiency. There were no changes in the stroke volume index (SVI in the NO group, while inhaled Iloprost increased SVI (p<0.001. A probable cause of the increase in LV efficiency might have been the reduction of total peripheral vascular resistance (p<0.0001. There were no differences in SVI during NO inhala-tion. It should be noted in conclusion that Iloprost is more effective in decreasing mean PAP and PVR in heart transplant candidates. Inhaled Iloprost causes favorable changes in preload and afterload of the impaired LV and increases its performance.

  10. Ambulatory blood pressure monitoring and endothelium-dependent vasodilation in the elderly athletes.

    Science.gov (United States)

    Galetta, F; Franzoni, F; Plantinga, Y; Ghiadoni, L; Rossi, M; Prattichizzo, F; Carpi, A; Taddei, S; Santoro, G

    2006-09-01

    Regular exercise is a key component of cardiovascular risk prevention strategies, because it is associated with a variety of beneficial metabolic and vascular effects that reduce mortality and the incidence of cardiovascular adverse events. Endothelium plays an important role in the local regulation of vascular tone and structure, mainly by nitric oxide (NO) synthesis and action. Aim of the present study was to evaluate in elderly athletes the effect of regular aerobic exercise on arterial blood pressure (BP) and on endothelium-dependent flow-mediated dilation (FMD) of the brachial artery. The study population included 30 male subjects (mean age 65.6+/-5.6 years), who had practiced endurance running at a competitive level for at least 40 years, and 28 age- and sex-matched subjects (mean age 64.5+/-4.5 years) with sedentary lifestyle and free of cardiovascular disease. Athletes and control subjects underwent standard 12-lead ECG, clinic BP, 24-h ambulatory BP monitoring and endothelium-dependent FMD and endothelium-independent response to glyceryl trinitrate (GTN), 400 microg, in the brachial artery by high-resolution ultrasonography. Systolic clinic and ambulatory 24-h BP were significantly lower in the athletes, than in the controls (Pathletes (Pathletes also had a lower 24-h, day-time and night-time heart rate (HR) (Pathletes (Pathletes showed higher FMD than elderly sedentary subjects (Pphysical activity can counteract the age-related endothelial dysfunction that characterizes sedentary aging, preserving the capacity of the endothelium-dependent vasodilation and reduces BP values improving arterial pressure control.

  11. Morphine in the treatment of acute pulmonary oedema--Why?

    Science.gov (United States)

    Ellingsrud, C; Agewall, S

    2016-01-01

    Morphine has for a long time, been used in patients with acute pulmonary oedema due to its anticipated anxiolytic and vasodilatory properties, however a discussion about the benefits and risks has been raised recently. A literature search in Medline and Embase using the keywords "pulmonary oedema" OR "lung oedema" OR "acute heart failure" AND "morphine" was performed. A certain vasodilation has been described after morphine administration, but the evidence for this mechanism is relatively poor and morphine-induced anxiolysis may possibly be the most important factor of morphine in pulmonary oedema and therefore some authors have suggested benzodiazepines as an alternative treatment. Respiratory depression seems to be a less relevant clinical problem according to the literature, whereas vomiting is common, which may cause aspiration. In the largest outcome study, based on the ADHERE registry, morphine given in acute decompensated heart failure was an independent predictor of increased hospital mortality, with an odds ratio of 4.8 (95% CI: 4.52-5.18, pmorphine administration and mortality, which was lost after adjusting for confounding factors. Morphine is still used for pulmonary oedema in spite of poor scientific background data. A randomised, controlled study is necessary in order to determine the effect--and especially the risk--when using morphine for pulmonary oedema. Since the positive effects are not sufficiently documented, and since the risk for increased mortality cannot be ruled out, one can advocate that the use should be avoided.

  12. Acute effect of hydralazine administration on pulmonary artery hemodynamics in dogs with chronic heartworm disease.

    Science.gov (United States)

    Atkins, C E; Keene, B W; McGuirk, S M; Sato, T

    1994-02-01

    In an effort to better understand the role of vasodilators in the management of pulmonary hypertension associated with chronic heartworm disease (HWD), pulmonary hemodynamic measurements were obtained from 7 experimentally infected, anesthetized dogs before and after hydralazine administration (mean dose, 1.96 mg/kg of body weight). Five dogs were maintained on room air, while 2 were maintained on 100% oxygen during the hydralazine study. The hemodynamic effect of hydralazine in dogs with HWD was evaluated, using heart rate, cardiac index, mean pulmonary artery pressure, mean arterial pressure, total pulmonary resistance, total systemic resistance, total systemic resistance/total pulmonary resistance, left ventricular dP/dtmax, left ventricular end diastolic pressure, and left and right ventricular double products ([mean arterial pressure x heart rate] and [mean pulmonary artery pressure x heart rate], respectively). Responders were defined as those in which total pulmonary resistance decreased > or = 20% without an increase in mean pulmonary arterial pressure and in which heart rate increase was < or = 10%. Comparison was also made between maximal hemodynamic effect of hydralazine with that after 100% oxygen administration for 15 minutes to previously normoxemic dogs (n = 5). Significance was determined if P < 0.05, using the paired t-test. Hydralazine induced significant reductions in mean pulmonary and systemic arterial pressures and total pulmonary resistance, with no significant change in heart rate, cardiac index, total systemic resistance, left ventricular dP/dtmax, left ventricular end diastolic pressure, or right and left ventricular double products. Four (57%) of the 7 dogs studied were considered responders. Pretreatment cardiac index, mean pulmonary artery pressure, and total pulmonary resistance did not allow differentiation of responders from nonresponders.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Sensory nerves and nitric oxide contribute to reflex cutaneous vasodilation in humans.

    Science.gov (United States)

    Wong, Brett J

    2013-04-15

    We tested the hypothesis that inhibition of cutaneous sensory nerves would attenuate reflex cutaneous vasodilation in response to an increase in core temperature. Nine subjects were equipped with four microdialysis fibers on the forearm. Two sites were treated with topical anesthetic EMLA cream for 120 min. Sensory nerve inhibition was verified by lack of sensation to a pinprick. Microdialysis fibers were randomly assigned as 1) lactated Ringer (control); 2) 10 mM nitro-L-arginine methyl ester (L-NAME) to inhibit nitric oxide synthase; 3) EMLA + lactated Ringer; and 4) EMLA + L-NAME. Laser-Doppler flowmetry was used as an index of skin blood flow, and blood pressure was measured via brachial auscultation. Subjects wore a water-perfused suit, and oral temperature was monitored as an index of core temperature. The suit was perfused with 50°C water to initiate whole body heat stress to raise oral temperature 0.8°C above baseline. Cutaneous vascular conductance (CVC) was calculated and normalized to maximal vasodilation (%CVC(max)). There was no difference in CVC between control and EMLA sites (67 ± 5 vs. 69 ± 6% CVC(max)), but the onset of vasodilation was delayed at EMLA compared with control sites. The L-NAME site was significantly attenuated compared with control and EMLA sites (45 ± 5% CVC(max); P vasodilation during the early, but not latter, stages of heat stress, and full expression of reflex cutaneous vasodilation requires functional sensory nerves and NOS.

  14. The acute effect of vibration applications on jumping performance

    Directory of Open Access Journals (Sweden)

    Suat Yıldız

    2012-12-01

    Full Text Available Recently, vibration has become very popular as a method of exercise and training and drawn attention of researchers. The aim of this study was to analyses the acute affect of vibration applications as a method of exercise and training on jumping performance.In this study experimental group consists of 25 subjects who are studying at Physical Education and Sports Department of Sakarya University (age 22.2±1.7 years, height 179.2±4.8 cm. body weight 71.5±9.0 kg. This study included a vibration at density of 35 Hz (3x30 sec. frequency that result from aerobic exercise that has low density and b just methods of aerobic exercise (without any vibration that has low density. Subjects have taken the tests of countermovement and squat jumping after 2 minutes of each application. All applications and tests have been done in nonconsecutive days in a random scheme. In statistical analysis Wilcoxon has been applied in nonparametric scheme.For counter movement jumping; height of jumping, the difference between before and after the application of vibration related to the point of peak power and average power has been found significiant (respectively, p0.05; p>0.05; p>0.05.As a result, it is concluded that vibration that is applied at the range of 35 Hz frequency could increase the performance of acute countermovement jumping.

  15. Human Motor Cortex Functional Changes in Acute Stroke: Gender Effects

    Directory of Open Access Journals (Sweden)

    Vincenzo eDi Lazzaro

    2016-01-01

    Full Text Available The acute phase of stroke is accompanied by functional changes in the activity and interplay of both hemispheres. In healthy subjects, gender is known to impact the functional brain organization.We investigated whether gender influences also acute stroke functional changes. In thirty-five ischemic stroke patients, we evaluated the excitability of the affected (AH and unaffected hemisphere (UH by measuring resting and active motor threshold and motor-evoked potential amplitude under baseline conditions and after intermittent theta burst stimulation (iTBS of AH. We also computed an index of the excitability balance between the hemispheres, laterality indexes (LI, to evidence hemispheric asymmetry. Active motor threshold differed significantly between AH and UH only in the male group (p=0.004, not in females (p>0.200, and both LIAMT and LIRMT were significantly higher in males than in females (respectively p=0.033 and p=0.042. LTP-like activity induced by iTBS in AH was more frequent in females. Gender influences the functional excitability changes that take place after human stroke and the level of LTP that can be induced by repetitive stimulation. This knowledge is of high value in the attempt of individualizing to different genders any non-invasive stimulation strategy designed to foster stroke recovery.

  16. Rapid and slow nitric oxide responses during conducted vasodilation in the in vivo intestine and brain cortex microvasculatures.

    Science.gov (United States)

    Bohlen, H Glenn

    2011-11-01

    Conduction of arteriolar vasodilation is initiated by activation of nitric oxide (NO) mechanisms, but dependent on conduction of hyperpolarization. Most studies have used brief (vasodilation to evaluate the fast conduction processes. However, most arteriolar mechanisms involving NO production persist for minutes. In this study, fast and slower components of arteriolar conduction in the in vivo rat brain and small intestine were compared using three-minute stimulation of NO-dependent vasodilation and measurement of [NO] at the distal sites. Within 10-15 seconds, both vasculatures had a rapidly conducted vasodilation and dilation at distance had a fast but small [NO] component. A slower but larger distal vasodilation occurred after 60-90 seconds in the intestine, but not the brain, and was associated with a substantial increase in [NO]. This slowly developed dilation appeared to be caused by flow mediated responses of larger arterioles as smaller arterioles dilated to lower downstream resistance. These results indicate while the intestinal and cerebral arterioles have a fast conducted vasodilation system, the intestinal arterioles also have a slower but larger dilation of major arterioles that is NO related and dependent on the conduction of vasodilation between small arterioles.

  17. Interaction of selected vasodilating beta-blockers with adrenergic receptors in human cardiovascular tissues

    Energy Technology Data Exchange (ETDEWEB)

    Monopoli, A.; Forlani, A.; Bevilacqua, M.; Vago, T.; Norbiato, G.; Bertora, P.; Biglioli, P.; Alamanni, F.; Ongini, E. (Essex Italia, Subsidiary of Schering-Plough, Milan)

    1989-07-01

    beta- And alpha 1-adrenoceptor antagonist properties of bufuralol, carvedilol, celiprolol, dilevalol, labetalol, and pindolol were investigated in human myocardium and mammary artery using binding techniques and functional studies. In myocardial membranes, beta-adrenoceptor antagonists showed monophasic competition isotherms for (125I)pindolol binding with high affinity (Ki from 1-100 nM), except for celiprolol which displayed a biphasic competition isotherm (pKi = 6.4 +/- 0.06 for beta 1- and 4.8 +/- 0.07 for beta 2-adrenoceptors). Drug interactions with alpha 1-adrenoceptors were evaluated in human mammary artery by (3H)prazosin binding and by measuring contractile responses to norepinephrine (NE). Labetalol and carvedilol showed a moderate affinity for alpha 1-adrenoceptors (pKi = 6.2 +/- 0.01 and 6.1 +/- 0.06, respectively), and inhibited NE-induced contractions (pA2 = 6.93 +/- 0.23 and 8.64 +/- 0.24, respectively). Dilevalol, bufuralol, and pindolol displayed weak effect both in binding (Ki in micromolar range) and functional experiments (pA2 = 5.98, 5.54, and 6.23, respectively). Celiprolol did not show antagonist properties up to 100 microM in functional studies, but displayed a slight affinity for alpha 1-adrenoceptors in binding studies. The data indicate that the vasodilating activity of these beta-adrenoceptor antagonists is caused in some instances by an alpha 1-adrenoceptor antagonism (labetalol, carvedilol), whereas for the others alternative mechanisms should be considered.

  18. Central effect of histamine in a rat model of acute trigeminal pain.

    Science.gov (United States)

    Tamaddonfard, Esmaeal; Khalilzadeh, Emad; Hamzeh-Gooshchi, Nasrin; Seiednejhad-Yamchi, Sona

    2008-01-01

    In conscious rats implanted with an intracerebroventricular (icv) cannula, effect of icv injections of histamine, chlorpheniramine (H(1)-receptor antagonist) and ranitidine (H(2)-receptor blocker) was investigated in a rat model of acute trigeminal pain. Acute trigeminal pain was induced by putting a drop of 5 M NaCl solution on the corneal surface of the eye and the numbers of eye wipes were counted during the first 30 s. Histamine (20, 40 microg) and chlorpheniramine (80 microg) significantly decreased the numbers of eye wipes. Ranitidine alone had no effect. Pretreatment with chlorpheniramine did not change the histamine-induced analgesia, whereas the histamine effect on pain was inhibited with ranitidine pretreatment. These results indicate that the brain histamine, through central H(2) receptors, may be involved in the modulation of the acute trigeminal pain in rats.

  19. Protective effects of imipramine in murine endotoxin-induced acute lung injury.

    Science.gov (United States)

    Yang, Jin; Qu, Jie-ming; Summah, Hanssa; Zhang, Jin; Zhu, Ying-gang; Jiang, Hong-ni

    2010-07-25

    The tricyclic antidepressant imipramine has recently emerged as a cytoprotective agent, exerting beneficial effects in inflammatory tissue injury. The present study aimed to investigate therapeutic effects of imipramine in murine model of endotoxin-induced acute lung injury. Mice were administrated intraperitoneally with LPS (lipopolysaccharide) from Escherichia coli or vehicle. Imipramine was administrated intraperitoneally 30 min before LPS challenge. Pretreatment of mice with imipramine reduced lethality. Impramine also significantly attenuated lung inflammation, lung edema, MPO (myeloperoxidase) activity, lung tissue pathological changes and nuclear factor-kappaB DNA binding activity. The results of this study suggest that imipramine can exert protective effects in endotoxin-induced acute lung injury by suppressing nuclear factor-kappaB-mediated expression of inflammatory genes. Thus, imipramine could be a potential novel therapeutic agent for the treatment for acute lung injury.

  20. Acute endolymphatic hydrops has no direct effect on the vestibular evoked potential in the guinea pig

    NARCIS (Netherlands)

    Kingma, C. M.; Wit, H. P.

    2009-01-01

    To investigate the effect of an acute endolymphatic hydrops on the functioning of the vestibular system a hydrops was created by microinjection of artificial endolymph through the basilar membrane into scala media in 10 guinea pigs. To control for the effect of perforation of the basilar membrane, t

  1. Acute effects of cocaine and cannabis on response inhibition in humans: an ERP investigation

    NARCIS (Netherlands)

    Spronk, D.B.; De Bruijn, E.R.; van Wel, J.H.; Ramaekers, J.G.; Verkes, R.J.

    2016-01-01

    Substance abuse has often been associated with alterations in response inhibition in humans. Not much research has examined how the acute effects of drugs modify the neurophysiological correlates of response inhibition, or how these effects interact with individual variation in trait levels of impul

  2. Effects of serelaxin in acute heart failure patients with renal impairment : results from RELAX-AHF

    NARCIS (Netherlands)

    Liu, Licette C. Y.; Voors, Adriaan A.; Teerlink, John R.; Cotter, Gad; Davison, Beth A.; Felker, G. Michael; Filippatos, Gerasimos; Chen, Yakuan; Greenberg, Barry H.; Ponikowski, Piotr; Pang, Peter S.; Prescott, Margaret F.; Hua, Tsushung A.; Severin, Thomas M.; Metra, Marco

    2016-01-01

    Serelaxin showed beneficial effects on clinical outcome and trajectories of renal markers in patients with acute heart failure. We aimed to study the interaction between renal function and the treatment effect of serelaxin. In the current post hoc analysis of the RELAX-AHF trial, we included all pat

  3. A QUANTITATIVE COMPARISON OF THE EFFECTS OF ACUTE INHALED TOLUENE IN HUMAN RATS

    Science.gov (United States)

    The effects of acute exposure to toluene have been explored more thoroughly than other hydrocarbon solvents. These effects have been experimentally studied in humans and other species, e.g., rats, as well as in a number of in vitro preparations. The existence ofdosimetric and eff...

  4. Acute Effect of Decaffeinated Coffee on Heart Rate, Blood Pressure, and Exercise Performance in Healthy Subjects

    Science.gov (United States)

    Prakash, Ravi; Kaushik, Vidya S.

    1988-01-01

    The effect of decaffeinated coffee on the cardiovascular exercise performance in nine healthy volunteers was evaluated in a double-blind randomized fashion. The heart rate, blood pressure, and duration of exercise were unchanged, and no arrhythmias or ischemic changes were seen on the electrocardiogram after drinking decaffeinated coffee. It was concluded that decaffeinated coffee has no discernible, acute, adverse cardiovascular effects. PMID:3339645

  5. Effect of acute mesenteric ischemia on rat small intestinal contractility

    DEFF Research Database (Denmark)

    Zhao, Jingbo; Gregersen, Hans

    2015-01-01

    bath containing physiological Krebs solution. Luminal pressure and intestinal diameter changes were obtained for (i) basic contractions, (ii) flow-induced contractions with different outlet resistance pressures, and (iii) contractions induced by ramp distension. Contraction frequency and amplitude were......Objective: Acute mesenteric ischemia (AMI) accounts for 1–2% of gastrointestinal illnesses. This study investigated changes of intestinal motility in relation to time-dependent exposure to AMI. Methods: After anesthesia with Hypnorm and Dormicum, a midline laparotomy incision was made in 40 male...... Wistar rats. A segment of middle jejunum was made ischemic by ligating five mesenteric arterial branches to the segment. The ischemic period lasted for 15, 30, 60, and 120 min with 10 rats in each group. Another 10 rats were used as normal controls. The motility experiments were carried out in an organ...

  6. Reversible effects of acute hypertension on proximal tubule sodium transporters

    DEFF Research Database (Denmark)

    Zhang, Y; Magyar, C E; Norian, J M

    1998-01-01

    Acute hypertension provokes a rapid decrease in proximal tubule sodium reabsorption with a decrease in basolateral membrane sodium-potassium-ATPase activity and an increase in the density of membranes containing apical membrane sodium/hydrogen exchangers (NHE3) [Y. Zhang, A. K. Mircheff, C. B....... Renal cortex lysate was fractionated on sorbitol gradients. Basolateral membrane sodium-potassium-ATPase activity (but not subunit immunoreactivity) decreased one-third to one-half after BP was elevated and recovered after BP was normalized. After BP was elevated, 55% of the apical NHE3 immunoreactivity......, smaller fractions of sodium-phosphate cotransporter immunoreactivity, and apical alkaline phosphatase and dipeptidyl-peptidase redistributed to membranes of higher density enriched in markers of the intermicrovillar cleft (megalin) and endosomes (Rab 4 and Rab 5), whereas density distributions...

  7. Renal Protective Effects of 17β-Estradiol on Mice with Acute Aristolochic Acid Nephropathy.

    Science.gov (United States)

    Shi, Min; Ma, Liang; Zhou, Li; Fu, Ping

    2016-10-18

    Aristolochic acid nephropathy (AAN) is a progressive kidney disease caused by a Chinese herb containing aristolochic acid. Excessive death of renal tubular epithelial cells (RTECs) characterized the acute phase of AAN. Therapies for acute AAN were limited, such as steroids and angiotensin-receptor blockers (ARBs)/angiotensin-converting enzyme inhibitors (ACEIs). It was interesting that, in acute AAN, female patients showed relative slower progression to renal failure than males. In a previous study, female hormone 17β-estradiol (E2) was found to attenuate renal ischemia-reperfusion injury. Thus, the aim of this study was to investigate the potential protective role of E2 in acute AAN. Compared with male C57BL/6 mice of acute AAN, lower serum creatinine (SCr) and less renal injury, together with RTEC apoptosis in females, were found. Treatment with E2 in male AAN mice reduced SCr levels and attenuated renal tubular injury and RTEC apoptosis. In the mice kidney tissue and human renal proximal tubule cells (HK-2 cells), E2 both attenuated AA-induced cell apoptosis and downregulated the expression of phosphor-p53 (Ser15), p53, and cleaved-caspase-3. This study highlights that E2 exhibited protective effects on the renal injury of acute AAN in male mice by reducing RTEC apoptosis, which might be related to inhibiting the p53 signaling pathway.

  8. Renal Protective Effects of 17β-Estradiol on Mice with Acute Aristolochic Acid Nephropathy

    Directory of Open Access Journals (Sweden)

    Min Shi

    2016-10-01

    Full Text Available Aristolochic acid nephropathy (AAN is a progressive kidney disease caused by a Chinese herb containing aristolochic acid. Excessive death of renal tubular epithelial cells (RTECs characterized the acute phase of AAN. Therapies for acute AAN were limited, such as steroids and angiotensin-receptor blockers (ARBs/angiotensin-converting enzyme inhibitors (ACEIs. It was interesting that, in acute AAN, female patients showed relative slower progression to renal failure than males. In a previous study, female hormone 17β-estradiol (E2 was found to attenuate renal ischemia-reperfusion injury. Thus, the aim of this study was to investigate the potential protective role of E2 in acute AAN. Compared with male C57BL/6 mice of acute AAN, lower serum creatinine (SCr and less renal injury, together with RTEC apoptosis in females, were found. Treatment with E2 in male AAN mice reduced SCr levels and attenuated renal tubular injury and RTEC apoptosis. In the mice kidney tissue and human renal proximal tubule cells (HK-2 cells, E2 both attenuated AA-induced cell apoptosis and downregulated the expression of phosphor-p53 (Ser15, p53, and cleaved-caspase-3. This study highlights that E2 exhibited protective effects on the renal injury of acute AAN in male mice by reducing RTEC apoptosis, which might be related to inhibiting the p53 signaling pathway.

  9. Augmented H2S production via cystathionine-beta-synthase upregulation plays a role in pregnancy-associated uterine vasodilation.

    Science.gov (United States)

    Sheibani, Lili; Lechuga, Thomas J; Zhang, Honghai; Hameed, Afshan; Wing, Deborah A; Kumar, Sathish; Rosenfeld, Charles R; Chen, Dong-Bao

    2017-03-01

    Endogenous hydrogen sulfide (H2S) synthesized via metabolizing L-cysteine by cystathionine-beta-synthase (CBS) and cystathionine-gamma-lyase (CSE) is a potent vasodilator and angiogenic factor. The objectives of this study were to determine if human uterine artery (UA) H2S production increases with augmented expression and/or activity of CBS and/or CSE during the menstrual cycle and pregnancy and whether exogenous H2S dilates UA. Uterine arteries from nonpregnant (NP) premenopausal proliferative (pPRM) and secretory (sPRM) phases of the menstrual cycle and pregnant (P) women were studied. H2S production was measured by the methylene blue assay. CBS and CSE mRNAs were assessed by quantitative real-time PCR, and proteins were assessed by immunoblotting and semiquantitative immunofluorescence microscopy. Effects of H2S on rat UA relaxation were determined by wire myography ex vivo. H2S production was greater in NP pPRM and P than NP sPRM UAs and inhibited by the specific CBS but not CSE inhibitor. CBS but not CSE mRNA and protein were greater in NP pPRM and P than NP sPRM UAs. CBS protein was localized to endothelium and smooth muscle and its levels were in a quantitative order of P >NP UAs of pPRM>sPRM. CSE protein was localized in UA endothelium and smooth muscle with no difference among groups. A H2S donor relaxed P > NP UAs but not mesentery artery. Thus, human UA H2S production is augmented with endothelium and smooth muscle CBS upregulation, contributing to UA vasodilation in the estrogen-dominant physiological states in the proliferative phase of the menstrual cycle and pregnancy. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Thalidomide effect in endothelial cell of acute radiation proctitis

    Institute of Scientific and Technical Information of China (English)

    Ki-Tae Kim; Hiun-Suk Chae; Jin-Soo Kim; Hyung-Keun Kim; Young-Seok Cho; Whang Choi; Kyu-Yong Choi; Sang-Young Rho; Suk-Jin Kang

    2008-01-01

    AIM: To determine whether thalidomide prevents microvascular injury in acute radiation proctitis in white rats. METHODS: Fourteen female Wistar rats were used:six in the radiation group,six in the thalidomide group,and two in normal controls.The radiation and thalidomide groups were irradiated at the pelvic area using a single 30 Gy exposure.The thalidomide (150 mg/kg) was injected into the peritoneum for 7 d from the day of irradiation.All animals were sacrificed and the rectums were removed on day 8 after irradiation.The microvessels of resected specimens were immunohistochemically stained with thrombomodulin (TM),yon Willebrand Factor (vWF),and vascular endothelial growth factor (VEGF).RESULTS: The microscopic scores did not differ significantly between the radiation and thalidomide groups,but both were higher than in the control group.Expression of TM was significantly lower in the endothelial cells (EC) of the radiation group than in the control and thalidomide groups (P < 0.001).The number of capillaries expressing vWF in the EC was higher in the radiation group (15.3 ± 6.8) than in the control group (3.7 ± 1.7),and the number of capillaries expressing vWF was attenuated by thalidomide (10.8 ± 3.5,P < 0.001).The intensity of VEGF expression in capillaries was greater in the radiation group than in the control group and was also attenuated by thalidomide (P = 0.003).CONCLUSION: The mechanisms of acute radiationinduced proctitis in the rats are related to endothelial cell injury of microvessel,which may be attenuated with thalidomide.

  11. The acute effect of vibration applications on jumping performance

    Directory of Open Access Journals (Sweden)

    Şener Soylu

    2012-12-01

    Full Text Available Recently, vibration has become very popular as a method of exercise and training and drawn attention of researchers. The aim of this study was to analyses the acute affect of vibration applications as a method of exercise and training on jumping performance. In this study experimental group consists of 25 subjects who are studying at Physical Education and Sports Department of Sakarya University (age 22.2±1.7 years, height 179.2±4.8 cm. body weight 71.5±9.0 kg. This study included a vibration at density of 35 Hz (3x30 sec. frequency  that result from  aerobic exercise that has low density and b just  methods of aerobic exercise (without any vibration that has  low density. Subjects have taken the tests of countermovement and squat jumping after 2 minutes of each application. All applications and tests have been done in nonconsecutive days in a random scheme. In statistical analysis Wilcoxon has been applied in nonparametric scheme. For counter movement jumping; height of jumping,  the difference between before and after  the application of vibration related to the point of peak power and average power has been found significiant (respectively, p<0.05; p<0.05; p<0.01. In addition to this, no statistical difference was found for squat vertical jumping before and after the application of vibration related to the point of peak power and average power (respectively, p>0.05; p>0.05; p>0.05. As a result, it is concluded that vibration that is applied at the range of 35 Hz frequency could increase the performance of acute countermovement jumping. 

  12. Management of acute heart failure and the effect of systolic blood pressure on the use of intravenous therapies

    Science.gov (United States)

    Harjola, Veli-Pekka; Tolonen, Jukka; Siirilä-Waris, Krista; Nieminen, Markku S; Lassus, Johan

    2013-01-01

    Aims: To examine the use of the treatments for acute heart failure (AHF) recommended by ESC guidelines in different clinical presentations and blood pressure groups. Methods: The use of intravenous diuretics, nitrates, opioids, inotropes, and vasopressors as well as non-invasive ventilation (NIV) was analysed in 620 patients hospitalized due to AHF. The relation between AHF therapies and clinical presentation, especially systolic blood pressure (SBP) on admission, was also assessed. Results: Overall, 76% of patients received i.v. furosemide, 42% nitrates, 29% opioids, 5% inotropes and 7% vasopressors, and 24% of patients were treated with NIV. Furosemide was the most common treatment in all clinical classes and irrespective of SBP on admission. Nitrates were given most often in pulmonary oedema and hypertensive AHF. Overall, only SBP differed significantly between patients with and without the studied treatments. SBP was higher in patients treated with nitrates than in those who were not (156 vs. 141 mmHg, p<0.001). Still, only one-third of patients presenting acute decompensated heart failure and SBP over 120 mmHg were given nitrates. Inotropes and vasopressors were given most frequently in cardiogenic shock and pulmonary oedema, and their use was inversely related to initial SBP (p<0.001). NIV was used only in half of the cardiogenic shock and pulmonary oedema patients. Conclusions: The management of AHF differs between ESC clinical classes and the use of i.v. vasoactive therapies is related to the initial SBP. However, there seems to be room for improvement in administration of vasodilators and NIV. PMID:24222833

  13. Effect of Antiepileptic Drugs for Acute and Chronic Seizures in Children with Encephalitis.

    Directory of Open Access Journals (Sweden)

    Kuang-Lin Lin

    Full Text Available Encephalitis presents with seizures in the acute phase and increases the risk of late unprovoked seizures and epilepsy. This study aimed to evaluate the effect of antiepileptic drugs in pediatric patients with acute seizures due to encephalitis and epilepsy.Cases of acute pediatric encephalitis between January 2000 and December 2010 were reviewed. Clinical data, including onset at age, seizure type, seizure frequency, effects of antiepileptic drugs, and prognosis were analyzed.During the study period, 1038 patients (450 girls, 588 boys were enrolled. Among them, 44.6% (463 had seizures in the acute phase, 33% had status epilepticus, and 26% (251 developed postencephalitic epilepsy. At one year of follow-up, 205 of the 251 patients with postencephalitic epilepsy were receiving antiepileptic drugs while 18% were seizure free even after discontinuing the antiepileptic drugs. Among those with postencephalitic epilepsy, 67% had favorable outcomes and were using <2 anti-epileptic drugs while 15% had intractable seizures and were using ≥ 2 antiepileptic drugs. After benzodiazepines, intravenous phenobarbital was preferred over phenytoin as treatment of postencephalitic seizures in the acute phase. For refractory status epilepticus, high-dose topiramate combined with intravenous high-dose phenobarbital or high-dose lidocaine had less side effects.Children with encephalitis have a high rate of postencephalitic epilepsy. Phenobarbital and clonazepam are the most common drugs used, alone or in combination, for postencephalitic epilepsy.

  14. Acute and training effects of resistance exercise on heart rate variability.

    Science.gov (United States)

    Kingsley, J Derek; Figueroa, Arturo

    2016-05-01

    Heart rate variability (HRV) has been used as a non-invasive method to evaluate heart rate (HR) regulation by the parasympathetic and sympathetic divisions of the autonomic nervous system. In this review, we discuss the effect of resistance exercise both acutely and after training on HRV in healthy individuals and in those with diseases characterized by autonomic dysfunction, such as hypertension and fibromyalgia. HR recovery after exercise is influenced by parasympathetic reactivation and sympathetic recovery to resting levels. Therefore, examination of HRV in response to acute exercise yields valuable insight into autonomic cardiovascular modulation and possible underlying risk for disease. Acute resistance exercise has shown to decrease cardiac parasympathetic modulation more than aerobic exercise in young healthy adults suggesting an increased risk for cardiovascular dysfunction after resistance exercise. Resistance exercise training appears to have no effect on resting HRV in healthy young adults, while it may improve parasympathetic modulation in middle-aged adults with autonomic dysfunction. Acute resistance exercise appears to decrease parasympathetic activity regardless of age. This review examines the acute and chronic effects of resistance exercise on HRV in young and older adults. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  15. Botulinum neurotoxin type A (BoNTA) decreases the mechanical sensitivity of nociceptors and inhibits neurogenic vasodilation in a craniofacial muscle targeted for migraine prophylaxis.

    Science.gov (United States)

    Gazerani, Parisa; Au, Sammy; Dong, Xudong; Kumar, Ujendra; Arendt-Nielsen, Lars; Cairns, Brian E

    2010-12-01

    The mechanism by which intramuscular injection of BoNTA into the craniofacial muscles decreases migraine headaches is not known. In a blinded study, the effect of BoNTA on the mechanical and chemical responsiveness of individual temporalis muscle nociceptors and muscle neurogenic vasodilation was investigated in female rats. Mechanical threshold was measured for 3h following intramuscular injection of BoNTA or vehicle, and for 10 min after a subsequent injection of the algogen glutamate. Injection of BoNTA significantly increased the mechanical threshold of muscle nociceptors without altering the muscle surface temperature and blocked glutamate-induced mechanical sensitization and neurogenic vasodilation. None of these effects were reproduced by pancuronium-induced muscle paralysis. Western blot analysis of temporalis muscles indicated that BoNTA significantly decreased SNAP-25. Measurement of interstitial glutamate concentration with a glutamate biosensor indicated that BoNTA significantly reduced glutamate concentrations. The mechanical sensitivity of muscle nociceptors is modulated by glutamate concentration through activation of peripheral NMDA receptors. Immunohistochemical experiments were conducted and they indicated that half of the NMDA-expressing temporalis nerve fibers co-expressed substance P or CGRP. Additional electrophysiology experiments examined the effect of antagonists for NMDA, CGRP and NK1 receptors on glutamate-induced effects. Glutamate-induced mechanical sensitization was only blocked by the NMDA receptor antagonist, but muscle neurogenic vasodilation was attenuated by NMDA or CGRP receptor antagonists. These data suggest that injection of BoNTA into craniofacial muscles acts to decrease migraine headaches by rapidly decreasing the mechanical sensitivity of temporalis muscle nociceptors through inhibition of glutamate release and by attenuating the provoked release of CGRP from muscle nociceptors.

  16. Acute kidney injury in acute liver failure: a review.

    Science.gov (United States)

    Moore, Joanna K; Love, Eleanor; Craig, Darren G; Hayes, Peter C; Simpson, Kenneth J

    2013-11-01

    Acute liver failure is a rare and often devastating condition consequent on massive liver cell necrosis that frequently affects young, previously healthy individuals resulting in altered cognitive function, coagulopathy and peripheral vasodilation. These patients frequently develop concurrent acute kidney injury (AKI). This abrupt and sustained decline in renal function, through a number of pathogenic mechanisms such as renal hypoperfusion, direct drug-induced nephrotoxicity or sepsis/systemic inflammatory response contributes to increased morbidity and is strongly associated with a worse prognosis. Improved understanding of the pathophysiology AKI in the context of acute liver failure may be beneficial in a number of areas; the development of new and sensitive biomarkers of renal dysfunction, refining prognosis and organ allocation, and ultimately leading to the development of novel treatment strategies, these issues are discussed in more detail in this expert review.

  17. Pulmonary vascular responses during acute and sustained respiratory alkalosis or acidosis in intact newborn piglets.

    Science.gov (United States)

    Gordon, J B; Rehorst-Paea, L A; Hoffman, G M; Nelin, L D

    1999-12-01

    Acute alkalosis-induced pulmonary vasodilation and acidosis-induced pulmonary vasoconstriction have been well described, but responses were generally measured within 5-30 min of changing pH. In contrast, several in vitro studies have found that relatively brief periods of sustained alkalosis can enhance, and sustained acidosis can decrease, vascular reactivity. In this study of intact newborn piglets, effects of acute (20 min) and sustained (60-80 min) alkalosis or acidosis on baseline (35% O2) and hypoxic (12% O2) pulmonary vascular resistance (PVR) were compared with control piglets exposed only to eucapnia. Acute alkalosis decreased hypoxic PVR, but sustained alkalosis failed to attenuate either baseline PVR or the subsequent hypoxic response. Acute acidosis did not significantly increase hypoxic PVR, but sustained acidosis markedly increased both baseline PVR and the subsequent hypoxic response. Baseline PVR was similar in all piglets after resumption of eucapnic ventilation, but the final hypoxic response was greater in piglets previously exposed to alkalosis than in controls. Thus, hypoxic pulmonary vasoconstriction was not attenuated during sustained alkalosis, but was accentuated during sustained acidosis and after the resumption of eucapnia in alkalosis-treated piglets. Although extrapolation of data from normal piglets to infants and children with pulmonary hypertension must be done with caution, this study suggests that sustained alkalosis may be of limited efficacy in treating acute hypoxia-induced pulmonary hypertension and the risks of pulmonary hypertension must be considered when using ventilator strategies resulting in permissive hypercapnic acidosis.

  18. [Effect of acute alcohol intoxication on lipid peroxidation in testis and adrenal glands of rats].

    Science.gov (United States)

    Khokha, A M; Kashko, M F; Antsulevich, S N; Doroshkevich, N A; Voronov, P P

    1993-01-01

    Hormones level and lipid peroxidation processes under influence of acute alcohol intoxication are tested in testes and adrenals of rats. Ethanol marker effects--the rise of corticosterone biosynthesis and depression of testosterone concentration--were reproduced in the experiment. At the moment of maximal changes in steroid levels indices characterising lipid peroxidation didn't differ from the control. At the early stage of the experiment transient shifts in malonic dialdehyde and dienic conjugates levels were noted. The data obtained does not agree with the hypothesis of acute ethanol effects in testes and adrenals being mediated through the changes of lipid peroxidation rate.

  19. [Cardioprotective effect of drugs with antioxidant activity in acute cerebral ischemia].

    Science.gov (United States)

    Stoliarova, V V

    2001-01-01

    The bioelectric cardiac activity was studied in the experiments on white mice with an acute cerebral blood circulation disorder. It was found that he resulting EEG changes possess a specific character, with the sympathoadrenal system stimulation playing an important role in the acute cerebrocardiac syndrome development. The antioxidant-type agents such as emoxypine (50 mg/kg), mexidol (50 mg/kg), and cytochrome C (10 mg/kg) produce a significant cardioprotective effect in the test animals with experimental cerebral ischemia, which was comparable with the effect of propranolol (obsidane) (0.1 mg/kg).

  20. Antiarrhythmic and electrophysiologic effects of flecainide on acutely induced atrial fibrillation in healthy horses

    DEFF Research Database (Denmark)

    Haugaard, Maria Mathilde; Pehrson, S.; Carstensen, Helena

    2015-01-01

    parameters: ability to terminate acute pacing-induced AF (≥ 15 minutes), and drug-induced changes in atrial effective refractory period, AF duration, AF vulnerability, and ventricular depolarization and repolarization times. Parameters were assessed at baseline and after flecainide by programmed electrical...... between 8 and 20 minutes after initiation of flecainide infusion, but no ventricular arrhythmias were detected. CONCLUSIONS AND CLINICAL IMPORTANCE: Flecainide had clear antiarrhythmic properties in terminating acute pacing-induced AF, but showed no protective properties against immediate reinduction...... of AF. Flecainide caused temporary prolongation in the ventricular repolarization, which may be a proarrhythmic effect....

  1. Direct suppressive effect of acute metabolic and respiratory alkalosis on parathyroid hormone secretion in the dog.

    Science.gov (United States)

    Lopez, Ignacio; Rodriguez, Mariano; Felsenfeld, Arnold J; Estepa, Jose Carlos; Aguilera-Tejero, Escolastico

    2003-08-01

    Acute alkalosis may directly affect PTH secretion. The effect of acute metabolic and respiratory alkalosis was studied in 20 dogs. PTH values were lower in the metabolic (5.6 +/- 0.8 pg/ml) and respiratory (1.8 +/- 0.6 pg/ml) alkalosis groups than in the control group (27 +/- 5 pg/ml). Acute alkalosis is an independent factor that decreases PTH values during normocalcemia and delays the PTH response to hypocalcemia. We recently showed that acute metabolic and respiratory acidosis stimulated PTH secretion. This study was designed to evaluate whether acute metabolic and respiratory alkalosis suppressed parathyroid hormone (PTH) secretion. Three groups of 10 dogs were studied: control, acute metabolic alkalosis, and acute respiratory alkalosis. Metabolic alkalosis was induced with an infusion of sodium bicarbonate and respiratory alkalosis by hyperventilation. Calcium chloride was infused to prevent alkalosis-induced hypocalcemia during the first 60 minutes. During the next 30 minutes, disodium EDTA was infused to induce hypocalcemia and to evaluate the PTH response to hypocalcemia. Because the infusion of sodium bicarbonate resulted in hypernatremia, the effect of hypernatremia was studied in an additional group that received hypertonic saline. After 60 minutes of a normocalcemic clamp, PTH values were less (p respiratory (1.8 +/- 0.6 pg/ml) alkalosis groups than in the control group (27 +/- 5 pg/ml); the respective blood pH values were 7.61 +/- 0.01, 7.59 +/- 0.02, and 7.39 +/- 0.02. The maximal PTH response to hypocalcemia was similar among the three groups. However, the maximal PTH response was observed after a decrease in ionized calcium of 0.20 mM in the control group but not until a decrease of 0.40 mM in the metabolic and respiratory alkalosis groups. In contrast to the metabolic alkalosis group, hypernatremia (157 +/- 2 mEq/liter) in the hypertonic saline group was associated with an increased PTH value (46 +/- 4 pg/ml). Finally, the half-life of intact PTH

  2. Acetylcholine released from cholinergic nerves contributes to cutaneous vasodilation during heat stress

    Science.gov (United States)

    Shibasaki, Manabu; Wilson, Thad E.; Cui, Jian; Crandall, Craig G.

    2002-01-01

    Nitric oxide (NO) contributes to active cutaneous vasodilation during a heat stress in humans. Given that acetylcholine is released from cholinergic nerves during whole body heating, coupled with evidence that acetylcholine causes vasodilation via NO mechanisms, it is possible that release of acetylcholine in the dermal space contributes to cutaneous vasodilation during a heat stress. To test this hypothesis, in seven subjects skin blood flow (SkBF) and sweat rate were simultaneously monitored over three microdialysis membranes placed in the dermal space of dorsal forearm skin. One membrane was perfused with the acetylcholinesterase inhibitor neostigmine (10 microM), the second membrane was perfused with the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME; 10 mM) dissolved in the aforementioned neostigmine solution (l-NAME(Neo)), and the third membrane was perfused with Ringer solution as a control site. Each subject was exposed to approximately 20 min of whole body heating via a water-perfused suit, which increased mean body temperature from 36.4 +/- 0.1 to 37.5 +/- 0.1 degrees C (P heat stress, SkBF at each site was normalized to its maximum value, identified by administration of 28 mM sodium nitroprusside. Mean body temperature threshold for cutaneous vasodilation was significantly lower at the neostigmine-treated site relative to the other sites (neostigmine: 36.6 +/- 0.1 degrees C, l-NAME(Neo): 37.1 +/- 0.1 degrees C, control: 36.9 +/- 0.1 degrees C), whereas no significant threshold difference was observed between the l-NAME(Neo)-treated and control sites. At the end of the heat stress, SkBF was not different between the neostigmine-treated and control sites, whereas SkBF at the l-NAME(Neo)-treated site was significantly lower than the other sites. These results suggest that acetylcholine released from cholinergic nerves is capable of modulating cutaneous vasodilation via NO synthase mechanisms early in the heat stress but not after

  3. Effect of moderate- and high-intensity acute exercise on appetite in obese individuals

    DEFF Research Database (Denmark)

    Martins, Catia; Stensvold, Dorthe; Finlayson, Graham

    2015-01-01

    cycling (MICC) or short-duration HIIC (S-HIIC) (125 kcal) and a resting control condition on the appetite hormone responses, subjective feelings of appetite, energy intake (EI), and food reward in overweight/obese individuals. METHODS: This study is a randomized crossover study on 12 overweight/obese......, hunger or fullness ratings, EI, or food reward. CONCLUSIONS: Our findings suggest that, in overweight/obese individuals, isocaloric bouts of moderate- or high-intensity exercise lead to a similar appetite response. This strengthens previous findings in normal-weight individuals that acute exercise, even......PURPOSE: The effect of acute exercise, and exercise intensity, on appetite control in obese individuals requires further study. The aim of this study was to compare the effects of acute isocaloric bouts (250 kcal) of high-intensity intermittent cycling (HIIC) and moderate-intensity continuous...

  4. The effect of streptokinase on chest pain in acute myocardial infarction

    DEFF Research Database (Denmark)

    Christensen, J H; Sørensen, H T; Rasmussen, S E;

    1991-01-01

    Treatment with intravenous streptokinase is known to restore blood flow to the ischaemic myocardium in patients with acute myocardial infarction. However, little is known about its effect on chest pain. In a retrospective cohort study, 76 patients treated with streptokinase were compared to 76...... patients not treated with streptokinase. All patients had acute myocardial infarction and less than 6 h of cardiac symptoms. Patients treated with streptokinase had a significantly lower need for nicomorphine (median 20 mg) than patients not treated with streptokinase (median 41 mg). Correspondingly......, the median duration (3.5 h) of pain was reduced significantly in patients treated with streptokinase compared to patients not treated (24 h). We conclude that intravenous streptokinase given in the acute phase of myocardial infarction is effective in reducing the duration of cardiac chest pain....

  5. Effect of Danshu capsules combined with Xiyanping on acute cholecystitis treatment

    Institute of Scientific and Technical Information of China (English)

    Hong-Liang Wang; Lv-Rong Yuan; Ya-Ming Liu

    2016-01-01

    Objective:To observe the effect of Danshu capsules combined with Xiyanping on acute cholecystitis treatment and offer help to acute cholecystitis treatment.Methods: A total of 180 patients with acute cholecystitis were selected and randomly divided into groups: the observation group (90 people) and the control group (90 people). The patients in the control group were treated with conventional therapy and the patients in the observation group were treated with Danshu capsules combined with Xiyanping on the basis of conventional therapy. Immunological cell, cholecystitis related factors, inflammatory factors, and the coagulation function related factors were detected and analyzed before and after treatment.Results:Coagulation function related factors (PT and APTT), CD8+, cholecystitis related factors (total bilirubin, amylase and PCT), inflammatory factor (hs-CRP, TNF-α, IL-6 and IL-10) in both groups after treatment significantly decreased. PA, immunological cell (CD3+, CD4+ and CD4+/CD8+) significantly increased compared with that before treatment (P0.05). Coagulation function related factors (PT and APTT), CD8+, cholecystitis related factors (total bilirubin, amylase and PCT), and inflammatory factor (hs-CRP, TNF-α, IL-6 and IL-10) in observation group after treatment decreased more significantly than that in control group (P<0.05).Conclusions: Danshu capsules combined with Xiyanping can perfect effectively immunological cell, cholecystitis related factors, inflammatory factors and coagulation function related factors on patients with acute cholecystitis, and it has important clinical significance for acute cholecystitis.

  6. Acute effects of aerobic stretching, health and happiness improving movement exercise on cortical activity of children.

    Science.gov (United States)

    Choi, Hyungsoo; Park, Sangjun; Kim, Kyekyoon Kevin; Lee, Kwanghee; Rhyu, Hyun-Seung

    2016-08-01

    Acute high-intensity physical exercise is known to improve cognitive performance of children, including those with attention-deficit/hyperactivity disorder (ADHD). In this work, we investigated the acute effect of an aerobic stretching and moderate-intensity, health and happiness improving movement (HHIM) exercise on the cortical activity of children with and without ADHD using electroencephalography (EEG). Children aged 12 to 14 yr with combined-type ADHD and age-matched healthy controls participated in the study, performing two individual movements (n=79, 35 controls) and a single exercise bout (n=45, 18 controls). electroencephalographic signals were recorded before and immediately after each movement, and before and after acute exercise under resting conditions, to obtain absolute and relative power estimates for the theta (3.5-8 Hz), alpha (8-12 Hz), sensory motor rhythm (12-16 Hz), and beta (16-25 Hz) bands. After acute HHIM exercise, all children showed significant changes in their relative EEG, mainly in the theta and alpha bands. Individual movements were found to influence relative theta, alpha and beta, and theta-to-beta ratios. He presents aerobic stretching HHIM exercise has demonstrated acute effect on the cortical activity of children.

  7. Effect of acute ethanol ingestion on fat absorption.

    Science.gov (United States)

    Boquillon, M

    1976-12-01

    A test meal (300 mg casein, 600 mg sucrose, 100 mg corn oil, tracer dose of 9.10(3)H oleic acid) was given to fasting adult rats with intestinal lymph fistulas. One group received an acute oral dose of ethanol (3.2 g/kg body weight) simultaneously with the test meal. Controls received 2.5 ml of water instead of ethanol. Ingestion of ethanol temporarily delayed the removal of lipid radioactivity from the stomachs. More than 25% of radioactivity fed remained 8 hr after feeding whereas with control rats less than 10% of lipid radioactivity fed remained 6 hr after feeding. In controls and ethanol-treated rats, the amounts of exogenous lipids in the intestinal lumen and mucosa were low and similar enough. Quantities of endogenous and exogenous lipids found in the lymph collected during 24 hr after feeding were similar in the two groups, but the fat absorption peak was found after 6 hr in alcoholic rats and before 6 hr in controls. This delay was probably due to the retention of lipids in the stomach. More of the exogenous lipid was always transported by small particles moving in the region of alpha1 globulins in cellulose acetate electrophoresis than by larger particles remaining at the origin. This proportion was enhanced in the ethanol-treated animals. The larger fat particles were richer in endogenous fatty acids in alcohol-treated rats than in controls.

  8. Effect of Vagotomy on Acute Pancreatitis in Rats

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    One hundred and eighty-two SD rats were randomly divided into the normal control group, fast operating group and food-intake operating group. The experimental model of acute pancreatitis (AP) in rats was established by injecting 5 % sodium taurocholate into the pancreatic duct of rat according to Aho's method. The sandostatin was used for positive contrast. The concentrations of serum amylase, calcium, C reaction protein (CRP) and interleukin-6 (IL-6) were assayed respectively at different time points. The pathological sections were observed. Each operating group contained 10 rats. The mortality of the operating groups was observed during the 24 h. The serum amylase level in the AP rats was reduced after receiving vagotomy (VG, P<0.05). Although the serum calcium level in most groups was decreased, the reduction in the group with VG plus sandostatin was not obvious (P>0.05). The increase of CRP and IL-6 was not obvious after VG (P>0.05). The change of mortality was not significant (P>0.05). The pathological sections showed that the AP pathological change was mild after VG. The disease condition of food-intake operating group was more serious than that of fast operating group. It was suggested that VG had some influence on the prognosis of AP in rats.

  9. Cognitive and physiological effects of an acute physical activity intervention in elementary school children

    Directory of Open Access Journals (Sweden)

    Katja eJäger

    2014-12-01

    Full Text Available The aim of the present study was to investigate the effects of an acute physical activity intervention including cognitive engagement on executive functions and on cortisol level in young elementary school children. Half of the 104 participating children (6 to 8 years old attended a 20-minute sport sequence, which included cognitively engaging and playful forms of physical activity. The other half was assigned to a resting control condition. Individual differences in children`s updating, inhibition, and shifting performance as well as salivary cortisol were assessed before (pre-test, immediately after (post-test, and 40 minutes after (follow-up the intervention or control condition respectively. Results revealed a significantly stronger improvement in inhibition in the experimental group compared to the control group, while it appeared that acute physical activity had no specific effect on updating and shifting. The intervention effect on inhibition levelled out 40 minutes after physical activity. Salivary cortisol increased significantly more in the experimental compared to the control group between post-test and follow-up and results support partly the assumed inverted U-shaped relationship between cortisol level and cognitive performance. In conclusion, results indicate that acute physical activity including cognitive engagement may have immediate positive effects on inhibition, but not necessarily on updating and shifting in elementary school children. This positive effect may partly be explained trough cortisol elevation after acute physical activity.

  10. Evaluation the protective effect of diphenhydramine against acute toxicity induced by levamisole in male mice

    Directory of Open Access Journals (Sweden)

    M.Y. Matti

    2015-06-01

    Full Text Available The aim of this study was to evaluate the protective effect of different doses of diphenhydramine against acute toxicosis with Levamisole. The Mechanism of levamisole induced acute toxicity and that of protective effect of diphenhydramine against Levamisole toxicosis also examined on the level of cholinesterase (ChE activity. Subcutanous injection of 100mg/kg levamisole in male mice with induced cholinergic over stimulation and death in 100% of animals. The Toxicosis was not related to the significantly decreased in plasma, red blood cells and brain ChE activity. Injection low dose of diphenhydramin 2.5mg/kg S.C. 15 min before levamisole produced protective effect against acute toxicity with levamisole. Significantly decreased the severity of toxicosis and increased survival rates to 100%. Diphenhydramine at low dose alone or with acute dose of levamisole did not Produced Significantly inhibition in ChE activity.The data suggested that the toxic effect of Levamisole was not related to inhibition of ChE. The low dose of diphenhydramine protected mice from Levamisole toxicity. The antidoatal effect of diphenhydramine not at the level of protection from ChE inhibition. There was no adverse interaction between two drugs.

  11. Side effects induced by the acute levodopa challenge in Parkinson’s Disease and atypical parkinsonisms

    Science.gov (United States)

    Mostile, Giovanni; Dibilio, Valeria; Sciacca, Giorgia; Contrafatto, Donatella; Cicero, Calogero Edoardo; Raciti, Loredana; Luca, Antonina; Zappia, Mario

    2017-01-01

    Introduction Acute levodopa challenge may be performed to predict levodopa chronic responsiveness. The aim of the study was to investigate frequency of side effects during the acute levodopa challenge in PD and atypical parkinsonisms. Methods We enrolled 34 de novo PD patients and 29 patients affected by atypical parkinsonisms (Multiple System Atrophy, MSA, n = 10; Progressive Supranuclear Palsy, PSP, n = 12 and Corticobasal Degeneration, CBD, n = 7) who underwent an acute levodopa challenge. Side effects occurring during test were recorded. Results Side effects were more frequent among atypical parkinsonisms as unique group when compared to PD patients (64.3% versus 23.5%; p-value 0.002) with an adjusted OR of 4.36 (95%CI 1.40–13.5). Each atypical parkinsonisms showed almost double occurrence of side effects (MSA 90%, PSP 41.7% and CBD 57%). Conclusions Side effects during acute levodopa challenge may be frequent in atypical parkinsonisms. This information could be useful in order to better prepare the patient for the test. Furthermore, it could represent a useful cue in differential diagnosis with PD. PMID:28207803

  12. Chronic hyperleptinemia induces resistance to acute natriuretic and NO-mimetic effects of leptin.

    Science.gov (United States)

    Bełtowski, Jerzy; Wójcicka, Grazyna; Jamroz-Wiśniewska, Anna; Wojtak, Andrzej

    2010-01-01

    Apart from controlling energy balance, leptin, secreted by adipose tissue, is also involved in the regulation of cardiovascular function. Previous studies have demonstrated that acutely administered leptin stimulates natriuresis and vascular nitric oxide (NO) production and that these effects are impaired in obese animals. However, the mechanism of resistance to leptin is not clear. Because obesity is associated with chronically elevated leptin, we examined if long-term hyperleptinemia impairs acute effects of leptin on sodium excretion and NO production in the absence of obesity. Hyperleptinemia was induced in lean rats by administration of exogenous leptin at a dose of 0.5mg/kg/day for 7 days, and then acute effect of leptin (1mg/kg i.v.) was studied under general anesthesia. Leptin increased fractional sodium excretion and decreased Na(+),K(+)-ATPase activity in the renal medulla. In addition, leptin increased the level of NO metabolites and cyclic GMP in plasma and aortic wall. These acute effects of leptin were impaired in hyperleptinemic animals. In both control and hyperleptinemic groups the effect of leptin on Na(+) excretion and renal Na(+),K(+)-ATPase was abolished by phosphoinositide 3-kinase (PI3K) inhibitor, wortmannin, but not by protein kinase B/Akt inhibitor, triciribine,. In contrast, acute effect of leptin on NO metabolites and cGMP was abolished by triciribine but not by wortmannin. Leptin stimulated Akt phosphorylation at Ser(473) in aortic tissue but not in the kidney, and this effect was comparable in control and hyperleptinemic groups. These results suggest that hyperleptinemia may mediate "renal" and "vascular" leptin resistance observed in obesity.

  13. Mechanisms of K(+) induced renal vasodilation in normo- and hypertensive rats in vivo

    DEFF Research Database (Denmark)

    Magnusson, Linda Helena Margaretha; Sørensen, Charlotte Mehlin; Braunstein, T H;

    2011-01-01

    Aim: We investigated the mechanisms behind K(+) -induced renal vasodilation in vivo in normotensive Sprague-Dawley (SD) rats and spontaneously hypertensive rats (SHR). Methods: Renal blood flow (RBF) was measured utilizing an ultrasonic Doppler flow probe. Renal vascular resistance (RVR) was calc......Aim: We investigated the mechanisms behind K(+) -induced renal vasodilation in vivo in normotensive Sprague-Dawley (SD) rats and spontaneously hypertensive rats (SHR). Methods: Renal blood flow (RBF) was measured utilizing an ultrasonic Doppler flow probe. Renal vascular resistance (RVR......) was calculated as the ratio of mean arterial pressure (MAP) and RBF (RVR = MAP/RBF). Test drugs were introduced directly into the renal artery. Inward rectifier K(+) (K(ir) ) channels and Na(+) ,K(+) -ATPase were blocked by Ba(2+) and ouabain (estimated plasma concentrations ~20 and ~7 µm) respectively. Results...

  14. Effect of Ramadan fasting on acute upper gastrointestinal bleeding

    Directory of Open Access Journals (Sweden)

    El Mekkaoui Amine

    2013-01-01

    Full Text Available Background: Prolonged fasting may precipitate or exacerbate gastrointestinal complaints. The aim of this study was to evaluate the relation between Ramadan fasting and acute upper gastrointestinal bleeding (AUGIB, and to assess characteristics of those occurred in the holly month. Materials and Methods: Retrospective analysis was conducted for all patients, who underwent endoscopy for AUGIB in Ramadan (R and the month before Ramadan (BR. Epidemiological, clinical and etiological characteristics and outcome of patients having AUGIB were compared between the two periods from 2001 to 2010. Results: Two hundred and ninety-one patients had endoscopy for AUGIB during the two periods study. There was an increasing trend in the overall number of patients in Ramadan period (n = 132, 45.4% versus n = 159, 54.6%, especially with duodenal ulcer (n = 48, 37.2% versus n = 81, 62.8%. The most frequent etiology was peptic ulcer but it was more observed in group R than in group BR (46.2% versus 57.9%, P = 0.04, especially duodenal ulcer (36.4% versus 50.3%, P = 0.01; this finding persisted in multivariable modeling (adjusted odds ratio: 1.67; 95% confidence interval, 1.03-2.69, P = 0.03. In contrast, there was a decreasing trend in rate of variceal bleeding from BR period (26.5% to R period (18.9%; P = 0.11. Regarding the outcome, there were no significant differences between the two periods of the study: Recurrent bleeding (10.6% versus 7.5%, P = 0.36 and mortality rate (5.3% versus 4.4%, P = 0.7. Conclusion: The most frequent etiology of AUGIB was peptic ulcer during Ramadan. However, Ramadan fasting did not influence the outcome of the patients. Prophylactic measures should be taken for people with risk factors for peptic ulcer disease.

  15. No acute effects of grape juice on appetite, implicit memory, and mood

    OpenAIRE

    Richard D Mattes; Hendrickson, Sara J

    2008-01-01

    Background: Animal experiments document effects of grape juice on cognitive performance and motor skills, and observational studies in humans suggest an inverse association between flavonoid intake and cognitive decline. These effects may be related to the antioxidant properties of polyphenols. Juice consumption and flavonoid intake may also affect appetite. Objective: To study the acute effects of grape juice consumption on appetite, mood and implicit memory during a time of increased lethar...

  16. Effects of acute exercise on salivary free insulin-like growth factor 1 ...

    African Journals Online (AJOL)

    Effects of acute exercise on salivary free insulin-like growth factor 1 and ... whether a short bout of sport training can alter some salivary immune biomarkers. Aim: To ... salivary flow rate and levels of free IGF-1 and IL-10 were determined using ...

  17. Effects of hyperflexion on acute stress responses in ridden dressage horses

    NARCIS (Netherlands)

    Christensen, J.W.; Beekmans, M; van Dalum, M; van Dierendonck, M.C.

    2014-01-01

    The effects of hyperflexion on the welfare of dressage horses have been debated. This study aimed to investigate acute stress responses of dressage horses ridden in three different Head-and-Neck-positions (HNPs). Fifteen dressage horses were ridden by their usual rider in a standardised 10-min dress

  18. Time to Reperfusion and Treatment Effect for Acute Ischemic Stroke : A Randomized Clinical Trial

    NARCIS (Netherlands)

    Fransen, Puck S S; Berkhemer, Olvert A; Lingsma, Hester F; Beumer, Debbie; van den Berg, Lucie A; Yoo, Albert J; Schonewille, Wouter J; Vos, Jan Albert; Nederkoorn, Paul J; Wermer, Marieke J H; van Walderveen, Marianne A A; Staals, Julie; Hofmeijer, Jeannette; van Oostayen, Jacques A; Lycklama À Nijeholt, Geert J; Boiten, Jelis; Brouwer, Patrick A; Emmer, Bart J; de Bruijn, Sebastiaan F; van Dijk, Lukas C; Kappelle, L Jaap; Lo, Rob H; van Dijk, Ewoud J; de Vries, Joost; de Kort, Paul L M; van den Berg, J S Peter; van Hasselt, Boudewijn A A M; Aerden, Leo A M; Dallinga, René J; Visser, Marieke C; Bot, Joseph C J; Vroomen, Patrick C; Eshghi, Omid; Schreuder, Tobien H C M L; Heijboer, Roel J J; Keizer, Koos; Tielbeek, Alexander V; den Hertog, Heleen M; Gerrits, Dick G; van den Berg-Vos, Renske M; Karas, Giorgos B; Steyerberg, Ewout W; Flach, H Zwenneke; Marquering, Henk A; Sprengers, Marieke E S; Jenniskens, Sjoerd F M; Beenen, Ludo F M; van den Berg, René; Koudstaal, Peter J; van Zwam, Wim H; Roos, Yvo B W E M; van Oostenbrugge, Robert J; Majoie, Charles B L M; van der Lugt, Aad; Dippel, Diederik W J

    2016-01-01

    Importance: Intra-arterial treatment (IAT) for acute ischemic stroke caused by intracranial arterial occlusion leads to improved functional outcome in patients treated within 6 hours after onset. The influence of treatment delay on treatment effect is not yet known. Objective: To evaluate the influe

  19. Time to Reperfusion and Treatment Effect for Acute Ischemic Stroke : A Randomized Clinical Trial

    NARCIS (Netherlands)

    Fransen, Puck S S; Berkhemer, Olvert A; Lingsma, Hester F; Beumer, Debbie; van den Berg, Lucie A; Yoo, Albert J; Schonewille, Wouter J; Vos, Jan Albert; Nederkoorn, Paul J; Wermer, Marieke J H; van Walderveen, Marianne A A; Staals, Julie; Hofmeijer, Jeannette; van Oostayen, Jacques A; Lycklama À Nijeholt, Geert J; Boiten, Jelis; Brouwer, Patrick A; Emmer, Bart J; de Bruijn, Sebastiaan F; van Dijk, Lukas C; Kappelle, L Jaap; Lo, Rob H; van Dijk, Ewoud J; de Vries, Joost; de Kort, Paul L M; van den Berg, J S Peter; van Hasselt, Boudewijn A A M; Aerden, Leo A M; Dallinga, René J; Visser, Marieke C; Bot, Joseph C J; Vroomen, Patrick C; Eshghi, Omid; Schreuder, Tobien H C M L; Heijboer, Roel J J; Keizer, Koos; Tielbeek, Alexander V; den Hertog, Heleen M; Gerrits, Dick G; van den Berg-Vos, Renske M; Karas, Giorgos B; Steyerberg, Ewout W; Flach, H Zwenneke; Marquering, Henk A; Sprengers, Marieke E S; Jenniskens, Sjoerd F M; Beenen, Ludo F M; van den Berg, René; Koudstaal, Peter J; van Zwam, Wim H; Roos, Yvo B W E M; van Oostenbrugge, Robert J; Majoie, Charles B L M; van der Lugt, Aad; Dippel, Diederik W J

    2016-01-01

    IMPORTANCE: Intra-arterial treatment (IAT) for acute ischemic stroke caused by intracranial arterial occlusion leads to improved functional outcome in patients treated within 6 hours after onset. The influence of treatment delay on treatment effect is not yet known. OBJECTIVE: To evaluate the influe

  20. Acute-lethal toxicity (LC50) effect of Moringa oleifera (Lam.) Fresh ...

    African Journals Online (AJOL)

    SH

    Acute-lethal toxicity is a tool used in piscicide bio-safety assessment in fish farming prior to its proper application in ... assessment because of their effects on non-target aquatic species in fish pond. ... food fish from aquaculture for human.

  1. Adiponectin potentiates the acute effects of leptin in arcuate Pomc neurons

    Directory of Open Access Journals (Sweden)

    Jia Sun

    2016-10-01

    Conclusions: Our results demonstrate a requirement for PI3K signaling in the acute adiponectin-induced effects on the cellular activity of arcuate melanocortin neurons. Moreover, these data provide evidence for PI3K as a substrate for both leptin and adiponectin to regulate energy balance and glucose metabolism via melanocortin activity.

  2. Effect of glutathione S-transferases on the survival of patients with acute myeloid leukaemia

    DEFF Research Database (Denmark)

    Autrup, Judith; Hokland, Peter; Pedersen, Lars

    2002-01-01

    The objective of the study was to investigate the effect of genetic polymorphisms in glutathione S-transferases (GST) on the survival of acute myeloid leukaemia patients receiving adriamycin induction therapy. A total of 89 patients were included in the study. Patients who carried at least one GS...

  3. Limited evidence for effects of intranasal corticosteroids on symptom relief for recurrent acute rhinosinusitis

    NARCIS (Netherlands)

    van Loon, J.W.L.; van Harn, R.P.; Venekamp, R.P.; Kaper, N.M.; Sachs, A.P.E.; van der Heijden, G.J.M.G.

    2013-01-01

    Objective To systematically review the evidence base on the effectiveness of intranasal corticosteroids in adult patients with recurrent acute rhinosinusitis. Data Sources Pubmed, EMBASE, and the Cochrane Library. Review Methods A comprehensive search was performed up to March 20, 2013. Two reviewer

  4. Effect of probiotics on diarrhea in children with severe acute malnutrition

    DEFF Research Database (Denmark)

    Grenov, Benedikte; Namusoke, Hanifa; Lanyero, Betty

    2017-01-01

    OBJECTIVES: To assess the effect of probiotics on diarrhea during in- and outpatient treatment of children with severe acute malnutrition (SAM). METHODS: A randomized, double-blind, placebo-controlled study was conducted involving 400 children admitted with SAM. Patients received one daily dose...

  5. ACUTE BEHAVORIAL EFFECTS FROM EXPOSURE TO TWO-STROKE ENGINE EXHAUST

    Science.gov (United States)

    Benefits of changing from two-stroke to four-stroke engines (and other remedial requirements) can be evaluated (monetized) from the standpoint of acute behavioral effects of human exposure to exhaust from these engines. The monetization process depends upon estimates of the magn...

  6. Effects of losartan and captopril on left ventricular systolic and diastolic function after acute myocardial infarction

    DEFF Research Database (Denmark)

    Møller, Jacob E; Dahlström, Ulf; Gøtzsche, Ole

    2004-01-01

    BACKGROUND: Angiotensin-converting enzyme inhibitors have been shown to attenuate adverse remodeling after acute myocardial infarction (AMI), and the same has been suggested for angiotensin II type 1 receptor antagonists in animal models. Therefore the aim of the study was to compare the effects...

  7. Acute effects of high- and low-intensity exercise bouts on leukocyte counts

    Directory of Open Access Journals (Sweden)

    Pedro Rogério Da Silva Neves

    2015-06-01

    Conclusion: When the same participants were submitted to different exercise intensities, the acute and short-term effects of exercise on white blood cells were intensity-dependent immediately after exercise (i.e., lymphocytosis and monocytosis and 2 hours after passive recovery (i.e., neutrophilia.

  8. Chemotherapy-Related Side Effects in Childhood Acute Lymphoblastic Leukemia in Indonesia: Parental Perceptions

    NARCIS (Netherlands)

    Sitaresmi, M.N.; Mostert, S.; Purwanto, I.; Gundy, C.; Sutaryo, N.N.; Veerman, A.J.P.

    2009-01-01

    Noncompliance with prescribed medication has been associated with increased chance of relapse and poor outcome. Side effects may be an important cause of noncompliance. Fifty-one parents of children with acute lymphoblastic leukemia in a tertiary care hospital in Indonesia were interviewed about the

  9. The effect of chronic ammonia exposure on acute phase proteins, immunoglobulin and cytokines in laying hens

    Science.gov (United States)

    Ammonia is a potential health hazard to both humans and animals, causing systemic low-grade inflammation based on its levels and durations. The objective of this study was to examine the effect of 45 weeks of exposure to 30 ppm NH3 on the concentrations of acute phase proteins, immunoglobulins and c...

  10. Acute psychomotor effects of MDMA and ethanol (co-) administration over time in healthy volunteers

    NARCIS (Netherlands)

    Dumont, G J H; Schoemaker, R C; Touw, D J; Sweep, F C G J; Buitelaar, J K; van Gerven, J M A; Verkes, R J

    2010-01-01

    In Western societies, a considerable percentage of young people use 3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy'). The use of alcohol (ethanol) in combination with ecstasy is common. The aim of the present study was to assess the acute psychomotor and subjective effects of (co-) administrati

  11. Chemotherapy-Related Side Effects in Childhood Acute Lymphoblastic Leukemia in Indonesia: Parental Perceptions

    NARCIS (Netherlands)

    Sitaresmi, M.N.; Mostert, S.; Purwanto, I.; Gundy, C.; Sutaryo, N.N.; Veerman, A.J.P.

    2009-01-01

    Noncompliance with prescribed medication has been associated with increased chance of relapse and poor outcome. Side effects may be an important cause of noncompliance. Fifty-one parents of children with acute lymphoblastic leukemia in a tertiary care hospital in Indonesia were interviewed about the

  12. State/Trait Anxiety and Anxiolytic Effects of Acute Physical Exercises

    Science.gov (United States)

    Guszkowska, Monika

    2009-01-01

    Study aim: To determine anxiolytic effects of acute physical exertions in relation to the initial anxiety state and trait in women. Material and methods: A group of 163 women aged 16-56 years, attending fitness clubs in Warsaw, participated in the study. They selected a single exercise to perform--strength, aerobic or mixed, lasting 30 to over 60…

  13. Timing of the effect of acetaminophen on body temperature in patients with acute ischemic stroke

    NARCIS (Netherlands)

    Dippel, DWJ; van Breda, EJ; van der Worp, H. Bart; van Gemert, HMA; Kappelle, LJ; Algra, A; Koudstaal, PJ

    2003-01-01

    The authors assessed the time of onset of the hypothermic effect of acetaminophen in 102 patients with acute ischemic stroke. These patients were randomized to treatment with either 1000 mg of acetaminophen (n=52) or placebo (n=50), given six times daily. Treatment with high-dose acetaminophen resul

  14. Effects of energy restriction on acute adrenoceptor and metabolic responses to exercise in obese subjects

    NARCIS (Netherlands)

    Kempen, K.P.G.; Saris, W.H.M.; Senden, J.M.G.; Menheere, P.P.C.A.; Blaak, E.E.; van Baak, M.A.

    1994-01-01

    Effects of energy restriction on acute adrenoceptor and metabolic responses to exercise in obese subjects. Kempen KP, Saris WH, Senden JM, Menheere PP, Blaak EE, van Baak MA. Department of Human Biology, University of Limburg, Maastricht, The Netherlands. This study was intended to investigate the e

  15. Acute and long-term cardiovascular effects of coffee: implications for coronary heart disease.

    NARCIS (Netherlands)

    Riksen, N.P.; Rongen, G.A.P.J.M.; Smits, P.

    2009-01-01

    Despite decades of research, the question as to whether coffee intake increases the risk of coronary heart disease (CHD) remains controversial. In the current paper, we discuss the acute and long-term cardiovascular effects of coffee, and its major constituents, which could underlie such an

  16. Acute Alcohol Effects on Repetition Priming and Word Recognition Memory with Equivalent Memory Cues

    Science.gov (United States)

    Ray, Suchismita; Bates, Marsha E.

    2006-01-01

    Acute alcohol intoxication effects on memory were examined using a recollection-based word recognition memory task and a repetition priming task of memory for the same information without explicit reference to the study context. Memory cues were equivalent across tasks; encoding was manipulated by varying the frequency of occurrence (FOC) of words…

  17. Acute and phase-shifting effects of ocular and extraocular light in human circadian physiology

    NARCIS (Netherlands)

    Ruger, M; Gordijn, MCM; Beersma, DGM; de Vries, B; Daan, S

    2003-01-01

    Light can influence physiology and performance of humans in two distinct ways. It can acutely change the level of physiological and behavioral parameters, and it can induce a phase shift in the circadian oscillators underlying variations in these levels. Until recently, both effects were thought to

  18. Hemodynamic effects of partial liquid ventilation with perfluorocarbon in acute lung injury

    NARCIS (Netherlands)

    R.J.M. Houmes (Robert Jan); S.J.C. Verbrugge (Serge); E. Hendrik (Edwin); B.F. Lachmann (Burkhard)

    1995-01-01

    textabstractObjective: To assess the effect of partial liquid ventilation with perfluorocarbons on hemodynamics and gas exchange in large pigs with induced acute lung injury (ALI). Design: Randomized, prospective, double-control, experimental study. Setting: Experimental intensive care unit of a uni

  19. Venous thromboembolism in adults treated for acute lymphoblastic leukaemia: Effect of fresh frozen plasma supplementation

    NARCIS (Netherlands)

    I. Lauw (Ivoune); B. van der Holt (Bronno); S. Middeldorp (Saskia); J.C.M. Meijers; J.J. Cornelissen (Jan); B.J. Biemond (Bart)

    2013-01-01

    textabstractTreatment of acute lymphoblastic leukaemia (ALL) is frequently complicated by venous thromboembolism (VTE). The efficacy and optimal approach of VTE prevention are unclear, particularly in adult patients. We assessed the effect of thromboprophylaxis on symptomatic VTE incidence in cycle

  20. Effects of energy restriction on acute adrenoceptor and metabolic responses to exercise in obese subjects

    NARCIS (Netherlands)

    Kempen, K.P.G.; Saris, W.H.M.; Senden, J.M.G.; Menheere, P.P.C.A.; Blaak, E.E.; van Baak, M.A.

    1994-01-01

    Effects of energy restriction on acute adrenoceptor and metabolic responses to exercise in obese subjects. Kempen KP, Saris WH, Senden JM, Menheere PP, Blaak EE, van Baak MA. Department of Human Biology, University of Limburg, Maastricht, The Netherlands. This study was intended to investigate the e

  1. The Effects of the Acute Hypoxia to the Fundamental Frequency of the Speech Signal

    Directory of Open Access Journals (Sweden)

    MILIVOJEVIC, Z. N.

    2012-05-01

    Full Text Available When people that live at the small altitudes (up to 400 m above the sea level climb on the mountain, they are exposed to the effects of an acute hypoxia. As a consequence, theirs oxygen concentration decreases in the tissue. This paper presents the analysis of the acute hypoxia effects to the speech signal at the altitudes up to 2600 m above the sea level. For the experiment, the articulation of vowels (A, E, I, O, U from the test group of persons was recorded at different altitudes, which creates the speech signal database. The speech signal from database is processed by the original algorithm. As the results, the fundamental frequency and the energy of dissonant intervals of speech signal are obtained. Furthermore, the acute hypoxia effect to the energy distribution in the dissonant intervals of the speech signal is analyzed. At the end, the comparative analysis of the acute hypoxia effects shows that the level of the hypoxia can be determined by the change of the fundamental frequency and the energy of the dissonant intervals of speech signal. Hence, it is possible to bring conclusions about the degree of hypoxia, which in many situations can be of importance for avoiding catastrophic consequences.

  2. Acute cognitive effects of MRI related magnetic fields: the role of vestibular sensitivity.

    NARCIS (Netherlands)

    van Nierop, Lotte; Slottje, Pauline; van Zandvoort, Matine; Kingma, Herman; Kromhout, Hans

    2014-01-01

    OBJECTIVES: Movement in the magnetic fields around MRI systems showed acute negative effects on concentration, memory, visuo-spatial orientation and postural body sway. A crucial role of the vestibular system has been hypothesised. We aimed to gain more insight whether subjects with a relatively (un

  3. Effect of acute metabolic acid/base shifts on the human airway calibre.

    NARCIS (Netherlands)

    Brijker, F.; Elshout, F.J.J. van den; Heijdra, Y.F.; Bosch, F.H.; Folgering, H.T.M.

    2001-01-01

    Acute metabolic alkalosis (NaHCO(3)), acidosis (NH(4)Cl), and placebo (NaCl) were induced in 15 healthy volunteers (12 females, median age 34 (range 24-56) years) in a double blind, placebo controlled study to evaluate the presence of the effects on airway calibre. Acid-base shifts were determined b

  4. Acute and chronic effects of dinner with alcoholic beverages on nitric oxide metabolites in healthy men

    NARCIS (Netherlands)

    Sierksma, A.; Gaag, M.S. van der; Grobbee, D.E.; Hendriks, H.F.J.

    2003-01-01

    1. The present study investigated the acute and chronic effect of dinner with alcoholic beverages on serum nitric oxide (NO) metabolites, namely nitrate and nitrite (NOx), in 11 healthy, non-smoking middle-aged men. 2. In a randomized, diet-controlled, cross-over trial, subjects consumed dinner with

  5. Effect of fluvastatin on ischaemia following acute myocardial infarction : a randomized trial

    NARCIS (Netherlands)

    Liem, AH; van Boven, AJ; Veeger, NJGM; Withagen, AJ; de Medina, RMR; Tijssen, JGP; van Veldhuisen, DJ

    2002-01-01

    Alms Residual ischaemia following acute myocardial infarction (AMI) is related to an adverse outcome, although the effect of early initiation of statin therapy is unknown. Methods A randomized, placebo-controlled, double-blind, parallel study was performed, which compared fluvastatin 80 mg daily

  6. Neurobehavorial effects of acute exposure to four solvents: meta-abalyses

    Science.gov (United States)

    Meta-and re-analyses of the available data for the neurobehavioral effects of acute inhalation exposure to toluene were reported by Benignus et al. (2007). The present study was designed to test the generality of the toluene results in as many other solvents as possible by furthe...

  7. Acute and long-term cardiovascular effects of coffee: implications for coronary heart disease.

    NARCIS (Netherlands)

    Riksen, N.P.; Rongen, G.A.P.J.M.; Smits, P.

    2009-01-01

    Despite decades of research, the question as to whether coffee intake increases the risk of coronary heart disease (CHD) remains controversial. In the current paper, we discuss the acute and long-term cardiovascular effects of coffee, and its major constituents, which could underlie such an associat

  8. Acute cortisol effects on immediate free recall and recognition of nouns depend on stimulus valence

    NARCIS (Netherlands)

    Tops, M.; van der Pompe, G.; Baas, D; Mulder, L.J.M.; Den Boer, J.A.; Meijman, T.F.; Korf, J

    The present study investigated the acute effects of cortisol administration in normal healthy male volunteers on immediate free recall and recognition of pleasant, unpleasant, and neutral nouns using a between-subjects double-blind design. Two hours after cortisol (10 mg) or placebo administration,

  9. [Renoprotective effects of statins under the conditions of acute renal failure, caused by rhabdomyolysis].

    Science.gov (United States)

    Zamorskiĭ, I I; Zeleniuk, V G

    2014-01-01

    The experiment on white rats was targeted at the examination of influence of statins (atorvastatin, lovastatin, simvastatin) under the conditions of acute renal failure, caused by rhabdomyolysis. Renoprotective effects of statins were demonstrated by reduction of hyperazotemia and proteinuria and improvement of renal excretory function, which correlated with antioxidant properties of drugs.

  10. Cost-effectiveness Analysis of Rivaroxaban in the Secondary Prevention of Acute Coronary Syndromes in Sweden

    NARCIS (Netherlands)

    Begum, N.; Stephens, S.; Schoeman, O.; Fraschke, A.; Kirsch, B.; Briere, J.B.; Verheugt, F.W.A.; Hout, B.A. van

    2015-01-01

    BACKGROUND: Worldwide, coronary heart disease accounts for 7 million deaths each year. In Sweden, acute coronary syndrome (ACS) is a leading cause of hospitalization and is responsible for 1 in 4 deaths. OBJECTIVE: The aim of this analysis was to assess the cost-effectiveness of rivaroxaban 2.5 mg t

  11. Hepatoprotective Effect of Opuntia robusta and Opuntia streptacantha Fruits against Acetaminophen-Induced Acute Liver Damage

    NARCIS (Netherlands)

    Gonzalez Ponce, Herson Antonio; Consolacion Martinez-Saldana, Maria; Rosa Rincon-Sanchez, Ana; Teresa Sumaya-Martinez, Maria; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han; Jaramillo-Juarez, Fernando

    2016-01-01

    Acetaminophen (APAP)-induced acute liver failure (ALF) is a serious health problem in developed countries. N-acetyl-L-cysteine (NAC), the current therapy for APAP-induced ALF, is not always effective, and liver transplantation is often needed. Opuntia spp. fruits are an important source of nutrients

  12. Hepatoprotective Effect of Opuntia robusta and Opuntia streptacantha Fruits against Acetaminophen-Induced Acute Liver Damage

    NARCIS (Netherlands)

    Antonio Gonzalez-Ponce, Herson; Consolacion Martinez-Saldana, Maria; Rosa Rincon-Sanchez, Ana; Teresa Sumaya-Martinez, Maria; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han; Jaramillo-Juarez, Fernando

    2016-01-01

    Acetaminophen (APAP)-induced acute liver failure (ALF) is a serious health problem in developed countries. N-acetyl-L-cysteine (NAC), the current therapy for APAP-induced ALF, is not always effective, and liver transplantation is often needed. Opuntia spp. fruits are an important source of nutrients

  13. Late cardiac effects of anthracycline containing therapy for childhood acute lymphoblastic leukemia

    DEFF Research Database (Denmark)

    Rathe, Mathias; Carlsen, Niels L T; Oxhøj, Henrik

    2007-01-01

    At present about 80% of children with acute lymphoblastic leukemia (ALL) will be cured following treatment with multi-drug chemotherapy. A major concern for this growing number of survivors is the risk of late effects of treatment. The aim of this study was to determine whether signs...

  14. Nephroprotective effect of ethanolic extract of abutilon indicum root in gentamicin induced acute renal failure

    Directory of Open Access Journals (Sweden)

    Jacob Jesurun RS

    2016-06-01

    Conclusions: The ethanolic extract of abutilon indicum root has nephron protective effect in gentamicin induced acute renal failure. Nephro protective action in this study could be due to the antioxidant and other phytochemical of abutilon indicum root. [Int J Basic Clin Pharmacol 2016; 5(3.000: 841-845

  15. THE EFFECT OF ANISODAMINE ON CEREBRAL RESUSCITATION OF RATS IN ACUTE CEREBRAL ISCHEMIA FROM CARDIAC ARREST

    Institute of Scientific and Technical Information of China (English)

    彭新琦; 曹苏谊; 可君

    1995-01-01

    In order to investigate the mechanisms of acute cerebral ischemia,and to look for effective drugs on cerebral resuscitation,we made a model of acute complete global brain ischemia,reperfusion and resuscita-tion on rats according to Garavilla's method.Our results showed that the event of cerebral ischemia and reperfusion injury could result in the in-crease of total brain calcium content,and anisodamine has the same reducing brain calcium contents as dil-tiazem's,while improving neurological outcome and alleviating injury to neurons.

  16. The effect of sand storms on acute asthma in Riyadh, Saudi Arabia.

    Science.gov (United States)

    Alangari, Abdullah A; Riaz, Muhammad; Mahjoub, Mohamed Osman; Malhis, Nidal; Al-Tamimi, Saleh; Al-Modaihsh, Abdullah

    2015-01-01

    Major sand storms are frequent in the Middle East. This study aims to investigate the role of air particulate matter (PM) level in acute asthma in children in Riyadh, Saudi Arabia. An aerosol spectrometer was used to evaluate PM 1000 μg/m(3), representing major sand storms, plus the following 5 days and other days with PM10storms, even major ones, had no significant impact on acute asthma exacerbations in children in Riyadh, Saudi Arabia. The very high levels of PM, however, deserve further studying especially of their long-term effects.

  17. [Study of long-lasting effects of acute prenatal stress induced forced swimming].

    Science.gov (United States)

    Volodina, M A; Sebentsova, E A; Levitskaia, N G; Kamenskiĭ, A A

    2010-01-01

    The aim of the present work was to assess long-lasting effects of acute prenatal stress in white rats. Forced swimming in cold water on the 7th or the 14th gestational day was used as a prenatal stressor. The prenatal stress led to low birthweight of offspring and their delayed growth rate during the second month of life. Prenatally stressed animals showed abnormalities in exploratory behavior and anxiety, increased emotionality and impaired learning capabilities at the age of 1-2 month. Consequently, acute stress on the 7th and at the 14th day of pregnancy induced long-lasting negative behavioral changes in offspring of stressed white rats.

  18. EFFECTS OF GLUTAMATE ON SODIUM CHANNEL IN ACUTELY DISSOCIATED HIPPOCAMPAL CA1 PYRAMIDAL NEURONS OF RATS

    Institute of Scientific and Technical Information of China (English)

    高宾丽; 伍国锋; 杨艳; 刘智飞; 曾晓荣

    2011-01-01

    Objective To observe the effects of glutamate on sodium channel in acutely dissociated hippocampal CA1 pyramidal neurons of rats.Methods Voltage-dependent sodium currents (INa) in acutely dissociated hippocampal CA1 pyramidal neurons of neonate rats were recorded by whole-cell patchclamp of the brain slice technique when a series of doses of glutamate (100-1000μmol/L) were applied.Results Different concentrations of glutamate could inhibit INa,and higher concentration of glutamate affected greater inhibitio...

  19. Acute exposure to silica nanoparticles aggravate airway inflammation: different effects according to surface characteristics

    OpenAIRE

    Park, Hye Jung; Sohn, Jung-Ho; Kim, Yoon-Ju; Park, Yoon Hee; Han, Heejae; Park, Kyung Hee; Lee, Kangtaek; Choi, Hoon; Um, Kiju; Choi,In-Hong; Park, Jung-Won; Lee, Jae-Hyun

    2015-01-01

    Silica nanoparticles (SNPs) are widely used in many scientific and industrial fields despite the lack of proper evaluation of their potential toxicity. This study examined the effects of acute exposure to SNPs, either alone or in conjunction with ovalbumin (OVA), by studying the respiratory systems in exposed mouse models. Three types of SNPs were used: spherical SNPs (S-SNPs), mesoporous SNPs (M-SNPs), and PEGylated SNPs (P-SNPs). In the acute SNP exposure model performed, 6-week-old BALB/c ...

  20. Acute effects of alcohol on feedback processing and outcome evaluation during risky decision-making: an ERP study

    NARCIS (Netherlands)

    A.S. Euser (Anja); C.S. Meel (Catharine); M. Snelleman (Michelle); I.H.A. Franken (Ingmar)

    2011-01-01

    textabstractRationale: Although risky decision-making is one of the hallmarks of alcohol use disorders, relatively little is known about the acute psychopharmacological effects of alcohol on decision-making processes. Objective: The present study investigated the acute effects of alcohol on neural m

  1. Crosstalk between nitrite, myoglobin and reactive oxygen species to regulate vasodilation under hypoxia.

    Science.gov (United States)

    Totzeck, Matthias; Hendgen-Cotta, Ulrike B; Kelm, Malte; Rassaf, Tienush

    2014-01-01

    The systemic response to decreasing oxygen levels is hypoxic vasodilation. While this mechanism has been known for more than a century, the underlying cellular events have remained incompletely understood. Nitrite signaling is critically involved in vessel relaxation under hypoxia. This can be attributed to the presence of myoglobin in the vessel wall together with other potential nitrite reductases, which generate nitric oxide, one of the most potent vasodilatory signaling molecules. Questions remain relating to the precise concentration of nitrite and the exact dose-response relations between nitrite and myoglobin under hypoxia. It is furthermore unclear whether regulatory mechanisms exist which balance this interaction. Nitrite tissue levels were similar across all species investigated. We then investigated the exact fractional myoglobin desaturation in an ex vivo approach when gassing with 1% oxygen. Within a short time frame myoglobin desaturated to 58±12%. Given that myoglobin significantly contributes to nitrite reduction under hypoxia, dose-response experiments using physiological to pharmacological nitrite concentrations were conducted. Along all concentrations, abrogation of myoglobin in mice impaired vasodilation. As reactive oxygen species may counteract the vasodilatory response, we used superoxide dismutase and its mimic tempol as well as catalase and ebselen to reduce the levels of reactive oxygen species during hypoxic vasodilation. Incubation of tempol in conjunction with catalase alone and catalase/ebselen increased the vasodilatory response to nitrite. Our study shows that modest hypoxia leads to a significant nitrite-dependent vessel relaxation. This requires the presence of vascular myoglobin for both physiological and pharmacological nitrite levels. Reactive oxygen species, in turn, modulate this vasodilation response.

  2. Nitric oxide-mediated endothlium-dependent vasodilation is impaired with borderline high-LDL cholesterol.

    Science.gov (United States)

    Diehl, Kyle J; Stauffer, Brian L; Greiner, Jared J; Weil, Brian R; DeSouza, Christopher A

    2012-02-01

    The experimental aims of this study were to determine: (1) whether nitric oxide-mediated endothelium-dependent vasodilation is blunted in adult humans with borderline high plasma low-density lipoprotein (LDL)-cholesterol compared with adults with optimal/near optimal LDL-cholesterol levels; and, if so: (2) whether the magnitude of impairment in adults with borderline high LDL-cholesterol is similar to adults with high LDL-cholesterol. Forearm blood flow responses to intraarterial infusions of acetylcholine and sodium nitroprusside were measured in 50 middle-aged (43-64 year) adults: 20 in the optimal/near optimal LDL-cholesterol range (<130 mg/dL); 20 with borderline high LDL-cholesterol (130-159 mg/dL); and 10 with high LDL-cholesterol ($160 mg/dL). In addition, blood flow responses to acetylcholine were determined in the absence and presence of the endothelial nitric oxide synthase inhibitor N(G) -monomethyl-L-arginine (L-NMMA). Vasodilation to acetylcholine was ~20% lower (p < 0.05) in the borderline high (from 4.3 ± 0.2 to 12.3 ± 0.8 mL/100 mL tissue/min) and high (from 4.3 ± 0.3 to 12.0 ± 0.5 mL/100 mL tissue/min) LDL-cholesterol groups compared with the optimal/near optimal (from 4.4 ± 0.2 to 14.5 ± 0.5 mL/100 mL tissue/min) LDL-cholesterol group. L-NMMA significantly reduced (~30%) the vasodilator response to acetylcholine in the optimal/near optimal LDL-cholesterol group but not the borderline high or high LDL-cholesterol groups. Borderline high LDL-cholesterol is associated with impaired nitric oxide-mediated endothelium-dependent vasodilation.

  3. Hypoadiponectinemia predicts impaired endothelium-independent vasodilation in newly diagnosed type 2 diabetic patients: an 8-year prospective study

    Institute of Scientific and Technical Information of China (English)

    LI Hui; XIAO Yang; LIU Hui; CHEN Xiao-yan; LI Xin-ying; TANG Wei-li; LIU Shi-ping; XU Ai-min; ZHOU Zhi-guang

    2011-01-01

    Background Adiponectin is an adipokine with insulin-sensitising and anti-atherogenic properties.The aim of this study was to investigate whether low adiponectin levels predict the impairment of endothelial function in newly diagnosed type 2 diabetic patients in an 8-year prospective study.Methods In the prospective study,we enrolled 133 newly diagnosed type 2 diabetic patients without subclinical atherosclerosis and gave them intensive therapy; the mean treatment period was 8 years.Intensive treatment was a stepwise implementation of behavior modification and pharmacological therapy targeting hyperglycaemia,hypertension,dyslipidaemia and obesity.We measured baseline circulating adiponectin with an enzyme-linked immunosorbent assay,endothelium-dependent and -independent vasodilation by high-resolution vascular ultrasound.At year 8,102 patients were reexamined for endothelium-dependent and -independent vasodilation.Results Sex-adjusted adiponectin level was positively correlated with endothelium-independent vasodilation both at baseline (r=0.150,P=0.043) and at year 8 (r=0.339,P=0.001),whereas no association was found between adiponectin and endothelium-dependent vasodilation.In a stepwise multivariate linear regression model,adiponectin was an independent predictor for impaired endothelium-independent vasodilation at year 8 (P=0.001).Conclusions Plasma adiponectin concentration was associated with endothelium-independent vasodilation and hypoadiponectinemia predicted the impairment of endothelium-independent vasodilation in newly diagnosed type 2 diabetic patients under multifactorial intervention.These data support the causative link of impairment of endothelium-independent vasodilation with hypoadiponectinemia.

  4. Cardiocirculatory pathophysiological mechanisms in severe acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Mónica; García; José; Julián; Calvo

    2010-01-01

    Acute pancreatitis (AP) is a common and potentially lethal acute inflammatory process. Although the majority of patients have a mild episode of AP, 10%-20% develop a severe acute pancreatitis (SAP) and suffer systemic inflammatory response syndrome (SIRS) and/or pancreatic necrosis. The main aim of this article is to review the set of events, f irst localized in the pancreas, that lead to pancreatic inflammation and to the spread to other organs contributing to multiorganic shock. The early pathogenic mechanisms in SAP are not completely understood but both premature activation of enzymes inside the pancreas, related to an impaired cytosolic Ca2+ homeostasis, as well as release of pancreatic enzymes into the bloodstream are considered important events in the onset of pancreatitis disease. Moreover, afferent f ibers within the pancreas release neurotransmitters in response to tissue damage. The vasodilator effects of these neurotransmitters and the activation of pro-inflammatory substances play a crucial role in amplifying the inflammatory response, which leads to systemic manifestation of AP. Damage extension to other organs leads to SIRS, which is usually associated with cardiocirculatoryphysiology impairment and a hypotensive state. Hypotension is a risk factor for death and is associated with a signif icant hyporesponsiveness to vasoconstrictors. This indicates that stabilization of the patient, once this pathological situation has been established, would be a very diff icult task. Therefore, it seems particularly necessary to understand the pathological mechanisms involved in the f irst phases of AP to avoid damage beyond the pancreas. Moreover, efforts must also be directed to identify those patients who are at risk of developing SAP.

  5. The effect of acute exercise on collagen turnover in human tendons

    DEFF Research Database (Denmark)

    Mørch, Lina Steinrud; Pingel, Jessica; Boesen, Mikael;

    2013-01-01

    Mechanical loading of human tendon stimulates collagen synthesis, but the relationship between acute loading responses and training status of the tendon is not clear. We tested the effect of prolonged load deprivation on the acute loading-induced collagen turnover in human tendons, by applying...... and compared to values obtained by 72-h post-exercise. Power Doppler was used to monitor alterations in intratendinous blood flow velocity of the Achilles tendon and MRI used to quantitate changes in tendon cross-section area. Acute loading resulted in an increased collagen synthesis 72 h after the run in both...... the contra-lateral leg was used habitually. Following the procedure both Achilles tendons and calf muscles were loaded with the same absolute load during a 1-h treadmill run. Tissue collagen turnover was measured by microdialysis performed post-immobilization but pre-exercise around both Achilles tendons...

  6. Substantial effect of acute hydration on blood pressure in patients with autonomic failure

    DEFF Research Database (Denmark)

    Mehlsen, J; Boesen, F

    1987-01-01

    The effect of acute hydration on arterial blood pressure levels was investigated in ten patients with severe postural hypotension due to autonomic failure. Blood pressure and heart rate were determined in the supine and 60-degree head-up tilted position. Plasma volume and left ventricular ejection...... fraction were measured in the supine position. Measurements were repeated after rapid infusion of 11 of isotonic saline. Acute hydration resulted in increased supine mean blood pressure levels (P less than 0.01) despite normal plasma volumes in all patients. The postural reductions in mean blood pressure...... were reduced from 40 mmHg before to 20 mmHg after saline (median values, P less than 0.01). The results indicate that normal plasma volumes do not ensure optimal circulatory status in patients with autonomic failure. Acute hydration with isotonic saline may be used for immediate corrections of blood...

  7. [Effect of somatostatin on the hemodynamic changes induced by acute experimental pancreatitis in the conscious rat].

    Science.gov (United States)

    Ais, G; Novo, C; Ortega, M; González, A; Jiménez, I; López, J; Romeo, J M

    1994-03-01

    The aim of this study was to determine the hemodynamic effect of somatostatin, either prophylactically or therapeutically, in shock caused by acute necrohemorragic pancreatitis in conscious rats. For this purpose, radioactive microspheres were used in 3 groups (control pancreatitis, therapeutic somatostatin and prophylactic somatostatin), performing a basal and final hemodynamic study. In the control group, acute necrohemorragic pancreatitis resulted in overwhelming shock with decrease of 55% in cardiac output, 58% in renal blood flow, increase in total peripheral resistances of 342%, and death after 70 min. Therapeutic somatostatin decreased cardiac output by 42%, renal blood flow by 47%, and increased total peripheral resistances by 153%. Prophylactic somatostatin decreased cardiac output by 24%, and renal blooded flow by 28%; it increased peripheral resistances by 146%, and improved survival up to 97 min. In conclusion, therapeutic somatostatin, and particularly prophylactic somatostatin, improved hemodynamic shock after acute necrohemorragic pancreatitis in conscious rats.

  8. The effect of inhaled nitric oxide in acute respiratory distress syndrome in children and adults

    DEFF Research Database (Denmark)

    Karam, O; Gebistorf, F; Wetterslev, J

    2017-01-01

    Acute respiratory distress syndrome is associated with high mortality and morbidity. Inhaled nitric oxide has been used to improve oxygenation but its role remains controversial. Our primary objective in this systematic review was to examine the effects of inhaled nitric oxide administration...... on mortality in adults and children with acute respiratory distress syndrome. We included all randomised, controlled trials, irrespective of date of publication, blinding status, outcomes reported or language. Our primary outcome measure was all-cause mortality. We performed several subgroup and sensitivity......% CI) 1.59 (1.17-2.16)) with inhaled nitric oxide. In conclusion, there is insufficient evidence to support inhaled nitric oxide in any category of critically ill patients with acute respiratory distress syndrome despite a transient improvement in oxygenation, since mortality is not reduced and it may...

  9. An effective system to measure and report quality indicators in acute medical units.

    Science.gov (United States)

    Atkinson, J; Barton, L; Harrison, A; Roper, N

    2012-01-01

    The Society for Acute Medicine has developed a number of clinical quality indicators by which all UK Acute Medicine Units can bench mark their activity. These will help to ensure high quality care for patients, inform the continuing development of acute medical services and demonstrate the positive impact of this new specialty. Prospective collection of these data may be a challenge for many busy units. This paper describes a local solution developed in house in a North East hospital. It demonstrates how the data collected can be analysed to assess the effect of changes in consultant presence on the unit and also time taken for patients to be seen by a doctor. The limitations of the system and potential for future development are considered.

  10. Oscillatory dynamics of vasoconstriction and vasodilation identified by time-localized phase coherence

    Science.gov (United States)

    Sheppard, L. W.; Vuksanović, V.; McClintock, P. V. E.; Stefanovska, A.

    2011-06-01

    We apply wavelet-based time-localized phase coherence to investigate the relationship between blood flow and skin temperature, and between blood flow and instantaneous heart rate (IHR), during vasoconstriction and vasodilation provoked by local cooling or heating of the skin. A temperature-controlled metal plate (≈10 cm2) placed on the volar side of the left arm was used to provide the heating and cooling. Beneath the plate, the blood flow was measured by laser Doppler flowmetry and the adjacent skin temperature by a thermistor. Two 1 h datasets were collected from each of the ten subjects. In each case a 30 min basal recording was followed by a step change in plate temperature, to either 24 °C or 42 °C. The IHR was derived from simultaneously recorded ECG. We confirm the changes in the energy and frequency of blood flow oscillations during cooling and heating reported earlier. That is, during cooling, there was a significant decrease in the average frequency of myogenic blood flow oscillations (p vasodilation, except in the myogenic interval. Weak phase coherence between temperature and blood flow was observed for unperturbed skin, but it increased in all frequency intervals as a result of heating. It was not significantly affected by cooling. We also show that significant (p vasodilation and vasoconstriction, in response to temperature change, are oscillatory in nature and are independent of central sources of variability.

  11. Impaired endothelium independent vasodilation in the cutaneous microvasculature of young obese adults.

    Science.gov (United States)

    Patik, Jordan C; Christmas, Kevin M; Hurr, Chansol; Brothers, R Matthew

    2016-03-01

    Microvascular dysfunction contributes to the development of cardiovascular and metabolic disease. This study tested the hypothesis that young obese (BMI>30 kg m(-2)), otherwise healthy, adults (N=15) have impaired microvascular function relative to age and sex matched, lean (BMIvasodilator methacholine (MCh) and the other for the endothelium-independent vasodilator sodium nitroprusside (SNP). Local temperature at each site was clamped at 33 °C and cutaneous blood flow was indexed by laser Doppler flowmetry (LDF). LDF was recorded while 7 doses of each drug (MCh: 10(-6)-1M; SNP: 5 × 10(-8)-5 × 10(-2)M) were infused at a rate of 2 μl/min for 8 min per dose. Both sites finished with heating to 43 °C and 5 × 10(-2)M SNP to achieve site specific maximal vasodilation. Mean arterial blood pressure (MAP) was assessed in the last minute of each dose and was used for subsequent calculation of cutaneous vascular conductance (CVC; LDF/MAP) and responses were normalized to each individual site's maximal response (%CVCmax). Group four-parameter dose response curves were compared with an extra sum of squares F-test. SNP EC50 was greater in obese relative to lean (-2.931 ± 0.10 vs -3.746 ± 0.18 Log[SNP]M, P0.05). These results suggest attenuated endothelium-independent response to nitric oxide while endothelium-dependent vasodilation function is maintained.

  12. Mechanisms of decompensation and organ failure in cirrhosis: From peripheral arterial vasodilation to systemic inflammation hypothesis.

    Science.gov (United States)

    Bernardi, Mauro; Moreau, Richard; Angeli, Paolo; Schnabl, Bernd; Arroyo, Vicente

    2015-11-01

    The peripheral arterial vasodilation hypothesis has been most influential in the field of cirrhosis and its complications. It has given rise to hundreds of pathophysiological studies in experimental and human cirrhosis and is the theoretical basis of life-saving treatments. It is undisputed that splanchnic arterial vasodilation contributes to portal hypertension and is the basis for manifestations such as ascites and hepatorenal syndrome, but the body of research generated by the hypothesis has revealed gaps in the original pathophysiological interpretation of these complications. The expansion of our knowledge on the mechanisms regulating vascular tone, inflammation and the host-microbiota interaction require a broader approach to advanced cirrhosis encompassing the whole spectrum of its manifestations. Indeed, multiorgan dysfunction and failure likel