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Sample records for rabbit renal afferent

  1. Rapid inhibition of vasoconstriction in renal afferent arterioles by aldosterone.

    Science.gov (United States)

    Uhrenholt, T R; Schjerning, J; Hansen, P B; Nørregaard, R; Jensen, B L; Sorensen, G L; Skøtt, O

    2003-12-12

    Aldosterone has been suggested to elicit vessel contraction via a nongenomic mechanism. We tested this proposal in microdissected, perfused rabbit renal afferent arterioles. Aldosterone had no effect on internal diameter in concentrations from 10(-10) to 10(-5) mol/L, but aldosterone abolished the ability of 100 mmol/L KCl to induce vascular contraction. The inhibitory effect of aldosterone was observed from 1 pmol/L. The inhibitory effect was significant after 5 minutes and maximal after 20 minutes and was fully reversible. Actinomycin D (10(-6) mol/L) prolonged the effect of aldosterone. The effect was abolished by the mineralocorticoid receptor antagonist spironolactone (10(-7) mol/L) but not by the glucocorticoid receptor antagonist mifepristone (10(-6) mol/L). The K+-mediated increase of intracellular calcium concentration in afferent arterioles was not affected by aldosterone. Mineralocorticoid receptor was detected by reverse transcription-polymerase chain reaction and immunohistochemistry in rat renal vasculature and rabbit endothelial cells. Inhibition of phosphatidylinositol (PI)-3 kinase with LY 294002 (3x10(-6) mol/L) restored sensitivity to K+ in the presence of aldosterone, and afferent arterioles were immunopositive for PI-3 kinase subunit p110alpha. Inhibition of NO formation by L-NAME (10(-4) mol/L) or inhibition of soluble guanylyl cyclase with 1H-(1,2,4)Oxadiazolo[4,3-a]quinoxaline-1-one restored K+-induced vasoreactivity in the presence of aldosterone. Similar to aldosterone, the NO donor sodium nitroprusside inhibited K+-induced vascular contraction. Geldanamycin (10(-6) mol/L), an inhibitor of heat shock protein 90, abolished aldosterone-induced vasorelaxation. We conclude that aldosterone inhibits depolarization-induced vasoconstriction in renal afferent arterioles by a rapid nongenomic mechanism that is initiated by mineralocorticoid receptor activation and involves PI-3 kinase, protein kinase B, and heat shock protein 90-mediated

  2. Resting Afferent Renal Nerve Discharge and Renal Inflammation: Elucidating the Role of Afferent and Efferent Renal Nerves in Deoxycorticosterone Acetate Salt Hypertension.

    Science.gov (United States)

    Banek, Christopher T; Knuepfer, Mark M; Foss, Jason D; Fiege, Jessica K; Asirvatham-Jeyaraj, Ninitha; Van Helden, Dusty; Shimizu, Yoji; Osborn, John W

    2016-12-01

    Renal sympathetic denervation (RDNx) has emerged as a novel therapy for hypertension; however, the therapeutic mechanisms remain unclear. Efferent renal sympathetic nerve activity has recently been implicated in trafficking renal inflammatory immune cells and inflammatory chemokine and cytokine release. Several of these inflammatory mediators are known to activate or sensitize afferent nerves. This study aimed to elucidate the roles of efferent and afferent renal nerves in renal inflammation and hypertension in the deoxycorticosterone acetate (DOCA) salt rat model. Uninephrectomized male Sprague-Dawley rats (275-300 g) underwent afferent-selective RDNx (n=10), total RDNx (n=10), or Sham (n=10) and were instrumented for the measurement of mean arterial pressure and heart rate by radiotelemetry. Rats received 100-mg DOCA (SC) and 0.9% saline for 21 days. Resting afferent renal nerve activity in DOCA and vehicle animals was measured after the treatment protocol. Renal tissue inflammation was assessed by renal cytokine content and T-cell infiltration and activation. Resting afferent renal nerve activity, expressed as a percent of peak afferent nerve activity, was substantially increased in DOCA than in vehicle (35.8±4.4 versus 15.3±2.8 %Amax). The DOCA-Sham hypertension (132±12 mm Hg) was attenuated by ≈50% in both total RDNx (111±8 mm Hg) and afferent-selective RDNx (117±5 mm Hg) groups. Renal inflammation induced by DOCA salt was attenuated by total RDNx and unaffected by afferent-selective RDNx. These data suggest that afferent renal nerve activity may mediate the hypertensive response to DOCA salt, but inflammation may be mediated primarily by efferent renal sympathetic nerve activity. Also, resting afferent renal nerve activity is elevated in DOCA salt rats, which may highlight a crucial neural mechanism in the development and maintenance of hypertension. © 2016 American Heart Association, Inc.

  3. The role of the renal afferent and efferent nerve fibers in heart failure.

    Science.gov (United States)

    Booth, Lindsea C; May, Clive N; Yao, Song T

    2015-01-01

    Renal nerves contain afferent, sensory and efferent, sympathetic nerve fibers. In heart failure (HF) there is an increase in renal sympathetic nerve activity (RSNA), which can lead to renal vasoconstriction, increased renin release and sodium retention. These changes are thought to contribute to renal dysfunction, which is predictive of poor outcome in patients with HF. In contrast, the role of the renal afferent nerves remains largely unexplored in HF. This is somewhat surprising as there are multiple triggers in HF that have the potential to increase afferent nerve activity, including increased venous pressure and reduced kidney perfusion. Some of the few studies investigating renal afferents in HF have suggested that at least the sympatho-inhibitory reno-renal reflex is blunted. In experimentally induced HF, renal denervation, both surgical and catheter-based, has been associated with some improvements in renal and cardiac function. It remains unknown whether the effects are due to removal of the efferent renal nerve fibers or afferent renal nerve fibers, or a combination of both. Here, we review the effects of HF on renal efferent and afferent nerve function and critically assess the latest evidence supporting renal denervation as a potential treatment in HF.

  4. Impaired excitability of renal afferent innervation after exposure to the inflammatory chemokine CXCL1.

    Science.gov (United States)

    Ditting, Tilmann; Freisinger, Wolfgang; Rodionova, Kristina; Schatz, Johannes; Lale, Nena; Heinlein, Sonja; Linz, Peter; Ott, Christian; Schmieder, Roland E; Scrogin, Karie E; Veelken, Roland

    2016-03-01

    Recently, we showed that renal afferent neurons exhibit a unique firing pattern, i.e., predominantly sustained firing, upon stimulation. Pathological conditions such as renal inflammation likely alter excitability of renal afferent neurons. Here, we tested whether the proinflammatory chemokine CXCL1 alters the firing pattern of renal afferent neurons. Rat dorsal root ganglion neurons (Th11-L2), retrogradely labeled with dicarbocyanine dye, were incubated with CXCL1 (20 h) or vehicle before patch-clamp recording. The firing pattern of neurons was characterized as tonic, i.e., sustained action potential (AP) firing, or phasic, i.e., renal afferents treated with vehicle, 58.9% exhibited a tonic firing pattern vs. 7.8%, in unlabeled, nonrenal neurons (P renal neurons; hence the occurrence of tonic neurons with sustained firing upon electrical stimulation decreased (35.6 vs. 58.9%, P renal afferents from a predominantly tonic to a more phasic firing pattern, suggesting that CXCL1 reduced the sensitivity of renal afferent units upon stimulation.

  5. Constriction velocities of renal afferent and efferent arterioles of mice are not related to SMB expression.

    Science.gov (United States)

    Patzak, Andreas; Petzhold, Daria; Wronski, Thomas; Martinka, Peter; Babu, Gopal J; Periasamy, Muthu; Haase, Hannelore; Morano, Ingo

    2005-12-01

    Constriction of renal arterioles contributes significantly to the control of perfusion and glomerular filtration. Afferent but not efferent arterioles express smooth muscle myosin heavy chain B (SMB) (with a 5'-insert of seven amino acids). The aim of the present study was to investigate (1) the constriction characteristics of afferent and efferent arterioles under physiologic load and (2) whether expression of SMB may causally contribute to these constriction characteristics. We compared constriction parameters [constriction amplitude, maximal rate of constriction velocity ("dc/dt(max)"), and time to half-maximal constriction (t(1/2)) of in vitro perfused renal afferent and efferent arterioles of wild-type (smb(+/+)] and homozygous SMB knockout [smb(-/-)] mice upon stimulation with angiotensin II (Ang II) (10(-8) mol/L) and potassium chloride (KCl) (100 mmol/L). SMB expression was investigated by double-labeling immunofluorescence. Contraction amplitude and dc/dt(max) of mouse afferent arterioles upon Ang II stimulation were significantly greater compared to efferent arterioles. However, constriction amplitudes, dc/dt(max), and t(1/2) of afferent as well as efferent arterioles upon Ang II stimulation were similar in smb(+/+) and smb(-/-) mice. Constriction amplitudes upon KCl stimulation of afferent arterioles were similar in both smb(+/+) and smb(-/-) mice. Furthermore, KCl-induced dc/dt(max) and t(1/2) of afferent arterioles were similar in both smb(+/+) and smb(-/-) mice. SMB expression could be detected in afferent but not efferent arterioles in smb(+/+) mice. No SMB expression in either arteriole could be observed in smb(-/-) mice. Our results suggest that the presence of different alternatively 5'-spliced smooth muscle-myosin heavy chain (SM-MHC) isoforms does not dominate the different contractile features of physiologically loaded renal afferent or efferent arterioles.

  6. Vasodilatation of afferent arterioles and paradoxical increase of renal vascular resistance by furosemide in mice

    DEFF Research Database (Denmark)

    Oppermann, Mona; Hansen, Pernille B; Castrop, Hayo;

    2007-01-01

    Loop diuretics like furosemide have been shown to cause renal vasodilatation in dogs and humans, an effect thought to result from both a direct vascular dilator effect and from inhibition of tubuloglomerular feedback. In isolated perfused afferent arterioles preconstricted with angiotensin II or N...... that furosemide, despite its direct vasodilator potential in isolated afferent arterioles, causes a marked increase in flow resistance of the vascular bed of the intact mouse kidney. We suggest that generation of angiotensin II and/or a vasoconstrictor prostaglandin combined with compression of peritubular...

  7. Superoxide enhances Ca2+ entry through L-type channels in the renal afferent arteriole.

    Science.gov (United States)

    Vogel, Paul A; Yang, Xi; Moss, Nicholas G; Arendshorst, William J

    2015-08-01

    Reactive oxygen species regulate cardiovascular and renal function in health and disease. Superoxide participates in acute calcium signaling in afferent arterioles and renal vasoconstriction produced by angiotensin II, endothelin, thromboxane, and pressure-induced myogenic tone. Known mechanisms by which superoxide acts include quenching of nitric oxide and increased ADP ribosyl cyclase/ryanodine-mediated calcium mobilization. The effect(s) of superoxide on other calcium signaling pathways in the renal microcirculation is poorly understood. The present experiments examined the acute effect of superoxide generated by paraquat on calcium entry pathways in isolated rat afferent arterioles. The peak increase in cytosolic calcium concentration caused by KCl (40 mmol/L) was 99±14 nmol/L. The response to this membrane depolarization was mediated exclusively by L-type channels because it was abolished by nifedipine but was unaffected by the T-type channel blocker mibefradil. Paraquat increased superoxide production (dihydroethidium fluorescence), tripled the peak response to KCl to 314±68 nmol/L (Psuperoxide and not of hydrogen peroxide. Unaffected by paraquat and superoxide was calcium entry through store-operated calcium channels activated by thapsigargin-induced calcium depletion of sarcoplasmic reticular stores. Also unresponsive to paraquat was ryanodine receptor-mediated calcium-induced calcium release from the sarcoplasmic reticulum. Our results provide new evidence that superoxide enhances calcium entry through L-type channels activated by membrane depolarization in rat cortical afferent arterioles, without affecting calcium entry through store-operated entry or ryanodine receptor-mediated calcium mobilization.

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

    Science.gov (United States)

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

    2002-04-01

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

  9. Vascular reactivity of rabbit isolated renal and femoral resistance arteries in renal wrap hypertension.

    Science.gov (United States)

    Khammy, Makhala M; Angus, James A; Wright, Christine E

    2016-02-15

    In rabbits with cellophane renal wrap hypertension, hindquarter and total vascular resistance changes to pressor and depressor agents are amplified compared to those of normotensive rabbits. The aim of the present study was to evaluate the in vitro pharmacodynamics of hypertensive and normotensive rabbit small artery segments isolated from the renal and hindquarter vascular beds. Using wire myography, the full range (Emax) and sensitivity (EC50) to a range of agonists of segments of renal interlobar (≈ 600 µm i.d.), renal arcuate (≈ 250 µm i.d.) and deep femoral branch (≈ 250 µm i.d.) arteries were assessed under normalised conditions of passive tension. Interlobar arteries from hypertensive rabbits were more sensitive (EC50) than those from normotensive rabbits to noradrenaline (6-fold), methoxamine (3-fold) and angiotensin II (3-fold). Arcuate artery reactivity was largely unaffected by hypertension. Deep femoral arteries from hypertensive rabbits had enhanced sensitivity only to noradrenaline (2-fold) and methoxamine (4-fold). Sensitivity to relaxation by acetylcholine was unaffected by hypertension in all arteries. Deep femoral arteries from hypertensive rabbits were more sensitive to sodium nitroprusside than normotensive counterparts. Adenosine caused little relaxation in renal arteries, but full relaxation in deep femoral arteries, unaltered by hypertension. This study found substantial heterogeneity in the pharmacodynamic profile of vessels isolated from different vascular beds and between arterial segments within the kidney. These profiles were differentially affected by hypertension suggesting that hypertension per se is not a resultant of general vascular dysfunction.

  10. Mechanism of renal effects of intracerebroventricular histamine in rabbits.

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    Kook, Y J; Kim, K K; Yang, D K; Ahn, D S; Choi, B K

    1988-01-01

    Histamine, when given intracerebroventricularly (i.c.v.), has been reported to produce antidiuresis in the rabbit. In this study it was attempted to elucidate the mechanism involved in the effect. Histamine (H), 100 micrograms/kg i.c.v., produced antidiuresis with decreases in renal plasma flow and glomerular filtration rate in urethane-anesthetized rabbits. With larger doses, a tendency towards increased electrolyte excretion was noted in spite of decreased filtration. In the denervated kidney, marked diuresis and natriuresis were observed following i.c.v. H, whereas the contralateral innervated kidney responded with typical antidiuresis. Reserpinized rabbits also responded with marked natriuresis to i.c.v. H. Diphenhydramine (D), 250 micrograms/kg i.c.v., increased urine flow rate, sodium and potassium excretion, along with increase in renal perfusion. With 750 micrograms/kg i.c.v., marked natriuresis was observed in spite of decreased filtration. When H was given after D (250 micrograms/kg) the antidiuresis was completely abolished, and diuresis became more prominent. Cimetidine, 250 micrograms/kg i.c.v., elicited antidiuresis with decreases in renal hemodynamics, the pretreatment with cimetidine did not influence the antidiuresis by H and no natriuresis was noted. The present study suggests that histamine, given i.c.v., influences renal function in dual ways, i.e., antidiuresis by increasing the sympathetic tone to the kidney and diuresis due to some humoral natriuretic factor, the latter becoming apparent only when the former influence has been removed, and further suggests that H1-receptors might be involved in the nerve-mediated antidiuresis, whereas H2-receptors might mediate the humorally induced natriuresis and diuresis.

  11. Effect of stimulation of afferent renal nerves on plasma levels of vasopressin

    Energy Technology Data Exchange (ETDEWEB)

    Caverson, M.M.; Ciriello, J.

    1987-04-01

    Experiments were done in ..cap alpha..-chloralose-anesthetized, paralyzed and artificially ventilated cats with vagus, cervical sympathetic, aortic depressor, and carotid sinus nerves cut bilaterally to investigate the effect of afferent renal nerve (ARN) stimulation on circulating levels of vasopressin (AVP). Electrical stimulation of ARN elicited a pressor response that had two components, a primary (1/sup 0/) component locked in time with the stimulus and a secondary (2/sup 0/) component that had a long onset latency and that outlasted the stimulation period. The 1/sup 0/ and 2/sup 0/ components of the pressor response were largest at stimulation frequencies of 30 and 40 Hz, respectively. Autonomic blockage with hexamethonium bromide and atropine methylbromide abolished the 1/sup 0/ component. Administration of the vasopressin V/sub 1/-vascular receptor antagonist d(CH/sub 2/)/sub 5/ VAVP during autonomic blockade abolished the 2/sup 0/C component. Plasma concentrations of AVP measured by radioimmunoassay increased from control levels of 5.2 +/- 0.9 to 53.6 +/- 18.6 pg/ml during a 5-min period of stimulation of ARN. Plasma AVP levels measured 20-40 min after simulation were not significantly different from control values. These data demonstrate that sensory information originating in the kidney alters the release of vasopressin from the neurohypophysis and suggest that ARN are an important component of the neural circuitry involved in homeostatic mechanisms controlling arterial pressure.

  12. Evaluation of Arterial Impairment after Experimental Gelatin Sponge Embolization in a Rabbit Renal Model

    OpenAIRE

    Oh, Jung Suk; Lee, Hae Giu; Chun, Ho Jong; Choi, Byung Gil; Choi, Yeong Jin

    2015-01-01

    Objective Arterial stenosis is a major obstacle for subsequent interventional procedures. We hypothesized that the stenosis is caused by gelatin sponge embolization and performed an experimental study in a rabbit renal model. Materials and Methods A total of 24 rabbits were embolized with porcine gelatin sponge particles injected into the renal arteries. Four rabbits were sacrificed on 1 day, 4 days, 1 week, 2 weeks, 3 weeks, and 4 weeks after embolization. Microscopic evaluations were perfor...

  13. A comparative study of changes operated by sympathetic nervous system activation on spindle afferent discharge and on tonic vibration reflex in rabbit jaw muscles.

    Science.gov (United States)

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

    1996-03-07

    The effect of sympathetic activation on the spindle afferent response to vibratory stimuli eliciting the tonic vibration reflex in jaw closing muscles was studied in precollicularly decerebrate rabbits. Stimulation of the cervical sympathetic trunk, at frequencies within the physiologic range, consistently induced a decrease in spindle response to muscle vibration, which was often preceded by a transient enhancement. Spindle discharge was usually correlated with the EMG activity in the masseter muscle and the tension reflexly developed by jaw muscles. The changes in spindle response to vibration were superimposed on variations of the basal discharge which exhibited different patterns in the studied units, increases in the firing rate being more frequently observed. These effects were mimicked by close arterial injection of the selective alpha 1-adrenoceptor agonist phenylephrine. Data presented here suggest that sympathetically-induced modifications of the tonic vibration reflex are due to changes exerted on muscle spindle afferent information.

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

    Institute of Scientific and Technical Information of China (English)

    Chen Wang; James G.Whitwam

    2004-01-01

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

  15. Intercellular calcium signaling and nitric oxide feedback during constriction of rabbit renal afferent arterioles

    DEFF Research Database (Denmark)

    Uhrenholt, Torben Rene; Schjerning, J; Vanhoutte, Paul M. G.

    2007-01-01

    Vasoconstriction and increase in the intracellular calcium concentration ([Ca(2+)](i)) of vascular smooth muscle cells may cause an increase of endothelial cell [Ca(2+)](i), which, in turn, augments nitric oxide (NO) production and inhibits smooth muscle cell contraction. This hypothesis was tested...

  16. Intrarenal artery injection of capsaicin activates spontaneous activity of renal afferent nerve fibers%肾动脉内注射辣椒素兴奋肾神经传入纤维的自发活动

    Institute of Scientific and Technical Information of China (English)

    马慧娟; 武宇明; 马会杰; 张丽华; 何瑞荣

    2003-01-01

    The effects of intrarenal artery injection of capsaicin on multi- and single-unit spontaneous discharges of renal afferent nerve fibers were investigated in anesthetized rabbits. The results obtained are as follows: ( 1 ) intrarenal artery injection of capsaicin (20, 40, and 60 nmol/kg) increased the renal afferent nerve activity (ARNA) in a dose-dependent manner with unchanged arterial pressure; (2) pretreatment with ruthenium red (40 mmol/kg), a capsaicin receptor antagonist, completely abolished the effect of capsaicin; and (3) pretreatment with a nitric oxide synthase inhibitor L-NAME ( N6-nitro-L-arginine methylester, 0. 1 mmol/kg), significantly enhanced the ARNA response to capsaicin. The results suggest that intrarenal artery injection of capsaicin can activate ARNA via capsaicin receptors in anesthetized rabbits and that nitric oxide may be involved in regulating the activity of renal sensory nerve fibers as an inhibitory neurotransmitter.%应用记录肾传入神经多单位和单位放电的方法,观察肾动脉内注射辣椒素对麻醉家兔肾神经传入纤维自发放电活动的影响.结果表明:(1)肾动脉内注射辣椒素20、40和60nmol/kg可呈剂量依赖性地兴奋肾传入纤维的活动,而动脉血压不变;(2)静脉内预先应用辣椒素受体阻断剂钌红(40 mmok/kg),可完全阻断辣椒素对肾传入纤维的兴奋作用.(3)静脉内预先注射一氧化氮合酶抑制剂L-NAME(0.1 mmo/kg),能延长并增强肾传入神经对辣椒素的反应.以上结果提示:肾动脉内应用辣椒素可兴奋肾传入纤维的自发放电活动.一氧化氮作为抑制因素参与辣椒素诱导的肾传入神经兴奋.

  17. Differential effects of superoxide and hydrogen peroxide on myogenic signaling, membrane potential, and contractions of mouse renal afferent arterioles.

    Science.gov (United States)

    Li, Lingli; Lai, En Yin; Wellstein, Anton; Welch, William J; Wilcox, Christopher S

    2016-06-01

    Myogenic contraction is the principal component of renal autoregulation that protects the kidney from hypertensive barotrauma. Contractions are initiated by a rise in perfusion pressure that signals a reduction in membrane potential (Em) of vascular smooth muscle cells to activate voltage-operated Ca(2+) channels. Since ROS have variable effects on myogenic tone, we investigated the hypothesis that superoxide (O2 (·-)) and H2O2 differentially impact myogenic contractions. The myogenic contractions of mouse isolated and perfused single afferent arterioles were assessed from changes in luminal diameter with increasing perfusion pressure (40-80 mmHg). O2 (·-), H2O2, and Em were assessed by fluorescence microscopy during incubation with paraquat to increase O2 (·-) or with H2O2 Paraquat enhanced O2 (·-) generation and myogenic contractions (-42 ± 4% vs. -19 ± 4%, P contractions (-10 ± 1% vs. -19 ± 2%, P contractions with paraquat without preventing the reduction in Em Myogenic contractions were independent of the endothelium and largely independent of nitric oxide. We conclude that O2 (·-) and H2O2 activate different signaling pathways in vascular smooth muscle cells linked to discreet membrane channels with opposite effects on Em and voltage-operated Ca(2+) channels and therefore have opposite effects on myogenic contractions.

  18. Chloride regulates afferent arteriolar contraction in response to depolarization

    DEFF Research Database (Denmark)

    Hansen, P B; Jensen, B L; Skott, O

    1998-01-01

    . The results show that K+-induced contraction of smooth muscle cells in the afferent arteriole is highly sensitive to chloride, whereas neurotransmitter release and ensuing contraction is not dependent on chloride. Thus, there are different activation pathways for depolarizing vasoconstrictors......-Renal vascular reactivity is influenced by the level of dietary salt intake. Recent in vitro data suggest that afferent arteriolar contractility is modulated by extracellular chloride. In the present study, we assessed the influence of chloride on K+-induced contraction in isolated perfused rabbit...... afferent arterioles. In 70% of vessels examined, K+-induced contraction was abolished by acute substitution of bath chloride. Consecutive addition of Cl- (30, 60, 80, 100, 110, and 117 mmol/L) restored the sensitivity to K+, and half-maximal response was observed at 82 mmol/L chloride. The calcium channel...

  19. US Features of Experimentally-induced Transient Ischemia and Infarct of Renal Segmental Artery of Rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byung Kwan [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Seung Hyup; Moon, Min Hoan [Samsung Medical Center, Sungkyunkwan University College of Medicine, Seoul (Korea, Republic of)

    2004-09-15

    The goal of this study was to analyze and compare the changes in renal parenchymal morphology and cortical perfusion following transient arterial ischemia and infarct in rabbits using ultrasonography (US). Six rabbits were divided into the ischemia (n=3) and infarct groups (n=3). In the ischemia group, a lower polar branch of the left renal artery was surgically ligated for a duration of 60 minutes and then released, in order to induce transient renal ischemia and reperfusion. In the infarct group, a lower polar branch of the left renal artery was permanently ligated without release, in order to induce renal infarction. Gray-scale and contrast-enhanced color/power Doppler US were performed in the two groups at specific times, namely before ligation, immediately after release or ligation (for the ischemia and infarct groups, respectively?), and on the 1st, 3rd, 7th, 14th and 28th postoperative days. The left kidneys of all rabbits were harvested after the last US, for the purpose of evaluating the pathologic correlations. In the US images, swelling, hypo- or hyperechoic areas of the involved parenchyma, tissue loss and perfusion defects were more predominant in the infarct group than in the ischemia group. In successive images, hyperechoic renal parenchyma with no reperfusion changed into renal infarct, while that with reperfusion became normal tissue. In the pathologic analysis, the specimens obtained from the ischemia group revealed mild parenchymal infarct with interstitial fibrosis, whereas those from the infarct group revealed extensive tissue loss and scarring in the involved area of the lower pole. Gray-scale and contrast-enhanced color/power Doppler US can demonstrate the morphological and hemodynamic changes in cases of renal ischemia and infarct

  20. Effect of tadalafil in chronic renal failure rabbits: relevance to erectile dysfunction

    Institute of Scientific and Technical Information of China (English)

    Meng-yuan ZHANG; Qiang FU; Wei BIAN

    2011-01-01

    It is of great importance to investigate an effective and reliable medication against chronic renal failure (CRF)-related erectile dysfunction (ED), which aims to improve patients' life qualities. The concentrations of cyclic guanosine monophosphate (cGMP) in the corpus cavernosal smooth muscle of both CRF and control rabbits were measured. The effects of various concentrations of tadalafil, papaverine, and sodium nitroprusside on the relaxation responses of corpus cavernosal smooth muscle pre-contracted with phenylephrine in CRF rabbits were observed. There was significant difference in the concentration of cGMP between CRF and control rabbits (P<0.01). Tadalafil had the greatest impacts on CRF rabbits when given the same concentration of papaverine or sodium nitroprusside and particularly significant differences were identified under the concentration levels of 10-5 and 10-4 mol/L (P<0.01). The results suggest that the cGMP concentrations of the corpus cavernosum had been greatly reduced in CRF rabbits compared with control rabbits and that tadalafil may be an ideal medication for use in the treatment of CRF-related ED.

  1. Chloride is essential for contraction of afferent arterioles after agonists and potassium

    DEFF Research Database (Denmark)

    Jensen, B L; Ellekvist, Peter; Skøtt, O

    1997-01-01

    A depolarizing chloride efflux has been suggested to activate voltage-dependent calcium channels in renal afferent arteriolar smooth muscle cells in response to vasoconstrictors. To test this proposal, rabbit afferent arterioles were microperfused, and the contractile dose responses to norepineph......A depolarizing chloride efflux has been suggested to activate voltage-dependent calcium channels in renal afferent arteriolar smooth muscle cells in response to vasoconstrictors. To test this proposal, rabbit afferent arterioles were microperfused, and the contractile dose responses......). Reintroduction of chloride fully restored the sensitivity to norepinephrine. Contractions after ANG II and potassium were totally abolished in the absence of chloride (n = 6). In additional experiments (n = 7), the arteriolar contraction to 100 mM potassium was abolished only 1 min after removal of extracellular...... chloride. We conclude that norepinephrine and ANG II use different mechanisms for contraction and that extracellular chloride is essential for contraction in afferent arterioles after activation of voltage-dependent calcium channels. We suggest that a chloride influx pathway is activated concomitantly...

  2. Modelling of the dynamic relationship between arterial pressure, renal sympathetic nerve activity and renal blood flow in conscious rabbits.

    Science.gov (United States)

    Berger, C S; Malpas, S C

    1998-12-01

    A linear autoregressive/moving-average model was developed to describe the dynamic relationship between mean arterial pressure (MAP), renal sympathetic nerve activity (SNA) and renal blood flow (RBF) in conscious rabbits. The RBF and SNA to the same kidney were measured under resting conditions in a group of eight rabbits. Spectral analysis of the data sampled at 0.4 Hz showed that the low-pass bandwidth of the signal power for RBF was approximately 0. 05 Hz. An autoregressive/moving-average model with an exogenous input (ARMAX) was then derived (using the iterative Gauss-Newton algorithm provided by the MATLAB identification Toolbox), with MAP and SNA as inputs and RBF as output, to model the low-frequency fluctuations. The model step responses of RBF to changes in SNA and arterial pressure indicated an overdamped response with a settling time that was usually less than 2 s. Calculated residuals from the model indicated that 79 5 % (mean s.d., averaged over eight independent experiments) of the variation in RBF could be accounted for by the variations in arterial pressure and SNA. Two additional single-input models for each of the inputs were similarly obtained and showed conclusively that changes in RBF, in the conscious resting rabbit, are a function of both SNA and MAP and that the SNA signal has the predominant effect. These results indicate a strong reliance on SNA for the dynamic regulation of RBF. Such information is likely to be important in understanding the diminished renal function that occurs in a variety of disease conditions in which overactivity of the sympathetic nervous system occurs.

  3. Histotripsy and metastasis: Assessment in a renal VX-2 rabbit tumor model

    Science.gov (United States)

    Styn, Nicholas R.; Hall, Timothy L.; Fowlkes, J. Brian; Cain, Charles A.; Roberts, William W.

    2012-10-01

    Histotripsy is a non-invasive, pulsed ultrasound technology where controlled cavitation is used to homogenize targeted tissue. We sought to assess the possibility that histotripsy may increase metastatic spread of tumor by quantifying the number of lung metastasis apparent after histotripsy treatment of aggressive renal VX-2 tumor compared to nontreated controls. VX-2 tumor was implanted in the left kidneys of 28 New Zealand White rabbits. Twenty rabbits were treated with histotripsy (day 13 after implantation) while 8 served as controls. All rabbits underwent left nephrectomy (day 14) and then were euthanized (day 19). This study was powered to detect a doubling in metastatic rate. Homogenized tumor was seen in all treated nephrectomy specimens. Whole-mount, coronal lung sections were viewed to calculate number and density of metastases. Viable tumor was present in all 28 lungs examined. Histology confirmed fractionation of tumor in all treatment rabbits. There was not a statistical difference in total lung metastases (88.7 vs. 72.5; p=0.29) or metastatic density (8.9 vs. 7.0 mets/cm2; p=0.22) between treated and control rabbits. Further investigation is planned to validate these results in the VX-2 model and to assess metastatic rates in less aggressive tumors treated with histotripsy.

  4. Rabbit anti-thymocyte globulin induction in renal transplantation: review of the literature

    Directory of Open Access Journals (Sweden)

    Andress L

    2014-01-01

    Full Text Available Leah Andress,1 Anjali Gupta,2 Nida Siddiqi,3 Kwaku Marfo2,3 1University at Buffalo School of Pharmacy and Pharmaceutical Sciences, Department of Pharmacy Practice, Buffalo, 2Montefiore Medical Center, The University Hospital for Albert Einstein College of Medicine Department of Abdominal Organ Transplant Program, Bronx, 3Montefiore Medical Center, Department of Pharmacy, Bronx, NY, USA Abstract: Rabbit anti-thymocyte globulin (rATG has proven benefit as induction therapy in renal transplant recipients, achieving reduced acute rejection rates and better short-term allograft function, with slightly higher rates of complications such as infections and malignancy. Compared with other agents, the most benefit from rATG induction has been observed in renal transplant recipients at high immunologic risk for rejection. However, in special populations, such as pediatrics, the elderly, and hepatitis C-positive and human immunodeficiency virus-positive renal transplant recipients, additional information is needed to delineate the absolute benefit of rATG induction compared with other induction agents. Selection of rATG as the choice of induction therapy in renal transplant recipients should be guided by a cost-effective approach in balancing efficacy, safety, and cost. This review summarizes the published literature on efficacy, safety, and cost of rATG induction in renal transplantation. Keywords: anti-thymocyte globulin, renal transplantation, induction therapy

  5. Evaluation of arterial impairment after experimental gelatin sponge embolization in a rabbit renal model

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jung Suk; Lee, Hae Gi; Chun, Ho Jong; Choi, Byung Gil; Choi, Yeong Jin [Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2015-02-15

    Arterial stenosis is a major obstacle for subsequent interventional procedures. We hypothesized that the stenosis is caused by gelatin sponge embolization and performed an experimental study in a rabbit renal model. A total of 24 rabbits were embolized with porcine gelatin sponge particles injected into the renal arteries. Four rabbits were sacrificed on 1 day, 4 days, 1 week, 2 weeks, 3 weeks, and 4 weeks after embolization. Microscopic evaluations were performed on hematoxylin-eosin and smooth muscle actin immunohistochemical stained sections. Gelatin sponge particles were mainly observed in the segmental and interlobar arteries. Transmural inflammation of the embolized arterial wall and mild thickening of the media were observed 1 week after embolization. Resorption of the gelatin sponge and organization of thrombus accompanied by foreign body reactions, were observed from 2 to 4 weeks after embolization. Microscopic images of the 3 weeks group showed vessel lumens filled mostly with organized thrombi, resulting in severe stenosis. Additionally, vessels showed a thickened intima that contained migrating smooth muscle cells and accompanying interruption of the internal elastic lamina. The migrating smooth muscle cells were distributed around the recanalized arterial lumen. Gelatin sponge embolization may induce arterial stenosis by causing organized thrombus and intimal hyperplasia, which consists of migrating smooth muscle cells and intimal collagen deposits.

  6. The depolarizing action of 5-hydroxytryptamine on rabbit vagal primary afferent and sympathetic neurones and its selective blockade by MDL 72222.

    Science.gov (United States)

    Azami, J; Fozard, J R; Round, A A; Wallis, D I

    1985-02-01

    MDL 72222 (1 alpha H,3 alpha,5 alpha H-tropan-3-yl-3,5-dichlorobenzoate) is a novel compound with potent and selective blocking actions at certain excitatory 5-hydroxytryptamine (5-HT) receptors on mammalian peripheral neurones. In the present study, the sucrose-gap technique has been used to record depolarizing responses to 5-HT from the cells of the rabbit nodose and superior cervical ganglia and to investigate the potency and selectivity of MDL 72222 as an antagonist of these responses. On nodose ganglia, responses to 5-HT were inhibited surmountably by MDL 72222 at concentrations up to 100 nmol/l. The threshold for antagonism was 2-10 nmol/l and the apparent pA2 value (Schild 1947) was 7.7 +/- 0.2, n = 10. Blockade was selective since responses to GABA and noradrenaline were unaffected by MDL 72222, 100 nmol/l. With concentrations of MDL 72222 higher than 100 nmol/l, antagonism was concentration-related but not in a manner consistent with simple competitive antagonism and even a concentration of 1 mumol/l failed to abolish the response to 5-HT. The results from the superior cervical ganglion were essentially similar to those obtained from the nodose ganglion. The threshold concentration of MDL 72222 for inhibition of 5-HT was 1-10 nmol/l and blockade was selective in that depolarizing responses to dimethylphenyl-piperazinium (DMPP) was unaffected by a concentration of MDL 72222 of 1 mumol/l. The data provide direct evidence that MDL 72222 is a potent and selective antagonist of the receptors for 5-HT which mediate depolarizing responses in vagal primary afferent cell bodies and in sympathetic ganglion cells.

  7. [Determining the aortic and renal hemodynamic effects of propofol on rabbits using Doppler ultrasonography].

    Science.gov (United States)

    Apan, Alpaslan; Karadeniz Bilgili, M Yasemin; Cağlayan, Fatma

    2004-03-01

    The hemodynamic effects of propofol-fentanyl anesthesia were known to reduce arterial pressure and heart rate. We aimed to determine the effects of propofol-fentanyl anesthesia on renal artery blood flow and aorta by using Doppler ultrasonography on an animal model. The study was conducted on 8 male New Zaeland White strain rabbits. The initial aortic and renal hemodynamic measurements were determined on animals using ketamin anesthesia. Later the right femoral arteries were cannulated for determining arterial blood pressure and pulse oximetry was followed from the ear. Propofol 5-7 mg/kg with fentanyl 1-2 microg/kg was injected via the ear vein. Doppler parameters (RI, RI, Vmax, Vmin) of the renal artery and aorta were determined after the anesthesia. According to the basal measurements, arterial blood pressure and breath rates declined significantly (27% and 53% respectively, p<0.05); however there were no statistical alteration of aortic and renal artery Doppler parameters. Anesthesia induced by propofol-fentanyl did not induce a statistically significant difference in Doppler parameters obtained from the renal artery and aorta. It is clinically important to know that determining the changes in RI and PI during the postoperative period is not related to the propofol-fentanyl anesthesia.

  8. Renal and vascular studies of aqueous extract of Urtica dioica in rats and rabbits

    Directory of Open Access Journals (Sweden)

    K.F. Dizaye

    2013-06-01

    Full Text Available Urtica dioica has a variety of uses in traditional medicine for genitourinary ailments kidney disorders, allergies, diabetes, anemia, gastrointestinal tract ailments, musculoskeletal aches and alopecia. However, only a few of these uses have scientific bases that support their clinical uses. This study was done to evaluate some of the in vivo and in vitro pharmacological actions of this plant. Eighteen local domestic rabbits (Oryctolagus cuniculus were used for in vitro studies (effect of the plant extract on isolated pulmonary arteries and isolated urinary bladder smooth muscle and in vivo studies (effect of the extract on renal function. Six male albino rats were used for studying the effects of the plant extract on blood pressure and heart rate. Urtica dioica extract produced a significant increase in urine volume and urinary Na+ excretion without significant changes in K+ excretion rates in experimental rabbits. No changes occurred in Glomerular filtration rate and %Na+ reabsorption of filtered load. Neither vasodilatation nor vasoconstriction of isolated pulmonary arteries of the rabbit was seen after applying the aqueous extract of U. dioica. Besides it could not reverse the vasoconstrictor effect of phenylephrine. Urtica dioica has no detectable effects on the isolated bladder; moreover it did not reverse the contraction that was produced by pilocarpine. In experimental rats, the plant extract produced a profound drop in blood pressure associated with decreased heart rate. In conclusion the aqueous extract of U. dioica produced diuretic and natriuretic effects with out significant effect on the K+ excretion rate in rabbits. Moreover it produced a profound drop in blood pressure and heart rate.

  9. Cymbopogon citratus protects against the renal injury induced by toxic doses of aminoglycosides in rabbits

    Directory of Open Access Journals (Sweden)

    N Ullah

    2013-01-01

    Full Text Available Renal injury is the most common side-effect of aminoglycosides. These antimicrobial drugs are particularly effective against Gram-negative microorganisms. The present study was conducted to investigate the renal protective activity of Cymbopogon citratus in gentamicin-induced nephrotoxicity. Male rabbits were divided into four groups (n=6 including group 1 (0.9% saline treated, group 2 (80 mg/kg/day gentamicin-treated, group 3 (200 mg/kg/day Cymbopogon citratus treated and group 4 (80 mg/kg/day gentamicin and 200 mg/kg/day Cymbopogon citratus treated. Biochemical kidney functioning parameters, urinary enzymes and histopathological examination were performed. The results of the present study showed that simultaneous administration of Cymbopogon citrates and gentamicin significantly protected alteration in body weight, blood urea nitrogen, serum creatinine, creatinine clearance, serum uric acid, serum electrolytes, urinary volume, urinary protein, urinary lactate dehydrogenase and urinary alkaline phosphatase induced by gentamicin. Histological examination of the kidney also suggested the same. It is concluded from the current study that co-administration of Cymbopogon citratus with gentamicin for 3 weeks successfully prevented renal damage associated with aminoglycosides.

  10. Quantitative evaluation of acute renal failure in rabbits with contrast-enhanced ultrasound

    Institute of Scientific and Technical Information of China (English)

    DONG Yi; WANG Wen-ping; CAO Jia-ying; FAN Pei-li; LIN Xi-yuan

    2012-01-01

    Background Assessment of perfusion in the early period of acute renal failure (ARF) is important,and can not be made by conventional ultrasound.The aim of this study was to prospectively test in a rabbit ARF model whether real-time contrast-enhanced ultrasound (CEUS) can quantitatively evaluate the hemodynamic changes of renal cortex in the early period.Methods The model of ARF was induced in 30 healthy New Zealand white rabbits (2.5-3.0 kg),by intramuscular injection of 50% glycerin solution (12 ml/kg).CEUS were performed on right kidneys before,6 and 24 hours after glycerin injection.CEUS quantitative indexes were measured in renal cortex using QLAB software.Comparisons between different stages were performed using paired t test.The sensitivity of CEUS in diagnosing ARF was compared with blood serum urea nitrogen (BUN),serum creatinine (SCr) level and color Doppler flow imaging (CDFI).Results Among quantitative indexes,time to peak (TTP) and area under curve (AUC) increased significantly from (5.86±2.57) seconds and (124.4±46.7) dB.s before glycerin injection to (7.66±2.05) seconds and (288.1±64.9) dB.s 6 hours after injection (P <0.05).Slope rate of ascending curve (A) and descending curve (α) decreased slightly from (3.00±1.22) dB/s and (0.19±0.15) 1/s to (2.80±1.45) dB.s and (0.09±0.02) 1/s (P <0.05).Twenty-four hours later,only AUC increased significantly from (124.4±46.7) dB.s to (466.2±52.2) dB.s (P<0.05).Conclusion Quantitative indexes of CEUS might be useful in predicting the hemodynamic changes of renal cortex in the early six hours of ARF model.

  11. 肾神经在肾缺血预处理对麻醉家兔心脏保护中的作用%Role of renal nerve in cardioprotection provided by renal ischemic preconditioning in anesthetized rabbits

    Institute of Scientific and Technical Information of China (English)

    丁延峰; 张蔓蔓; 何瑞荣

    2001-01-01

    The effects of renal ischemic preconditioning (RIP) on ischemia-reperfused myocardium were examined in the urethane-anesthetized rabbit to determine whether RIP may provide cardioprotection and to observe the role of the renal nerve in such condition. The results obtained are as follows: (1) During 45 min myocardial ischemia and subsequent 180 min reperfusion, blood pressure, heart rate and myocardial oxygen consumption decreased progressively. Epicardial electrographic ST-segment was elevated significantly in the period of ischemia and returned to the baseline gradually in the course of reperfusion. The myocardial infarct size occupied 55.80±1.25% of the area at risk. (2) RIP significantly reduced the myocardial infarct size to 36.51±2.80% (P<0.01), indicating the cardioprotective effect of such an intervention. (3) Renal nerve section (RNS) completely abolished the cardioprotection afforded by RIP, though RNS per se did not affect the myocardial infarct size produced by ischemia-reperfusion. (4) During 10 min renal ischemia, the averaged multi-unit discharge rate of the renal afferent was increased from 0.14±0.08 to 0.65±0.12 imp/s (P<0.01). (5) Pretreatment with an adenosine receptor antagonist 8-phenyltheophylline (10 mg/kg) markedly attenuated the discharge rate of the renal afferent induced by transient renal ischemia, implying that adenosine released in ischemic kidney activated the renal afferent. It is suggested that activation of renal afferents by transient renal ischemia-reperfusion plays an important role in the cardioprotection afforded by RIP.%在氨基甲酸乙酯麻醉家兔上, 观察肾脏缺血预处理(RIP)对缺血-再灌注心肌的影响, 旨在证实RIP对心肌有无保护效应, 并明确肾神经在其中的作用。所得结果如下: (1)在心脏45 min缺血和180 min再灌注过程中, 血压、心率和心肌耗氧量呈进行性下降;心外膜电图ST段在缺血期明显抬高, 再灌注过程中逐渐恢复到基础对照

  12. Effect of radiologic contrast media on cell volume regulation in rabbit proximal renal tubules.

    Science.gov (United States)

    Galtung, H K; Løken, M; Sakariassen, K S

    2001-05-01

    Most radiographic contrast media are hyperosmotic and able to shrink cells with which they are in contact. The authors studied cell volume control in rabbit proximal renal tubules after incubation with three contrast media: iohexol, ioxaglate, and iodixanol. Proximal renal tubules were isolated from rabbit kidneys. The tubules were exposed to Ringer solutions containing 5% vol/vol iohexol (final osmolality, 330 mOsm), ioxaglate (323 mOsm), iodixanol (305 mOsm), or mannitol (control solutions with identical osmolalities), and tubule volumes were monitored. After 2 hours of incubation, the tubules were stimulated with a hyposmotic Ringer solution (165 mOsm). Three groups of 10 experiments were performed. All solutions induced cell shrinkage (8.3%+/-3.8 [standard error] to 15.4%+/-0.5), which was completely or partly reversible in most experiments (volume increase, 44.8%+/-14.7 to 149.9%+/-107.3) but not those with iohexol and iodixanol. With exposure to the hyposmotic solution, the cells swelled by 11.0%+/-1.8 to 39.7%+/-4.8. In general, the tubules that had been exposed to the most hyperosmotic solution swelled the most. Those exposed to contrast media showed less swelling than the mannitol-exposed controls. In all control experiments, the cells exhibited a gradual shrinkage (43.6%+/-28.5 to 87.0%+/-13). This regulatory response was partly inhibited in tubules exposed to iohexol (39.9%+/-15.8 shrinkage) or iodixanol (8.9%+/-15.8) and completely inhibited in those exposed to ioxaglate. Iohexol and ioxaglate exposure also led to a decrease in water permeability. Exposure to hyperosmotic contrast medium tends to induce prolonged cell shrinkage, decrease the water permeability of the cellular plasma membranes, and compromise the ability to regulate cellular volume. These changes seem to reflect both the hyperosmolality of the solutions and their inherent chemical properties.

  13. Vascular smooth muscle cells express the alpha(1A) subunit of a P-/Q-type voltage-dependent Ca(2+)Channel, and It is functionally important in renal afferent arterioles

    DEFF Research Database (Denmark)

    Hansen, Pernille B. Lærkegaard; Jensen, Boye L.; Andreasen, D

    2000-01-01

    in rat aorta, brain, aortic smooth muscle cells (A7r5), VSMCs, and mesangial cells. Immunolabeling with an anti-alpha(1A) antibody was positive in acid-macerated, microdissected preglomerular vessels and in A7r5 cells. Patch-clamp experiments on aortic A7r5 cells showed 22+/-4% (n=6) inhibition of inward...... Ca(2+) current by omega-Agatoxin IVA (10(-8) mol/L), which in this concentration is a specific inhibitor of P-type VDCCs. Measurements of intracellular Ca(2+) in afferent arterioles with fluorescence-imaging microscopy showed 32+/-9% (n=10) inhibition of the K(+)-induced rise in Ca(2...... preglomerular resistance vessels and aorta, as well as mesangial cells, and that P-type VDCCs contribute to Ca(2+) influx in aortic and renal VSMCs and are involved in depolarization-mediated contraction in renal afferent arterioles....

  14. Astragalus membranaceus reduces free radical-mediated injury to renal tubules in rabbits receiving high-energy shock waves

    Institute of Scientific and Technical Information of China (English)

    SHENG Bin-wu; CHEN Xing-fa; ZHAO Jun; HE Da-lin; NAN Xun-yi

    2005-01-01

    Background Recent studies have revealed the important role of free radicals in renal damage induced by high-energy shock waves (HESW). This study aimed at investigating the effects of Astragalus membranaceus, a traditional Chinese medicinal herb, on free radical-mediated HESW-induced damage to renal tubules in a live rabbit model.Methods Forty-five healthy male New Zealand white rabbits were randomly divided into three groups: control group (n=15), sham group (n=15), and herb-treated group (n=15). Three days prior to HESW application, the controls received verapamil (0.4 mg/kg), the shams received physiological saline (20 ml), and the herb-treated animals received Astragalus membranaceus (2.4 g/kg) intravenously. HESW (1500 shocks, 18kV) was applied to the right kidneys of all anesthetized rabbits. We measured superoxide dismutase (SOD) and malondialdehyde (MDA) levels before and after shock treatment in blood and kidney homogenates. Histopathological changes were also observed.Results MDA levels increased and SOD activity decreased significantly in the sham group (P0.05). SOD values were significantly higher in the controls than in the shams (P<0.05). By contrast, SOD levels recovered rapidly in the rabbits receiving Astragalus membranaceus, reaching a nadir within 24 hours, and returning to baseline more quickly than in control and sham rabbits (P<0.05). Histopathological examinations showed that renal tubular damage in the controls was less severe than in the shams, while damage in the Astragalus membranaceus group was even more mild, with rapid recovery in comparison with the controls.Conclusion This study provides preliminary evidence indicating that Astragalus membranaceus has strong protective effects on free radical-mediated renal tubular damage induced by HESW and that these effects are superior to the effects of verapamil.

  15. Cell death during the postnatal morphogenesis of the normal rabbit kidney and in experimental renal polycystosis.

    Science.gov (United States)

    García-Porrero, J A; Ojeda, J L; Hurlé, J M

    1978-01-01

    We have studied, by means of optic and electron microscopy, the normal and abnormal cell death that takes place during the postnatal morphogenesis of rabbit kidney, and in the experimental renal polycystosis produced by methylprednisolone acetate. In the normal kidney intertubular cell death can be observed during the first 20 days of the postnatal development. However, cell death in the normal metanephric blastema is a very rare event. In the polycystic kidney numerous dead cells can be seen between the third and forty eighth days after injection. The topography and morphology of the dead cells depend on the stage in the evolution of the disease. In the 'stage of renal immaturity', dying and dead cells are present in the nephrogenic tissue, in the dilating collecting tubules and in the intertubular spaces. In this stage the cellular pathology is essentially nuclear. In the stage of tubular cysts, the dead cells are mostly located in the walls of cysts, with some dead cells, but mostly cellular debris in their lumina. At this stage the cellular pathology is basically cytoplasmic. The dead cells are eventually digested by what appear to be phagocytes of tubular epithelial origin. It is suggested that cell death is an important factor in the evolution of the lesions of renal polycystosis induced by corticosteroids, and probably in the initiation of the pathological process as well. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 PMID:670065

  16. [Role of paraventricular nucleus in natriuresis and diuresis induced by volume expansion in rabbits].

    Science.gov (United States)

    Zhang, B; Lin, M Z; Han, G C

    2000-02-01

    In sham-lesioned and paraventricular nucleus (PVN) lesioned rabbits, the peak increases of urine volume (UV) induced by volume expansion (VE) were 0.59+/-0.09 and 0.31+/-0.03 ml/min (P0.05). In rabbits with renal denervation there was no significant change in natriuretic response after PVN lesion (P>0.05), but lesion of PVN significantly attenuated diuretic response (P0.05). These results suggest that PVN is involved in the regulation of natriuresis and diuresis induced by VE, which are mediated by vagal afferent nerve, whereas the renal sympathetic efferent nerve may be involved in natriuretic response.

  17. The depolarizing action of 5-hydroxytryptamine on rabbit vagal afferent and sympathetic neurones in vitro and its selective blockade by ICS 205-930.

    OpenAIRE

    1986-01-01

    Depolarizing responses to 5-hydroxytryptamine (5-HT) were recorded from rabbit nodose (NG) and superior cervical (SCG) ganglia using the sucrose-gap technique. The antagonist potency and selectivity of ICS 205-930 ([3 alpha-tropanyl]-1H-indole-3-carboxylic acid ester) were investigated. In NG, 5-HT (5 to 80 nmol) evoked depolarizations of graded amplitude. The ED50 was 18.2 (10.9-30.5) nmol (geometric mean, 95% confidence limits). Responses were blocked surmountably by ICS 205-930, 10(-11) an...

  18. Far infrared radiation promotes rabbit renal proximal tubule cell proliferation and functional characteristics, and protects against cisplatin-induced nephrotoxicity.

    Science.gov (United States)

    Chiang, I-Ni; Pu, Yeong-Shiau; Huang, Chao-Yuan; Young, Tai-Horng

    2017-01-01

    Far infrared radiation, a subdivision of the electromagnetic spectrum, is beneficial for long-term tissue healing, anti-inflammatory effects, growth promotion, sleep modulation, acceleration of microcirculation, and pain relief. We investigated if far infrared radiation is beneficial for renal proximal tubule cell cultivation and renal tissue engineering. We observed the effects of far infrared radiation on renal proximal tubules cells, including its effects on cell proliferation, gene and protein expression, and viability. We also examined the protective effects of far infrared radiation against cisplatin, a nephrotoxic agent, using the human proximal tubule cell line HK-2. We found that daily exposure to far infrared radiation for 30 min significantly increased rabbit renal proximal tubule cell proliferation in vitro, as assessed by MTT assay. Far infrared radiation was not only beneficial to renal proximal tubule cell proliferation, it also increased the expression of ATPase Na+/K+ subunit alpha 1 and glucose transporter 1, as determined by western blotting. Using quantitative polymerase chain reaction, we found that far infrared radiation enhanced CDK5R1, GNAS, NPPB, and TEK expression. In the proximal tubule cell line HK-2, far infrared radiation protected against cisplatin-mediated nephrotoxicity by reducing apoptosis. Renal proximal tubule cell cultivation with far infrared radiation exposure resulted in better cell proliferation, significantly higher ATPase Na+/K+ subunit alpha 1 and glucose transporter 1 expression, and significantly enhanced expression of CDK5R1, GNAS, NPPB, and TEK. These results suggest that far infrared radiation improves cell proliferation and differentiation. In HK-2 cells, far infrared radiation mediated protective effects against cisplatin-induced nephrotoxicity by reducing apoptosis, as indicated by flow cytometry and caspase-3 assay.

  19. The depolarizing action of 5-hydroxytryptamine on rabbit vagal afferent and sympathetic neurones in vitro and its selective blockade by ICS 205-930.

    Science.gov (United States)

    Round, A; Wallis, D I

    1986-06-01

    Depolarizing responses to 5-hydroxytryptamine (5-HT) were recorded from rabbit nodose (NG) and superior cervical (SCG) ganglia using the sucrose-gap technique. The antagonist potency and selectivity of ICS 205-930 ([3 alpha-tropanyl]-1H-indole-3-carboxylic acid ester) were investigated. In NG, 5-HT (5 to 80 nmol) evoked depolarizations of graded amplitude. The ED50 was 18.2 (10.9-30.5) nmol (geometric mean, 95% confidence limits). Responses were blocked surmountably by ICS 205-930, 10(-11) and 10(-10) M, the threshold for blockade being below 10(-11) M. Parallel, rightward shifts in dose-response curves were seen with these concentrations of antagonist, but at higher concentrations (10(-9) and 10(-8) M) there was a further rightward shift with reduction in slope and maximum of the curves. In SCG, where 5-HT (20 to 320 nmol) evoked depolarizations of graded amplitude and the ED50 was 55.8 (22.3-139.6) nmol (geometric mean, 95% confidence limits), ICS 205-930 had a similar inhibitory effect to that observed in NG. The apparent pA2 values for the surmountable blockade produced by ICS 205-930 at concentrations of 10(-11) and 10(-10) M were 10.2 +/- 0.2 for NG and 10.4 +/- 0.1 for SCG (means +/- s.e. mean). ICS 205-930 was selective in its action since it had no effect on dimethylphenylpiperazinium (DMPP) responses in either ganglion or on GABA responses in NG. This study provides quantitative evidence on the blocking action of ICS 205-930 at neuronal 5-HT receptors using a technique that allows the depolarizing responses evoked by the amine to be directly recorded.

  20. Extracellular ascorbic acid fluctuation during the protective process of ischemic preconditioning in rabbit renal ischemia-reperfusion model measured

    Institute of Scientific and Technical Information of China (English)

    LIU Lei; LIN Yu-qing; YAN Long-tao; HONG Kai; HOU Xiao-fei; MAO Lan-qun; MA Lu-lin

    2010-01-01

    Background Ascorbic acid has important antioxidant properties, and may play a role in the protective effects of ischemic preconditioning on later ischemia-reperfusion. Herein, we examined the role of endogenous extracellular ascorbic acid in ischemic preconditioning in the kidney.Methods We developed a solitary rabbit kidney model where animals received ischemia-reperfusion only (ischemia-reperfusion group, n=15) or ischemic preconditioning followed by ischemia-reperfusion (ischemic preconditioning group, n=15). Ischemia-reperfusion was induced by occluding and loosening of the renal pedicle. The process of ischemic preconditioning included 15-minute brief ischemia and 10-minute reperfusion. In vivo microdialysis coupled with online electrochemical detection was used to determine levels of endogenous extracellular ascorbic acid in both groups. The extent of tissue damage was determined in kidney sections stained with hematoxylin and eosin. Serum creatinine and urea nitrogen were also detected to assess renal function.Results During ischemia-reperfusion, the extracellular ascorbic acid concentration during ischemia increased rapidly to the peak level ((130.01 ±9.98)%), and then decreased slowly to near basal levels. Similar changes were observed during reperfusion (peak level, (126.78±18.24)%). In the ischemic preconditioning group there was a similar pattern of extracellular ascorbic acid concentration during ischemic preconditioning. However, the ascorbic acid level was significantly lower during the ischemia and early reperfusion stage compared to the ischemia-reperfusion group. Additionally, the extent of glomerular ischemic collapse, tubular dilation, tubular denudation, and loss of brush border were markedly attenuated in the ischemic preconditioning group. Levels of serum creatinine and urea nitrogen were also decreased significantly in the ischemic preconditioning group.Conclusions Ischemic preconditioning may protect renal tissue against ischemia

  1. A STUDY ON LIMITATION OF HIGH-ENERGY SHOCK WAVE-INDUCED RENAL DAMAGE BY SALVIA MILTIORRHIZAE INJECTION IN RABBIT MODEL

    Institute of Scientific and Technical Information of China (English)

    陈兴发; 盛斌武; 贺大林

    2004-01-01

    Objective To study the protective function of Salvia Miltiorrhizae on high-energy shockwaves (HESW) induced renal damage. Methods Thirty healthy New Zealand adult male white rabbits were randomly divided into Salvia Miltiorrhizae group and control group with 15 in each. Three days before extracorpeal shock wave lithotripsy (ESWL) the two groups were injected Salvia Miltiorrhizae and physiological saline respectively. Plasma endothelin-1 (ET-1), Superoxide dismutase (SOD) and malondialdehyde (MDA) were determined and renal morphology was observed. Results After ESWL, levels of ET-1 and MDA increased significantly, the activity of SOD decreased significantly compared with those before ESWL in control group (P0.05). After shocking, SOD, related to renal protection, in Salvia Miltiorrhizae group was significantly higher than that of controls (P<0.05). Renal morphological injury was slight in Salvia Miltiorrhizae group. Conclusion Salvia Miltiorrhizae injection has protective function on renal toxicity induced by high-energy shock waves.

  2. Modelo cirúrgico de insuficiência renal crônica: estudo em coelhos Surgical model of chronic renal failure: study in rabbits

    Directory of Open Access Journals (Sweden)

    Andrei Ferreira Nicolau da Costa

    2009-02-01

    Full Text Available OBJETIVO: Estabelecer um modelo de insuficiência renal crônica (IRC em coelhos, com perspectivas de seu uso para ações terapêuticas e reparadoras. MÉTODO: Foram utilizados 19 coelhos da linhagem Nova Zelândia, machos, adultos, aleatoriamente distribuídos em três Grupos: Grupo 1 - Controle (n =5, Grupo 2- Simulação (n =7, Grupo 3 - Experimental (n =7. Os animais foram anestesiados com Cetamina e Diazepam e Fentanil por via intramuscular e Sevorane, através de vaporizador. No Grupo 3 realizou-se uma nefrectomia bipolar esquerda e após quatro semanas, uma nefrectomia direita. Todas as amostras do parênquima renal foram pesadas. O Grupo 2 foi submetido a duas laparotomias, sem nefrectomia.. Em todos os grupos foram realizadas avaliações: bioquímicas com dosagens de uréia, creatinina, sódio e potássio; ultra-sonográficas abdominais; cintigráficas e histológicas. RESULTADOS: No Grupo 3 houve aumento progressivo da uréia (p=0.0001, creatinina (p=0,0001, sódio (p= 0,0002 e potássio (p=0,0003. A comparação destes resultados com os dos Grupos 1 e 2, nos diversos intervalos, também revelou elevação sérica, com significância estatística (p OBJECTIVES: To establish a model of chronic renal failure in rabbits, with perspectives of its use for therapeutic and repairing actions. METHODS: Nineteen males, adults rabbits (New Zealand randomly distributed into three groups were used: Group 1 - Control (n =5; Group 2-Sham (n =7; and Group 3 - Experimental (n =7. They were anaesthetized by using intramuscular Cetamine, Diazepam and Fentanyl followed by Sevorane with vaporizer device. In Group 3, a bipolar left nephrectomy was carried out and after four weeks, it was also done a right nephrectomy. All the samples of the renal tissue were weighed. The Group 2 was only submitted to both abdominal laparotomies, without nephrectomy. Biochemical evaluations, with urea, creatinina, sodium and potassium measurement; abdominal ultrasound scan

  3. 肾脏缺血预处理对麻醉家兔心脏保护的神经机制%Involvement of neural mechanism in cardioprotection provided by renal ischemic preconditioniong in anesthetized rabbits

    Institute of Scientific and Technical Information of China (English)

    丁延峰; 史明珠; 牛新清; 李东亮; 何瑞荣

    2002-01-01

    目的探讨肾神经在肾脏缺血预处理(RIP)心肌保护中的作用.方法在麻醉家兔心肌缺血/再灌注(MIR)模型上,观察MIR和RIP对家兔血流动力学、心肌耗氧量、心外膜电图和心肌梗死范围的影响.结果在MIR过程中,血流动力学指标和心肌耗氧量均明显持续性降低;心外膜电图ST段在缺血期明显升高,再灌注过程中恢复到基础对照值.单纯MIR时的心肌梗塞范围占缺血心肌的(55.80±1.25)%,RIP后心肌梗塞范围为(36.51±2.8)%,较单纯MIR显著减少(P<0.01).肾神经切断后对MIR所致的心肌梗死范围无明显影响,但可取消RIP对心肌的保护效应.结论 RIP具有心肌保护作用,肾短暂缺血-再灌注所诱发的肾神经传入活动可能参与此心肌保护效应.%Objective To investigate the role of renal nerve in cardioprotection provided by renal ischemic preconditioning(RIP).Methods The effects of ischemia-reperfusion and RIP on the hemodynamics, myocardial oxygen consumption, epicardial electrography and infarct size were examined in anesthetized rabbit.Results During the 45 min of myocardial ischemia and 180 min of reperfusion, all hemodynamic parameters and myocardial oxygen consumption decreased progressively significantly. Epicardial electrographic ST-segment was elevated significantly during myocardial ischemia and return to baseline progressively in the course of reperfusion. The myocardial infarct size occupied 55.80±1.25% of area at risk,and RIP significantly reduced the myocardial infarct size to 36.51±2.80%(P<0.01). The renal nerve section (RNS) per se didn't affect myocardial infarct size produced by ischemia-reperfusion, while cardioprotection afforded by RIP was completely abolished by RNS.Conlusion RIP have the protective effect on heart, and activation of renal afferents by transient ischemia-reperfusion play an important role in such a cardioprotection.

  4. Beneficial Effect of Paljeong-san Pharmacopuncture Treatment Combined with Peritoneal Injection on Glycerol-Induced Acute Renal Failure in Rabbits

    Directory of Open Access Journals (Sweden)

    Chi-Yeon Lim

    2010-09-01

    Full Text Available Purpose: The present study was carried out to determine if Paljeong-san extract (PJS treatment exerts beneficial effect against the glycerol-induced acute renal failure in rabbits. Material and Method: PJS was selected in the basis of invigorating kidney which can eliminate pathogens. Rabbits were treated with PJS pharmacopuncture on Shin-shu (BL23 point for 5 days right after the injection of 50% concentration of glycerol (5㎖/㎏ body weight. Results and Conclusions: Glycerol injection caused an increase in serum creatinine and BUN level and urine glucose secretion, which were accompanied by a reduction in GFR. PJS Pharmacopuncture treatment combined with peritoneal injection showed beneficial effect on glycerol-induced acute renal failure by inhibition of serum creatinine increase and GFR decrease.

  5. DHEA-induced modulation of renal gluconeogenesis, insulin sensitivity and plasma lipid profile in the control- and dexamethasone-treated rabbits. Metabolic studies.

    Science.gov (United States)

    Kiersztan, Anna; Nagalski, Andrzej; Nalepa, Paweł; Tempes, Aleksandra; Trojan, Nina; Usarek, Michał; Jagielski, Adam K

    2016-02-01

    In view of antidiabetic and antiglucocorticoid effects of dehydroepiandrosterone (DHEA) both in vitro and in vivo studies were undertaken: (i) to elucidate the mechanism of action of both dexamethasone phosphate (dexP) and DHEA on glucose synthesis in primary cultured rabbit kidney-cortex tubules and (ii) to investigate the influence of DHEA on glucose synthesis, insulin sensitivity and plasma lipid profile in the control- and dexP-treated rabbits. Data show, that in cultured kidney-cortex tubules dexP significantly stimulated gluconeogenesis by increasing flux through fructose-1,6-bisphosphatase (FBPase). DexP-induced effects were dependent only upon glucocorticoid receptor. DHEA decreased glucose synthesis via inhibition of glucose-6-phosphatase (G6Pase) and suppressed the dexP-induced stimulation of renal gluconeogenesis. Studies with the use of inhibitors of DHEA metabolism in cultured renal tubules showed for the first time that DHEA directly affects renal gluconeogenesis. However, in view of analysis of glucocorticoids and DHEA metabolites levels in urine, it seems likely, that testosterone may also contribute to DHEA-evoked effects. In dexP-treated rabbits, plasma glucose level was not altered despite increased renal and hepatic FBPase and G6Pase activities, while a significant elevation of both plasma insulin and HOMA-IR was accompanied by a decline of ISI index. It thus appears that increased insulin levels were required to maintain normoglycaemia and to compensate the insulin resistance. DHEA alone affected neither plasma glucose nor lipid levels, while it increased insulin sensitivity and diminished both renal and hepatic G6Pase activities. Surprisingly, DHEA co-administrated with dexP did not alter insulin sensitivity, while it partially suppressed the dexP-induced elevation of renal G6Pase activity and plasma cholesterol and triglyceride contents. As (i) gluconeogenic pathway in rabbit is similar to that in human, and (ii) DHEA counteracts several

  6. [Renal blood flow investigations with 133xenon and the Anger scintillation camera in the hyperacute xenograft rejection of the rabbit kidney (author's transl)].

    Science.gov (United States)

    Heidenreich, P; Erhardt, W; Oberdorfer, M; Krüger, P; Pielsticker, K; Hör, G

    1976-08-25

    The aim of this study was to demonstrate the advantage and validity of 133Xe-washout externally monitored by the scintillation camera. Until now there were no reports on quantitative blood flow studies in Hyperacute rejection of transplanted kidneys using a scintillation camera. Within 35 minutes after e-vivo hemoperfusion of rabbit kidneys by cats we found a simultaneous progressive decrease of renal blood flow, renal cortical blood flow as well as of the intrarenal distribution of renal cortical blood flow in all cases. The hyperacute rejection of xenografts could be verified in every case histologically. Using the scintillation camera we were able to detect regional perfusion defects caused by artifical air embolism as well as by preexisting cortical infarction.

  7. Genioglossus muscle responses to upper airway pressure changes: afferent pathways.

    Science.gov (United States)

    Mathew, O P; Abu-Osba, Y K; Thach, B T

    1982-02-01

    The afferent pathway of an upper airway reflex in which genioglossus muscle electromyographic (GG EMG) activity is influenced by pharyngeal pressure changes was investigated in 20 anesthetized rabbits. We took advantage of the fact that the upper airway was separated into two compartments by pharyngeal closure occurring when the animals breathe through a tracheostomy. This allowed pressure to be delivered selectively either to the nose and nasopharynx or to the larynx and hypopharynx. Midcervical vagotomy did not eliminate the GG EMG response to pressure stimuli. On the other hand high cervical vagotomy or superior laryngeal nerve section eliminated the response in the laryngeal compartment, but not in the nasopharyngeal compartment. Topical anesthesia of the mucosa of the nose, pharynx, and larynx abolished the response in both compartments. Therefore we conclude that more than one afferent pathway exists for this upper airway pressure reflex; the primary afferent pathway from the laryngeal compartment is the superior laryngeal branch of the vagus nerve, whereas the primary afferent pathway for the nasopharynx is nonvagal. Trigeminal nerve, glossopharyngeal nerve, and/or nervus intermedius carry nonvagal afferents from the nasopharynx and nose. The topical anesthetic and nerve section studies suggest that superficial receptors mediate this response. The occurrence of swallowing in response to upper airway pressure changes and its elimination by topical anesthesia or superior mechanoreceptors may mediate both genioglossus respiratory responses and swallowing responses.

  8. EFFECT OF CYCLOSPORINE A ON THE KIDNEY OF RABBIT: A LIGHT AND ULTRASTRUCTURAL STUDY

    Directory of Open Access Journals (Sweden)

    Fathy Ahmed Fetouh

    2014-12-01

    Full Text Available Background: Nephrotoxicity is a relatively common problem in patients immunosuppressed with cyclosporine A (CsA with an incidence reaching up to thirty percent. The present work aimed to study the histological and ultrastructural effects of CsA on the kidney of rabbit. Materials and Methods: Two groups of Egyptian adult rabbits were used for this study (5 rabbits for each. One group was used as a control and the other group (experimental was treated with CsA in a dose of 15 mg/kg of body weight for two weeks. The animals were anaesthetized; and kidney specimens were obtained, fixed and processed for light and electron microscopic examinations. Results: CsA had adverse effects on the kidney especially renal corpuscles, proximal convoluted tubules, distal convoluted tubules and afferent glomerular arterioles. The renal corpuscles were observed with shrunken glomeruli, widening of Bowmanʼs space and thickening of the Bowmanʼs capsule. Also, there was obvious increase in mesangial cell number and overall glomerular obliteration due to large lining endothelial cells and encroachment of the mesangial cell matrix onto the capillary lumen. The renal tubules showed vacuolization and PAS positive inclusion bodies. The cells showed disordered brush border of microvilli. Many fibrocytes appeared inbetween the tubules. Peritubular capillary congestion was observed with an increase in the surrounding connective tissue. Ultrastructurally, the proximal convoluted tubules showed thick basement membrane with loss of the basal infolding. The mitochondria appeared degenerated with damaged transverse cristae. Electron dense lysosomes were seen in the cytoplasm. In distal convoluted tubules, the cells showed degenerated mitochondria and pyknotic nuclei. The afferent glomerular arterioles appeared with hyperplasia of juxtaglomerular cells that contained massive renin granules. The lining endothelial cells appeared protruding their nuclei into the lumen due to

  9. Feedback control of temperature evolution in rabbit kidney in vivo using MRI guided focused ultrasound. Application to renal VX2 carcinoma ablation

    Science.gov (United States)

    Delemazure, A. S.; Salomir, R.; Grenier, N.; Palussière, J.; Deminière, C.; Mougenot, C.; Moonen, C. W.

    2005-03-01

    A significant number of patients with small renal tumours may get benefit from in situ thermo-ablation techniques. Focused ultrasound is a non-invasive approach which offers excellent flexibility. On the other hand, real time MR thermometry is a valuable tool for monitoring and controlling therapy. In this study, coupling of focused ultrasound with PRF-based, respiratory-gated MR thermometry was used to provide temperature feedback control for local hyperthermia in the rabbit kidney. Two heating protocols were initially used in healthy kidneys (medulla and cortex): 1. fixed focal point heating; 2. spiral trajectories of the focal point. Further, five VX2 renal carcinomas were treated with multiple focal point heating in each tumour. Post-treatment MRI follow up and post mortem histology were performed. The shape and size of the lesions (MRI, histology) were compared to the calculated thermal dose map. The standard deviation of the MR thermometry ranged from 0.5°C to 1°C. The temperature controller matched the objective curve with approximately 1°C precision (fixed focal point mode). Several technical and physiological difficulties for spiral heating could not be overcome with the available setup. Thermal ablation with temperature feedback control in healthy and tumour bearing kidney was demonstrated to be feasible and effective, despite specific challenges (deep seated organ, respiratory motion, high blood perfusion).

  10. Cerebellar and afferent ataxias.

    Science.gov (United States)

    Pandolfo, Massimo; Manto, Mario

    2013-10-01

    Ataxia is the predominant manifestation of many acquired and inherited neurologic disorders affecting the cerebellum, its connections, and the afferent proprioceptive pathways. This article reviews the phenomenology and etiologies of cerebellar and afferent ataxias and provides indications for a rational approach to diagnosis and management. The pathophysiology of ataxia is being progressively understood and linked to the functional organization of the cerebellum. The impact of cerebellar diseases on different neurologic functions has been better defined and shown not to be limited to loss of motor coordination. The role of autoimmunity is increasingly recognized as a cause of sporadic cases of ataxia. Large collaborative studies of long duration are providing crucial information on the clinical spectrum and natural history of both sporadic ataxias (such as the cerebellar form of multiple system atrophy) and inherited ataxias. New dominant and recessive ataxia genes have been identified. On the therapeutic front, progress mostly concerns the development of treatments for Friedreich ataxia. Ataxia is the clinical manifestation of a wide range of disorders. In addition to accurate clinical assessment, MRI plays a major role in the diagnostic workup, allowing us to distinguish degenerative conditions from those due to other types of structural damage to the cerebellar or proprioceptive systems. Diagnostic algorithms based on clinical features, imaging, and neurophysiologic and biochemical parameters can be used to guide genetic testing for hereditary ataxias, the diagnosis of which is likely to be greatly improved by the introduction of new-generation DNA-sequencing approaches. Some rare forms of ataxia can be treated, so their diagnosis should not be missed. Proven symptomatic treatments for ataxia are still lacking, but intensive physical therapy appears to be helpful.

  11. The feasibility of using CDFI to evaluate rabbit renal ischemia-reperfusion injury%彩色多普勒血流显像评价兔肾缺血再灌注损伤的可行性研究

    Institute of Scientific and Technical Information of China (English)

    陈晓梅; 李明星; 宣吉晴; 罗志建; 李昆萍; 叶帆; 张敏

    2012-01-01

    目的:探讨彩色多普勒血流显像(CKFI)评价肾缺血再灌注损伤发生的可行性.方法:48只大白兔随机分为假手术对照(S)组、缺血再灌注(I/R)组.应用CDFI检测各级兔肾动脉的血流动力学变化,测定兔肾组织肿瘤坏死因子α(TNF-α)的平均光密度(OD)并做相关性分析.结果:与S组比较,I/R 2 h组无明显血流动力学改变,I/R 8 h、24 h组分别出现SRA、IRA的RI增大和MRA、SRA、IRA的Vmax、PI、RI增大(P<0.05).I/R8h,24 h组TNF-α的OD高于S组(P<0.05).I/R各组MRA、SRA和IRA的Vmax,PI,RI与兔肾组织TNF-α的OD变化呈正相关(P<0.05).结论:CDFI是一种无创、及时的评价肾缺血再灌注损伤发生的可行方法.%Objective To study the feasibility of using CDFI to evaluate rabbit renal ischemia-reperfusion injury. Methods 48 rabbits were randomly divided into sham operation control group (S) and ischemia-reperfusion injury group ( I/R) .The hemodynamicparametersof rabbit renal artery and the expression of TNF-a in rabbit kidney tissue were respectively measured by color Doppler flow imaging (CDFI) and TNF-a kit. The correlationanalysis was studied between CDFI parameters andTNF-a expression. Results I/R 2 h group had no significant changes in hemodynamic parameters compared to S group. The hemodynamic parameters of I/R long time group were significantly changed such as RI of rabbits SRA and IRA.The TNF-a level of rabbits renalwas increased in I/R 8 h、 24 h group. Vmax,PI,RI of rabbits MRA, SRA and IRA had positive correlation with TNF-alevel (P < 0.05). Conclusion CDFI is a feasible method to evaluate the incidence of renal ischemia/reperfusion injury.

  12. A correlative study on the resistance index of rabbit renal artery after ischemia-reperfusion and the TNF-α expression in renal tissue%缺血再灌注的兔肾动脉阻力指数与肾组织TNF-α表达的相关性研究

    Institute of Scientific and Technical Information of China (English)

    陈晓梅; 李明星; 李昆萍; 宣吉晴

    2011-01-01

    目的 探讨肾组织肿瘤坏死因子(TNF-α)表达与肾缺血再灌注(I/R)后肾动脉阻力指数(RI)的相关性,为评价肾缺血再灌注损伤(IRI)的发生提供可行方法.方法 将48只大白兔随机分为假手术组、I/R组.应用彩色多普勒血流显像(CDFI)监测各组大白兔主肾动脉(MRA)、段动脉(SRA)、叶间动脉(IRA)的RI变化,免疫组化检测肾组织中TNF-α的表达.结果 与假手术组比较,I/R组大白兔再灌注2 h肾动脉无明显RI改变,再灌注8 h 及24 h分别出现SRA、IRA的 RI增大及MRA、SRA、IRA 的RI增大(P<0.05).I/R组8、24 h大白兔肾组织的TNF-α表达水平高于假手术组(P<0.05).各组MRA、SRA和IRA的RI与肾组织TNF-α表达呈正相关(P<0.05).结论 利用CDFI检测缺血再灌注的肾动脉的RI是一种无创、及时的评价肾IRI发生的可行方法.%Objective To explore the correlation of expression of tumor necrosis factor-alpha(TNF-α) in renal tissue and the resistance index (RI) of renal artery after renal ischemia-reperfusion(I/R) , and provide a feasible method to evaluate the occurrence of renal I/R injury. Methods 48 rabbits were randomly divided into sham operation group and I/R group. Color Doppler flow imaging (CDFI) was adopted to monitor the changes of RI of main renal artery (MRA) ,segmental renal artery (SRA) and interlobar renal artery (IRA) of rabbits in each group. Immunohistochemistry was employed to detect the expression of TNF-α in renal tissue. Results Compared with sham operation group, RI of renal artery showed no significant changes in rabbits subjected to 2 hours of reperfusion in I/R group,while that of SRA,IRA and that of MRA,SRA,IRA increased in rabbits subjected to 8 and 24 hours of reperfusion in I/R group,respectively(Prenal tissue of rabbits in I/R 8,24 h group was higher than that in sham operation group(P<0. 05). RI of MRA, SRA and IRA in each group had positive correlation with its TNF

  13. Effect of acute acid-base disturbances on ErbB1/2 tyrosine phosphorylation in rabbit renal proximal tubules.

    Science.gov (United States)

    Skelton, Lara A; Boron, Walter F

    2013-12-15

    The renal proximal tubule (PT) is a major site for maintaining whole body pH homeostasis and is responsible for reabsorbing ∼80% of filtered HCO3(-), the major plasma buffer, into the blood. The PT adapts its rate of HCO3(-) reabsorption (JHCO3(-)) in response to acute acid-base disturbances. Our laboratory previously showed that single isolated perfused PTs adapt JHCO3(-) in response to isolated changes in basolateral (i.e., blood side) CO2 and HCO3(-) concentrations but, surprisingly, not to pH. The response to CO2 concentration can be blocked by the ErbB family tyrosine kinase inhibitor PD-168393. In the present study, we exposed enriched rabbit PT suspensions to five acute acid-base disturbances for 5 and 20 min using a panel of phosphotyrosine (pY)-specific antibodies to determine the influence of each disturbance on pan-pY, ErbB1-specific pY (four sites), and ErbB2-specific pY (two sites). We found that each acid-base treatment generated a distinct temporal pY pattern. For example, the summated responses of the individual ErbB1/2-pY sites to each disturbance showed that metabolic acidosis (normal CO2 concentration and reduced HCO3(-) concentration) produced a transient summated pY decrease (5 vs. 20 min), whereas metabolic alkalosis produced a transient increase. Respiratory acidosis (normal HCO3(-) concentration and elevated CO2 concentration) had little effect on summated pY at 5 min but produced an elevation at 20 min, whereas respiratory alkalosis produced a reduction at 20 min. Our data show that ErbB1 and ErbB2 in the PT respond to acute acid-base disturbances, consistent with the hypothesis that they are part of the signaling cascade.

  14. 极低频磁场对兔血常规和肝肾功能的影响%Effect of Extremely Low Frequency Magnetic Field Exposure on Blood Routine, Liver and Renal Functions of Rabbits

    Institute of Scientific and Technical Information of China (English)

    李玥; 刘兴发; 张丞; 魏树峰; 张建功; 宋涛

    2013-01-01

    为研究极低频磁场长期暴露对日本长耳大白兔血常规及肝肾功能的影响,验证现行电磁场限值合理性,选用80只日本长耳大白兔(雌雄各半)在不同强度磁场(磁感应强度分别为30、100、200 μT,频率为50 Hz)中暴露4个月,磁场暴露前和磁场暴露期间,每月记录兔体质量,同时检测血常规和肝肾功能.实验结果显示:暴露期间,兔体质量逐渐增加,各组间无显著性差异(概率P>0.05).与对照组(磁感应强度为0)相比,血常规及肝肾功能无明显差异(P>0.05).结果表明,选定的实验条件下ELE-MF对日本长耳大白兔体质量无影响,对血常规和肝肾功能也无影响.%We experimentally investigated the effects of extremely low frequency magnetic fields (ELF-MF) exposure on blood routine and the liver/renal functions of rabbits to verify the validity of current limitation on electromagnetic fields. In the experiment, 80 Japanese rabbits (half male and half female) were exposed in 50 Hz magnetic field of different intensities (30 μT, 100 μT, 200 μT) for 4 months. Weight, blood routine, and the liver/renal functions of the rabbits were determined before and monthly during the magnetic field exposure. The results show that the body weights increase, but no obvious difference appears among groups; compared with the sham group (0 μT), no obvious difference(probability, P>0. 05)is found in the liver and renal functions either. These results indicate that, with the presented parameters, the ELE-MF does not influence the weight, the blood routine, and the liver/renal functions of Japanese rabbits.

  15. Pharmacology of airway afferent nerve activity

    Directory of Open Access Journals (Sweden)

    Carr Michael J

    2001-05-01

    Full Text Available Abstract Afferent nerves in the airways serve to regulate breathing pattern, cough, and airway autonomic neural tone. Pharmacologic agents that influence afferent nerve activity can be subclassified into compounds that modulate activity by indirect means (e.g. bronchial smooth muscle spasmogens and those that act directly on the nerves. Directly acting agents affect afferent nerve activity by interacting with various ion channels and receptors within the membrane of the afferent terminals. Whether by direct or indirect means, most compounds that enter the airspace will modify afferent nerve activity, and through this action alter airway physiology.

  16. Characteristics of gray-scale ultrasonic images of acute closed renal trauma in rabbits%兔急性闭合性肾外伤的灰阶超声特征观察

    Institute of Scientific and Technical Information of China (English)

    袁桂忠; 李叶阔; 王莎莎; 许瑞雪; 周群芳; 李婷

    2013-01-01

    Objective To observe the dynamic characteristics of gray-scale ultrasonic images of acute blunt renal trauma (BRT) in rabbits.Methods The acute BRT model was reproduced in 9 New Zealand white rabbits by SMS impactor with a 106.2N impact force.The gray-scale ultrasonic images of kidneys before impact,and immediate to 1 hour after impact were observed dynamically and videotaped.Then the rabbits were sacrificed and the kidneys were harvested,the macroscopic injury was observed,and the histopathological changes were evaluated under light microscope after HE staining.Results Gray-scale ultrasonic examination revealed enhanced echo with irregular shapes and relatively clear margins in injured renal parenchyma,but the extent of damage detected by ultrasound was smaller than the actual damage; the sequence of echo was interrupted when renal pelvis was injured.The existence of active bleeding or bleeding stopped by spontaneous coagulation could be judged preliminarily according to the amount of fluid under the renal capsule and the echo changes in injured area.Macroscopic examination revealed trauma of grade Ⅱ-Ⅳ in most rabbits.Histopathological examination revealed renal tissue injuries in different degrees.Macroscopic and microscopic hematuria could be seen in all rabbits.Conclusion Gray-scale ultrasound may be used to evaluate the trauma of renal parenchyma and pelvis,and roughly judge the existence of active bleeding and blood coagulation,but hard to estimate the degree of damage accurately.%目的 研究急性闭合性肾外伤(BRT)灰阶超声的动态变化特征.方法 健康新西兰大耳白兔9只,采用SMS型撞击器以106.2N的力量进行撞击建立急性BRT模型.撞击前行超声检查,采用高频灰阶超声全程观察撞击后1h声像图的变化情况并录制影像.然后处死实验动物,取出伤肾观察大体损伤情况,并行肾组织HE染色,光镜下观察病理组织学变化.结果 灰阶超声显示:肾实质损伤时,局部回声

  17. GABA in Paraventricular Nucleus Regulates Adipose Afferent Reflex in Rats.

    Directory of Open Access Journals (Sweden)

    Lei Ding

    Full Text Available Chemical stimulation of white adipose tissue (WAT induces adipose afferent reflex (AAR, and thereby causes a general sympathetic activation. Paraventricular nucleus (PVN is important in control of sympathetic outflow. This study was designed to investigate the role of γ-aminobutyric acid (GABA in PVN in regulating the AAR.Experiments were carried out in anesthetized rats. Renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP were continuously recorded. AAR was evaluated by the RSNA and MAP responses to electrical stimulation of the right epididymal WAT (eWAT afferent nerve. Electrical stimulation of eWAT afferent nerve increase RSNA. Bilateral microinjection of the GABAA receptor agonist isoguvacine or the GABAB receptor agonist baclofen attenuated the AAR. The effect of isoguvacine on the AAR was greater than that of baclofen. The GABAA receptor antagonist gabazine enhanced the AAR, while the GABAB receptor antagonist CGP-35348 had no significant effect on the AAR. Bilateral PVN microinjection of vigabatrin, a selective GABA-transaminase inhibitor, to increase endogenous GABA levels in the PVN abolished the AAR. The inhibitory effect of vigabatrin on the AAR was attenuated by the pretreatment with gabazine or CGP-35348. Pretreatment with combined gabazine and CGP-35348 abolished the effects of vigabatrin.Activation of GABAA or GABAB receptors in the PVN inhibits the AAR. Blockade of GABAA receptors in the PVN enhances the AAR. Endogenous GABA in the PVN plays an important role in regulating the AAR.

  18. Disposable rabbit

    Science.gov (United States)

    Lewis, Leroy C.; Trammell, David R.

    1986-01-01

    A disposable rabbit for transferring radioactive samples in a pneumatic transfer system comprises aerated plastic shaped in such a manner as to hold a radioactive sample and aerated such that dissolution of the rabbit in a solvent followed by evaporation of the solid yields solid waste material having a volume significantly smaller than the original volume of the rabbit.

  19. Disposal rabbit

    Science.gov (United States)

    Lewis, L.C.; Trammell, D.R.

    1983-10-12

    A disposable rabbit for transferring radioactive samples in a pneumatic transfer system comprises aerated plastic shaped in such a manner as to hold a radioactive sample and aerated such that dissolution of the rabbit in a solvent followed by evaporation of the solid yields solid waste material having a volume significantly smaller than the original volume of the rabbit.

  20. Effects of Acute Cold Exposure on Rabbit Heart, Liver and Renal Function%急性低温暴露对家兔心肝肾功能的影响

    Institute of Scientific and Technical Information of China (English)

    吴丽珍; 杜兴华; 雷艳; 蔡颖; 董兆君

    2013-01-01

    目的 探讨急性低温暴露对家兔心、肝、肾功能的影响.方法 15只家兔随机分为3组,20℃组、-20℃组、2℃组,每组5只.动物经腹腔注射麻醉后行左侧颈总动脉插管术,按分组分别置于20℃室温、2℃和-20 ℃实验冰柜中.各组在置于实验温度后0、30、60、90、120 min时间点经颈动脉插管采血并分离血浆,采用生化方法测定肝功能指标包括门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、碱性磷酸酶(ALP)、L-γ谷氨酰基转移酶(GGT);肾功能指标尿素(BU)、肌酐(CREA)、尿酸(UA);心肌酶谱指标包括门冬氨酸氨基转移酶(AST)、肌酸激酶(CK)及同工酶(CKMB)、乳酸脱氢酶(LDH)和α一羟丁酸脱氢酶(a-HBDH)的含量.结果 急性低温暴露能显著影响家兔心、肝、肾功能血生化指标,-20℃暴露组更明显.结论 急性低温暴露可对家兔心、肝、肾功能造成损伤,低温暴露强度越强损伤越明显.%Objective To explore the effects of acute cold exposure on the rabbits heart,liver and renal function.Methods 15 rabbits were randomly divided into 3 groups,20℃ group,-20℃ group and 2℃ group,with 5 rabbits in each group.Animals were anesthetized by intraperitoneal injection,then were treated with the left common carotid artery intubation.According to the grouping,they were exposed to freezer at 20℃,2 ℃ and-20 ℃,respectively.At 0,30,60,90 and 120 min after exposure,the blood was collected by the way of carotid intubation,and plasma was separated.Then,the biochemical method was used to determine the contents of liver function indexes including aspartate aminotransferase (AST),alanine aminotransferase (ALT),alkaline phosphatase (ALP) and L-γ-glutamyl transferase (GGT) ; of renal function indexes including urea (BU),creatinine (CREA),uric acid (UA) ; and of heart function indexes including aspartate aminotransferase myocardial enzyme (AST),creatine kinase (CK) and isoenzyme (CKMB

  1. Impact of Pregnancy on Underlying Renal Disease

    OpenAIRE

    Baylis, Chris

    2003-01-01

    Normal pregnancy involves marked renal vasodilation and large increases in glomerular filtration rate (GFR). Studies in rats reveal that the gestational renal vasodilation is achieved by parallel reductions in tone in afferent and efferent arterioles so GFR rises without a change in glomerular blood pressure. There is some evidence from animal studies that increased renal generation of nitric oxide (NO) may be involved. Although chronic renal vasodilation has been implicated in causing progre...

  2. Effects of combined parenteral vitamins C and E administration on the severity of anaemia, hepatic and renal damage in Trypanosoma brucei brucei infected rabbits.

    Science.gov (United States)

    Umar, I A; Wuro-Chekke, A U; Gidado, A; Igbokwe, I O

    1999-08-16

    Rabbits infected with Trypanosoma brucei brucei (Basa isolate) were intraperitoneally administered with vitamins C and E at 100 mg/kg and 10 mg/kg body weight, respectively, from day 7 before infection to day 12 post-infection (p.i.). Another group of rabbits were similarly infected, but received no vitamin treatment. The uninfected (control) rabbits were either untreated or treated with vitamins like the infected group. Treatment of the infected animals did not affect the onset and level of parasitaemia. On day 12 p.i., the anaemia tended to be ameliorated, but insignificantly, by the treatment. The infection increased (pvitamins boosted their storage in hepatic cells, but not in erythrocytes and glomeruli, to annul any cellular injury due to infection. It is concluded that this may be an indirect evidence that the hepatic damage may be principally due to oxidative injury.

  3. INHIBITORY EFFECTS OF NITRIC OXIDE AND ATRIAL NATRI- URETIC PEPTIDE ON THE INCREASE IN RENAL AFFERENT NERVE ACTIVITY INDUCED BY INTR ARENAL ARTERIAL INJECTION OF ET-1 IN ANESTHETIZED RATS%NO和ANP对内皮素引起大鼠肾神经 传入放电增加的阻抑作用

    Institute of Scientific and Technical Information of China (English)

    夏晓红; 何瑞荣

    2001-01-01

    目的和方法:采用电生理学技术观察一氧化氮(NO)和心房钠尿肽(A NP)对肾动脉内注射内皮索(ET)所致麻醉大鼠肾神经传入放电(RANA)的影响。结 果:①肾动脉内注射ET-1后平均动脉压(MAP)先有短暂的降低随后为较显著的持 久增高,RANA明显增加;②肾动脉内分别注射NO前体L-Arg和ANP后,ET-1的上述效应 即被阻抑。结论:肾动脉内注射ET-1引起RANA明显增加,而此效应可 被同一途径注射NO和ANP所消除。%By using electrophysiological technique, the effects of nitric oxide (NO) and atrial natriuretic peptide (ANP) on renal afferent nerve activity (RANA) induced by intrarenal arterial injection of endothelin-1(ET-1) were examined in anesthetized rat. Results: (1) In response to intrarenal arterial injection of ET-1 (1μg/kg)MAP was initially decreased and subsequently increased, and RANA was increased to 208.33±16.60%(P<0.001). ( 2)Pretreatment with L-Arg or ANP could effectively inhibit the above biological actions induced by ET-1. Conclusion: Intrarenal arterial in jection of ET-1 can markedly induce the increase in RANA, an effect which is ab olishd by L-arg or ANP administered by the same route.

  4. Effect of polyethylene oxide on renal hemodynamics in rabbits with endotoxin shock%聚环氧乙烷对内毒素休克兔肾血流动力学的影响

    Institute of Scientific and Technical Information of China (English)

    方琴; 胡振华; 陈仲清; 段星星; 陈辉; 傅卫军; 魏红云

    2012-01-01

    Objective To investigate the effect of polyethylene oxide (PEO) on renal blood flow and its renoprotective effect in rabbits with endotoxin sepsis.Methods Twenty normal New Zealand white rabbits were randomly divided into normal saline (NS) group and PEO group (n=10),and endotoxin shock was induced by an intravenous injection of 0.6 mg/kg lipopolysaccharide.Resuscitation was performed when the blood pressure of the rabbits showed a 30% decline,using NS (in NS group) or the mixture of equal volumes of NS and 20 ng/g PEO (in PEO group) perfused at the rate of 5 ml/kg per hour.Before and during shock and at 1 h after resuscitation,the renal hemodynamics was monitored by ultrasound and the venous blood was extracted to examine the renal functions.The heart rate and arterial blood pressure were monitored throughout the experiment.Results The rabbits in both groups showed a significantly lower renal artery blood flow velocity during the shock (P<0.05) with significantly increased pulsatility index (PI) and resistance index (RI) compared with those before the shock.One hour after resuscitation,the blood flow velocity in the renal arteries at all levels and the tertiary veins were reduced in NS group without obvious reduction of the PI and RI; in PEO group,the blood flow velocities in the renal arteries increased significantly compared to those before shock (P<0.05),and the PI and RI of the tertiary arteries were significantly lower than those in NS group (P<0.05).In both groups,BUN and Cr increased during endotoxin shock stage,and 1 h after resuscitation,PEO group showed significantly lower BUN and Cr levels than NS group (P<0.05).Conclusion A small dose of PEO can significantly promote renal perfusion in rabbits with septic shock,thus offering renoprotective effect against early damage in septicopyemia and septic shock.%目的 应用超声监测内毒素休克新西兰免肾血流,观察聚环氧乙烷(PEO)对内毒素休克免肾血流的影响

  5. 声触诊组织定量技术评估兔慢性肾病肾纤维化的实验研究%Renal Fibrosis Assessment in Rabbits with Chronic Renal Nephropathy Using Virtual Touch Tissue Quantiifcation Technique:Experimental Study

    Institute of Scientific and Technical Information of China (English)

    陆敏; 杜联芳; 王迎春; 徐荣

    2014-01-01

    目的:建立新西兰兔慢性肾病模型,应用声触诊组织定量(VTQ)技术监测兔慢性肾病的发展,为VTQ评估慢性肾病肾纤维化提供实验依据。材料与方法选取38只健康新西兰大白兔,其中32只每天经耳缘静脉注射阳离子牛血清白蛋白(C-BSA)诱导慢性肾病模型,另外6只未注射C-BSA设为对照组。于0周、2周、4周、6周、8周采用VTQ测量兔肾皮质硬度,随后解剖兔,评估肾脏的病理变化,并分析VTQ参数与病理参数的相关性。结果兔肾皮质0周、2周、4周、6周、8周的VTQ值分别为(1.68±0.25)m/s、(1.70±0.31)m/s、(1.87±0.35)m/s、(2.19±0.31)m/s、(2.46±0.46)m/s,6周VTQ值与4周比较差异有统计学意义(P<0.05),8周VTQ值与4周、6周比较差异有统计学意义(P<0.05)。4周、6周、8周肾小球硬化指数分别为0.81±0.40、1.43±0.46、2.15±0.46,肾间质胶原纤维面积分别为(14.29±4.62)%、(26.28±11.06)%、(42.37±10.09)%,均明显高于0周、2周,且纤维化随病程进展逐渐增高,差异有统计学意义(P<0.05)。肾皮质VTQ与肾小球硬化指数、肾间质胶原纤维面积呈正相关(r=0.663、0.652, P<0.05)。结论VTQ可以检测到兔慢性肾病发展过程中肾皮质硬度增高,与肾纤维化呈正相关,提示VTQ可以成为评价肾纤维化的重要方法。%Purpose Chronic nephropathy model was established with New Zealand rabbit, and the development of chronic nephropathy was monitored using virtual touch tissue quantification (VTQ) technique, to provide the experimental basis for chronic renal fibrosis assessment using VTQ technique. Materials and Methods Thirty-eight healthy New Zealand white rabbits were selected, of which 32 were induced into chronic nephropathy model with daily intravenous ear vein injection of cationic bovine serum albumin (C-BSA), with the other 6 rabbits without C-BSA injection as control

  6. Interpretation of muscle spindle afferent nerve response to passive muscle stretch recorded with thin-film longitudinal intrafascicular electrodes.

    Science.gov (United States)

    Djilas, Milan; Azevedo-Coste, Christine; Guiraud, David; Yoshida, Ken

    2009-10-01

    In this study, we explored the feasibility of estimating muscle length in passive conditions by interpreting nerve responses from muscle spindle afferents recorded with thin-film longitudinal intrafascicular electrodes. Afferent muscle spindle response to passive stretch was recorded in ten acute rabbit experiments. A newly proposed first-order model of muscle spindle response to passive sinusoidal muscle stretch manages to capture the relationship between afferent neural firing rate and muscle length. We demonstrate that the model can be used to track random motion trajectories with bandwidth from 0.1 to 1 Hz over a range of 4 mm with a muscle length estimation error of 0.3 mm (1.4 degrees of joint angle). When estimation is performed using four-channel ENG there is a 50% reduction in estimate variation, compared to using single-channel recordings.

  7. Blockade of chloride channels by DIDS stimulates renin release and inhibits contraction of afferent arterioles

    DEFF Research Database (Denmark)

    Jensen, B L; Skøtt, O

    1996-01-01

    arterioles with the chloride channel blocker 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). Renin secretion was equally enhanced by omission of extracellular calcium and by addition of 0.5 mM DIDS. The inhibitory effect of calcium was blocked by DIDS. The stimulatory effects of low calcium [with....... Norepinephrine (5 x 10(-7)-1 x 10(-6) M) and angiotensin II (1 x 10(-8)-10(-6) M) evoked reversible and dose-dependent contractions of microperfused rabbit afferent arterioles. DIDS (0.5 mM) did not affect the basal diameter of the arterioles but strongly inhibited the response to angiotensin II and attenuated...... the duration of the contractile response to norepinephrine. The results support the hypothesis that DIDS-sensitive calcium-activated chloride channels are involved in regulation of renin release and in the afferent arteriolar contraction after angiotensin II but do not play a pivotal role in the response...

  8. A Double-Blind, Double-Dummy, Flexible-Design Randomized Multicenter Trial: Early Safety of Single- Versus Divided-Dose Rabbit Anti-Thymocyte Globulin Induction in Renal Transplantation.

    Science.gov (United States)

    Stevens, R B; Wrenshall, L E; Miles, C D; Farney, A C; Jie, T; Sandoz, J P; Rigley, T H; Osama Gaber, A

    2016-06-01

    A previous nonblinded, randomized, single-center renal transplantation trial of single-dose rabbit anti-thymocyte globulin induction (SD-rATG) showed improved efficacy compared with conventional divided-dose (DD-rATG) administration. The present multicenter, double-blind/double-dummy STAT trial (Single dose vs. Traditional Administration of Thymoglobulin) evaluated SD-rATG versus DD-rATG induction for noninferiority in early (7-day) safety and tolerability. Ninety-five patients (randomized 1:1) received 6 mg/kg SD-rATG or 1.5 mg/kg/dose DD-rATG, with tacrolimus-mycophenolate maintenance immunosuppression. The primary end point was a composite of fever, hypoxia, hypotension, cardiac complications, and delayed graft function. Secondary end points included 12-month patient survival, graft survival, and rejection. Target enrollment was 165 patients with an interim analysis scheduled after 80 patients. Interim analysis showed primary end point noninferiority of SD-rATG induction (p = 0.6), and a conditional probability of <1.73% of continued enrollment producing a significant difference (futility analysis), leading to early trial termination. Final analysis (95 patients) showed no differences in occurrence of primary end point events (p = 0.58) or patients with no, one, or more than one event (p = 0.81), or rejection, graft, or patient survival (p = 0.78, 0.47, and 0.35, respectively). In this rigorously blinded trial in adult renal transplantation, we have shown SD-rATG induction to be noninferior to DD-rATG induction in early tolerability and equivalent in 12-month safety. (Clinical Trials.gov #NCT00906204.).

  9. The Influence of Fish Bile on the Renal Function of Rabbits and Preliminary Study on Its Mechanism%鱼胆汁对兔肾功能的影响及其机制初探

    Institute of Scientific and Technical Information of China (English)

    罗竞超; 任龙; 韩雨晨; 严翘; 米绪华; 马行一; 余卫平

    2012-01-01

    目的 探讨鱼胆汁对兔肾脏的影响及其机制.方法 将实验新西兰大耳白兔随机分为灌胃组(GP组,n=19)与静脉注射组(Ⅵ组,n=15),根据体重分别按3mL/kg、0.3mL/kg的剂量通过灌胃或耳缘静脉注射方式给予鱼胆汁.采集鱼胆汁处理前与处理后1~5 h的血标本,测定肾功能、酸碱平衡及电解质指标,记录GP组每个采样点前20min尿量及鱼胆汁处理前、处理后5h的尿常规.鱼胆汁处理后5h处死动物取肾做病理学检查.结果 给予一定量鱼胆汁后5h内,两组兔血肌酐(Scr)、尿素氮、K+呈升高趋势(P均<0.05),而血HCO3浓度呈下降趋势(P<0.05),其中Ⅵ组兔Scr、血K+改变早于GP组.GP组记录尿量明显下降,尿pH值升高,蛋白定量试验、隐血试验结果均呈阳性.两组兔肾组织病理检查均显示肾小球血管充盈,少量中性粒细胞浸润;肾小管水肿及间质充血,部分有局灶性出血,肾间质损伤较肾小球更为严重.结论 无论经由消化道还是血管给予实验兔鱼胆汁均可导致急性肾功能损伤,与鱼胆汁造成急性肾实质损伤、特别是肾小管间质损伤有关.%Objective To observe the influence offish bile on the renal function of rabbits and to explore its mechanism. Methods Rabbits were randomly split into bile gastric-perfusion group (GP group, n=19) and bile venous-injection group (VI group, n=15). A bile dose of 3 mL/kg and 0.3 mlVkg was given to rabbits in the above two groups respectively. The plasma indicators associated with renal function, water-electrolyte balance and acid-base balance were measured before and 1-5 hours after bile treatment, respectively. The amount of the urine every 20 minutes before collecting the blood samples was recorded, and pH of the urinary samples was determined. Urinary protein qualitative and occult blood tests were performed before and 5 hours after bile treatment in GP group. Finally, the kidneys of rabbits of both groups were

  10. Whisker-related afferents in superior colliculus.

    Science.gov (United States)

    Castro-Alamancos, Manuel A; Favero, Morgana

    2016-05-01

    Rodents use their whiskers to explore the environment, and the superior colliculus is part of the neural circuits that process this sensorimotor information. Cells in the intermediate layers of the superior colliculus integrate trigeminotectal afferents from trigeminal complex and corticotectal afferents from barrel cortex. Using histological methods in mice, we found that trigeminotectal and corticotectal synapses overlap somewhat as they innervate the lower and upper portions of the intermediate granular layer, respectively. Using electrophysiological recordings and optogenetics in anesthetized mice in vivo, we showed that, similar to rats, whisker deflections produce two successive responses that are driven by trigeminotectal and corticotectal afferents. We then employed in vivo and slice experiments to characterize the response properties of these afferents. In vivo, corticotectal responses triggered by electrical stimulation of the barrel cortex evoke activity in the superior colliculus that increases with stimulus intensity and depresses with increasing frequency. In slices from adult mice, optogenetic activation of channelrhodopsin-expressing trigeminotectal and corticotectal fibers revealed that cells in the intermediate layers receive more efficacious trigeminotectal, than corticotectal, synaptic inputs. Moreover, the efficacy of trigeminotectal inputs depresses more strongly with increasing frequency than that of corticotectal inputs. The intermediate layers of superior colliculus appear to be tuned to process strong but infrequent trigeminal inputs and weak but more persistent cortical inputs, which explains features of sensory responsiveness, such as the robust rapid sensory adaptation of whisker responses in the superior colliculus. Copyright © 2016 the American Physiological Society.

  11. Reticulospinal actions on primary afferent depolarization of cutaneous and muscle afferents in the isolated frog neuraxis.

    Science.gov (United States)

    González, H; Jiménez, I; Rudomin, P

    1993-01-01

    The effects of the brainstem reticular formation on the intraspinal excitability of low threshold cutaneous and muscle afferents were studied in the frog neuraxis isolated together with the right hindlimb nerves. Stimulation of low threshold fibers (less than two times threshold) in cutaneous nerves produced short latency, negative field potentials in the ipsilateral dorsal neuropil (200-400 microns depth) that reversed to positivity at deeper regions (500-700 microns). Stimulation of low threshold fibers (less than two times threshold) in muscle nerves produced, instead, negative response that acquired their maximum amplitude in the ventral neuropil (700-900 microns depth). These electrophysiological findings suggest, in agreement with observations in the cat, that low threshold cutaneous and muscle afferents end at different sites in the spinal cord. Intraspinal microstimulation applied within the dorsal neuropil produced antidromic responses in low threshold cutaneous afferents that were increased in size following stimulation of the dorsal or ventral roots, as well as of the brainstem reticular formation. This increase in excitability is interpreted as being due to primary afferent depolarization (PAD) of the intraspinal terminals of cutaneous fibers. Antidromic responses recorded in muscle nerves following intraspinal stimulation within the ventral neuropil were also increased following conditioning stimulation of adjacent dorsal or ventral roots. However, stimulation of the bulbar reticular formation produced practically no changes in the antidromic responses, but was able to inhibit the PAD of low threshold muscle afferents elicited by stimulation of the dorsal or ventral roots. It is suggested that the PAD of low threshold cutaneous and muscle afferents is mediated by independent sets of interneurons. Reticulospinal fibers would have excitatory connections with the interneurons mediating the PAD of cutaneous fibers and inhibitory connections with the

  12. Copy of Acute Renal Failure in Rabbits and Experimental Treatment%急性肾衰竭动物模型的复制及实验性治疗

    Institute of Scientific and Technical Information of China (English)

    葛贺; 李冰; 黄晓莉; 杨丽娟; 陈立松; 芦丽莉; 刘艳波

    2013-01-01

    Objective To copy the acute renal failure ( ARF) animal model and execute an experimental treatment of it in rabbits, to lay a foundation for the implementation of comprehensive experiment for undergraduate students. Method ARF model was set up through the injection of 50% glycerol (10 mL/kg). All the rabbits were monitored with ECG, Sodium bicarbonate solution, furosemide solution and CaCl2 solution were infused through the external jugular vein to the rabbits in the treatment group. Serum urea nitrogen ( BUN), serum creatinine (Cre)level,plasma pH,urine volume and urine creatinine changes of the rabbits were detected after 24 hours. Results The application of 50% glycerol intramuscular injection could replicate typical animal models with acute renal failure. Serum BUN and Cre levels concentration in the model group were obviously higher than those in the negative control group, the urine Cre concentration was also higher, while the urine volume per minute was less and a metabolic acidosis happened at the same time. In the treatment group, serum BUN and Cre levels were significantly lower than those in the model group, while urine volume per minute was more than that in the control group, and the metabolic acidosis was improved. The blood pressure of animals in the treatment group was a litter higher,but there was no difference compared with that in the negative control group, T wave was high and giant, and the QRS wave was widened in the model group compared with those in the negative control group. After the treatment,ECG of the animals in the model group gradually returned to normal state. Conclusion The method of intramuscular injection of 50% glycerol could be reliable to replicate the animal model with acute renal failure, and can be taken as a comprehensive experimental teaching method and widely used in the teaching of medical functional experiment.%目的 复制家免急性肾衰竭动物模型并进行实验性治疗,为本科学生综合性实

  13. Unmyelinated visceral afferents exhibit frequency dependent action potential broadening while myelinated visceral afferents do not.

    Science.gov (United States)

    Li, Bai-Yan; Feng, Bin; Tsu, Hwa Y; Schild, John H

    2007-06-21

    Sensory information arising from visceral organ systems is encoded into action potential trains that propagate along afferent fibers to target nuclei in the central nervous system. These information streams range from tight patterns of action potentials that are well synchronized with the sensory transduction event to irregular, patternless discharge with no clear correlation to the sensory input. In general terms these afferent pathways can be divided into unmyelinated and myelinated fiber types. Our laboratory has a long standing interest in the functional differences between these two types of afferents in terms of the preprocessing of sensory information into action potential trains (synchrony, frequency, duration, etc.), the reflexogenic consequences of this sensory input to the central nervous system and the ionic channels that give rise to the electrophysiological properties of these unique cell types. The aim of this study was to determine whether there were any functional differences in the somatic action potential characteristics of unmyelinated and myelinated vagal afferents in response to different rates of sensory nerve stimulation. Our results showed that activity and frequency-dependent widening of the somatic action potential was quite prominent in unmyelinated but not myelinated vagal afferents. Spike broadening often leads to increased influx of Ca(2+) ions that has been associated with a diverse range of modulatory mechanisms both at the cell body and central synaptic terminations (e.g. increased neurotransmitter release.) We conclude that our observations are indicative of fundamentally different mechanisms for neural integration of sensory information arising from unmyelinated and myelinated vagal afferents.

  14. Renal vascular effects of calcium channel blockers in hypertension.

    Science.gov (United States)

    Benstein, J A; Dworkin, L D

    1990-12-01

    Recent evidence suggests that calcium channel blockers have specific effects on renal hemodynamics in patients with hypertension and may also slow the progression of chronic renal failure. When these agents are studied in vitro, their predominant effect is to reverse afferent arteriolar vasoconstriction induced by catecholamines or angiotensin II. Because efferent resistance may remain high, glomerular filtration rate rises while renal blood flow remains low. The effects in vivo are less consistent. In human hypertension, calcium channel blockers lower renal resistance and may raise both renal blood flow and glomerular filtration rate. In experimental models of chronic renal disease, calcium channel blockers slow the progression of renal damage; however, variable effects on renal hemodynamics have been found. Other factors implicated in the progression of renal damage, including compensatory renal hypertrophy, platelet aggregation, and calcium deposition, may also be favorably influenced by these agents. Recent studies suggest that calcium channel blockers may have similar protective effects in patients with hypertension and chronic renal disease.

  15. 前列地尔对兔肾缺血再灌注时细胞凋亡的保护作用%Alprostadil effects of prostavasin on apoptosis by renal ischemia-reperfusion injury in rabbits

    Institute of Scientific and Technical Information of China (English)

    郭凌燕; 胡世雄

    2011-01-01

    Objective To study the alprostadil effects of alprostadil on apoptosis by renal ischemia-reperfusion injury (IR[) in rabbits. Methods The rabbit IRI models were made, and randourly divided into three groups: control group, IR[group and prostavasin intervention group. The creatinine (Ct) and blood urea nitrogen (BUN) were determined. Malondialdehyde ( MDA), superoxide dismutase (SOD),myeloperoxidase ( MPO), bcl-2, bax, Caspase-3 and apoptosis were assayed at 60 min after reperfusion.Results The Cr and BUN levels in plasma in IRI group and Prostavasin intervention group were increased obviously after reperfusion. The Cr levels at 60 min after repeffusion in alprostadil intervention group (231.32 + 17. 57 ) μmol/L were significantly lower than in IRI group ( 390. 61 ± 20. 42 ) μ mol/L, ( P <0. 05 ). The levels of bcl-2, bax, Caspase-3 in the renal tissue in IRI group were significantly higher than in control group ( P < 0. 05 ), and those in alprostadil intervention group were lower than in IRI group, but markedly higher than in control group (P < 0. 05 ). The number of apoptotic cells in alprostadil intervention group and IRI group was increased as compared with control group, and that in alprostadil intervention group was reduced as compared with IRI group. The contents of MDA, SOD and MPO in renal tissue of IRI group and Prostavasin intervention group were significantly higher than in control group ( P < 0. 05 ), and those in IRI group were significantly lower than in alprostadil intervention group (P <0. 05 ). Conclusion Alprostadil could be used to protect renal ischemia-reperfusion injury probably by decreasing oxygen free radicals generation, inhibiting neutrophils aggregating and activating in the renal tissues, thereby inhibiting the expression of bcl-2, bax, Caspase-3.%目的 观察前列地尔对兔肾缺血再灌注损伤时肾小管上皮细胞凋亡的保护作用.方法 建立兔肾缺血再灌注损伤动物模型,将实验兔随机分为3

  16. Rabbit hematology.

    Science.gov (United States)

    Marshall, Kemba L

    2008-09-01

    Using laboratory animal medicine as an established resource, companion animal veterinarians have access to many physiologic and basic science studies that we can now merge with our clinical impressions. By working with reference laboratories, companion animal veterinarians are poised to accelerate our knowledge of the normal rabbit rapidly. The aim of this article is to discuss normal hematopoiesis and infectious and metabolic diseases that specifically target the hemolymphatic system. Additionally, photographic representation of cell types is provided.

  17. Pain processing by spinal microcircuits: afferent combinatorics.

    Science.gov (United States)

    Prescott, Steven A; Ratté, Stéphanie

    2012-08-01

    Pain, itch, heat, cold, and touch represent different percepts arising from somatosensory input. How stimuli give rise to these percepts has been debated for over a century. Recent work supports the view that primary afferents are highly specialized to transduce and encode specific stimulus modalities. However, cross-modal interactions (e.g. inhibition or exacerbation of pain by touch) support convergence rather than specificity in central circuits. We outline how peripheral specialization together with central convergence could enable spinal microcircuits to combine inputs from distinctly specialized, co-activated afferents and to modulate the output signals thus formed through computations like normalization. These issues will be discussed alongside recent advances in our understanding of microcircuitry in the superficial dorsal horn.

  18. Estimation of the number of angiotensin II AT1 receptors in rat kidney afferent and efferent arterioles

    DEFF Research Database (Denmark)

    Razga, Zsolt; Nyengaard, Jens Randel

    2007-01-01

    of angiotensin II AT1 receptors along the length of the arterioles and per arteriole, we combined immunoelectron microscopy with stereology. RESULTS: The number of AT1 receptor molecules was significantly lower in the renin-positive smooth muscle cells (SMCs) than in the renin-negative SMCs of the afferent......OBJECTIVE: To examine the effects of the renin-angiotensin system (RAS) on renal arterioles to determine the association between the distribution of angiotensin II AT1 receptors and the morphologic and physiologic heterogeneity of renal arterioles. STUDY DESIGN: To estimate the number...... and efferent arterioles. There were no significant differences along and between the afferent and efferent arterioles in relative number of AT1 receptors of endothelial cells or SMCs. CONCLUSION: Our results suggest that the heterogeneous activity of angiotensin II in SMCs and the different permeabilities...

  19. Models of utricular bouton afferents: role of afferent-hair cell connectivity in determining spike train regularity.

    Science.gov (United States)

    Holmes, William R; Huwe, Janice A; Williams, Barbara; Rowe, Michael H; Peterson, Ellengene H

    2017-05-01

    Vestibular bouton afferent terminals in turtle utricle can be categorized into four types depending on their location and terminal arbor structure: lateral extrastriolar (LES), striolar, juxtastriolar, and medial extrastriolar (MES). The terminal arbors of these afferents differ in surface area, total length, collecting area, number of boutons, number of bouton contacts per hair cell, and axon diameter (Huwe JA, Logan CJ, Williams B, Rowe MH, Peterson EH. J Neurophysiol 113: 2420-2433, 2015). To understand how differences in terminal morphology and the resulting hair cell inputs might affect afferent response properties, we modeled representative afferents from each region, using reconstructed bouton afferents. Collecting area and hair cell density were used to estimate hair cell-to-afferent convergence. Nonmorphological features were held constant to isolate effects of afferent structure and connectivity. The models suggest that all four bouton afferent types are electrotonically compact and that excitatory postsynaptic potentials are two to four times larger in MES afferents than in other afferents, making MES afferents more responsive to low input levels. The models also predict that MES and LES terminal structures permit higher spontaneous firing rates than those in striola and juxtastriola. We found that differences in spike train regularity are not a consequence of differences in peripheral terminal structure, per se, but that a higher proportion of multiple contacts between afferents and individual hair cells increases afferent firing irregularity. The prediction that afferents having primarily one bouton contact per hair cell will fire more regularly than afferents making multiple bouton contacts per hair cell has implications for spike train regularity in dimorphic and calyx afferents.NEW & NOTEWORTHY Bouton afferents in different regions of turtle utricle have very different morphologies and afferent-hair cell connectivities. Highly detailed computational

  20. Modulation of long-latency afferent inhibition by the amplitude of sensory afferent volley.

    Science.gov (United States)

    Turco, Claudia V; El-Sayes, Jenin; Fassett, Hunter J; Chen, Robert; Nelson, Aimee J

    2017-07-01

    Long-latency afferent inhibition (LAI) is the inhibition of the transcranial magnetic stimulation (TMS) motor-evoked potentials (MEP) by the sensory afferent volley following electrical stimulation of a peripheral nerve. It is unknown how the activation of sensory afferent fibers relates to the magnitude of LAI. This study investigated the relationship between LAI and the sensory nerve action potentials (SNAP) from the median nerve (MN) and the digital nerves (DN) of the second digit. LAI was obtained by delivering nerve stimulation 200 ms before a TMS pulse delivered over the motor cortex. Experiment 1 assessed the magnitude of LAI following stimulation of the contralateral MN or DN using nerve stimulus intensities relative to the maximum SNAP (SNAPmax) of that nerve and two TMS intensities (0.5- and 1-mV MEP). Results indicate that MN LAI is maximal at ~50% SNAPmax, when presumably all sensory afferents are recruited for TMS of 0.5-mV MEP. For DN, LAI appears at ~50% SNAPmax and does not increase with further recruitment of sensory afferents. Experiment 2 investigated the magnitude of LAI following ipsilateral nerve stimulation at intensities relative to SNAPmax Results show minimal LAI evoked by ipsilateral MN and no LAI following ipsilateral DN stimulation. Implications for future studies investigating LAI include adjusting nerve stimulation to 50% SNAPmax to obtain maximal LAI. Additionally, MN LAI can be used as a marker for neurological disease or injury by using a nerve stimulation intensity that can evoke a depth of LAI capable of increasing or decreasing.NEW & NOTEWORTHY This is the first investigation of the relationship between long-latency afferent inhibition (LAI) and the sensory afferent volley. Differences exist between median and digital nerve LAI. For the median nerve, LAI increases until all sensory fibers are presumably recruited. In contrast, digital nerve LAI does not increase with the recruitment of additional sensory fibers but rather is

  1. MR imaging findings of renal infarction induced by renal artery

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jun Woo; Kim, Suck; Kim, Yong Woo; Hu, Jin Sam; Choi, Sang Yoel; Moon, Tae Yong; Lee, Suck Hong; Kim, Byung Su; Lee, Chang Hun [Pusan National Univ., Pusan (Korea, Repulic of). Coll. of Medicine

    1998-02-01

    To assess the usefulness of diffusion-weighted imaging (DWI) in evaluating serial parenchymal changes in renal infarction induced by renal artery ligation, by comparing this with the conventional spin echo technique and correlating the results with the histopathological findings. In 22 rabbits, renal infarction was induced by ligation of the renal artery. Spin-echo T1-weighted imaging (T1WI), turbo spin-echo (TSE) T2-weighted imaging (T2WI), and DWI were performed, using a 1.5-T superconductive unit, at 30 minutes, 1 hour, 2,3,6, 12 and 24 hours, and 2, 3, 7 and 20 days after left renal artery ligation. Changes in signal intensity on T1WI, T2WI, and DWI were correlated with histopathologic findings. Diffusion-weighted imaging is useful for the detection of hyperacute renal infarction, and the apparent diffusion coefficient may provide additional information concerning its evolution. (author). 21 refs., 9 figs.

  2. Hair-Cell Versus Afferent Adaptation in the Semicircular Canals

    OpenAIRE

    Rabbitt, R. D.; Boyle, R.; Holstein, G. R.; Highstein, S. M.

    2004-01-01

    The time course and extent of adaptation in semicircular canal hair cells was compared to adaptation in primary afferent neurons for physiological stimuli in vivo to study the origins of the neural code transmitted to the brain. The oyster toadfish, Opsanus tau, was used as the experimental model. Afferent firing-rate adaptation followed a double-exponential time course in response to step cupula displacements. The dominant adaptation time constant varied considerably among afferent fibers an...

  3. K+ Currents in Isolated Vestibular Afferent Calyx Terminals

    National Research Council Canada - National Science Library

    Dhawan, Ritu; Mann, Scott E; Meredith, Frances L; Rennie, Katherine J

    2010-01-01

    Vestibular hair cells transduce mechanical displacements of their hair bundles into an electrical receptor potential which modulates transmitter release and subsequent action potential firing in afferent neurons...

  4. Clinical symptoms and diagnosis of encephalitozoonosis in pet rabbits.

    Science.gov (United States)

    Künzel, Frank; Gruber, Andrea; Tichy, Alexander; Edelhofer, Renate; Nell, Barbara; Hassan, Jasmin; Leschnik, Michael; Thalhammer, Johann G; Joachim, Anja

    2008-02-14

    Infections with Encephalitozoon cuniculi in rabbits are observed at increasing frequency and are known as opportunistic infections in immunocompromised humans. 191 pet rabbits with suspected encephalitozoonosis, presented at the Animal Hospital of the Veterinary University of Vienna (Austria), were included in this study. Rabbits were serologically examined for antibodies against E. cuniculi (144 positive out of 184 rabbits with suspected encephalitozoonosis compared to 14 positive out of 40 clinically healthy rabbits tested as part of a standard health check) and Toxoplasma gondii (8 positive out of 157). Of the 144 seropositive rabbits with clinical signs, 75% showed neurological symptoms, 14.6% demonstrated phacoclastic uveitis and 3.5% suffered from renal failure. 6.9% of the animals had combined symptoms. Vestibular disease dominated within the rabbits that showed neurological symptoms. Polymerase chain reaction (PCR) could not detect parasite DNA in urine or cerebrospinal fluid (CSF), but did so in 4 out of 5 samples of liquefied lens material in cases with phacoclastic uveitis due to lens capsule rupture. Additionally further diagnostic procedures, such as inspection of the external ear canal (N=69), radiography of the tympanic bullae (N=65) were performed to rule out differential diagnosis. 54.2% of the patients exhibiting neurological symptoms recovered within a few days, while 87.5% of the rabbits suffering from renal failure died or had to be euthanized.

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

    Science.gov (United States)

    Hausberg, M; Tokmak, F

    2013-11-01

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

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

    Science.gov (United States)

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

    2012-11-01

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

  7. Extraocular muscle afferent signals modulate visual attention.

    Science.gov (United States)

    Balslev, Daniela; Newman, William; Knox, Paul C

    2012-10-09

    Extraocular muscle afferent signals contribute to oculomotor control and visual localization. Prompted by the close links between the oculomotor and attention systems, it was investigated whether these proprioceptive signals also modulated the allocation of attention in space. A suction sclera contact lens was used to impose an eye rotation on the nonviewing, dominant eye. With their viewing, nondominant eye, participants (n = 4) fixated centrally and detected targets presented at 5° in the left or right visual hemifield. The position of the viewing eye was monitored throughout the experiment. As a control, visual localization was tested using finger pointing without visual feedback of the hand, whereas the nonviewing eye remained deviated. The sustained passive rotation of the occluded, dominant eye, while the other eye maintained central fixation, resulted in a lateralized change in the detectability of visual targets. In all participants, the advantage in speed and accuracy for detecting right versus left hemifield targets that occurred during a sustained rightward eye rotation of the dominant eye was reduced or reversed by a leftward eye rotation. The control experiment confirmed that the eye deviation procedure caused pointing errors consistent with an approximately 2° shift in perceived eye position, in the direction of rotation of the nonviewing eye. With the caveat of the small number of participants, these results suggest that extraocular muscle afferent signals modulate the deployment of attention in visual space.

  8. Impact of pregnancy on underlying renal disease.

    Science.gov (United States)

    Baylis, Chris

    2003-01-01

    Normal pregnancy involves marked renal vasodilation and large increases in glomerular filtration rate (GFR). Studies in rats reveal that the gestational renal vasodilation is achieved by parallel reductions in tone in afferent and efferent arterioles so GFR rises without a change in glomerular blood pressure. There is some evidence from animal studies that increased renal generation of nitric oxide (NO) may be involved. Although chronic renal vasodilation has been implicated in causing progression of renal disease in nonpregnant states by glomerular hypertension, there are no long-term deleterious effects of pregnancies on the kidney when maternal renal function is normal because glomerular blood pressure remains normal. When maternal renal function is compromised before conception, there are no long-term adverse effects on renal function in most types of renal disease, providing that the GFR is well maintained before conception. When serum creatinine exceeds approximately 1.4 mg/dL, pregnancy may accelerate the renal disease increases and when serum creatinine >2 mg/dL, the chances are greater than 1 in 3 that pregnancy will hasten the progression of the renal disease. The available animal studies suggest that glomerular hypertension does not occur despite diverse injuries. Thus, the mechanisms of the adverse interaction between pregnancy and underlying renal disease remain unknown.

  9. TRPA1 Mediates Amplified Sympathetic Responsiveness to Activation of Metabolically Sensitive Muscle Afferents in Rats with Femoral Artery Occlusion

    Directory of Open Access Journals (Sweden)

    Jihong eXing

    2015-09-01

    Full Text Available Autonomic responses to stimulation of mechanically and metabolically sensitive muscle afferent nerves during static contraction are augmented in rats with femoral artery occlusion. Moreover, metabolically sensitive transient receptor potential cation channel subfamily A, member 1 (TRPA1 has been reported to contribute to sympathetic nerve activity (SNA and arterial blood pressure (BP responses evoked by static muscle contraction. Thus, in the present study, we examined the mechanisms by which afferent nerves’ TRPA1plays a role in regulating amplified sympathetic responsiveness due to a restriction of blood flow directed to the hindlimb muscles. Our data show that 24-72 hrs of femoral artery occlusion 1 upregulates the protein levels of TRPA1 in dorsal root ganglion (DRG tissues; 2 selectively increases expression of TRPA1 in DRG neurons supplying metabolically sensitive afferent nerves of C-fiber (group IV; and 3 enhances renal SNA and BP responses to AITC (a TRPA1 agonist injected into the arterial blood supply of the hindlimb muscles. In addition, our data demonstrate that blocking TRPA1 attenuates SNA and BP responses during muscle contraction to a greater degree in ligated rats than those responses in control rats. In contrast, blocking TRPA1 fails to attenuate SNA and BP responses during passive tendon stretch in both groups. Overall, results of this study indicate that alternations in muscle afferent nerves’TRPA1 likely contribute to enhanced sympathetically mediated autonomic responses via the metabolic component of the muscle reflex under circumstances of chronic muscle ischemia.

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

    Science.gov (United States)

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

    2016-08-03

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

  11. Viral infections of rabbits.

    Science.gov (United States)

    Kerr, Peter J; Donnelly, Thomas M

    2013-05-01

    Viral diseases of rabbits have been used historically to study oncogenesis (e.g. rabbit fibroma virus, cottontail rabbit papillomavirus) and biologically to control feral rabbit populations (e.g. myxoma virus). However, clinicians seeing pet rabbits in North America infrequently encounter viral diseases although myxomatosis may be seen occasionally. The situation is different in Europe and Australia, where myxomatosis and rabbit hemorrhagic disease are endemic. Advances in epidemiology and virology have led to detection of other lapine viruses that are now recognized as agents of emerging infectious diseases. Rabbit caliciviruses, related to rabbit hemorrhagic disease, are generally avirulent, but lethal variants are being identified in Europe and North America. Enteric viruses including lapine rotavirus, rabbit enteric coronavirus and rabbit astrovirus are being acknowledged as contributors to the multifactorial enteritis complex of juvenile rabbits. Three avirulent leporid herpesviruses are found in domestic rabbits. A fourth highly pathogenic virus designated leporid herpesvirus 4 has been described in Canada and Alaska. This review considers viruses affecting rabbits by their clinical significance. Viruses of major and minor clinical significance are described, and viruses of laboratory significance are mentioned. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Chicken (Gallus domesticus) inner ear afferents

    Science.gov (United States)

    Hara, H.; Chen, X.; Hartsfield, J. F.; Hara, J.; Martin, D.; Fermin, C. D.

    1998-01-01

    Neurons from the vestibular (VG) and the statoacoustic (SAG) ganglion of the chick (Gallus domesticus) were evaluated histologically and morphometrically. Embryos at stages 34 (E8 days), 39 (E13 days) and 44 (E18 days) were sacrificed and temporal bones microdissected. Specimens were embedded in JB-4 methacrylate plastic, and stained with a mixture of 0.2% toluidine blue (TB) and 0.1% basic Fuschin in 25% ethanol or with a mixture of 2% TB and 1% paraphenylenediamine (PDA) for axon and myelin measurement study. Images of the VIIIth nerve were produced by a V150 (R) color imaging system and the contour of 200-300 neuronal bodies (perikarya) was traced directly on a video screen with a mouse in real time. The cross-sectional area of VG perikarya was 67.29 micrometers2 at stage 34 (E8), 128.46 micrometers2 at stage 39 (E13) and 275.85 micrometers2 at stage 44 (E18). The cross-sectional area of SAG perikarya was 62.44 micrometers2 at stage 34 (E8), 102.05 micrometers2 at stage 39 (E13) and 165.02 micrometers2 at stage 44 (E18). A significant cross-sectional area increase of the VG perikarya between stage 39 (E13) and stage 44 (E18) was determined. We randomly measured the cross-sectional area of myelin and axoplasm of hatchling afferent nerves, and found a correspondence between axoplasmic and myelin cross-sectional area in the utricular, saccular and semicircular canal nerve branches of the nerve. The results suggest that the period between stage 34 (E8) and 39 (E13) is a critical period for afferent neuronal development. Physiological and behavioral vestibular properties of developing and maturing hatchlings may change accordingly. The results compliment previous work by other investigators and provide valuable anatomical measures useful to correlate physiological data obtained from stimulation of the whole nerve or its parts.

  13. The Rabbit Stream Cipher

    DEFF Research Database (Denmark)

    Boesgaard, Martin; Vesterager, Mette; Zenner, Erik

    2008-01-01

    The stream cipher Rabbit was first presented at FSE 2003, and no attacks against it have been published until now. With a measured encryption/decryption speed of 3.7 clock cycles per byte on a Pentium III processor, Rabbit does also provide very high performance. This paper gives a concise...... description of the Rabbit design and some of the cryptanalytic results available....

  14. Power doppler ultrasound findings of renal infarct after experimental renal artery occlusion: comparison with spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Eun; Shinn, Kyung Sub; Kim, Hak Hee; Mun, Seok Hwan; Lee, Young Joon; Lee, Bae Young; Choi, Byung Gil; Lee, Jae Mun; Lee, Hee Jeong [The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

    1999-02-01

    To evaluate the efficacy of power Doppler ultrasonography (PDUS) in depicting renal infarction in rabbits during experimental renal segmental arterial occlusion, and to compare the results with those of CT scanning. In 28 rabbits weighing 2.5 4kg, the segmental renal artery was occluded through the left main renal artery by embolization with Ivalon (Nycomed, Paris, France). Power Doppler ultrasonography and spiral CT scanning were performed before and at 2, 5, 8, 15, and 24 hours, and 3 and 7 days after occlusion of the segmental renal artery. The location of infarcted areas and collaterals, as seen on PDUS and CT scans, was evaluated by two radiologists. In all cases, as seen on power Doppler ultrasonography, infarcted areas-when compared with normal parenchyma, clearly demonstrated wedge-shaped perfusion defects in the kidney. The location of the lesion closely corresponded to the location seen during CT scanning. After renal arterial occlusion, transiently congested capsular arteries, which were named 'capsular sign', were seen in 63% of rabbits in the two and five-hour groups. No significant cortical rim sign was demonstrated on power Doppler ultrasonography, though it was noted on spiral CT at 15 and 24 hours, and 3 and 7 days after renal arterial occlusion. Power Doppler ultrasonography was useful for the diagnosis of renal infarction. Congested capsular artery seen in the early stage of renal infarction might be a characteristic finding of this condition, as seen on power Doppler ultrasonography.

  15. Patterns of primary afferent depolarization of segmental and ascending intraspinal collaterals of single joint afferents in the cat.

    Science.gov (United States)

    Rudomin, P; Lomelí, J

    2007-01-01

    We have examined in the anesthetized cat the threshold changes produced by sensory and supraspinal stimuli on intraspinal collaterals of single afferents from the posterior articular nerve (PAN). Forty-eight fibers were tested in the L3 segment, in or close to Clarke's column, and 70 fibers in the L6-L7 segments within the intermediate zone. Of these, 15 pairs of L3 and L6-L7 collaterals were from the same afferent. Antidromically activated fibers had conduction velocities between 23 and 74 m/s and peripheral thresholds between 1.1 and 4.7 times the threshold of the most excitable fibers (xT), most of them below 3 xT. PAN afferents were strongly depolarized by stimulation of muscle afferents and by cutaneous afferents, as well as by stimulation of the bulbar reticular formation and the midline raphe nuclei. Stimulation of muscle nerves (posterior biceps and semitendinosus, quadriceps) produced a larger PAD (primary afferent depolarization) in the L6-L7 than in the L3 terminations. Group II were more effective than group I muscle afferents. As with group I muscle afferents, the PAD elicited in PAN afferents by stimulation of muscle nerves could be inhibited by conditioning stimulation of cutaneous afferents. Stimulation of the cutaneous sural and superficial peroneal nerves increased the threshold of few terminations (i.e., produced primary afferent hyperpolarization, PAH) and reduced the threshold of many others, particularly of those tested in the L6-L7 segments. Yet, there was a substantial number of terminals where these conditioning stimuli had minor or no effects. Autogenetic stimulation of the PAN with trains of pulses increased the intraspinal threshold in 46% and reduced the threshold in 26% of fibers tested in the L6-L7 segments (no tests were made with trains of pulses on fibers ending in L3). These observations indicate that PAN afferents have a rather small autogenetic PAD, particularly if this is compared with the effects of heterogenetic stimulation

  16. Chaos and non-linear phenomena in renal vascular control

    DEFF Research Database (Denmark)

    Yip, K P; Holstein-Rathlou, N H

    1996-01-01

    Renal autoregulation of blood flow depends on the functions of the tubuloglomerular feedback (TGF) system and the myogenic response of the afferent arteriole. Studies of the dynamic aspects of these control mechanisms at the level of both the single nephron and the whole kidney have revealed a va...

  17. Renal origin of rat urinary epidermal growth factor

    DEFF Research Database (Denmark)

    Nexø, Ebba; Poulsen, Steen Seier

    1984-01-01

    was below the detection limit of the assay. Renal production of EGF was confirmed by immunohistochemistry demonstrating EGF immunoreactivity in the afferent arteriole of the juxtaglomerular apparatus. EGF in the submandibular glands and in urine was found to differ with chromatofocusing and reverse...

  18. Trauma renal Renal trauma

    Directory of Open Access Journals (Sweden)

    Gerson Alves Pereira Júnior

    1999-02-01

    Full Text Available Apresentamos uma revisão sobre trauma renal, com ênfase na avaliação radiológica, particularmente com o uso da tomografia computadorizada, que tem se tornado o exame de eleição, ao invés da urografia excretora e arteriografia. O sucesso no tratamento conservador dos pacientes com trauma renal depende de um acurado estadiamento da extensão da lesão, classificado de acordo com a Organ Injury Scaling do Colégio Americano de Cirurgiões. O tratamento conservador não-operatório é seguro e consiste de observação contínua, repouso no leito, hidratação endovenosa adequada e antibioti- coterapia profilática, evitando-se uma exploração cirúrgica desnecessária e possível perda renal. As indicações para exploração cirúrgica imediata são abdome agudo, rápida queda do hematócrito ou lesões associadas determinadas na avaliação radiológica. Quando indicada, a exploração renal após controle vascular prévio é segura, permitindo cuidadosa inspeção do rim e sua reconstrução com sucesso, reduzindo a probabilidade de nefrectomia.We present a revision of the renal trauma with emphasis in the radiographic evaluation, particularly CT scan that it has largely replaced the excretory urogram and arteriogram in the diagnostic worh-up and management of the patient with renal trauma. The successful management of renal injuries depends upon the accurate assessment of their extent in agreement with Organ Injury Scaling classification. The conservative therapy managed by careful continuous observation, bed rest, appropriate fluid ressuscitation and prophylactic antibiotic coverage after radiographic staging for severely injured kidneys can yield favorable results and save patients from unnecessary exploration and possible renal loss. The indications for immediate exploratory laparotomy were acute abdomen, rapidly dropping hematocrit or associated injuries as determinated from radiologic evaluation. When indicated, renal exploration

  19. Primary afferent response to signals in the intestinal lumen.

    Science.gov (United States)

    Raybould, H

    2001-02-01

    The first recordings of vagal afferent nerve fibre activity were performed by Paintal in the early 1950s. In these experiments, he showed that phenyldiguanide (later recognized as a 5-HT3 receptor agonist) stimulated the firing of C-fibres innervating the intestine. In the following years, ample physiological and psychological studies have demonstrated the importance of afferent information arising from the gut in the regulation of gastrointestinal function and behaviour. Many stimuli are capable of eliciting these functional effects and of stimulating afferent fibre discharge, including mechanical, chemical, nutrient- and immune-derived stimuli. Studies in the last 10 years have begun to focus on the precise sensory transduction mechanisms by which these visceral primary afferent nerve terminals are activated and, like the contribution by Zhu et al. in this issue of The Journal of Physiology, are revealing some novel and exciting findings.

  20. Variant rabbit hemorrhagic disease virus in young rabbits, Spain.

    Science.gov (United States)

    Dalton, Kevin P; Nicieza, Inés; Balseiro, Ana; Muguerza, María A; Rosell, Joan M; Casais, Rosa; Álvarez, Ángel L; Parra, Francisco

    2012-12-01

    Outbreaks of rabbit hemorrhagic disease have occurred recently in young rabbits on farms on the Iberian Peninsula where rabbits were previously vaccinated. Investigation identified a rabbit hemorrhagic disease virus variant genetically related to apathogenic rabbit caliciviruses. Improved antivirus strategies are needed to slow the spread of this pathogen.

  1. Contribution of renal purinergic receptors to renal vasoconstriction in angiotensin II-induced hypertensive rats.

    Science.gov (United States)

    Franco, Martha; Bautista, Rocio; Tapia, Edilia; Soto, Virgilia; Santamaría, José; Osorio, Horacio; Pacheco, Ursino; Sánchez-Lozada, L Gabriela; Kobori, Hiroyuki; Navar, L Gabriel

    2011-06-01

    To investigate the participation of purinergic P2 receptors in the regulation of renal function in ANG II-dependent hypertension, renal and glomerular hemodynamics were evaluated in chronic ANG II-infused (14 days) and Sham rats during acute blockade of P2 receptors with PPADS. In addition, P2X1 and P2Y1 protein and mRNA expression were compared in ANG II-infused and Sham rats. Chronic ANG II-infused rats exhibited increased afferent and efferent arteriolar resistances and reductions in glomerular blood flow, glomerular filtration rate (GFR), single-nephron GFR (SNGFR), and glomerular ultrafiltration coefficient. PPADS restored afferent and efferent resistances as well as glomerular blood flow and SNGFR, but did not ameliorate the elevated arterial blood pressure. In Sham rats, PPADS increased afferent and efferent arteriolar resistances and reduced GFR and SNGFR. Since purinergic blockade may influence nitric oxide (NO) release, we evaluated the role of NO in the response to PPADS. Acute blockade with N(ω)-nitro-l-arginine methyl ester (l-NAME) reversed the vasodilatory effects of PPADS and reduced urinary nitrate excretion (NO(2)(-)/NO(3)(-)) in ANG II-infused rats, indicating a NO-mediated vasodilation during PPADS treatment. In Sham rats, PPADS induced renal vasoconstriction which was not modified by l-NAME, suggesting blockade of a P2X receptor subtype linked to the NO pathway; the response was similar to that obtained with l-NAME alone. P2X1 receptor expression in the renal cortex was increased by chronic ANG II infusion, but there were no changes in P2Y1 receptor abundance. These findings indicate that there is an enhanced P2 receptor-mediated vasoconstriction of afferent and efferent arterioles in chronic ANG II-infused rats, which contributes to the increased renal vascular resistance observed in ANG II-dependent hypertension.

  2. Renal arteriography

    Science.gov (United States)

    ... Read More Acute arterial occlusion - kidney Acute kidney failure Aneurysm Atheroembolic renal disease Blood clots Renal cell carcinoma Renal venogram X-ray Review Date 1/5/2016 Updated by: Jason Levy, ...

  3. Presynaptic selection of afferent inflow in the spinal cord.

    Science.gov (United States)

    Rudomin, P

    1999-01-01

    The synaptic effectiveness of sensory fibers ending in the spinal cord of vertebrates can be centrally controlled by means of specific sets of GABAergic interneurons that make axo-axonic synapses with the terminal arborizations of the afferent fibers. In the steady state, the intracellular concentration of chloride ions in these terminals is higher than that predicted from a passive distribution, because of an active transport mechanism. Following the release of GABA by spinal interneurons and activation of GABA(A) receptors in the afferent terminals, there is an outwardly directed efflux of chloride ions that produces primary afferent depolarization (PAD) and reduces transmitter release (presynaptic inhibition). Studies made by intrafiber recording of PAD, or by measuring changes in the intraspinal threshold of single afferent terminals (which is reduced during PAD), have further indicated that muscle and cutaneous afferents have distinctive, but modifiable PAD patterns in response to segmental and descending stimuli. This has suggested that PAD and presynaptic inhibition in the various types of afferents is mediated by separate sets of last-order GABAergic interneurons. Direct activation, by means of intraspinal microstimulation, of single or small groups of last-order PAD-mediating interneurons shows that the monosynaptic PAD elicited in Ia and Ib afferents can remain confined to some sets of the intraspinal collaterals and not spread to nearby collaterals. The local character of PAD allows cutaneous and descending inputs to selectively inhibit the PAD of segmental and ascending intraspinal collaterals of individual muscle spindle afferents. It thus seems that the intraspinal branches of the sensory fibers are not hard wired routes that diverge excitation to spinal neurons, but are instead dynamic pathways that can be centrally controlled to address information to selected neuronal targets. This feature appears to play an important role in the selection of

  4. Visceral perception: sensory transduction in visceral afferents and nutrients.

    Science.gov (United States)

    Raybould, H E

    2002-07-01

    The possible mechanisms that may be involved in nutrient detection in the wall of the gastrointestinal tract are reviewed. There is strong functional and electrophysiological evidence that both intrinsic and extrinsic primary afferent neurones mediate mechano- and chemosensitive responses in the gastrointestinal tract. This review focuses on the extrinsic afferent pathways as these are the ones that convey information to the central nervous system which is clearly necessary for perception to occur.

  5. Biliary stone causing afferent loop syndrome and pancreatitis

    Institute of Scientific and Technical Information of China (English)

    André Roncon Dias; Roberto Iglesias Lopes

    2006-01-01

    We report the case of an 84-year-old female who had a partial gastrectomy with Billroth-Ⅱ anastomosis 24years ago for a benign peptic ulcer who now presented an acute pancreatitis secondary to an afferent loop syndrome. The syndrome was caused by a gallstone that migrated through a cholecystoenteric fistula. This is the first description in the literature of a biliary stone causing afferent loop syndrome.

  6. Poikilocytosis in rabbits: prevalence, type, and association with disease.

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    Mary M Christopher

    Full Text Available Rabbits (Oryctolagus cuniculus are a popular companion animal, food animal, and animal model of human disease. Abnormal red cell shapes (poikilocytes have been observed in rabbits, but their significance is unknown. The objective of this study was to investigate the prevalence and type of poikilocytosis in pet rabbits and its association with physiologic factors, clinical disease, and laboratory abnormalities. We retrospectively analyzed blood smears from 482 rabbits presented to the University of California-Davis Veterinary Medical Teaching Hospital from 1990 to 2010. Number and type of poikilocytes per 2000 red blood cells (RBCs were counted and expressed as a percentage. Acanthocytes (>3% of RBCs were found in 150/482 (31% rabbits and echinocytes (>3% of RBCs were found in 127/482 (27% of rabbits, both healthy and diseased. Thirty-three of 482 (7% rabbits had >30% acanthocytes and echinocytes combined. Mild to moderate (>0.5% of RBCs fragmented red cells (schistocytes, microcytes, keratocytes, spherocytes were found in 25/403 (6% diseased and 0/79 (0% healthy rabbits (P = 0.0240. Fragmentation and acanthocytosis were more severe in rabbits with inflammatory disease and malignant neoplasia compared with healthy rabbits (P<0.01. The % fragmented cells correlated with % polychromasia, RDW, and heterophil, monocyte, globulins, and fibrinogen concentrations (P<0.05. Echinocytosis was significantly associated with renal failure, azotemia, and acid-base/electrolyte abnormalities (P<0.05. Serum cholesterol concentration correlated significantly with % acanthocytes (P<0.0001, % echinocytes (P = 0.0069, and % fragmented cells (P = 0.0109, but correlations were weak (Spearman ρ <0.02. These findings provide important insights into underlying pathophysiologic mechanisms that appear to affect the prevalence and type of naturally-occurring poikilocytosis in rabbits. Our findings support the need to carefully document poikilocytes in research

  7. [ELECTRIC STIMULATION OF VAGUS NERVE MODULATES A PROPAGATION OF OXYGEN EPILEPSY IN RABBITS].

    Science.gov (United States)

    Zhilyaev, S Yu; Moskvin, A N; Platonova, T F; Demchenko, I T

    2015-11-01

    The activation of autonomic afferents (achieved through the vagus nerve (VN) electrical stimulation) on CNS O2 toxicity and cardiovascular function was investigated. In conscious rabbits at 5 ATA 02, prodromal signs of CNS O2 toxicity and convulsion latency were determined with and without vagus nerve (VN) stimulation. EEG, ECG and respiration were also recorded. In rabbits at 5 ATA, sympathetic overdrive and specific patterns on the EEG (synchronization of slow-waves), ECG (tachycardia) and respiration (respiratory minute volume increase) preceded motor convulsions. Vagus nerve stimulation increased parasympathetic component of autonomic drive and significantly delayed prodromal signs of oxygen toxicity and convulsion latency. Autonomic afferent input to the brain is a novel target for preventing CNS toxicity in HBO2.

  8. Experimentally induced acute uric acid nephropathy in rabbits: Findings of high resolution gray scale and doppler ultrasonographies

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ik; Chung, Soo Young; Lee, Kyung Won; Kim, Hong Dae; Ko, Eun Young; Won, Mi Sook; Noh, Jung Woo [Hallym University College of Medicine, Seoul (Korea, Republic of); Park, Moon Hyang [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2001-12-15

    To evaluate changes of the high-resolution (HR) gray scale and doppler ultrasonographic (US) characteristics of experimentally induced acute uric acid (UA) nephropathy in rabbits. Acute UA nephropathy was induced in ten rabbits using supersaturated lithium carbonate solution. The rabbits were divided in two groups. Group I consisted of five rabbits, and they were injected with a single dose of 150 ml of saturated UA over one hour. During tis period, serial US studies of the kidneys of these rabbits were performed every ten minutes. Group II consisted of the remaining five rabbits, and three injections of 50 ml of saturated UA solution were given on the first, fifth and eight day and follow-up was done upto twenty fifth day. Sequential HR and Doppler US, renal biopsy and blood sampling were performed on day 1, 5, 8, 21, and 25 in the group II rabbits. In group I, HR and Doppler US examination revealed the normal resistive index without significant abnormality. On the other hand, US studies of group II showed poor renal corticomedullary differentiation, decreased renal blood flow and elevated resistive index. There was statistically significant correlation among US findings, histologic characteristics and chemical index (BUN, creatinine) of renal function. In addition, sequentially increased size and volume of the kidney were noted in both groups. HR gray scale and doppler US characteristics of experimentally induced acute UA nephropathy in rabbits were similar to those of acute renal failure caused by other well-known causes.

  9. Distribution of diuretics and hypoglycemic sulfonylureas in rabbit erythrocytes.

    Science.gov (United States)

    Yoshitomi, H; Kiko, S; Ikeda, K; Goto, S

    1983-03-01

    The distribution of three sulfonylureas and six diuretics in rabbit erythrocytes was studied in vitro at 37 degrees C. The drugs were taken up by the erythrocyte compartment, and distribution equilibrium was reached within 60 min of incubation. A distribution percentage in erythrocyte compartment was maintained at roughly constant value over the whole concentration range of drugs. Therefore, a linear relationship was established between total concentrations of drug in whole blood or erythrocyte suspension and in the erythrocyte compartment. Bovine serum albumin combined with the erythrocyte suspension appeared to reduce drug distribution in the erythrocyte compartment. Whole blood obtained from renal failure rabbits showed greater distribution of drug in the erythrocyte compartment compared with the whole blood of a normal rabbit. This might be due to a change in plasma protein binding ability related to the progress of renal failure.

  10. Afferent innervation of the utricular macula in pigeons

    Science.gov (United States)

    Si, Xiaohong; Zakir, Mridha Md; Dickman, J. David

    2003-01-01

    Biotinylated dextran amine (BDA) was used to retrogradely label afferents innervating the utricular macula in adult pigeons. The pigeon utriclar macula consists of a large rectangular-shaped neuroepithelium with a dorsally curved anterior edge and an extended medioposterior tail. The macula could be demarcated into several regions based on cytoarchitectural differences. The striola occupied 30% of the macula and contained a large density of type I hair cells with fewer type II hair cells. Medial and lateral extrastriola zones were located outside the striola and contained only type II hair cells. A six- to eight-cell-wide band of type II hair cells existed near the center of the striola. The reversal line marked by the morphological polarization of hair cells coursed throughout the epithelium, near the peripheral margin, and through the center of the type II band. Calyx afferents innervated type I hair cells with calyceal terminals that contained between 2 and 15 receptor cells. Calyx afferents were located only in the striola region, exclusive of the type II band, had small total fiber innervation areas and low innervation densities. Dimorph afferents innervated both type I and type II hair cells with calyceal and bouton terminals and were primarily located in the striola region. Dimorph afferents had smaller calyceal terminals with few type I hair cells, extended fiber branches with bouton terminals and larger innervation areas. Bouton afferents innervated only type II hair cells in the extrastriola and type II band regions. Bouton afferents innervating the type II band had smaller terminal fields with fewer bouton terminals and smaller innervation areas than fibers located in the extrastriolar zones. Bouton afferents had the most bouton terminals on the longest fibers, the largest innervation areas with the highest innervation densities of all afferents. Among all afferents, smaller terminal innervation fields were observed in the striola and large fields were

  11. 15-脱氧-△12,14-前列腺素J2在兔肾近曲小管钠和碳酸氢根转运作用及机制%Effects and Mechanisms of 15-deoxy-△12,14-prostaglandin J2 on Na+/HCO3-Transport in Rabbit Renal Proximal Tubular

    Institute of Scientific and Technical Information of China (English)

    李月红; 王茹; 王梅

    2011-01-01

    Objective To examine the effects of 15-deoxy- Δ12,14-prostaglandin J2 (15d-PGJ2), the selective ligand of PPAR-γ, on Na+/HCO3- transport in rabbit proximal tubular and the underlying mechanisms. Methods The responses Na+/HCO3-cotransporter induced by different 15d-PGJ2 concentrations were compared in isolated rabbit renal proximal tubules, with or without MAPKK/MEK inhibitor PD98059 or PPAR-γ antagonist GW9662. The phospholipase of ERK was examined by Western blotting. Results 15d-PGJ2 stimulated the activity of Na+/HCO3- cotransporter with the concentration increase (0.1 μmol/L, 0.3 μmol/L, 1 μmol/L and 10 μmol/L). The stimulation of NBC activity induced by 0.3 μmol/1 of 15d-PGJ2 was inhibited by a MAPKK/MEK inhibitor PD98059 as well as by a PPAR-γ antagonist GW9662. In rabbit renal tubular, 0.3 μmol/L dPGJ2 and 0.3 μmol/L pioglitazone both induced the ERK phosphorylation but it was inhibited by PPAR-γ antagonist. Conclusion The PPAR-γ-dependent ERK activation was involved in PPAR-γ ligand (15-dPGJ2)-induced Na+/HCO3- cotransport stimulation in rabbit renal proximal tubular.%目的 探讨过氧化物酶体增生物活化受体-y(PPAR-y)的选择性配体15-脱氧-△12,14-前列腺素J2(15dPGJ2)在兔肾近曲小管钠和碳酸氢根的转运作用及其传导通路.方法 在15d-PGJ2(0.1、0.3、1.0、10.0 μmol/L)及PPAR-y拮抗剂(5 μmol/L GW9662)或MAPKK/ MEK抑制剂(10 μmol/L PD98059)作用下,观察兔肾近曲小管钠和碳酸氢根转运活动度的变化,Western blotting法测定细胞外信号调节激酶(extracellular signal regulated kinase,ERK)的磷酸化.结果 15d-PGJ2刺激兔肾近曲小管钠和碳酸氢根的转运,随浓度增加刺激作用增强.0.3μmol/L 15d-PGJ2引起的刺激作用被MAPKK/MEK抑制剂及PPAR-y拮抗剂阻止.PPAR-y的两种选择性配体0.3 μmol/L 15d-PGJ2和0.3 μmol/L吡格列酮刺激ERK磷酸化,并被PPAR-y拮抗剂阻滞.结论 通过PPAR-y依赖的ERK磷酸化介导15d-PGJ2在兔肾近曲小管钠和碳酸氢根的转运.

  12. Fluorescence histochemistry and autoradiography of adrenergic nerves in the renal juxtaglomerular complex of mammals and man, with special regard to the efferent arteriole.

    Science.gov (United States)

    Dolezel, S; Edvinsson, L; Owman, C; Owman, T

    1976-06-14

    The adrenergic innervation of the juxtaglomerular complex was studied in kidneys from mice, rats, guinea-pigs, rabbits, cats, dogs, pigs, monkeys, and humans using fluorescence histochemistry of neuronal noradrenaline and autoradiography of 3H-noradrenaline. The localization of the nerves was established by phase contrast optics or by perfusing the vascular system with India ink. Adrenergic nerve terminals, exhibiting a formaldehyde-induced fluorescence and having the ability to take up and accumulate 3H-noradrenaline, were easily identified when they enclosed the glomerular afferent arteriole. They continued in between and close to the macula densa and lacis cells to supply the glomerular efferent arteriole. The nerves could be seen to accompany this arteriole for a considerable distance until they branched off to the vasa recta in the juxtamedullary region and to adjacent cortical veins. This innervation pattern was found to be a constant feature except in kidneys from guinea-pigs and cats, in which post-glomerular units. The fluorescence in all adrenergic fibres supplying the juxtaglomerular complex disappeared after removal of the aortico-renal ganglion, showing that they belong to a common system of renal sympathetic nerves.

  13. Sympathetic preganglionic efferent and afferent neurons mediated by the greater splanchnic nerve in rabbit

    Science.gov (United States)

    Torigoe, Yasuhiro; Cernucan, Roxana D.; Nishimoto, Jo Ann S.; Blanks, Robert H. I.

    1985-01-01

    As a part of the study of the vestibular-autonomic pathways involved in motion sickness, the location and the morphology of preganglionic sympathetic neurons (PSNs) projecting via the greater splanchnic nerve were examined. Retrograde labeling of neurons was obtained by application of horseradish peroxidase to the cut end of the greater splanchnic nerve. Labeled PSNs were found, ipsilaterally, within the T1 to T11 spinal cord segments, with the highest density of neurons in T6. Most PSNs were located within the intermediolateral column, but a significant portion also occurred within the lateral funiculus, the intercalated region, and the central autonomic area; the proportion of labeling between the four regions depended on the spinal cord segment.

  14. Patterns of connectivity of spinal interneurons with single muscle afferents.

    Science.gov (United States)

    Quevedo, J; Eguibar, J R; Lomeli, J; Rudomin, P

    1997-07-01

    A technique was developed to measure, in the anesthetized and paralyzed cat under artificial ventilation, changes of excitability to intraspinal stimulation simultaneously in two different afferent fibers or in two collaterals of the same afferent fiber. Intraspinal stimulation reduced the threshold of single muscle afferent fibers ending in the intermediate nucleus. This effect was seen with strengths below those required to activate the afferent fiber tested (1.5-12 microA), occurred at a short latency (1.5-2.0 ms), reached a maximum between 15 and 30 ms, and lasted up to 100 ms. The effects produced by graded stimulation applied at the shortest conditioning-testing stimulus time intervals increased by fixed steps, suggesting recruitment of discrete elements, most likely of last-order interneurons mediating primary afferent depolarization (PAD). The short-latency increases in excitability produced by the weakest effective intraspinal stimuli were usually detected only in the collateral closest to the stimulating micropipette, indicating that the stimulated interneurons mediating PAD have spatially restricted actions. The short-latency PAD produced by intraspinal stimuli, as well as the PAD produced by stimulation of the posterior biceps and semitendinosus (PBSt) nerve or by stimulation of the bulbar reticular formation (RF), was depressed 19-30 min after the i.v. injection of 0.5 mg/kg of picrotoxin, suggesting that all these effects were mediated by GABAergic mechanisms. The PAD elicited by stimulation of muscle and/or cutaneous nerves was depressed following the i.v. injection of (-)-baclofen, whereas the PAD elicited in the same collateral by stimulation of the RF was baclofen-resistant. The short-latency PAD produced by intraspinal stimulation was not always depressed by i.v. injections of (-)-baclofen. Baclofen-sensitive and baclofen-resistant monosynaptic PADs could be produced in different collaterals of the same afferent fiber. The results suggest that

  15. Gut vagal afferents differentially modulate innate anxiety and learned fear.

    Science.gov (United States)

    Klarer, Melanie; Arnold, Myrtha; Günther, Lydia; Winter, Christine; Langhans, Wolfgang; Meyer, Urs

    2014-05-21

    Vagal afferents are an important neuronal component of the gut-brain axis allowing bottom-up information flow from the viscera to the CNS. In addition to its role in ingestive behavior, vagal afferent signaling has been implicated modulating mood and affect, including distinct forms of anxiety and fear. Here, we used a rat model of subdiaphragmatic vagal deafferentation (SDA), the most complete and selective vagal deafferentation method existing to date, to study the consequences of complete disconnection of abdominal vagal afferents on innate anxiety, conditioned fear, and neurochemical parameters in the limbic system. We found that compared with Sham controls, SDA rats consistently displayed reduced innate anxiety-like behavior in three procedures commonly used in preclinical rodent models of anxiety, namely the elevated plus maze test, open field test, and food neophobia test. On the other hand, SDA rats exhibited increased expression of auditory-cued fear conditioning, which specifically emerged as attenuated extinction of conditioned fear during the tone re-exposure test. The behavioral manifestations in SDA rats were associated with region-dependent changes in noradrenaline and GABA levels in key areas of the limbic system, but not with functional alterations in the hypothalamus-pituitary-adrenal grand stress. Our study demonstrates that innate anxiety and learned fear are both subjected to visceral modulation through abdominal vagal afferents, possibly via changing limbic neurotransmitter systems. These data add further weight to theories emphasizing an important role of afferent visceral signals in the regulation of emotional behavior.

  16. Impact of Pregnancy on Zonisamide Pharmacokinetics in Rabbits

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    Kamal M. Matar

    2013-01-01

    Full Text Available Pregnancy is associated with various physiological changes which may lead to significant alterations in the pharmacokinetics of many drugs. The present study was aimed to investigate the potential effects of pregnancy on the pharmacokinetic profile of zonisamide (ZNM in the rabbit. Seven female rabbits were used in this study. The pregnant and nonpregnant rabbits received ZNM orally at a dose of 10 mg/kg and blood samples were collected from the animals just before receiving the drug and then serially for up to 24 h. The plasma samples were analyzed using tandem mass spectrometric method. Following a single oral dose of ZNM to the rabbits, the mean values of ZNM plasma concentrations at different times were consistently low in pregnant compared to nonpregnant rabbits. The mean values of ZNM’s Cmax and AUC0-∞ were significantly (P<0.05 decreased, whereas the CL/F exhibited substantial increase (P<0.05 in pregnant compared to nonpregnant rabbits. Tmax, t1/2abs, t1/2el, MRT, and Vd/F showed no significant differences between the two groups. The present study demonstrates that pregnancy decreased ZNM plasma concentrations in rabbits and that the decrease could be due to decreased extent of gastrointestinal absorption, induced hepatic metabolism, or enhanced renal elimination of the drug.

  17. Transforming growth factor-beta production in anti-glomerular basement membrane disease in the rabbit.

    OpenAIRE

    Coimbra, T.; Wiggins, R.; Noh, J. W.; Merritt, S.; Phan, S. H.

    1991-01-01

    The purpose of this study was to assay for the presence of collagen synthesis stimulatory activity in the kidney during immune-induced renal injury that results in severe fibrosis in both glomerular and interstitial compartments. A model of antiglomerular basement (anti-GBM) disease in the rabbit was induced on day 0 by the injection of anti-GBM antibody and renal cortex tissues were then sampled at various time points. Only conditioned media prepared from diseased renal cortical samples show...

  18. Comparison of diagnostic value of duplex and color Doppler ultrasound in experimental acute renal failure in rabbits%二维超声、频谱及彩色多普勒超声在评价实验性兔急性肾衰竭中的价值比较

    Institute of Scientific and Technical Information of China (English)

    黄晓玲; 高云华

    2000-01-01

    Objective To compare the diagnostic value of two-dimentional ultrasound, spectrum and color Doppler ultrasound in experimental acute renal failure(ARF)in rabbits.Methods 50%glycerin(12~15 ml/kg)were injected into the thigh muscle of the back leg of the rabbit to induce an animal model of ARF. Ultrasonic examination was performed on the day before(T0)and days 1,3…13 after the injection(T1,T3… T13).Renal size was evaluated by two-dimensional ultrasound.The hemodynamic changes of the kidney were quantitatively analysed by spectrum Doppler, while color Doppler flow imaging(CDFI)and color Doppler power imaging(CDPI)were used to qualitatively study the blood perfusion of the kidney during ARF. The renal imaging in CDFI and CDPI were classified three grades.Grade I, the blood perfusion of the kidney was normal and the flow singles could be seen at the site near to the renal capsule.Grade II, the blood perfusion of the kidney was slightly abnormal and the flow singles could be seen in the renal cortex but not near to the capsule. Grade Ⅲ, the blood perfusion was heavily abnormal and the flow singles could not be seen in the renal cortex.Results The changes of renal hemodynamics and renal size began at T3,peaked at T5 and T7,and returned to normal at T9. The renal imaging of all rabbits were grade I in CDPI and CDFI at T0.In CDFI, all were gradeⅢat T1~T9, at T11 and T13 most of them only returned to grade Ⅱ, no one returned to grade I.In CDPI, however, all were grade Ⅱ at T1 and T3,while only a few were grade Ⅲ at T5 and T7,and most have returned to grade Ⅰ at T9. Conclusions During the period of ARF, two-dimensional ultrasound is useful in showing the echo and measuring the depth of renal cortex.Spectrum Doppler is helpful in quantitatively analysing the renal hemodynamic hanges. CDPI is more sensitive than CDFI in showing the blood perfusion of the kidney%目的 比较二维超声、频谱及彩色多普勒超声在诊断

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

    Science.gov (United States)

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

    2014-03-01

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

  20. Autoantibody Production in Rabbits

    Science.gov (United States)

    Asherson, G. L.; Rose, M. Elaine

    1963-01-01

    The finding that the serum of apparently healthy rabbits fixed complement with rabbit liver and kidney has been confirmed. Experimental infection of rabbits with Eimeria stiedae, the cause of hepatic coccidiosis, led to a rise in the titre of serum complement-fixing factors. The rise was statistically significant 14, 21 and 28 days after infection. The factors were regarded as antibodies because they behaved as macroglobulins on diethylaminoethyl—cellulose chromatography and sucrose gradient centrifugation, and as autoantibodies because they fixed complement with the kidney of the rabbits in which they occurred. The antibody reacted with widely distributed antigen(s) with high activity in brain and low activity in skeletal muscle. The possibility that coccidial infection may be responsible for the natural autoantibody of rabbits is discussed. PMID:13965167

  1. Renal Osteodystrophy

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    Aynur Metin Terzibaşoğlu

    2004-12-01

    Full Text Available Chronic renal insufficiency is a functional definition which is characterized by irreversible and progressive decreasing in renal functions. This impairment is in collaboration with glomeruler filtration rate and serum creatinine levels. Besides this, different grades of bone metabolism disorders develop in chronic renal insufficiency. Pathologic changes in bone tissue due to loss of renal paranchyme is interrelated with calcium, phosphorus vitamine-D and parathyroid hormone. Clinically we can see high turnover bone disease, low turnover bone disease, osteomalacia, osteosclerosis and osteoporosis in renal osteodystropy. In this article we aimed to review pathology of bone metabolism disorders due to chronic renal insufficiency, clinic aspects and treatment approaches briefly.

  2. Immunity to nerve growth factor and the effect on motor unit reinnervation in the rabbit.

    Science.gov (United States)

    Finkelstein, D I; Luff, A R; Schuijers, J A

    1992-05-01

    The trophic effects of nerve growth factor (NGF) on sympathetic, peripheral afferent, and other neural crest-derived cells have been intensively investigated. More recently, NGF has been shown to have an influence on motoneurons. This study was undertaken to investigate whether NGF had any influence on the mechanical or histological properties of reinnervated motor units. Three groups of rabbits were used: normal rabbits, rabbits in which the nerve to medial gastrocnemius (MG) was cut and allowed to reinnervate for 56 days, and rabbits in which the MG nerve reinnervated in the presence of immunity to NGF. Immunity to NGF did not affect the ability of motor axons to reinnervate a muscle, nor were the contractile characteristics of the motor units altered. The size of horseradish peroxidase-labeled motoneurons was not influenced by immunization against NGF; however, the distribution of afferent neuron sizes was altered. Conduction velocity of motor axons proximal to the neuroma was significantly faster after immunization against NGF. Transection and subsequent reinnervation by a peripheral nerve normally causes an increase in myelin thickness proximal to the neuroma. However, immunization against NGF appeared to decrease the magnitude of myelin thickening. It was concluded that immunization against NGF affects motor axonal conduction velocity via an influence on the neural crest-derived Schwann cells.

  3. Ultrasound features of kidneys in the rabbit (Oryctolagus cuniculus

    Directory of Open Access Journals (Sweden)

    R S Dimitrov

    2012-10-01

    Full Text Available Purpose: To determine the normal sonographic features of rabbit kidneys with regard to their use in diagnostic imaging of renal lesions in this species. Materials: Twelve sexually mature clinically healthy New Zealand White rabbits weighing 2.8 kg to 3.2 kg were examined after anaesthesia. Methods: A diagnostic ultrasound system with microconvex multifrequency 6.5 MHz probe was used. The animals were positioned in dorsal recumbency. The transabdominal paravertebral imaging approach was used. Longitudinal and transverse scans of the kidneys were obtained. Six rabbits were sacrificed, their kidneys removed and studied in isotonic liquid medium. Results: The shape of kidneys was elliptical. The fibrous capsule was visualized as a straight hyperechoic band. The fatty capsule was hyperechoic and with irregular borders. The cortex exhibited a heterogeneous echogenicity. The acoustic density of the cortex was lower than that of the liver. The echoicity of the medulla was lower as compared to the cortex and the structures of the kidney pelvis. The latter appeared as a centrally located hyperechoic structure. The post mortem examination showed that kidneys were oval and hyperechoic. The kidney pelvis was seen as a centrally located longitudinal finding, and the renal hilum – as a centrally located hyperechoic finding. Conclusions: The transabdominal paravertebral approach was a good method for visualization of rabbit kidneys. The dorsal recumbency of the subjects allowed the visualization. The in vivo results corresponded to those from the post mortem study. The rabbit kidney was oval in shape. The hypoechoic peripheral zone is occupied by the cortex and the medulla, while the hyperechoic central zone – by the kidney pelvis. The cortex was less echoic than the liver parenchyma. The kidney pelvic cavity had a lower acoustic density than its walls, due to the presence of peripelvic adipose tissue. The present results could be used in the interpretation

  4. Zoonoses of rabbits and rodents.

    Science.gov (United States)

    Hill, William Allen; Brown, Julie Paige

    2011-09-01

    Millions of households in the US own rabbits or rodents, including hamsters, guinea pigs, and gerbils. Activities such as hunting and camping also involve human interactions with wild rabbits and rodents. In many environments, feral rabbits and rodents live in close proximity to humans, domesticated animals, and other wildlife. Education of rodent and rabbit owners and individuals with occupational or recreational exposures to these species is paramount to reduce the prevalence of zoonoses associated with rabbit and rodent exposure.

  5. Sensations evoked by microstimulation of single mechanoreceptive afferents innervating the human face and mouth.

    Science.gov (United States)

    Trulsson, M; Essick, G K

    2010-04-01

    Intraneural microneurography and microstimulation were performed on single afferent axons in the inferior alveolar and lingual nerves innervating the face, teeth, labial, or oral mucosa. Using natural mechanical stimuli, 35 single mechanoreceptive afferents were characterized with respect to unit type [fast adapting type I (FA I), FA hair, slowly adapting type I and II (SA I and SA II), periodontal, and deep tongue units] as well as size and shape of the receptive field. All afferents were subsequently microstimulated with pulse trains at 30 Hz lasting 1.0 s. Afferents recordings whose were stable thereafter were also tested with single pulses and pulse trains at 5 and 60 Hz. The results revealed that electrical stimulation of single FA I, FA hair, and SA I afferents from the orofacial region can evoke a percept that is spatially matched to the afferent's receptive field and consistent with the afferent's response properties as observed on natural mechanical stimulation. Stimulation of FA afferents typically evoked sensations that were vibratory in nature; whereas those of SA I afferents were felt as constant pressure. These afferents terminate superficially in the orofacial tissues and seem to have a particularly powerful access to perceptual levels. In contrast, microstimulation of single periodontal, SA II, and deep tongue afferents failed to evoke a sensation that matched the receptive field of the afferent. These afferents terminate more deeply in the tissues, are often active in the absence of external stimulation, and probably access perceptual levels only when multiple afferents are stimulated. It is suggested that the spontaneously active afferents that monitor tension in collagen fibers (SA II and periodontal afferents) may have the role to register the mechanical state of the soft tissues, which has been hypothesized to help maintain the body's representation in the central somatosensory system.

  6. Cloning and expression of the rabbit prostaglandin EP2 receptor

    OpenAIRE

    Guan, Youfei; Stillman, Brett A.; Zhang, Yahua; Schneider, André; Saito, Osamu; Davis, Linda S.; Redha, Reyadh; Breyer, Richard M.; Breyer, Matthew D.

    2002-01-01

    Background Prostaglandin E2 (PGE2) has multiple physiologic roles mediated by G protein coupled receptors designated E-prostanoid, or "EP" receptors. Evidence supports an important role for the EP2 receptor in regulating fertility, vascular tone and renal function. Results The full-length rabbit EP2 receptor cDNA was cloned. The encoded polypeptide contains 361 amino acid residues with seven hydrophobic domains. COS-1 cells expressing the cloned rabbit EP2 exhibited specific [3H]PGE2 binding ...

  7. Rabbit orthopedic surgery.

    Science.gov (United States)

    Rich, Gregory A

    2002-01-01

    Orthopedic surgery in rabbits poses several unique parameters for the veterinary surgeon. It is imperative for the veterinarian to be knowledgeable about the anatomic features of the surgical repair site and to become familiar with a rabbit's pain and discomfort often associated with orthopedic injuries. Handling the perioperative and postoperative pain and potential GI disturbances are crucial for a successful outcome of the surgical case. This article is designed to help the veterinary surgeon prepare for the orthopedic surgical procedure and the peripheral physiologic needs of the rabbit from presentation through recovery.

  8. RabbitMQ essentials

    CERN Document Server

    Dossot, David

    2014-01-01

    This book is a quick and concise introduction to RabbitMQ. Follow the unique case study of Clever Coney Media as they progressively discover how to fully utilize RabbitMQ, containing clever examples and detailed explanations.Whether you are someone who develops enterprise messaging products professionally or a hobbyist who is already familiar with open source Message Queuing software and you are looking for a new challenge, then this is the book for you. Although you should be familiar with Java, Ruby, and Python to get the most out of the examples, RabbitMQ Essentials will give you the push y

  9. The effect of sulfur dioxide on the response of rabbits to expiratory loads.

    Science.gov (United States)

    Davenport, P W; Freed, A N; Rex, K A

    1984-06-01

    The role of slowly adapting pulmonary stretch receptors (PSR) in the reflex control of expiratory duration was investigated in anesthetized, spontaneously breathing rabbits. Graded resistive and elastic loads were applied for single expirations to produce expiratory volume-time curves. The PSR were selectively blocked by administration of 200-400 ppm sulfur dioxide (SO2) to the inspired air of the rabbits. Volume-time curves were generated for pre-treatment, SO2 exposure, recovery and post-bilateral cervical vagotomy. SO2 exposure significantly reduced the volume-dependent modulation of expiratory duration from the pre-treatment levels. The response to the expiratory loads returned when the SO2 gas was removed. Vagotomy completely abolished any volume-dependent modulation of expiratory duration with expiratory loading. These results demonstrate that the response of rabbits to expiratory loads is vagally dependent. The hypothesis that PSR are the vagal afferents mediating this response is supported by these results.

  10. Gut chemosensing: interactions between gut endocrine cells and visceral afferents.

    Science.gov (United States)

    Raybould, Helen E

    2010-02-16

    Chemosensing in the gastrointestinal tract is less well understood than many aspects of gut mechanosensitivity; however, it is important in the overall function of the GI tract and indeed the organism as a whole. Chemosensing in the gut represents a complex interplay between the function of enteroendocrine (EEC) cells and visceral (primarily vagal) afferent neurons. In this brief review, I will concentrate on a new data on endocrine cells in chemosensing in the GI tract, in particular on new findings on glucose-sensing by gut EEC cells and the importance of incretin peptides and vagal afferents in glucose homeostasis, on the role of G protein coupled receptors in gut chemosensing, and on the possibility that gut endocrine cells may be involved in the detection of a luminal constituent other than nutrients, the microbiota. The role of vagal afferent pathways as a downstream target of EEC cell products will be considered and, in particular, exciting new data on the plasticity of the vagal afferent pathway with respect to expression of receptors for GI hormones and how this may play a role in energy homeostasis will also be discussed.

  11. Temperature-dependent variation in afferent nerve discharge in rat jejunum

    DEFF Research Database (Denmark)

    Gregersen, Hans; Yang, Jian; Zhao, Jingbo

    2015-01-01

    baseline discharge and on distension-induced afferent fibers innervating the rat jejunum. Methods: Multi-unit afferent activity was recorded in vitro from jejunum afferents from 9 Wistar rats. The segments were immersed in oxygenated Krebs solution varied between 21–43 °C. The mesenteric nerve bundle...

  12. Regenerating sprouts of axotomized cat muscle afferents express characteristic firing patterns to mechanical stimulation.

    Science.gov (United States)

    Johnson, R D; Munson, J B

    1991-12-01

    1. In cats, we studied the physiological properties of regenerating sprouts of muscle afferent fibers and compared them with sprouts from cutaneous afferent fibers. 2. Muscle nerves to the triceps surae and cutaneous sural nerves were axotomized in the popliteal fossa, and the proximal ends were inserted into nerve cuffs. Six days later, we recorded action potentials from single Groups I and II muscle and mostly Group II cutaneous afferents driven by mechanostimulation of the cuff. 3. Most muscle afferent sprouts (91%) had a regular slowly adapting discharge in response to sustained mechanical displacement of the cuff, particularly to sustained stretch stimuli, whereas most cutaneous afferents (92%) did not. Muscle afferents were more likely to have a spontaneous discharge and afterdischarge. 4. Group II muscle afferent sprouts had lower stretch thresholds and a higher incidence of spontaneous discharge compared with Group I fiber sprouts, whereas Group I fibers had a higher incidence of high-frequency afterdischarge to mechanical stimuli. 5. We conclude that, 6 days after axotomy, regenerating sprouts of muscle afferents, particularly Group II afferents, have become mechanosensitive in the absence of a receptor target and exhibit physiological properties similar to those found when innervating their native muscle but significantly different from sprouts of cutaneous afferents. Expression of these native muscle afferent firing patterns after the inappropriate reinnervation of hairy skin may be due to inherent properties of the muscle afferent fiber.

  13. DMPD: Afferent pathways of pyrogen signaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 9917870 Afferent pathways of pyrogen signaling. Blatteis CM, Sehic E, Li S. Ann N Y... Acad Sci. 1998 Sep 29;856:95-107. (.png) (.svg) (.html) (.csml) Show Afferent pathways of pyrogen signaling.... PubmedID 9917870 Title Afferent pathways of pyrogen signaling. Authors Blatteis CM, Sehic E, Li S. Publica

  14. Renal perfusion scintiscan

    Science.gov (United States)

    Renal perfusion scintigraphy; Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion ... supply the kidneys. This is a condition called renal artery stenosis. Significant renal artery stenosis may be ...

  15. Angiotensin II receptor alterations during pregnancy in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Brown, G.P.; Venuto, R.C.

    1986-07-01

    Despite activation of the renin-angiotensin system during pregnancy, renal and peripheral vascular blood flows increase, and the systemic blood pressure and the pressor response to exogenous angiotensin II (Ang II) fall. Gestational alterations in Ang II receptors could contribute to these changes. Ang II binding parameters were determining utilizing SVI-Ang II in vascular (glomeruli and mesenteric arteries) and nonvascular (adrenal glomerulosa) tissues from 24- to 28-day pregnant rabbits. Comparisons were made utilizing tissues from nonpregnant rabbits. Binding site concentrations (N) and dissociation constants (K/sub d/) were obtained by Scatchard analyses of binding inhibition data. Meclofenamate (M) inhibits prostaglandin synthesis, reduces plasma renin activity, and enhances the pressor response to infused Ang II in pregnant rabbits. Administration of M to pregnant rabbits increased N in glomerular and in mesenteric artery membranes. These data demonstrate that Ang II receptors in glomeruli and mesenteric arteries are down regulated during gestation in rabbits. Elevated endogenous Ang II during pregnancy in rabbits may contribute to the down regulation of vascular Ang II receptors.

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

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

  17. Effects of lead on the renin-angiotensin system. [Rabbits; rats

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, J.A.

    1982-01-01

    The renin-angiotensin system was evaluated in both acute and chronic lead-exposed rabbits and in unanaesthetized chronic lead-exposed rats. In addition, the acute effects of lead on in vitro secretion of renin were evaluated using rabbit and renal cortical slices. The clearance of renin was measured in chronic lead-exposed rats. Basal PRAs were significantly elevated in lead-exposed rats; renal renin activities were also significantly higher. In contrast, renin clearances were not different in the two groups. These findings support the hypothesis that the increase in basal PRA seen in lead-exposed rats is due to increased renin secretion not decreased hepatic removal of renin. In conclusion, we found no evidence for decreased renin degradation in the chronic lead-exposed rabbit or rat; rather, changes in renin secretion appear to account for observed increases in PRA. In contrast, acute lead-exposure inhibits both renin secretion and degradation in the rabbit.

  18. Strain-specific renal toxicity of heterologous antilymphocyte [gamma]-globulin in mice7

    NARCIS (Netherlands)

    Cohen, B.J.; Vries, M.J. de; Noord, M.J. van; Lubbe, F.H.

    1970-01-01

    Severe glomerulonephritis followed one to five weekly i.p. injections in TLFM mice of rabbit antimouse lymphocyte [gamma]-globulin (ALG). Glomerulonephritis did not occur in C57BL mice subjected to the same regimen. Administration of normal rabbit [gamma]-globulin (NRG) to RFM mice also caused renal

  19. Strain-specific renal toxicity of heterologous antilymphocyte [gamma]-globulin in mice7

    NARCIS (Netherlands)

    Cohen, B.J.; Vries, M.J. de; Noord, M.J. van; Lubbe, F.H.

    1970-01-01

    Severe glomerulonephritis followed one to five weekly i.p. injections in TLFM mice of rabbit antimouse lymphocyte [gamma]-globulin (ALG). Glomerulonephritis did not occur in C57BL mice subjected to the same regimen. Administration of normal rabbit [gamma]-globulin (NRG) to RFM mice also caused renal

  20. Different cardiovascular neuron groups in the ventral reticular formation of the rostral medulla in rabbits: single neurone studies.

    Science.gov (United States)

    Kishi, E; Ootsuka, Y; Terui, N

    2000-03-15

    To examine whether the cardiovascular neurons of the ventral medulla consist of functionally different kinds of neurons, single neuronal activity of the ventral medulla, activity of the renal sympathetic nerves (RSNA), blood flow of the ear (EarBF) and arterial pressure (AP) were recorded in urethane-anesthetized, vagotomized and immobilized rabbits during electrical stimulation of the aortic nerve (AN, baroreceptor afferent fibers) and electrical stimulation of the dorsomedial hypothalamus (DMH) that reduced EarBF but less affected on AP and RSNA. The dorsolateral funiculus of the second cervical cord was stimulated to evoke antidromic spikes of medullary neurons. Two kinds of reticulo-spinal neurons were identified. Activities of one kind of neurons were facilitated by stimulation of DMH (latency 48.6+/-27.6 ms, n=11) but they did not respond to stimulation of the AN. Therefore, it was presumed that these neurons controlled vasomotion of the ear through the vasoconstrictor neurons in the spinal cord but did not participate in regulation of systemic AP. Activities of the other neurons were inhibited by stimulation of the AN (latency 47.8+/-8 4 ms, n=16) but they did not respond to the DMH stimulation. These neurons were identical to those reported previously as the RVLM neurons, and they contributed to regulate systemic AP but might not participate in control of cutaneous vascular movement. The former neurons were located medially to the latter in the reticular formation of the rostral ventral medulla. These results provided evidence at the single neuronal level that the cardiovascular neurons in the ventral medulla were consisted of functionally different sympatho-excitatory neurons and they were located at the different sites in the rostral ventral medulla.

  1. Viral diseases of the rabbit.

    Science.gov (United States)

    Krogstad, Aric P; Simpson, Janet E; Korte, Scott W

    2005-01-01

    Viral disease in the rabbit is encountered infrequently by the clinical practitioner; however, several viral diseases were reported to occur in this species. Viral diseases that are described in the rabbit primarily may affect the integument, gastrointestinal tract or, central nervous system or maybe multi-systemic in nature. Rabbit viral diseases range from oral papillomatosis, with benign clinical signs, to rabbit hemorrhagic disease and myxomatosis, which may result in significant clinical disease and mortality. The wild rabbit may serve as a reservoir for disease transmission for many of these viral agents. In general, treatment of viral disease in the rabbit is supportive in nature.

  2. 黄芪和当归注射液对兔肾缺血再灌注损伤时腺苷三磷酸酶的影响%Effects of astragalus and angelica injections on adenosine triphosphate-ase in renal injury induced by ischemia / reperfusion in rabbits

    Institute of Scientific and Technical Information of China (English)

    李达兵; 赵春玲; 林海英; 李先华; 邬于川

    2005-01-01

    血再灌注组差异无显著性外,余均较单纯缺血再灌注组高(t=2.372~2.786,P<0.05).结论:黄芪、当归具有抑制ATP酶下降和改善肾局部血流调节紊乱的作用,为其通过保护ATP酶而减轻肾缺血再灌注损伤提供实验学基础.%BACKGROUND: It is indicated in researches of recent years that both astragalus and angelica act on anti-free radical and protect renal injury due to ischemia / reperfusion.OBJECTIVE: To observe the protection and its mechanism of astragalus and angelica injections on adenosine triphosphate-ase (ATPase) in renal injury due to ischemia/reperfusion.DESIGN: The observing controlled experiment based on experimental animals .SETTING: Physiological teaching & research room and teaching & research room of renal functional protection in a medical college. MATERIALS: The experiment was performed in Physiological Experimental Room of Luzhou Medical College from January 2001 to March 2001. Totally 33 Japanese big-ear white healthy adult rabbits of either sex were employed,provided by Experimental Animal Center of Luzhou Medical College, in the mass of(1.63 + 0. 22) kg. According to random number table, they were divided in sham-operation control(8 rabbits), simple ischemia/reperfusion group (8 rabbits), astragalus injection + ischemia/reperfusion group (astragalus group) (8 rabbits) and angelica injection + ischemia/reperfusion group(angelica group) (9 rabbits).METHODS: One day before operation, on the day of operation and 1 day after operation, successively, intravenous medical injections (astragalus 1.25 g/kg,angelica 12.5 g/kg) were administrated in astragalus and angelica groups everyday respectively, and injection with physiological saline 5 mL/kg was applied in the control and simple ischemia/reperfusion group. In 48 hours reperfusion after 1 hour ischemia in kidney, blood sample was collected from inferior vena cava. The upper tissue of the right kidney was collected and fixed by placed in 30 m

  3. Distinct recurrent versus afferent dynamics in cortical visual processing.

    Science.gov (United States)

    Reinhold, Kimberly; Lien, Anthony D; Scanziani, Massimo

    2015-12-01

    How intracortical recurrent circuits in mammalian sensory cortex influence dynamics of sensory representation is not understood. Previous methods could not distinguish the relative contributions of recurrent circuits and thalamic afferents to cortical dynamics. We accomplish this by optogenetically manipulating thalamus and cortex. Over the initial 40 ms of visual stimulation, excitation from recurrent circuits in visual cortex progressively increased to exceed direct thalamocortical excitation. Even when recurrent excitation exceeded thalamic excitation, upon silencing thalamus, sensory-evoked activity in cortex decayed rapidly, with a time constant of 10 ms, which is similar to a neuron's integration time window. In awake mice, this cortical decay function predicted the time-locking of cortical activity to thalamic input at frequencies thalamocortical synapses disrupted the fidelity of sensory transmission. Thus, we determine dynamics intrinsic to cortical recurrent circuits that transform afferent input in time.

  4. Bradykinin Contributes to Sympathetic and Pressor Responses Evoked by Activation of Skeletal Muscle Afferents P2X in Heart Failure

    Directory of Open Access Journals (Sweden)

    Jihong Xing

    2016-11-01

    Full Text Available Background/Aims: Published data suggest that purinergic P2X receptors of muscle afferent nerves contribute to the enhanced sympathetic nervous activity (SNA and blood pressure (BP responses during static exercise in heart failure (HF. In this study, we examined engagement of bradykinin (BK in regulating responses of SNA and BP evoked by P2X stimulation in rats with HF. We further examined cellular mechanisms responsible for BK. We hypothesized that BK potentiates P2X currents of muscle dorsal root ganglion (DRG neurons, and this effect is greater in HF due to upregulation of BK kinin B2 and P2X3 receptor. As a result, BK amplifies muscle afferents P2X-mediated SNA and BP responses. Methods: Renal SNA and BP responses were recorded in control rats and rats with HF. Western Blot analysis and patch-clamp methods were employed to examine the receptor expression and function of DRG neurons involved in the effects of BK. Results: BK injected into the arterial blood supply of the hindlimb muscles heightened the reflex SNA and BP responses induced by P2X activation with α,β-methylene ATP to a greater degree in HF rats. In addition, HF upregulated the protein expression of kinin B2 and P2X3 in DRG and the prior application of BK increased the magnitude of α,β-methylene ATP-induced currents in muscle DRG neurons from HF rats. Conclusion: BK plays a facilitating role in modulating muscle afferent P2X-engaged reflex sympathetic and pressor responses. In HF, P2X responsivness is augmented due to increases in expression of kinin B2 and P2X3 receptors and P2X current activity.

  5. NEURAL PATHWAYS OF TRIGEMINAL PROPRIOCEPTIVE AFFERENTS COORDINATE ORAL MOTOR BEHAVIORS

    Institute of Scientific and Technical Information of China (English)

    Luo Pifu; Zhang Jingdong; Li Jishuo

    2003-01-01

    Neural pathways and synaptic connections from the trigeminal mesencephalic nucleus (Vme) neurons to the cranial motor nuclei were studied in the rat using double labelling methodologies of intracellular Neurobiotin staining combined with retrograde horseradish peroxidase (HRP) transport, anterograde biotinylated dextran amine (BDA) tracing combined with retrograde HRP transport, and a dual fluorescent labelling of BDA anterograde combined tracing with Cholera Toxin B (CTB) retrograde transport. Direct projections and synapses were demonstrated from Vme neuronal boutons to motoneurons (MNs) of the trigeminal motor nucleus (Vmo), the hypoglossal nucleus (Ⅻ) and the ambiguus nucleus (Amb). Indirect projections and pathways from Vme neurons to the cranial motor nuclei including Vmo, Ⅻ, the facial nucleus (Ⅶ) and the cervical spinal cord (C1~5) were seen to relay on their premotor neurons. The premotor neurons of above cranial motor nuclei were overlapped in bilateral premotor neuronal pool including the parvocellular reticular formation (PCRt) and its alpha division (PCRtA), the dorsomedial part of the spinal trigeminal nucleus oralis (Vodm), and interpolaris (Vidm), the medullary reticular nucleus dorsal division (MdD), the supratrigeminal region (Vsup) and the dorsomedial part of the principal trigeminal sensory nucleus (Vpdm).Synapses between Vme neuronal boutons and Vmo and Ⅻ MNs and Ⅻ premotor neurons were predominantly asymmetric.There were four types of synaptic organizations, i.e. synaptic convergence; synaptic divergence presynaptic inhibition and afferent feedforward inhibition seen between Vme boutons and Vmno, Ⅻ MNs and between Vme boutons and Ⅻ premotor neurons.The results of present studies have demonstrated direct pathways from the trigeminal proprioceptive afferents to Vmo, Ⅻ and Amb MNs, and indirect pathways from the trigeminal proprioceptive afferents to bilateral Vmno, Ⅻ, Ⅶ and C1~s via their premotor neurons. It provides

  6. Mechanically insensitive afferents (MIAs) in cutaneous nerves of monkey.

    Science.gov (United States)

    Meyer, R A; Davis, K D; Cohen, R H; Treede, R D; Campbell, J N

    1991-10-11

    A problem in the study of nociceptors is that intense stimuli are used to locate the receptive field (RF), and thus the receptor may be damaged before the first responses are recorded. In addition, some nociceptors do not respond to the mechanical stimuli often used to search for the RF. To overcome these problems, an electrical search technique was developed to locate the RF of cutaneous nociceptors. In the hairy skin of anesthetized monkey, we used this technique to locate the RF of 63 A delta-fibers and 22 C-fibers that had extremely high thresholds or were unresponsive to mechanical stimuli. We refer to these afferents as mechanically insensitive afferents (MIAs). Ten A delta-fiber MIAs had a short latency response to stepped heat stimuli and could be responsible for first pain sensation. Five A delta-fiber MIAs and one C-fiber MIA did not respond to mechanical or heat stimuli but did respond to injection into the electrical RF of an artificial inflammatory soup containing histamine, bradykinin, prostaglandin E1, and serotonin. These chemoreceptors might be responsible for the pain and itch sensations that result from chemical stimuli. Some MIAs became more responsive to mechanical stimuli after injection into the RF of the inflammatory soup and, thus, may contribute to the hyperalgesia to mechanical stimuli associated with cutaneous injury. A large proportion of the A delta-fiber (48%) and C-fiber (30%) afferents in this study were insensitive to mechanical stimuli. The role of these MIAs in sensation needs to be studied further. The electrical search technique enables a systematic study of these afferents to be performed. This technique may also be of use to identify and characterize dorsal horn neurons that have inputs from MIAs.

  7. Enhanced Muscle Afferent Signals during Motor Learning in Humans.

    Science.gov (United States)

    Dimitriou, Michael

    2016-04-25

    Much has been revealed concerning human motor learning at the behavioral level [1, 2], but less is known about changes in the involved neural circuits and signals. By examining muscle spindle responses during a classic visuomotor adaptation task [3-6] performed by fully alert humans, I found substantial modulation of sensory afferent signals as a function of adaptation state. Specifically, spindle control was independent of concurrent muscle activity but was specific to movement direction (representing muscle lengthening versus shortening) and to different stages of learning. Increased spindle afferent responses to muscle stretch occurring early during learning reflected individual error size and were negatively related to subsequent antagonist activity (i.e., 60-80 ms thereafter). Relative increases in tonic afferent output early during learning were predictive of the subjects' adaptation rate. I also found that independent spindle control during sensory realignment (the "washout" stage) induced afferent signal "linearization" with respect to muscle length (i.e., signals were more tuned to hand position). The results demonstrate for the first time that motor learning also involves independent and state-related modulation of sensory mechanoreceptor signals. The current findings suggest that adaptive motor performance also relies on the independent control of sensors, not just of muscles. I propose that the "γ" motor system innervating spindles acts to facilitate the acquisition and extraction of task-relevant information at the early stages of sensorimotor adaptation. This designates a more active and targeted role for the human proprioceptive system during motor learning.

  8. Characterisation of the primary afferent spinal innervation of mouse uterus

    Directory of Open Access Journals (Sweden)

    Geraldine eHerweijer

    2014-07-01

    Full Text Available The primary afferent innervation of the uterus is incompletely understood. The aim of this study was to identify the location and characteristics of primary afferent neurons that innervate the uterine horn of mice and correlate the different morphological types of putative primary afferent nerve endings, immunoreactive to the sensory marker, calcitonin gene related peptide (CGRP. Using retrograde tracing, injection of 5-10µL of 1,1'-didodecyl-3,3,3,3'-tetramethylindocarbocyanine perchlorate (DiI into discrete single sites in each uterine horn revealed a biomodal distribution of sensory neurons in dorsal root ganglia (DRG with peak labelling occurring between T13-L3 and a second smaller peak between L6-S1. The mean cross sectional area of labelled cells was 463 µm2 +/- SEM. A significantly greater proportion of labelled neurons consisted of small cell bodies (<300 µm2 in the sacral spinal cord (S2 compared with peak labelling at the lumbar (L2 region. In both sections and whole mount preparations, immunohistochemical staining for CGRP revealed substantial innervation of the uterus by CGRP-positive nerve fibres located primarily at the border between the circular and longitudinal muscle layers (N=4. The nerve endings were classified into three distinct types: single, branching or complex, that often aligned preferentially in either the circular or longitudinal axis of the smooth muscles. Complex endings were often associated with mesenteric vessels. We have identified that the cell bodies of primary afferent neurons innervating the mouse uterus lie primarily in DRG at L2 and S1 spinal levels. Also, the greatest density of CGRP immunoreactivity lies within the myometrium, with at least three different morphological types of nerve endings identified. These findings will facilitate further investigations into the mechanisms underlying sensory transduction in mouse uterus.

  9. How to test for a relative afferent pupillary defect (RAPD

    Directory of Open Access Journals (Sweden)

    David C Broadway

    2012-01-01

    Full Text Available The 'swinging light test' is used to detect a relative afferent pupil defect (RAPD: a means of detecting differences between the two eyes in how they respond to a light shone in one eye at a time. The test can be very useful for detecting unilateral or asymmetrical disease of the retina or optic nerve (but only optic nerve disease that occurs in front of the optic chiasm.

  10. RENAL CRYOABLATION

    Directory of Open Access Journals (Sweden)

    A. V. Govorov

    2012-01-01

    Full Text Available Renal cryoablation is an alternative minimally-invasive method of treatment for localized renal cell carcinoma. The main advantages of this methodology include visualization of the tumor and the forming of "ice ball" in real time, fewer complications compared with other methods of treatment of renal cell carcinoma, as well as the possibility of conducting cryotherapy in patients with concomitant pathology. Compared with other ablative technologies cryoablation has a low rate of repeat sessions and good intermediate oncological results. The studies of long-term oncological and functional results of renal cryoablation are presently under way.

  11. Renal angiomyolipoma

    DEFF Research Database (Denmark)

    Holm-Nielsen, P; Sørensen, Flemming Brandt

    1988-01-01

    lesion. Three cases of renal angiomyolipoma, 2 of which underwent perfusion-fixation, were studied by electron microscopy to clarify the cellular composition of this lesion. In the smooth muscle cells abundant accumulation of glycogen was found, whereas the lipocytes disclosed normal ultrastructural......-specific vesicular structures. These findings suggest a secondary vascular damage, i.e. the thickened vessels may not be a primary, integral part of renal angiomyolipoma. Evidence of a common precursor cell of renal angiomyolipoma was not disclosed. It is concluded that renal angiomyolipoma is a hamartoma composed...

  12. Sex differences in pressure diuresis/natriuresis in rabbits.

    Science.gov (United States)

    Evans, R G; Stevenson, K M; Bergström, G; Denton, K M; Madden, A C; Gribben, R L; Weekes, S R; Anderson, W P

    2000-08-01

    We tested for sex-related differences in the pressure diuresis/natriuresis relationships in anaesthetized, renally denervated rabbits, using an extracorporeal circuit to perfuse the left kidney with the rabbit's own blood, through a series of step-wise increases in renal artery pressure (RAP) (from 65 to 130 mmHg). Urine flow, sodium excretion, and the fractional excretions of sodium and urine increased with increasing RAP, and were greater in male than in female rabbits at all levels of RAP-tested. However, these apparent sex-related differences in the acute pressure diuresis/natriuresis relationships were not reflected in alterations in chronic regulation of mean arterial pressure (MAP). Thus, in rabbits on a normal salt diet (0.85 g day(-1)), resting conscious MAP was significantly greater in males (87 +/- 3 mmHg) compared with females (77+/-1 mmHg). Chronically increasing daily salt intake to 4.98 g day(-1) for 28 days had no significant effect on resting conscious MAP in either sex. Thus, although our observations indicate sex differences, at least under the present experimental conditions, in the factors regulating extracellular fluid volume, these do not appear to have a major impact in setting the level of MAP in the long term.

  13. Effect of hypergravity on the development of vestibulocerebellar afferent fibers

    Science.gov (United States)

    Bruce, L. L.

    Gravity is a critical factor in the normal development of the vestibular system, as prolonged prenatal exposures to either micro- or hypergravity will alter the pattern of projections from specific vestibular organs to specific targets in the vestibular nuclei. This study addresses the effect of gravity on the development of vestibulocerebellar projections. In adult rats the semicircular canal afferents project mainly to the cerebellar nodulus whereas the otolith maculae project mainly to the ventral uvula of the cerebellum. To determine if the distribution pattern of these afferents is altered by exposures to altered gravity, 10 pregnant rats were exposed to hypergravity (1.5g) from embryonic day 12 (before vestibular ganglion neurons contact vestibular nuclei) to embryonic day 21 (near the time when the vestibular system becomes functional). Controls were exposed to Earth's gravity but otherwise received the same treatment. At the end of the exposure the embryos were deeply anesthetized and fixed by transcardiac perfusion with 4% paraformaldehyde in 0.1 M phosphate buffer (pH7.4). Filter strips coated with DiI and PTIR were implanted into the saccule (gravistatic vestibular receptor) or into the posterior vertical canal (angular acceleration receptor), and allowed to diffuse for 2 weeks at 37°C. Then the brains were dissected and sectioned for fluorescent confocal imaging. Examination of the control cerebella revealed that the canal and otolith afferents have reached the nodulus and uvula, and axons extend into the internal granular, Purkinje, and molecular layers. Projections from the saccule and posterior vertical canal were partially segregated into their respective domains, the uvula and nodulus. In contrast, in hypergravity-exposed rat fetuses the saccule and posterior vertical canal projections were poorly segregated, and both organs contributed labeled fibers to all layers of the nodulus and uvula. This contrasts with the increased afferent segregation

  14. Human intersegmental reflexes from intercostal afferents to scalene muscles.

    Science.gov (United States)

    McBain, Rachel A; Taylor, Janet L; Gorman, Robert B; Gandevia, Simon C; Butler, Jane E

    2016-10-01

    What is the central question of this study? The aim was to determine whether specific reflex connections operate between intercostal afferents and the scalene muscles in humans, and whether these connections operate after a clinically complete cervical spinal cord injury. What is the main finding and its importance? This is the first description of a short-latency inhibitory reflex connection between intercostal afferents from intercostal spaces to the scalene muscles in able-bodied participants. We suggest that this reflex is mediated by large-diameter afferents. This intercostal-to-scalene inhibitory reflex is absent after cervical spinal cord injury and may provide a way to monitor the progress of the injury. Short-latency intersegmental reflexes have been described for various respiratory muscles in animals. In humans, however, only short-latency reflex responses to phrenic nerve stimulation have been described. Here, we examined the reflex connections between intercostal afferents and scalene muscles in humans. Surface EMG recordings were made from scalene muscles bilaterally, in seven able-bodied participants and seven participants with motor- and sensory-complete cervical spinal cord injury (median 32 years postinjury, range 5 months to 44 years). We recorded the reflex responses produced by stimulation of the eighth or tenth left intercostal nerve. A short-latency (∼38 ms) inhibitory reflex was evident in able-bodied participants, in ipsilateral and contralateral scalene muscles. This bilateral intersegmental inhibitory reflex occurred in 46% of recordings at low stimulus intensities (at three times motor threshold). It was more frequent (in 75-85% of recordings) at higher stimulus intensities (six and nine times motor threshold), but onset latency (38 ± 9 ms, mean ± SD) and the size of inhibition (23 ± 10%) did not change with stimulus intensity. The reflex was absent in all participants with spinal cord injury. As the intercostal

  15. Renal cancer

    NARCIS (Netherlands)

    Corgna, Enrichetta; Betti, Maura; Gatta, Gemma; Roila, Fausto; De Mulder, Pieter H. M.

    2007-01-01

    In Europe, renal cancer (that is neoplasia of the kidney, renal pelvis or ureter (ICD-9 189 and ICD-10 C64-C66)) ranks as the seventh most common malignancy in men amongst whom there are 29,600 new cases each year (3.5% of all cancers). Tobacco, obesity and a diet poor in vegetables are all acknowle

  16. Renal fallure

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    920705 Endothelin and acute renal failure:study on their relationship and possiblemechanisms. LIN Shanyan(林善锬), et al.Renal Res Lab, Huashan Hosp, Shanghai MedUniv, Shanghai, 200040. Natl Med J China 1992;72(4): 201-205. In order to investigate the role of endothelin

  17. Renal cancer.

    NARCIS (Netherlands)

    Corgna, E.; Betti, M.; Gatta, G.; Roila, F.; Mulder, P.H.M. de

    2007-01-01

    In Europe, renal cancer (that is neoplasia of the kidney, renal pelvis or ureter (ICD-9 189 and ICD-10 C64-C66)) ranks as the seventh most common malignancy in men amongst whom there are 29,600 new cases each year (3.5% of all cancers). Tobacco, obesity and a diet poor in vegetables are all

  18. Renal cancer

    NARCIS (Netherlands)

    Corgna, Enrichetta; Betti, Maura; Gatta, Gemma; Roila, Fausto; De Mulder, Pieter H. M.

    2007-01-01

    In Europe, renal cancer (that is neoplasia of the kidney, renal pelvis or ureter (ICD-9 189 and ICD-10 C64-C66)) ranks as the seventh most common malignancy in men amongst whom there are 29,600 new cases each year (3.5% of all cancers). Tobacco, obesity and a diet poor in vegetables are all

  19. Hepatitis E Virus in Farmed Rabbits, Wild Rabbits and Petting Farm Rabbits in the Netherlands

    NARCIS (Netherlands)

    Burt, S.A.; Veltman, Jorg; Hakze-van der Honing, Renate; Schmitt, Heike; van der Poel, Wim H.M.

    2016-01-01

    Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates. Dut

  20. Hepatitis E Virus in Farmed Rabbits, Wild Rabbits and Petting Farm Rabbits in the Netherlands

    NARCIS (Netherlands)

    Burt, Sara A.; Veltman, Jorg; Hakze-van der Honing, Renate; Schmitt, Heike; Poel, van der Wim H.M.

    2016-01-01

    Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates.

  1. Hepatitis E Virus in Farmed Rabbits, Wild Rabbits and Petting Farm Rabbits in the Netherlands

    NARCIS (Netherlands)

    Burt, Sara A.; Veltman, Jorg; Hakze-van der Honing, Renate; Schmitt, Heike; Poel, van der Wim H.M.

    2016-01-01

    Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates.

  2. Hepatitis E Virus in Farmed Rabbits, Wild Rabbits and Petting Farm Rabbits in the Netherlands

    NARCIS (Netherlands)

    Burt, S.A.|info:eu-repo/dai/nl/140114432; Veltman, Jorg; Hakze-van der Honing, Renate; Schmitt, Heike; van der Poel, Wim H.M.

    2016-01-01

    Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates.

  3. Identification and function of adenosine A3 receptor in afferent arterioles.

    Science.gov (United States)

    Lu, Yan; Zhang, Rui; Ge, Ying; Carlstrom, Mattias; Wang, Shaohui; Fu, Yiling; Cheng, Liang; Wei, Jin; Roman, Richard J; Wang, Lei; Gao, Xichun; Liu, Ruisheng

    2015-05-01

    Adenosine plays an important role in regulation of renal microcirculation. All receptors of adenosine, A1, A2A, A2B, and A3, have been found in the kidney. However, little is known about the location and function of the A3 receptor in the kidney. The present study determined the expression and role of A3 receptors in mediating the afferent arteriole (Af-Art) response and studied the interaction of A3 receptors with angiotensin II (ANG II), A1 and A2 receptors on the Af-Art. We found that the A3 receptor expressed in microdissected isolated Af-Art and the mRNA levels of A3 receptor were 59% of A1. In the isolated microperfused Af-Art, A3 receptor agonist IB-MECA did not have a constrictive effect. Activation of A3 receptor dilated the preconstricted Af-Art by norepinephrine and blunted the vasoconstrictive effect of both adenosine A1 receptor activation and ANG II on the Af-Art, respectively. Selective A2 receptor antagonist (both A2A and A2B) had no effect on A3 receptor agonist-induced vasodilation, indicating that the dilatory effect of A3 receptor activation is not mediated by activation of A2 receptor. We conclude that the A3 receptor is expressed in the Af-Art, and activation of the A3 receptor dilates the Af-Art.

  4. THE RENAL HANDLING OF HEMOGLOBIN

    Science.gov (United States)

    Bunn, H. Franklin; Esham, William T.; Bull, Robert W.

    1969-01-01

    The glomerular filtration of hemoglobin (α2β2) was studied under conditions in which its dissociation into αβ dimers was experimentally altered. Rats receiving hemoglobin treated with the sulfhydryl reagent bis(N-maleimidomethyl) ether (BME) showed a much lower renal excretion and prolonged plasma survival as compared with animals injected with untreated hemoglobin. Plasma disappearance was also prolonged in dogs receiving BME hemoglobin. Gel filtration data indicated that under physiological conditions, BME hemoglobin had impaired subunit dissociation. In addition, BME hemoglobin showed a very high oxygen affinity and a decreased rate of auto-oxidation. Glomerular filtration was enhanced under conditions which favor the dissociation of hemoglobin into dimers. Cat hemoglobin, which forms subunits much more extensively than canine hemoglobin, was excreted more readily by the rat kidney. The renal uptake of 59Fe hemoglobin injected intra-arterially into rabbits varied inversely with the concentration of the injected dose. PMID:5778789

  5. Treatment of Steroid-Resistant Acute Renal Allograft Rejection With Alemtuzumab

    NARCIS (Netherlands)

    van den Hoogen, M. W. F.; Hesselink, D. A.; van Son, W. J.; Weimar, W.; Hilbrands, L. B.

    2013-01-01

    Steroid-resistant renal allograft rejections are commonly treated with rabbit antithymocyte globulin (RATG), but alemtuzumab could be an effective, safe and more convenient alternative. Adult patients with steroid-resistant renal allograft rejection treated with alemtuzumab (1530 mg s.c. on 2 subseq

  6. Treatment of steroid-resistant acute renal allograft rejection with alemtuzumab

    NARCIS (Netherlands)

    Hoogen, M.W. van den; Hesselink, D.A.; Son, W.J. van; Weimar, W.; Hilbrands, L.B.

    2013-01-01

    Steroid-resistant renal allograft rejections are commonly treated with rabbit antithymocyte globulin (RATG), but alemtuzumab could be an effective, safe and more convenient alternative. Adult patients with steroid-resistant renal allograft rejection treated with alemtuzumab (15-30 mg s.c. on 2 subse

  7. Corynebacterium renale as a cause of reactions to the complement fixation test for Johne's disease

    NARCIS (Netherlands)

    Gilmour, N.J.L.; Goudswaard, J.

    Complement fixation (C.F.) tests and fluorescent antibody (F.A.) tests were carried out on sera from rabbits inoculated with Corynebacterium renale and Mycobacterium johnei, and on sera from cattle with C. renale pyelonephritis and with Johne's disease. Cross-reactions were a feature of the C.F.

  8. Primary afferent depolarization of muscle afferents elicited by stimulation of joint afferents in cats with intact neuraxis and during reversible spinalization.

    Science.gov (United States)

    Quevedo, J; Eguibar, J R; Jiménez, I; Schmidt, R F; Rudomin, P

    1993-11-01

    1. In the anesthetized and artificially ventilated cat, stimulation of the posterior articular nerve (PAN) with low strengths (1.2-1.4 x T) produced a small negative response (N1) in the cord dorsum of the lumbosacral spinal cord with a mean onset latency of 5.2 ms. Stronger stimuli (> 1.4 x T) produced two additional components (N2 and N3) with longer latencies (mean latencies 7.5 and 15.7 ms, respectively), usually followed by a slow positivity lasting 100-150 ms. With stimulus strengths above 10 x T there was in some experiments a delayed response (N4; mean latency 32 ms). 2. Activation of posterior knee joint nerve with single pulses and intensities producing N1 responses only, usually produced no dorsal root potentials (DRPs), or these were rather small. Stimulation with strengths producing N2 and N3 responses produced distinct DRPs. Trains of pulses were clearly more effective than single pulses in producing DRPs, even in the low-intensity range. 3. Cooling the thoracic spinal cord to block impulse conduction, increased the DRPs and the N3 responses produced by PAN stimulation without significantly affecting the N2 responses. Reversible spinalization also increased the DRPs produced by stimulation of cutaneous nerves. In contrast, the DRPs produced by stimulation of group I afferents from flexors were reduced. 4. Conditioning electrical stimulation of intermediate and high-threshold myelinated fibers in the PAN depressed the DRPs produced by stimulation of group I muscle and of cutaneous nerves. 5. Analysis of the intraspinal threshold changes of single Ia and Ib fibers has provided evidence that stimulation of intermediate and high threshold myelinated fibers in the posterior knee joint nerve inhibits the primary afferent depolarization (PAD) of Ia fibers, and may either produce PAD or inhibit the PAD in Ib fibers, in the same manner as stimulation of cutaneous nerves. In 7/16 group I fibers the inhibition of the PAD was increased during reversible

  9. WEIGHTS or RABBITS

    African Journals Online (AJOL)

    heart and spleen from_male and femalerabbits were made, in rabbits fed graded levels (0, 4, 8, 12%) of oil palm indiets. ..... aeetyl CoA derived mainly from carbohydrate wasdepressed ... an integral part in the synthesis and metabolism of.

  10. A Clever Rabbit

    Institute of Scientific and Technical Information of China (English)

    呼振璞; 付晓明

    2002-01-01

    1. Once there lived an elephant and a lion in the mountains, who both wanted to be the king of the beasts. One day the lion caught a rabbit. Before he ate it, he said, “Do you know I am the king here? ”

  11. Rabbit Repellent Paint

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Five gallons of rabbit repellent paint were sent to George Wilson to be applied on the trees of the Tewaukon tree plot. Mr. Wilson requires a 3 or 4 in. brush for...

  12. The Cutaneous Rabbit Revisited

    Science.gov (United States)

    Flach, Rudiger; Haggard, Patrick

    2006-01-01

    In the cutaneous rabbit effect (CRE), a tactile event (so-called attractee tap) is mislocalized toward an adjacent attractor tap. The effect depends on the time interval between the taps. The authors delivered sequences of taps to the forearm and asked participants to report the location of one of the taps. The authors replicated the original CRE…

  13. Expression and significance of high mobility group box 1 in the renal tissues of urosepsis rabbits%高迁移率族蛋白-1在尿源性脓毒血症家兔肾脏组织中的表达及意义

    Institute of Scientific and Technical Information of China (English)

    张轶庠; 袁也晴; 魏育英; 张学齐; 黄建生; 黄东龙; 刘红燕; 杨江根

    2015-01-01

    目的 探讨高迁移率族蛋白-1(HMGB1)在尿源性脓毒血症家兔肾组织中的表达水平及意义.方法 健康雄性家兔随机分为假手术组(Sham组)和尿源性脓毒血症组(US组).采用肾盂内高压法制备家兔尿源性脓毒血症模型.分别于术后12、24、36 h检测血白细胞计数、肾功能、早期炎性因子肿瘤坏死因子-α(TNF-α)和白细胞介素-6(IL-6),以及肾组织中HMGB1 mRNA表达.结果 与同时间点Sham组比较,US组血白细胞计数[36 h(×109/L):17.22 ±0.32比9.54±0.24]、尿素氮(BUN)[36 h (mmol/L):11.71±0.35比7.14 ±0.12]、肌酐(Cr) [36 h(μmol/L):136.10 ±7.39比82.74 ±2.18]水平均明显升高(P<0.05);US组血清TNF-α和IL-6水平先升高后降低,12 h[TNF-α (ng/L):124.6 ±4.42比18.18±1.26;IL-6 (ng/L):120.5±6.99比51.65 ±2.26]和24 h[TNF-α (ng/L):96.94 ±7.95比19.04 ±0.89;IL-6 (ng/L):83.22±4.23比53.95±2.26]与Sham组比较差异有统计学意义(P<0.05);US组肾组织中HMGB1 mRNA表达逐渐升高,各时间点与Sham组比较差异有统计学意义(P<0.05).结论 尿源性脓毒症致急性肾损伤病程中,家兔肾组织HMGB1表达逐渐升高.%Objective To investigate the expression and significance of high mobility group box 1 (HMGB1) in the renal tissues of rabbits with urosepsis.Methods Male rabbits were randomly divided into two group:sham group and urosepsis group.The rabbit urosepsis model was established by artificial high pressure in the infected pelvis.The blood white blood cells (WBC) count,serum levels of blood urea nitrogen (BUN),creatinine (Cr),tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6),and the expression of HMGB1 mRNA in the renal tissues of the two groups were observed at 12th,24th and 36th h after operation.Results As compared with sham group,the WBC count [36 h (× 109/L):17.22 ± 0.32 vs.9.54 ±0.24],serum levels of BUN [36 h (mmol/L):11.71 ±0.35 vs.7.14 ±0.12] and Cr [36 h (μmol/L):136.10 ± 7.39 vs.82.74 ± 2.18] in urosepsis

  14. 门静脉淤血对肝脏缺血再灌注后肺脏和肾脏损伤的影响%The effect of portal blood stasis on lung and renal injury induced by hepatic ischemia reperfusion in a rabbit model

    Institute of Scientific and Technical Information of China (English)

    王野; 杨甲梅; 侯元凯; 李殿启; 胡明华; 刘鹏

    2008-01-01

    目的 探讨门静脉淤血对肝脏缺血再灌注后肺脏和肾脏损伤的影响及机制.方法 对24只新西兰大白兔行肝门阻断,同时经门静脉肝脏原位冷灌注30 min,恢复灌流时按门静脉淤血去除量的不同随机分为3组:A5组去除5 ml、A10组去除10 ml、B组不去除门静脉淤血,每组8只.另取8只作为对照(C组),仅行手术解剖,不做肝门阻断及肝脏灌注.检测去除门静脉淤血对恢复灌流4 h后血清内毒素、肿瘤坏死因子-α(TNF-α)、尿素氮(BUN)、肌酐(Cr)的影响;取肺脏、肾脏组织观察组织学改变并检测组织匀浆丙二醛(MDA)、超氧化物歧化酶(SOD)及肺湿/干重、肺灌洗液蛋白含量的变化.结果 去除门静脉淤血能降低复流后血清内毒素、TNF-α、BUN、Cr、肺湿/干重、肺灌洗液蛋白含量和肺脏、肾脏组织匀浆中MDA含量.其中A5组血清TNF-α、Cr、肺灌洗液蛋白含量、肾组织匀浆中MDA均明显低于B组(P<0.05);A10组血清内毒素、TNF-α肺湿/干重及肺组织匀浆中MDA也明显低于B组(P<0.05).去除门静脉淤血可增加肺脏、肾脏组织匀浆中SOD活性,其中A5组肾组织匀浆中SOD活性明显高于B组(P<0.05).同时,去除门静脉淤血能明显改善肺脏、肾脏组织学变化.结论 去除门静脉淤血可以减轻肝脏缺血再灌注后肺脏、肾脏功能的损伤,其机制可能与门静脉淤血去除减少内毒素吸收,进而降低了血清TNF-α产生有关.%Objective To investigate the effect and mechanism of portal blood stasis on lung and renal injury induced by hepatic ischemia reperfusion. Methods A rabbit hepatic ischemia reperfusion injury model was established by hepatic portal occlusion and in situ hypothermic irrigation for 30 min.Twenty-four New Zealand white rabbits were employed and randomly divided into 3 groups equally by different dosage of portal blood stasis removal:group A5(5 ml blood removal),group A10(10 ml blood removal),and group B

  15. An Experimental Study for Radiation Nephritis in Rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung Jae [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1972-09-15

    Experimental radiation nephritis was produced in 15 rabbits by X-irradiation. About 2, 000gamma(tissue doses) were given to both kidneys of a rabbit in 5 days. Other tissues and organs except both kidneys were protected with 2 mm thickened lead plates. 5 weeks after the last irradiation, blood pictures, blood pressures, B.U.N., serum creatinine, Ca, Mg, Fe levels and serum erythropoietin activity of the irradiated rabbits were studied. After finishing above studies, rabbits were sacrificed and both kidneys were removed and examined histopathologically. Same laboratory and pathological studies were performed in 6 control rabbits. In this study, the author obtained following results. 1) Both kidneys of rabbits with experimental radiation nephritis showed marked histopathological changes, i.e.: renal tubules showed diffuse cloudy swelling, impacted intraluminal hyaline casts and focal precipitations of lime salts on the tubular epithelium. Diffuse interstitial fatty necrosis and various degrees of fibrotic infiltrations on the interstitium were also seen in association with focal lymphocytic infiltrations. Hyaline degenerations were observed on the glomeruli and small vessels. 2) Experimental radiation nephritis rabbits showed marked lowering in R.B.C. counts, decreased hemoglobin levels, low hematocrit values and leucopenia in comparison with those of control rabbits. (P<0.01). (Table 1 and 2). 3) Mild proteinuria were observed in experimental radiation nephritis in rabbits. 4) The levels of B.U.N. and serum creatinine increased in experimental radiation nephritis. (P<0.01). (Table 1, 3 and 4). 5) The levels of serum Ca and Mg Showed no statistical difference in comparison with those of control rabbits. (P>0.05). (Table 3 and 4). 6) No statistical correlations were observable between the levels of B.U.N. and Hb. values. (gamma=-0. 223). No close correlations (gamma=-0.338) were noticed between the levels of B.U.N. and serum iron levels. 7) Erythropoietin activity (R

  16. TRPV1 marks synaptic segregation of multiple convergent afferents at the rat medial solitary tract nucleus.

    Directory of Open Access Journals (Sweden)

    James H Peters

    Full Text Available TRPV1 receptors are expressed on most but not all central terminals of cranial visceral afferents in the caudal solitary tract nucleus (NTS. TRPV1 is associated with unmyelinated C-fiber afferents. Both TRPV1+ and TRPV1- afferents enter NTS but their precise organization remains poorly understood. In horizontal brainstem slices, we activated solitary tract (ST afferents and recorded ST-evoked glutamatergic excitatory synaptic currents (ST-EPSCs under whole cell voltage clamp conditions from neurons of the medial subnucleus. Electrical shocks to the ST produced fixed latency EPSCs (jitter<200 µs that identified direct ST afferent innervation. Graded increases in shock intensity often recruited more than one ST afferent and ST-EPSCs had consistent threshold intensity, latency to onset, and unique EPSC waveforms that characterized each unitary ST afferent contact. The TRPV1 agonist capsaicin (100 nM blocked the evoked TRPV1+ ST-EPSCs and defined them as either TRPV1+ or TRPV1- inputs. No partial responses to capsaicin were observed so that in NTS neurons that received one or multiple (2-5 direct ST afferent inputs--all were either blocked by capsaicin or were unaltered. Since TRPV1 mediates asynchronous release following TRPV1+ ST-evoked EPSCs, we likewise found that recruiting more than one ST afferent further augmented the asynchronous response and was eliminated by capsaicin. Thus, TRPV1+ and TRPV1- afferents are completely segregated to separate NTS neurons. As a result, the TRPV1 receptor augments glutamate release only within unmyelinated afferent pathways in caudal medial NTS and our work indicates a complete separation of C-type from A-type afferent information at these first central neurons.

  17. Differential roles of stretch-sensitive pelvic nerve afferents innervating mouse distal colon and rectum.

    Science.gov (United States)

    Feng, Bin; Brumovsky, Pablo R; Gebhart, Gerald F

    2010-03-01

    Information about colorectal distension (i.e., colorectal dilation by increased intraluminal pressure) is primarily encoded by stretch-sensitive colorectal afferents in the pelvic nerve (PN). Despite anatomic differences between rectum and distal colon, little is known about the functional roles of colonic vs. rectal afferents in the PN pathway or the quantitative nature of mechanosensory encoding. We utilized an in vitro mouse colorectum-PN preparation to investigate pressure-encoding characteristics of colorectal afferents. The colorectum with PN attached was dissected, opened longitudinally, and pinned flat in a Sylgard-lined chamber. Action potentials of afferent fibers evoked by circumferential stretch (servo-controlled force actuator) were recorded from the PN. Stretch-sensitive fibers were categorized into the following four groups: colonic muscular, colonic muscular/mucosal, rectal muscular, and rectal muscular/mucosal. Seventy-nine stretch-sensitive PN afferents evenly distributed into the above four groups were studied. Rectal muscular afferents had significantly greater stretch-responses than the other three groups. Virtually all rectal afferents (98%) had low thresholds for response and encoded stimulus intensity into the noxious range without obvious saturation. Most colonic afferents (72%) also had low thresholds (18 mmHg) for response. These high-threshold colonic afferents were sensitized to stretch by inflammatory soup; response threshold was significantly reduced (from 23 to 12 mmHg), and response magnitude significantly increased. These results suggest that the encoding of mechanosensory information differs between colonic and rectal stretch-sensitive PN afferents. Rectal afferents have a wide response range to stretch, whereas high-threshold colonic afferents likely contribute to visceral nociception.

  18. The future of GI and liver research: editorial perspectives. IV. Visceral afferents: an update.

    Science.gov (United States)

    Raybould, Helen E

    2003-06-01

    The number of articles published in American Journal of Physiology Gastrointestinal and Liver Physiology over the last 15 years on visceral afferents has increased dramatically. This reflects our growing ability to study the characteristics and function of visceral afferents and also the recognition of their importance in the maintenance of homeostasis and also in a number of pathophysiological conditions. However, there are several key unanswered questions concerning the function of visceral afferents that await further investigation.

  19. Degeneration of primary afferent terminals following brachial plexus extensive avulsion injury in rats

    OpenAIRE

    Muñetón-Gómez, Vilma; Taylor, Julian S.; Averill, Sharon; Priestley, John V.; Nieto-Sampedro, Manuel

    2004-01-01

    Important breakthroughs in the understanding regeneration failure in an injured CNS have been made by studies of primary afferent neurons. Dorsal rhizotomy has provided an experimental model of brachial plexus (BP) avulsion. This is an injury in which the central branches of primary afferents are disrupted at their point of entry into the spinal cord, bringing motor and sensory dysfunction to the upper limbs. In the present work, the central axonal organization of primary afferents was examin...

  20. Renal denervation: a new therapeutic approach for resistant hypertension

    Institute of Scientific and Technical Information of China (English)

    Cao Longxing; Fu Qiang; Wang Binghui; Li Zhiliang

    2014-01-01

    Objective To review the advances in studies on renal denervation.Data sources References concerning renal denervation and resistant hypertension cited in this review were collected from PubMed published in English and those of renal denervation devices from official websites of device manufacturers up to January 2014.Study selection Articles with keywords "renal denervation" and "resistant hypertension" were selected.Results Renal and systemic sympathetic overactivity plays an important role in pathology of hypertension as well as other diseases characterized by sympathetic overactivity.Renal denervation is a new,catheter based procedure to reduce renal and systemic sympathetic overactivity by disruption of renal sympathetic efferent and afferent nerves through radiofrequency or ultrasound energy delivered to the endoluminal surface of both renal arteries.Although several studies have shown the efficacy and safety of renal denervation in the treatment of resistant hypertension and the potential benefit of the procedure in other diseases,Symplicity HTN 3 study,the most rigorous clinical trial of renal denervation to date,failed to meet its primary endpoint.The procedure also has other limitations such as the lack of long term,efficacy and safety data and the lack of the predictors for the blood pressure lowering response and nonresponse to the procedure.An overview of current renal denervation devices holding Conformité Européenne mark is also included in this review.Conclusions Renal denervation is a promising therapeutic approach in the management of resistant hypertension and other diseases characterized by sympathetic overactivity.In its early stage of clinical application,the efficacy of the procedure is still controversial.Large scale,blind,randomized,controlled clinical trials are still necessary to address the limitations of the procedure.

  1. Renal metabolism of calcitonin

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, R.E.; Hjelle, J.T.; Mahoney, C.; Deftos, L.J.; Lisker, W.; Kato, P.; Rabkin, R.

    1988-04-01

    The kidneys account for approximately two-thirds of the metabolism of calcitonin, but relatively little is known regarding the details thereof. To further characterize this process, we examined the renal handling and metabolism of human calcitonin (hCT) by the isolated perfused rat kidney. We also studied the degradation of radiolabeled salmon calcitonin (sCT) by subcellular fractions prepared from isolated rabbit proximal tubules. The total renal (organ) clearance of immunoreactive hCT by the isolated kidney was 1.96 +/- 0.18 ml/min. This was independent of the perfusate total calcium concentration from 5.5 to 10.2 mg/dl. Total renal clearance exceeded the glomerular filtration rate (GFR, 0.68 +/- 0.05 ml/min), indicating filtration-independent removal. Urinary calcitonin clearance as a fraction of GFR averaged 2.6%. Gel filtration chromatography of medium from isolated kidneys perfused with /sup 125/I-labeled sCT showed the principal degradation products to be low molecular weight forms eluting with monoiodotyrosine. Intermediate size products were not detected. In the subcellular fractionation experiments, when carried out at pH 5.0, calcitonin hydrolysis exclusively followed the activities of the lysosomal enzyme N-acetyl-beta-glucosaminidase. Typically, at pH 7.5, 42% of total degradation occurred in the region of the brush-border enzyme alanyl aminopeptidase and 29% occurred in the region of the cytosolic enzyme phosphoglucomutase. Although 9% of the calcitonin-degrading activity was associated with basolateral membrane fractions, most of this activity could be accounted for by the presence of brush-border membranes.

  2. Renal teratogens.

    Science.gov (United States)

    Morgan, Thomas M; Jones, Deborah P; Cooper, William O

    2014-09-01

    In utero exposure to certain drugs early in pregnancy may adversely affect nephrogenesis. Exposure to drugs later in pregnancy may affect the renin-angiotensin system, which could have an impact on fetal or neonatal renal function. Reduction in nephron number and renal function could have adverse consequences for the child several years later. Data are limited on the information needed to guide decisions for patients and providers regarding the use of certain drugs in pregnancy. The study of drug nephroteratogenicity has not been systematized, a large, standardized, global approach is needed to evaluate the renal risks of in utero drug exposures.

  3. Device-based approaches for renal nerve ablation for hypertension and beyond

    Directory of Open Access Journals (Sweden)

    Alicia Ann Thorp

    2015-07-01

    Full Text Available Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy of renal denervation over a sham procedure, prompting widespread re-evaluation of the therapy’s efficacy. Disrupting renal afferent sympathetic signalling to the hypothalamus with renal denervation lowers central sympathetic tone, which has the potential to confer additional clinical benefits beyond blood pressure control. Specifically, there has been substantial interest in the use of renal denervation as either a primary or adjunct therapy in pathological conditions characterized by central sympathetic over-activity such as renal disease, heart failure and metabolic-associated disorders. Recent findings from pre-clinical and proof-of–concept studies appear promising with renal denervation shown to confer cardiovascular and metabolic benefits, largely independent of changes in blood pressure. This review explores the pathological rationale for targeting sympathetic renal nerves for blood pressure control. Latest developments in renal nerve ablation modalities designed to improve procedural success are discussed along with prospective findings on the efficacy of renal denervation to lower blood pressure in treatment-resistant hypertensive patients. Preliminary evidence in support of renal denervation as a possible therapeutic option in disease states characterized by central sympathetic over-activity is also presented.

  4. Meningeal afferent signaling and the pathophysiology of migraine.

    Science.gov (United States)

    Burgos-Vega, Carolina; Moy, Jamie; Dussor, Gregory

    2015-01-01

    Migraine is the most common neurological disorder. Attacks are complex and consist of multiple phases but are most commonly characterized by intense, unilateral, throbbing headache. The pathophysiology contributing to migraine is poorly understood and the disorder is not well managed with currently available therapeutics, often rendering patients disabled during attacks. The mechanisms most likely to contribute to the pain phase of migraine require activation of trigeminal afferent signaling from the cranial meninges and subsequent relay of nociceptive information into the central nervous system in a region of the dorsal brainstem known as the trigeminal nucleus caudalis. Events leading to activation of meningeal afferents are unclear, but nerve endings within this tissue are mechanosensitive and also express a variety of ion channels including acid-sensing ion channels and transient receptor-potential channels. These properties may provide clues into the pathophysiology of migraine by suggesting that decreased extracellular pH and environmental irritant exposure in the meninges contributes to headache. Neuroplasticity is also likely to play a role in migraine given that attacks are triggered by routine events that are typically nonnoxious in healthy patients and clear evidence of sensitization occurs during an attack. Where and how plasticity develops is also not clear but may include events directly on the afferents and/or within the TNC. Among the mediators potentially contributing to plasticity, calcitonin gene-related peptide has received the most attention within the migraine field but other mechanisms may also contribute. Ultimately, greater understanding of the molecules and mechanisms contributing to migraine will undoubtedly lead to better therapeutics and relief for the large number of patients across the globe who suffer from this highly disabling neurological disorder.

  5. Kv1 channels and neural processing in vestibular calyx afferents

    Directory of Open Access Journals (Sweden)

    Frances L Meredith

    2015-06-01

    Full Text Available Potassium-selective ion channels are important for accurate transmission of signals from auditory and vestibular sensory end organs to their targets in the central nervous system. During different gravity conditions, astronauts experience altered input signals from the peripheral vestibular system resulting in sensorimotor dysfunction. Adaptation to altered sensory input occurs, but it is not explicitly known whether this involves synaptic modifications within the vestibular epithelia. Future investigations of such potential plasticity require a better understanding of the electrophysiological mechanisms underlying the known heterogeneity of afferent discharge under normal conditions. This study advances this understanding by examining the role of the Kv1 potassium channel family in mediating action potentials in specialized vestibular afferent calyx endings in the gerbil crista and utricle. Pharmacological agents selective for different sub-types of Kv1 channels were tested on membrane responses in whole cell recordings in the crista. Kv1 channels sensitive to α-dendrotoxin and dendrotoxin-K were found to prevail in the central regions, whereas K+ channels sensitive to margatoxin, which blocks Kv1.3 and 1.6 channels, were more prominent in peripheral regions. Margatoxin-sensitive currents showed voltage-dependent inactivation. Dendrotoxin-sensitive currents showed no inactivation and dampened excitability in calyces in central neuroepithelial regions. The differential distribution of Kv1 potassium channels in vestibular afferents supports their importance in accurately relaying gravitational and head movement signals through specialized lines to the central nervous system. Pharmacological modulation of specific groups of K+ channels could help alleviate vestibular dysfunction on earth and in space.

  6. Angiotensin II and renal prostaglandin release in the dog. Interactions in controlling renal blood flow and glomerular filtration rate.

    Science.gov (United States)

    Bugge, J F; Stokke, E S

    1994-04-01

    The relationship between angiotensin II and renal prostaglandins, and their interactions in controlling renal blood flow (RBF) and glomerular filtration rate (GFR) were investigated in 18 anaesthetized dogs with acutely denervated kidneys. Intrarenal angiotensin II infusion increased renal PGE2 release (veno-arterial concentration difference times renal plasma flow) from 1.7 +/- 0.9 to 9.1 +/- 0.4 and 6-keto-PGF1 alpha release from 0.1 +/- 0.1 to 5.3 +/- 2.1 pmol min-1. An angiotensin II induced reduction in RBF of 20% did not measurably change GFR whereas a 30% reduction reduced GFR by 18 +/- 8%. Blockade of prostaglandin synthesis approximately doubled the vasoconstrictory action of angiotensin II, and all reductions in RBF were accompanied by parallel reductions in GFR. When prostaglandin release was stimulated by infusion of arachidonic acid (46.8 +/- 13.3 and 15.9 +/- 5.4 pmol min-1 for PGE2, and 6-keto-PGF1 alpha, respectively), angiotensin II did not change prostaglandin release, but had similar effects on the relationship between RBF and GFR as during control. In an ureteral occlusion model with stopped glomerular filtration measurements of ureteral pressure and intrarenal venous pressure permitted calculations of afferent and efferent vascular resistances. Until RBF was reduced by 25-30% angiotensin II increased both afferent and efferent resistances almost equally, keeping the ureteral pressure constant. At greater reductions in RBF, afferent resistance increased more than the efferent leading to reductions in ureteral pressure. This pattern was not changed by blockade of prostaglandin synthesis indicating no influence of prostaglandins on the distribution of afferent and efferent vascular resistances during angiotensin II infusion. In this ureteral occlusion model glomerular effects of angiotensin II will not be detected, and it might well be that the shift from an effect predominantly on RBF to a combined effect on both RBF and GFR induced by inhibition

  7. Muscle weakness, afferent sensory dysfunction and exercise in knee osteoarthritis

    DEFF Research Database (Denmark)

    Roos, Ewa M.; Herzog, Walter; Block, Joel A

    2011-01-01

    Lower-extremity muscle strength and afferent sensory dysfunction, such as reduced proprioceptive acuity, are potentially modifiable putative risk factors for knee osteoarthritis (OA). Findings from current studies suggest that muscle weakness is a predictor of knee OA onset, while there is confli...... with previous knee injuries) are easily identified, and may benefit from exercise interventions to prevent or delay OA onset....... a possibility for achieving preventive structure or load modifications. In contrast, large randomized controlled trials of patients with established OA have failed to demonstrate beneficial effects of strengthening exercises. Subgroups of individuals who are at increased risk of knee OA (such as those...

  8. Sarcoidose renal

    Directory of Open Access Journals (Sweden)

    AQUINO MARIA ENEDINA CLAUDINO DE

    2001-01-01

    Full Text Available Em uma mulher de 62 anos, branca, em avaliação pré-operatória de facectomia, foram detectadas alterações urinárias, tendo sido firmados os diagnósticos de calculose renal esquerda e exclusão renal homolateral. No pré-operatório da nefrectomia foram evidenciados processo pulmonar intersticial bilateral e adenopatia torácica, cuja investigação foi adiada para após a cirurgia. No rim retirado foram detectados granulomas epitelióides não necrotizantes, o mesmo ocorrendo posteriormente em biópsia transbrônquica. A paciente foi tratada com metilprednisolona, com discreta melhora pulmonar, o que não ocorreu com a função renal. O diagnóstico final foi de sarcoidose com envolvimento pulmonar, ganglionar torácico e renal.

  9. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930150 Epidermal growth factor and its recep-tor in the renal tissue of patients with acute re-nal failure and normal persons.LIU Zhihong(刘志红),et al.Jinling Hosp,Nanjing,210002.Natl Med J China 1992;72(10):593-595.Epidermal growth factor(EGF)and its receptor(EGF-R)were identified by immunohis-tochemical method(4 layer PAP)in the renaltissue specimens obtained from 11 normal kid-neys and 17 cases of acute renal failure(ARF).The quantitative EGF and EGF-R in the tissuewere expressed as positive tubules per mm~2.The amount of EGF and EGF-R in renal tissue

  10. Renal failure

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    2005234 Association between serum fetuin-A and clinical outcome in end-stage renal disease patients. WANG Kai(王开), Dept Renal Dis, Renji Hosp Shanghai, 2nd Med Univ, Shanghai 200001. Chin J Nephrol, 2005;21(2):72-75. Objective: To investigate the change of serum fetuin-A level before and after dialysis, and the association of serum fetuin-A level with clinical parameters

  11. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    950351 Serum erythropoietin levels in chronic renalinsufficiency.ZHAI Depei(翟德佩),et al.DeptNephrol.General Hosp,Tianjin Med Univ,Tianjin,300000.Tianjin Med J 1995;23(1):19-21.Patients with chronic renal insufficiency(CRI) areoften associated with anemia.The deficiency of EPOproduction in the kidney is thought to be a key factorin the pathogenesis of renal anemia.Serum erythropoi-

  12. Renal failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008463 Protective effect of recombination rat augmenter of liver regeneration on kidney in acute renal failure rats. TANG Xiaopeng(唐晓鹏), et al. Dept Nephrol, 2nd Affili Hosp Chongqing Med Univ, Chongqing 400010.Chin J Nephrol 2008;24(6):417-421. Objective To investigate the protective effects of recombination rat augmenter of liver regeneration (rrALR) on tubular cell injury and renal dysfunction

  13. Renal Hemangiopericytoma

    Directory of Open Access Journals (Sweden)

    İbrahim Halil Bozkurt

    2015-03-01

    Full Text Available Hemangiopericytoma is an uncommon perivascular tumor originating from pericytes in the pelvis, head and tneck, and the meninges; extremely rarely in the urinary system. We report a case of incidentally detected renal mass in which radiologic evaluation was suggestive of renal cell carcinoma. First, we performed partial nephrectomy, and then, radical nephrectomy because of positive surgical margins and the pathological examination of the surgical specimen that revealed a hemangiopericytoma. No additional treatment was administered.

  14. Anatomy and physiology of the afferent visual system.

    Science.gov (United States)

    Prasad, Sashank; Galetta, Steven L

    2011-01-01

    The efficient organization of the human afferent visual system meets enormous computational challenges. Once visual information is received by the eye, the signal is relayed by the retina, optic nerve, chiasm, tracts, lateral geniculate nucleus, and optic radiations to the striate cortex and extrastriate association cortices for final visual processing. At each stage, the functional organization of these circuits is derived from their anatomical and structural relationships. In the retina, photoreceptors convert photons of light to an electrochemical signal that is relayed to retinal ganglion cells. Ganglion cell axons course through the optic nerve, and their partial decussation in the chiasm brings together corresponding inputs from each eye. Some inputs follow pathways to mediate pupil light reflexes and circadian rhythms. However, the majority of inputs arrive at the lateral geniculate nucleus, which relays visual information via second-order neurons that course through the optic radiations to arrive in striate cortex. Feedback mechanisms from higher cortical areas shape the neuronal responses in early visual areas, supporting coherent visual perception. Detailed knowledge of the anatomy of the afferent visual system, in combination with skilled examination, allows precise localization of neuropathological processes and guides effective diagnosis and management of neuro-ophthalmic disorders.

  15. Interactions between visceral afferent signaling and stimulus processing

    Directory of Open Access Journals (Sweden)

    Hugo D Critchley

    2015-08-01

    Full Text Available Visceral afferent signals to the brain influence thoughts, feelings and behaviour. Here we highlight the findings of a set of empirical investigations in humans concerning body-mind interaction that focus on how feedback from states of autonomic arousal shapes cognition and emotion. There is a longstanding debate regarding the contribution of the body, to mental processes. Recent theoretical models broadly acknowledge the role of (autonomically-mediated physiological arousal to emotional, social and motivational behaviours, yet the underlying mechanisms are only partially characterized. Neuroimaging is overcoming this shortfall; first, by demonstrating correlations between autonomic change and discrete patterns of evoked, and task-independent, neural activity; second, by mapping the central consequences of clinical perturbations in autonomic response and; third, by probing how dynamic fluctuations in peripheral autonomic state are integrated with perceptual, cognitive and emotional processes. Building on the notion that an important source of the brain’s representation of physiological arousal is derived from afferent information from arterial baroreceptors, we have exploited the phasic nature of these signals to show their differential contribution to the processing of emotionally-salient stimuli. This recent work highlights the facilitation at neural and behavioral levels of fear and threat processing that contrasts with the more established observations of the inhibition of central pain processing during baroreceptors activation. The implications of this body-brain-mind axis are discussed.

  16. Laparoscopic ovariectomy in rabbits

    Directory of Open Access Journals (Sweden)

    M. S. Al-Badrany

    2009-01-01

    Full Text Available A comparative evaluation of three different techniques of laparoscopic ovariectomy was carried out in 33 healthy female in rabbits, which included resection and removal of ovary after clip application, electrocautery of the ovary, then resection, and pulling ovary outside abdomen, ligation by silk, then ovary was removed. The ovaries and associated structures were better visualized by laparoscopy and all three techniques were carried out perfectly. All rabbits after operation were healthy and they were monitored for one month after operation. However, 3 of them died after operation, two of them died due to bleeding and the other of them died due to unknown causes. General anesthesia by using ketamine-xylazine i.m., was suitable for this technique, and the anesthesia provided good analgesia and good muscle relaxation. CO2 was used to establish pneumoperitoneum. In conclusion, resection and removal of the ovaries after clip application technique was found superior to the other two techniques.

  17. The researchers developed luminous rabbit

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>Their efforts produced two rabbits out of a litter of eight that went from being a normal, fluffy(蓬松的) white to glowing green in the dark. The rabbits were born at the University of Istanbul as part of a collaboration between scientists from universities in Turkey and Hawaii. The rabbits glow to show that a genetic manipulation technique can work efficiently,

  18. Effects of intratympanic gentamicin on vestibular afferents and hair cells in the chinchilla.

    Science.gov (United States)

    Hirvonen, Timo P; Minor, Lloyd B; Hullar, Timothy E; Carey, John P

    2005-02-01

    Gentamicin is toxic to vestibular hair cells, but its effects on vestibular afferents have not been defined. We treated anesthetized chinchillas with one injection of gentamicin (26.7 mg/ml) into the middle ear and made extracellular recordings from afferents after 5-25 (early) or 90-115 days (late). The relative proportions of regular, intermediate, and irregular afferents did not change after treatment. The spontaneous firing rate of regular afferents was lower (P galvanic currents was unaffected for all afferents. Intratympanic gentamicin treatment reduced the histological density of all hair cells by 57% (P = 0.04). The density of hair cells with calyx endings was reduced by 99% (P = 0.03), although some remaining hair cells had other features suggestive of type I morphology. Type II hair cell density was not significantly reduced. These findings suggest that a single intratympanic gentamicin injection causes partial damage and loss of vestibular hair cells, particularly type I hair cells or their calyceal afferent endings, does not damage the afferent spike initiation zones, and preserves enough hair cell synaptic activity to drive the spontaneous activity of vestibular afferents.

  19. Primary afferent depolarization and flexion reflexes produced by radiant heat stimulation of the skin.

    Science.gov (United States)

    Burke, R E; Rudomin, P; Vyklický, L; Zajac, F E

    1971-02-01

    1. The reflex effects of pulses of intense radiant heat applied to the skin of the central plantar pad have been studied in unanaesthetized (decerebrate) spinal cats.2. Pad heat pulses produced flexion of the ipsilateral hind limb and increased ipsilateral flexor monosynaptic reflexes, due to post-synaptic excitation of flexor alpha motoneurones. These effects were accompanied by reduction of extensor monosynaptic reflexes and post-synaptic inhibition of extensor motoneurones.3. Ipsilateral (and contralateral) pad heat pulses consistently evoked negative dorsal root potentials (DRPs) as well as increased excitability of both cutaneous and group Ib muscle afferent terminals. The excitability of group Ia afferents was sometimes also increased during pad heat pulses, but to a lesser extent.4. Pad heat pulses produced negative DRPs in preparations in which positive DRP components could be demonstrated following electrical stimulation of both skin and muscle nerves.5. The motor and primary afferent effects of heat pulses always accompanied one another, beginning after the pad surface temperature had reached rather high levels (usually 48-55 degrees C).6. Negative DRPs increased excitability of cutaneous and group Ib afferents, and motoneurone activation produced by pad heat pulses was essentially unmodified when conduction in large myelinated afferents from the central plantar pad was blocked by cooling the posterior tibial nerve trunk.7. It is concluded that adequate noxious activation of cutaneous afferents of small diameter produces primary afferent depolarization in a variety of large diameter afferent fibres, as well as post-synaptic effects in alpha motoneurones.

  20. Persistence of PAD and presynaptic inhibition of muscle spindle afferents after peripheral nerve crush.

    Science.gov (United States)

    Enríquez-Denton, M; Manjarrez, E; Rudomin, P

    2004-11-19

    Two to twelve weeks after crushing a muscle nerve, still before the damaged afferents reinnervate the muscle receptors, conditioning stimulation of group I fibers from flexor muscles depolarizes the damaged afferents [M. Enriquez, I. Jimenez, P. Rudomin, Changes in PAD patterns of group I muscle afferents after a peripheral nerve crush. Exp. Brain Res., 107 (1996), 405-420]. It is not known, however, if this primary afferent depolarization (PAD) is indeed related to presynaptic inhibition. We now show in the cat that 2-12 weeks after crushing the medial gastrocnemius nerve (MG), conditioning stimulation of group I fibers from flexors increases the excitability of the intraspinal terminals of both the intact lateral gastrocnemius plus soleus (LGS) and of the previously damaged MG fibers ending in the motor pool, because of PAD. The PAD is associated with the depression of the pre- and postsynaptic components of the extracellular field potentials (EFPs) evoked in the motor pool by stimulation of either the intact LGS or of the previously damaged MG nerves. These observations indicate, in contrast to what has been reported for crushed cutaneous afferents [K.W. Horch, J.W. Lisney, Changes in primary afferent depolarization of sensory neurones during peripheral nerve regeneration in the cat, J. Physiol., 313 (1981), 287-299], that shortly after damaging their peripheral axons, the synaptic efficacy of group I spindle afferents remains under central control. Presynaptic inhibitory mechanisms could be utilized to adjust the central actions of muscle afferents not fully recovered from peripheral lesions.

  1. CCK enhances response to gastric distension by acting on capsaicin-insensitive vagal afferents

    NARCIS (Netherlands)

    van de Wall, EHEM; Duffy, P; Ritter, RC

    2005-01-01

    Capsaicin treatment destroys vagal afferent C fibers and markedly attenuates reduction of food intake and induction of hindbrain Fos expression by CCK. However, both anatomical and electrophysiological data indicate that some gastric vagal afferents are not destroyed by capsaicin. Because CCK enhanc

  2. Modulation of gastrointestinal afferent sensitivity by a novel substituted benzamide (ecabapide).

    Science.gov (United States)

    Jiang, W; Grundy, D

    2000-01-14

    The effects of ecabapide, a novel substituted benzamide compound (3-[2-(3,4-dimethoxyphenyl)ethylcarbamoylmethyl]amino-N-methylb enzamide) that has gastrointestinal prokinetic action, were examined on the discharge of extrinsic afferent nerves supplying the stomach and jejunum in anaesthetized rats. Ecabapide (60 and 180 microg kg(-1), i.v.) had no effect on the baseline discharge of vagal gastric distension-sensitive afferents or the stimulus-response profile to gastric distension. Ecabapide also had no effect on either spontaneous jejunal mesenteric afferent nerve discharge or responses to intestinal distension. Ecabapide (180 microg kg(-1)) significantly inhibited the maximum discharge of jejunal afferents induced by cholecystokinin (CCK8; 50 pmol, i.v.), whereas it failed to inhibit the excitatory action of 2-methyl-5-hydroxytryptamine (2Me-5-HT; 10 microg, i.v.), a selective 5-HT3 receptor agonist. A model of acute focal intestinal ischaemia was used to evaluate the actions of ecabapide on the discharge of activated jejunal afferents. Ischaemia produced a substantial increase in afferent discharge which was reproducible when the duration of ischaemia was limited to less than 10 min and repeated every 15 min. Ecabapide at doses of 60 and 180 microg kg(-1) significantly reduced ischaemia-induced increases in afferent discharge. In addition to its therapeutic efficacy as a gastrointestinal prokinetic agent, these findings show also that ecabapide may also have an inhibitory action on the discharge of intestinal afferents activated by ischaemia.

  3. Total Reconstruction of the Afferent Loop for Treatment of Radiation-Induced Afferent Loop Obstruction with Segmental Involvement after Pancreaticoduodenectomy with Roux-en-Y Reconstruction

    Directory of Open Access Journals (Sweden)

    Konstantinos Blouhos

    2013-08-01

    Full Text Available As the literature on afferent loop obstruction (ALO after pancreaticoduodenectomy (PD is very limited, standardized rules for its management do not exist. Herein, we report the case of a 65-year-old male patient with chronic ALO who had undergone PD with single Roux-en-Y limb reconstruction and adjuvant chemoradiation therapy for pancreatic head adenocarcinoma 2 years earlier. The patient was brought to the operating room with the diagnosis of radiation enteritis of the afferent loop with segmental involvement and concurrent hepaticojejunostomy (HJ and pancreaticojejunostomy (PJ stricture. Complete mobilization of the afferent loop, removal of the affected segment and reconstruction were performed. Reconstruction of the afferent loop was a one-way option for the surgeons because the Roux-en-Y reconstruction limited endoscopic access to the afferent loop, and the segmental radiation injury of the afferent loop ruled out bypass surgery. However, mobilization of the affected segment through a field of dense adhesions and revision of the HJ and PJ were technically demanding.

  4. Ultrastructure of Reissner's membrane in the rabbit

    DEFF Research Database (Denmark)

    Qvortrup, K.; Rostgaard, Jørgen; Bretlau, P.

    1994-01-01

    Anatomy, Reissner's membrane, electron microscopy, tubulocisternal endoplasmic reticulum, subsurface cisterns, rabbit......Anatomy, Reissner's membrane, electron microscopy, tubulocisternal endoplasmic reticulum, subsurface cisterns, rabbit...

  5. Comparison between the effect of static contraction and tendon stretch on the discharge of group III and IV muscle afferents

    National Research Council Canada - National Science Library

    Shawn G. Hayes; Angela E. Kindig; Marc P. Kaufman

    2005-01-01

    ... afferents as does static contraction. We have tested the veracity of this assumption in decerebrated cats by comparing the responses of group III and IV muscle afferents to tendon stretch with those to static contraction...

  6. Presynaptic inhibition of muscle spindle and tendon organ afferents in the mammalian spinal cord.

    Science.gov (United States)

    Rudomin, P

    1990-12-01

    More than 30 years ago, Frank and Fuortes proposed that the synaptic effectiveness of muscle spindle afferents associated with spinal motoneurones could be diminished by the activation of nerves from flexor muscles. Since that time, research has focused on disclosing the mode of operation and the spinal pathways involved in this presynaptic inhibitory control. Initially, it was assumed that the same last-order interneurones mediated presynaptic inhibition of both muscle spindle and tendon organ afferent fibres. More recent evidence indicates that the synaptic effectiveness of these two groups of afferents is controlled by separate sets of GABAergic interneurones synapsing directly with the intraspinal terminals of the afferent fibres. This unique arrangement allows for selective control of the information on muscle length or muscle tension, despite the convergence of muscle spindle and tendon organ afferents on second-order interneurones.

  7. Bioeffect of lipohemia rabbits irradiated in oral mucosa with 650-nm diode-laser-accompanied oxygen inspiration and clinical application

    Science.gov (United States)

    Yang, Fu-Shou; Tang, Jin-Xian; Liu, Cheng; Yang, Xi-Cheng; Pang, Hi-Xiu

    1998-11-01

    The study on irradiating in oral mucosa of rabbits with 650 nm diode laser and clinical application has been reported in this paper. The result of animal experiment showed: the obvious decrease of cholesterin and triglyceride has been found among those highly lipohemia rabbits in the experiments of 650nm diode laser irradiating accompanying with oxygen, as well as the parameters of hemorheology obviously being improved, as compared with highly lipohemia rabbits un-irradiating, the statistical analysis showing P renal interstitial in the group of rabbits which are irradiated with laser and accompanying with oxygen inspiration, and even the perfectly recovered tissue in some rabbits has been seen. This experimental result is significantly for clinical application. The results of clinic application showed, that the patients employed this method which treatment cerebral infarction, lipohemia, the total effective ratio achieved 91.7 percent, perfect effect 30.6 percent.

  8. Effects of efonidipine hydrochloride on renal arteriolar diameters in spontaneously hypertensive rats.

    Science.gov (United States)

    Nakamura, Masuhisa; Notoya, Mitsuru; Kohda, Yuka; Yamashita, Junji; Takashita, Yuko; Gemba, Munekazu

    2002-09-01

    Efonidipine, a calcium antagonist, has been reported to dilate not only afferent but also efferent arterioles, thereby reducing glomerular hydrostatic pressure. We investigated the effect of chronic treatment with efonidipine or lisinopril on the afferent and efferent arteriolar diameters by the vascular cast technique. Four-week-old spontaneously hypertensive rats (SHR) were divided into three groups: untreated, efonidipine (25 mg/kg/day)-treated, and lisinopril (3 mg/kg/day)-treated. At 22 weeks of age, the renal vasculatures were fixed at the maximally dilated condition. The morphometrical measurements showed that the treatments with efonidipine and lisinopril caused structural alteration of the vasculature, resulting in significantly greater efferent arteriolar diameters than in untreated SHR. In addition, lisinopril-treated rats had wider afferent lumina. The renoprotective effect of efonidipine and lisinopril might be partly due to the structurally larger efferent arteriolar lumen.

  9. Mechanisms of Depressor Effect of Norepinephrine Injected into Subnucleus Commissuriu of Nucleus Solitarius Tractus in Rabbits

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi; SONG Yuanlong; GAO Linlin; LUO Hongyan; LIU Shenghong; YI Zhengrong; LI Ai; HU Xinwu; LIU Changjin; TANG Ming; LIU Lieju

    2005-01-01

    Summary: This experiment aimed to investigate the effect of adrenergic system in the subnucleus commissuriu of nucleus solitrius tractus (CNTS) on renal nerve discharges. Norepinephrine (NE) was microinjected into the CNTS of rabbits and mean arterial blood pressure (MAP) and renal nerve discharges (FRND) were synchronously recorded. The results indicated that (1) microinjection of norepinephine into the CNTS of rabbit could significantly attenuate the frequency of renal nerve discharge, and at the same time decrease markedly the mean arterial pressure. (2) Microinjection of 0.3 nmol yohimbin into CNTS had no significant influence on FRND and MAP, but could attenuate and even reverse the effects of NE on FRND and MAP. These results suggest that microinjection of NE into CNTS may activate the alpha-adrenorecptor located in CNTS and secondarily produce a depressor effect by attenuating the activity of peripheral sympathetic nervous system.

  10. Rabbit IgG distribution in skin, spinal cord and DRG following systemic injection in rat.

    Science.gov (United States)

    Tonra, J R; Mendell, L M

    1997-12-01

    In order to determine the distribution of antibodies such as anti-NGF following systemic injection in neonates, immunocytochemical techniques were used to examine the localization of rabbit IgG in rat skin, DRG, and spinal cord after treatments with normal rabbit serum or purified rabbit IgG. Daily subcutaneous injections beginning on postnatal day 2 or on day 15 were given for three days. On the fourth day the animals were sacrificed and tissues were processed for rabbit IgG-IR. In the dorsal and ventral spinal cord, staining intensities suggest a substantial increase in the blood-brain barrier during the first two weeks after birth. Staining intensity in the epidermis of the glabrous skin from the hindpaw was substantially lower than in the adjacent dermis. In addition, IgG infrequently accumulated intracellularly in intensely stained patches in the epidermis. IgG was also able to reach relatively high intracellular concentrations in a small number of sensory neurons. The IgG staining pattern in the skin was similar when anti-NGF itself was administered to the animals. The results are discussed in the context of the effects of anti-NGF on the development of nociceptive afferents.

  11. Observación de la reacción tisular del precinto comercial de poliamida empleado como método de ligadura en pedículo renal y ute rino en conejos Observation of tissular reaction of commercial polyamide seal used as a method of bond in renal and uterine pedicle in rabbits

    Directory of Open Access Journals (Sweden)

    R Rovere

    2007-01-01

    -absorbables (polypropilene, polyester and polyamide. Staples and vascular clips can also be employed for permanent haemostasia allowing a good occlusion of the vascular pedicles, but their high cost limits their use in veterinary surgery. In this study, tissular reaction at vascular pedicle level was evaluated in rabbits after using a polyamide seal. Six male rabbits underwent nephrectomy and the pedicle was ligatured with polyamide. The remaining six animals underwent ovariohysterectomy with the placement of a seal at uterine cervix level. The haemostasia provided by the implant was immediate and safe after its application. The macroscopic and microscopic observations of the animals showed that the tissular reaction was minimal. Neither tissular necrosis nor a severe inflammation degree were observed during histophatologic studies; nor signs of infection. The polyamide commercial seal is an easy to apply, safe technique, it also causes minimal tissular reaction and has a low cost, making possible its use in vascular pedicle ligatures at surgical veterinary practices.

  12. Hydrogen sulfide determines HNO-induced stimulation of trigeminal afferents.

    Science.gov (United States)

    Wild, Vanessa; Messlinger, Karl; Fischer, Michael J M

    2015-08-18

    Endogenous NO and hydrogen sulfide form HNO, which causes CGRP release via TRPA1 channel activation in sensory nerves. In the present study, stimulation of intact trigeminal afferent neuron preparations with NO donors, Na2S or both was analyzed by measuring CGRP release as an index of mass activation. Combined stimulation was able to activate all parts of the trigeminal system and acted synergistic compared to stimulation with both substances alone. To investigate the contribution of both substances, we varied their ratio and tracked intracellular calcium in isolated neurons. Our results demonstrate that hydrogen sulfide is the rate-limiting factor for HNO formation. CGRP has a key role in migraine pathophysiology and HNO formation at all sites of the trigeminal system should be considered for this novel means of activation.

  13. Selective cortical and segmental control of primary afferent depolarization of single muscle afferents in the cat spinal cord.

    Science.gov (United States)

    Eguibar, J R; Quevedo, J; Rudomin, P

    1997-03-01

    This study was primarily aimed at investigating the selectivity of the cortico-spinal actions exerted on the pathways mediating primary afferent depolarization (PAD) of muscle spindle and tendon organ afferents ending within the intermediate nucleus at the L6-L7 segmental level. To this end we analyzed, in the anesthetized cat, the effects produced by electrical stimulation of sensory nerves and of the cerebral cortex on (a) the intraspinal threshold of pairs of single group I afferent fibers belonging to the same or to different hindlimb muscles and (b) the intraspinal threshold of two collaterals of the same muscle afferent fiber. Afferent fibers were classified in three categories, according to the effects produced by stimulation of segmental nerves and of the cerebral cortex. Twenty-five of 40 fibers (62.5%) were depolarized by stimulation of group I posterior biceps and semitendinosus (PBSt) or tibialis (Tib) fibers, but not by stimulation of the cerebral cortex or of cutaneous and joint nerves, which instead inhibited the PBSt- or Tib-induced PAD (type A PAD pattern, usually seen in Ia fibers). The remaining 15 fibers (37.5%) were all depolarized by stimulation of the PBSt or Tib nerves and the cerebral cortex. Stimulation of cutaneous and joint nerves produced PAD in 10 of those 15 fibers (type B PAD pattern) and inhibited the PBSt- or Tib-induced PAD in the 5 remaining fibers (type C PAD pattern). Fibers with a type B or C PAD pattern are likely to be Ib. Not all sites in the cerebral cortex inhibited with the same effectiveness the segmentally induced PAD of group I fibers with a type A PAD pattern. With the weakest stimulation of the cortical surface, the most effective sites that inhibited the PAD of individual fibers were surrounded by less effective sites, scattered all along the motor cortex (area 4gamma and 6) and sensory cortex (areas 3, 2 and 1), far beyond the area of projection of group I fibers from the hindlimb. With higher strengths of

  14. The Year of the Rabbit

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Every year of the Chinese lunar calendar corresponds with an animal. The rat,ox, tiger, rabbit, dragon, snake, horse,sheep, monkey, rooster, dog and pig make up the Chinese zodiac, which repeats in a12-year cycle. This year’s Chinese NewYear rings in the Year of the Rabbit.

  15. Welfare assessment in pet rabbits

    NARCIS (Netherlands)

    Schepers, F.; Koene, P.; Beerda, B.

    2009-01-01

    One million pet rabbits are kept in The Netherlands, but there are no data available on their behaviour and welfare. This study seeks to assess the welfare of pet rabbits in Dutch households and is a first step in the development of a welfare assessment system. In an internet survey, housing

  16. Intermedin in the paraventricular nucleus attenuates cardiac sympathetic afferent reflex in chronic heart failure rats.

    Directory of Open Access Journals (Sweden)

    Xian-Bing Gan

    Full Text Available BACKGROUND AND AIM: Intermedin (IMD is a member of calcitonin/calcitonin gene-related peptide (CGRP family together with adrenomedullin (AM and amylin. It has a wide distribution in the central nervous system (CNS especially in hypothalamic paraventricular nucleus (PVN. Cardiac sympathetic afferent reflex (CSAR is enhanced in chronic heart failure (CHF rats. The aim of this study is to determine the effect of IMD in the PVN on CSAR and its related mechanisms in CHF rats. METHODOLOGY/PRINCIPAL FINDINGS: Rats were subjected to left descending coronary artery ligation to induce CHF or sham-operation (Sham. Renal sympathetic nerve activity (RSNA, mean arterial pressure (MAP and heart rate (HR were recorded. CSAR was evaluated by the RSNA and MAP responses to epicardial application of capsaicin. Acute experiments were carried out 8 weeks after coronary ligation or sham surgery under anesthesia. IMD and angiotensin II (Ang II levels in the PVN were up-regulated in CHF rats. Bilateral PVN microinjection of IMD caused greater decreases in CSAR and the baseline RSNA and MAP in CHF rats than those in Sham rats. The decrease of CSAR caused by IMD was prevented by pretreatment with AM receptor antagonist AM22-52, but not CGRP receptor antagonist CGRP8-37. Ang II in the PVN significantly enhanced CSAR and superoxide anions level, which was inhibited by PVN pretreatment with IMD or tempol (a superoxide anions scavenger in Sham and CHF rats. CONCLUSION: IMD in the PVN inhibits CSAR via AM receptor, and attenuates the effects of Ang II on CSAR and superoxide anions level in CHF rats. PVN superoxide anions involve in the effect of IMD on attenuating Ang II-induced CSAR response.

  17. INFECTIOUS MYXOMATOSIS OF RABBITS

    Science.gov (United States)

    Rivers, T. M.

    1930-01-01

    The virus of infectious myxomatosis of rabbits (Sanarelli) induces multiple lesions in the skin, lymph glands, tunica vaginalis,epididymis, testicle, spleen, and lungs. Growth and destruction of cells in the epidermis overlying the myxomatous masses leads to the formation of vesicles. Cytoplasmic inclusions are found in affected epidermal cells. Occasionally, similar inclusions are seen in other involved epithelial cells. The nature of the inclusions is an open question. In the myxomatous masses situated in the subcutaneous and other tissues, evidences of alteration and growth of certain cells are observed. PMID:19869741

  18. The White Rabbit project

    CERN Document Server

    Serrano, J; Gousiou, E; van der Bij, E; Wlostowski, T; Daniluk, G; Lipinski, M

    2013-01-01

    White Rabbit (WR) is a multi-laboratory, multi- company collaboration for the development of a new Ethernet-based technology which ensures sub-nanosecond synchronisation and deterministic data transfer. The project uses an open source paradigm for the development of its hardware, gateware and software components. This article provides an introduction to the technical choices and an explanation of the basic principles underlying WR. It then describes some possible applications and the current status of the project. Finally, it provides insight on current developments and future plans.

  19. Renal Cysts

    Science.gov (United States)

    ... as “simple” cysts, meaning they have a thin wall and contain water-like fluid. Renal cysts are fairly common in ... simple kidney cysts, meaning they have a thin wall and only water-like fluid inside. They are fairly common in ...

  20. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    970363 Effect on serum PTH and 1, 25(OH)2 D3levels of rapid correction of metabolic acidosis in CRFpatients with secondary hyperparathyroidism. YUANQunsheng(袁群生), et al. Renal Div, PUMC Hosp,Beijing, 100730. Chin J Nephrol 1996; 12(6): 328-331.

  1. Drug-induced renal injury

    African Journals Online (AJOL)

    Drugs can cause acute renal failure by causing pre-renal, intrinsic or post-renal toxicity. Pre-renal ... incidence of drug dose adjustment in renal impairment in the SAMJ. ... Fever, haemolytic anaemia, thrombocytopenia, renal impairment and.

  2. 输尿管不全梗阻致兔肾积水动物模型的肾功能MR相关评估%The renal function study of MR perfusion of hydronephrosis due to ureteropelvic junction obstruction in the rabbit model

    Institute of Scientific and Technical Information of China (English)

    杨洋; 张潍平; 彭芸; 温洋; 杨吉刚

    2011-01-01

    Objective To study the feasibility of MR perfusion imaging in assessing renal function of hydronephrosis in animal model.Methods Ten New Zealand rabbits(10-week-old,Male) underwent ureteropelvic junction obstruction by embolied the right ureter of ureteropelvic junction into a plastic cannula.Before and two months after the surgery,the animals were performed both on SPECT and MR perfusion,MR perfusion parameters were assessed,and statistical analyses were performed on the GFR of SPECT and MR perfusion parameters.Results Majority MR perfusion parameters,such as volume of renal parenchyma(7608.00±951.29 mm3) and pSRF(0.3455±0.1226 ml/min) after operation were decreased than those before operation(8400.82±1082.25 mm3,0.5709±0.1472 ml/min,respectively).Statistic analysis showed that pSRF had good statistically relationship with GFR of SPECT(preoperation r=0.712,p=0.041,postoperation r=0.633,p=0.037).However,there were no obvious relation of volume of renal parenchyma with GFR after operation(r=0.312,p=0.079).Conclusions MR perfusion imaging can accurately assess animal model' renal function in hydronephrosis.MR perfusion nephrogram can provide the sufficient message which may have statistically relation with GFR of SPECT.%目的 探讨MR灌注成像技术对积水肾脏肾功能的评估价值.方法 应用塑料套管压迫法建立肾盂输尿管连接部梗阻致肾积水动物模型10只.模型建立前后分别对样本行核医学肾动态显像(单光子发射计算机体层成像SPECT)及MR灌注成像,并以病理检查为佐证,观察样本手术前后各项参数的变化,进行MR灌注参数与核素GFR的统计学相关性分析.结论 积水肾脏皮髓质MR灌注参数,包括积水肾脏的肾实质体积,术前(8400.82±1082.25)mm3,术后(7608.00±951.29)mm3 (P=0.021);基于Patlak技术推算出的分肾功能(Patlak SRF,pSRF),术前(0.5709±0.1472)ml/min,术后(0.3455±0.1226)ml/min(P=0.0092)以及核素扫描测得的GFR,术前(277.6±214.5)ml

  3. Local control of information flow in segmental and ascending collaterals of single afferents.

    Science.gov (United States)

    Lomelí, J; Quevedo, J; Linares, P; Rudomin, P

    1998-10-08

    In the vertebrate spinal cord, the activation of GABA(gamma-amino-butyric acid)-releasing interneurons that synapse with intraspinal terminals of sensory fibres leading into the central nervous system (afferent fibres) produces primary afferent depolarization and presynaptic inhibition. It is not known to what extent these presynaptic mechanisms allow a selective control of information transmitted through specific sets of intraspinal branches of individual afferents. Here we study the local nature of the presynaptic control by measuring primary afferent depolarization simultaneously in two intraspinal collaterals of the same muscle spindle afferent. One of these collaterals ends at the L6-L7 segmental level in the intermediate nucleus, and the other ascends to segment L3 within Clarke's column, the site of origin of spinocerebellar neurons. Our results indicate that there are central mechanisms that are able to affect independently the synaptic effectiveness of segmental and ascending collaterals of individual muscle spindle afferents. Focal control of presynaptic inhibition thus allows the intraspinal branches of afferent fibres to function as a dynamic assembly that can be fractionated to convey information to selected neuronal targets. This may be a mechanism by which different spinal postsynaptic targets that are coupled by sensory input from a common source could be uncoupled.

  4. Distribution of presumptive chemosensory afferents with FMRFamide- or substance P-like immunoreactivity in decapod crustaceans.

    Science.gov (United States)

    Schmidt, M

    1997-01-23

    In five species of decapod crustaceans--Cherax destructor (crayfish), Carcinus maenas (crab), Homarus americanus (clawed lobster), Eriocheir sinensis (crab), Macrobrachium rosenbergii (shrimp)--immunocytochemical stainings revealed the presence of sensory afferents with FMRFamide-like immunoreactivity in the central nervous system. These afferents were extremely thin, very numerous, and innervated all sensory neuropils except the optic and olfactory lobes. In their target neuropils they gave rise to condensed net- or ball-like terminal structures. Only in Homarus americanus but not in any other studied species immunocytochemistry revealed a separate, non-overlapping class of sensory afferents with substance P-like immunoreactivity. Also the afferents with substance P-like immunoreactivity were very thin and numerous, innervated all sensory neuropils except optic and olfactory lobes, and gave rise to condensed terminal structures. From their morphological characteristics it can be concluded that likely both classes of afferents are chemosensory. The substance P-like immunoreactivity suggests a link with the nociceptor afferents of vertebrates, with which both classes of afferents share several other morphological features.

  5. Vagal afferents sense meal-associated gastrointestinal and pancreatic hormones: mechanism and physiological role.

    Science.gov (United States)

    Iwasaki, Yusaku; Yada, Toshihiko

    2012-12-01

    Some gastrointestinal and pancreatic hormones are potently secreted by meal intake and reduce food intake, therefore these hormones play a role in the meal-evoked satiety peptides. Previous reports have demonstrated that peripheral administration of these gastrointestinal or pancreatic hormones decrease feeding and the anorectic effects are abolished by lesions of vagal afferent nerves using surgical or chemical protocols, indicative of the involvement of the vagal afferents. Vagal afferent nerves link between several peripheral organs and the nucleus tractus solitarius of the brainstem. The present review focuses on cholecystokinin, peptide YY(3-36), pancreatic polypeptide, and nesfatin-1 released from endocrine cells of the gut and pancreas. These hormonal peptides directly act on and increase cytosolic Ca(2+) in vagal afferent nodose ganglion neurons and finally suppress food intake via vagal afferents. Therefore, peripheral terminals of vagal afferents could sense gastrointestinal and pancreatic hormones and regulate food intake. Here, we review how the vagal afferent neurons sense a variety of gastrointestinal and pancreatic hormones and discuss its physiological significance in regulation of feeding. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Lipolysis sensation by white fat afferent nerves triggers brown fat thermogenesis.

    Science.gov (United States)

    Garretson, John T; Szymanski, Laura A; Schwartz, Gary J; Xue, Bingzhong; Ryu, Vitaly; Bartness, Timothy J

    2016-08-01

    Metabolic challenges, such as a cold environment, stimulate sympathetic neural efferent activity to white adipose tissue (WAT) to drive lipolysis, thereby increasing the availability of free fatty acids as one source of fuel for brown adipose tissue (BAT) thermogenesis. WAT is also innervated by sensory nerve fibers that network to metabolic brain areas; moreover, activation of these afferents is reported to increase sympathetic nervous system outflow. However, the endogenous stimuli sufficient to drive WAT afferents during metabolic challenges as well as their functional relation to BAT thermogenesis remain unknown. We tested if local WAT lipolysis directly activates WAT afferent nerves, and then assessed whether this WAT sensory signal affected BAT thermogenesis in Siberian hamsters (Phodopus sungorus). 2-deoxyglucose, a sympathetic nervous system stimulant, caused β-adrenergic receptor dependent increases in inguinal WAT (IWAT) afferent neurophysiological activity. In addition, direct IWAT injections of the β3-AR agonist CL316,243 dose-dependently increased: 1) phosphorylation of IWAT hormone sensitive lipase, an indicator of SNS-stimulated lipolysis, 2) expression of the neuronal activation marker c-Fos in dorsal root ganglion neurons receiving sensory input from IWAT, and 3) IWAT afferent neurophysiological activity, an increase blocked by antilipolytic agent 3,5-dimethylpyrazole. Finally, we demonstrated that IWAT afferent activation by lipolysis triggers interscapular BAT thermogenesis through a neural link between these two tissues. These data suggest IWAT lipolysis activates local IWAT afferents triggering a neural circuit from WAT to BAT that acutely induces BAT thermogenesis.

  7. Renal failure (chronic)

    OpenAIRE

    Clase, Catherine

    2011-01-01

    Chronic renal failure is characterised by a gradual and sustained decline in renal clearance or glomerular filtration rate (GFR). Continued progression of renal failure will lead to renal function too low to sustain healthy life. In developed countries, such people will be offered renal replacement therapy in the form of dialysis or renal transplantation. Requirement for dialysis or transplantation is termed end-stage renal disease (ESRD).Diabetes, glomerulonephritis, hypertension, pyelone...

  8. Selective cortical control of information flow through different intraspinal collaterals of the same muscle afferent fiber.

    Science.gov (United States)

    Eguibar, J R; Quevedo, J; Jiménez, I; Rudomin, P

    1994-04-18

    We have analyzed in the anesthetized cat the effects of electrical stimulation of the cerebral cortex on the intraspinal threshold of two collaterals belonging to the same muscle spindle or tendon organ afferent fiber. The results obtained provide, for the first time, direct evidence showing that the motor cortex is able to modify, in a highly selective manner, the synaptic effectiveness of individual collaterals of the same primary afferent fiber. This presynaptic control could function as a mechanism that allows funneling of information to specific groups of spinal neurons in the presence of extensive intraspinal branching of the afferent fibers.

  9. Opioid Actions in Primary-Afferent Fibers—Involvement in Analgesia and Anesthesia

    Directory of Open Access Journals (Sweden)

    Tsugumi Fujita

    2011-01-01

    Full Text Available Opioids inhibit glutamatergic excitatory transmission from the periphery by activating G-protein coupled opioid receptors in the central terminals of primary-afferent neurons in the spinal substantia gelatinosa, resulting in antinociception. Opioid receptor activation in the peripheral terminals of primary-afferent neurons inhibits the production of action potentials in response to nociceptive stimuli given to the periphery, leading to antinociception. Opioids also exhibit a local anesthetic effect without opioid receptor activation in peripheral nerve fibers. This review article will focus on analgesia and anesthesia produced by the actions of opioids on primary-afferent fibers.

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

    Science.gov (United States)

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

    2007-02-01

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

  11. Analysis of interaction between TGF and the myogenic response in renal blood flow autoregulation

    DEFF Research Database (Denmark)

    Feldberg, R; Colding-Jørgensen, M; Holstein-Rathlou, N H

    1995-01-01

    The present study investigates the interaction between the tubuloglomerular feedback (TGF) response and the myogenic mechanism by use of a mathematical model. The two control mechanisms are implemented in a spatially distributed model of the rat renal juxtamedullary afferent arteriole. The model....... The contribution of TGF to smooth muscle activity is assumed to be a linear function of the glomerular capillary pressure. The results show that the myogenic response plays an important role in renal blood flow autoregulation. Without a myogenic response, mechanisms such as TGF that are localized in the distal...... located in the distal part of the afferent arteriole. An ascending myogenic response could enhance the regulatory efficiency of the TGF mechanism by increasing the open-loop gain of the system. However, such a synergistic interaction will only be observed when the two mechanisms operate on more or less...

  12. Oculoscopy in Rabbits and Rodents.

    Science.gov (United States)

    Jekl, Vladimir; Hauptman, Karel; Knotek, Zdenek

    2015-09-01

    Ophthalmic diseases are common in rabbits and rodents. Fast and definitive diagnosis is imperative for successful treatment of ocular diseases. Ophthalmic examination in rabbits and rodents can be challenging. Oculoscopy offers great magnification for the examination of the ocular structures in such animals, including the evaluation of cornea, anterior eye chamber, limbus, iris, lens, and retina. To date, oculoscopy has been described only sporadically and/or under experimental conditions. This article describes the oculoscopy technique, normal and abnormal ocular findings, and the most common eye disorders diagnosed with the aid of endoscopy in rabbits and rodents.

  13. Renale Osteopathie

    OpenAIRE

    Horn S

    2001-01-01

    Die renale Osteopathie umfaßt Erkrankungen des Knochens, die bei Patienten mit chronischen Nierenerkrankungen auftreten, wie den sekundären bzw. tertiären Hyperparathyreoidismus, die adynamische Knochenerkrankung und die Osteopathie nach Nierentransplantation. Durch die Identifikation des Kalzium-Sensing-Rezeptors bzw. des Vitamin D-Rezeptors hat sich unser Verständnis der Zusammenhänge in den letzten Jahren erheblich verbessert. Neue Medikamente versprechen effizientere Prophylaxe- und Thera...

  14. Renale Knochenerkrankungen

    Directory of Open Access Journals (Sweden)

    Mayer G

    2008-01-01

    Full Text Available Störungen des Mineral- und Knochenstoffwechsels sind bei fast allen Patienten mit chronischen Nierenerkrankungen anzutreffen. Pathogenetisch spielt eine Neigung zur Phosphatretention bei einer Reduktion der glomerulären Filtrationsrate die zentrale Rolle. Neben typischen, aber sehr variablen Veränderungen der Knochenstruktur (renale Osteopathie besteht auch eine sehr enge Assoziation zwischen diesen Störungen und dem massiv erhöhten kardiovaskulären Risiko der Patienten.

  15. Assessment of Renal Perfusion in a Canine Model Using FS069, A New Transpulmonary Echocontrast Agent.

    Science.gov (United States)

    Mobarek, Sameh K.; Kates, Marc A.; Murgo, Joseph P.; Moreno, Carlos A.; Revall, Susan; Cheirif, Jorge

    1997-09-01

    We have previously demonstrated the safety and efficacy of FS069, a new transpulmonary echocontrast agent, for myocardial opacification. To our knowledge, no information exists regarding the use of this agent for transcutaneous assessment of renal perfusion. We studied 14 mongrel dogs using intravenously administered FS069. Renal ultrasound imaging was performed with a Hewlett-Packard Sonos 1500 using a 3.5-MHz transducer. Renal blood flow (ReBF) was altered using renal artery occlusion in four dogs and dipyridamole (0.56 mg/kg IV) in ten dogs. Renal perfusion was quantitatively assessed before and after each intervention using background subtracted peak intensity. ReBF was assessed with radiolabeled microspheres in ten dogs. Renal opacification was observed in all 14 dogs at baseline. The intravenous contrast dose required to produce optimal renal opacification ranged from 0.3-0.7 cc. After renal artery occlusion, peak intensity was reduced from 5.4 +/- 5.8 to 0.93 +/- 1.1 units (r = 0.99, P change from baseline). The inverse relation between ReBF and peak intensity observed suggests vasoconstriction of the afferent arterioles in response to dipyridamole and a reduced clearance of the contrast. These findings are in agreement with previous data demonstrating decreased renal thallium clearance postdipyridamole administration. Our data document the feasibility to assess renal perfusion under various flow states after intravenous injection of FS069.

  16. Obesity and renal hemodynamics

    NARCIS (Netherlands)

    Bosma, R. J.; Krikken, J. A.; van der Heide, J. J. Homan; de Jong, P. E.; Navis, G. J.

    2006-01-01

    Obesity is a risk factor for renal damage in native kidney disease and in renal transplant recipients. Obesity is associated with several renal risk factors such as hypertension and diabetes that may convey renal risk, but obesity is also associated with an unfavorable renal hemodynamic profile

  17. Obesity and renal hemodynamics

    NARCIS (Netherlands)

    Bosma, R. J.; Krikken, J. A.; van der Heide, J. J. Homan; de Jong, P. E.; Navis, G. J.

    2006-01-01

    Obesity is a risk factor for renal damage in native kidney disease and in renal transplant recipients. Obesity is associated with several renal risk factors such as hypertension and diabetes that may convey renal risk, but obesity is also associated with an unfavorable renal hemodynamic profile inde

  18. Differential effect of T-type voltage-gated calcium channel disruption on renal plasma flow and glomerular filtration rate in vivo

    DEFF Research Database (Denmark)

    Thuesen, Anne D; Andersen, Henrik; Cardel, Majken

    2014-01-01

    of two T-type Cav knock-out mice strains. Continuous recordings of blood pressure and heart rate, and para-aminohippurate clearance (renal plasma flow) and inulin clearance (GFR) were performed in conscious, chronically catheterized, wild type and Cav 3.1-/- and Cav 3.2-/- mice. Contractility of afferent...

  19. Sympathetic nervous system and chronic renal failure.

    Science.gov (United States)

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

    2001-01-01

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

  20. Changes in PAD patterns of group I muscle afferents after a peripheral nerve crush.

    Science.gov (United States)

    Enríquez, M; Jiménez, I; Rudomin, P

    1996-01-01

    In the anesthetized cat we have analyzed the changes in primary afferent depolarization (PAD) evoked in single muscle spindle and tendon organ afferents at different times after their axons were crushed in the periphery and allowed to regenerate. Medial gastrocnemius (MG) afferents were depolarized by stimulation of group I fibers in the posterior biceps and semitendinosus nerve (PBSt), as soon as 2 weeks after crushing their axons in the periphery, in some cases before they could be activated by physiological stimulation of muscle receptors. Two to twelve weeks after crushing the MG nerve, stimulation of the PBSt produced PAD in all MG fibers reconnected with presumed muscle spindles and tendon organs. The mean amplitude of the PAD elicited in afferent fibers reconnected with muscle spindles was increased relative to values obtained from Ia fibers in intact (control) preparations, but remained essentially the same in fibers reconnected with tendon organs. Quite unexpectedly, we found that, between 2 and 12 weeks after crushing the MG nerve, stimulation of the bulbar reticular formation (RF) produced PAD in most afferent fibers reconnected with muscle spindle afferents. The mean amplitude of the PAD elicited in these fibers was significantly increased relative to the PAD elicited in muscle spindle afferents from intact preparations (from 0.08 +/- 0.4 to 0.47 +/- 0.34 mV). A substantial recovery was observed between 6 months and 2.5 years after the peripheral nerve injury. Stimulation of the sural (SU) nerve produced practically no PAD in muscle spindles from intact preparations, and this remained so in those afferents reconnected with muscle spindles impaled 2-12 weeks after the nerve crush. The mean amplitude of the PAD produced in afferent fibers reconnected with tendon organs by stimulation of the PBSt nerve and of the bulbar RF remained essentially the same as the PAD elicited in intact afferents. However, SU nerve stimulation produced a larger PAD in afferents

  1. Lipopolysaccharide-induced hyperalgesia of intracranial capsaicin sensitive afferents in conscious rats

    NARCIS (Netherlands)

    Kemper, RHA; Spoelstra, MB; Meijler, WJ; Ter Horst, GJ

    1998-01-01

    Migraineous and non-migraineous headache is reported to be at highest intensity after an infection. This study investigated whether activation of the immune system can induce hyperalgesia in intracranial capsaicin sensitive afferents. The effects of intraperitoneal injected lipopolysaccharides (LPS)

  2. Multiple clusters of release sites formed by individual thalamic afferents onto cortical interneurons ensure reliable transmission.

    Science.gov (United States)

    Bagnall, Martha W; Hull, Court; Bushong, Eric A; Ellisman, Mark H; Scanziani, Massimo

    2011-07-14

    Thalamic afferents supply the cortex with sensory information by contacting both excitatory neurons and inhibitory interneurons. Interestingly, thalamic contacts with interneurons constitute such a powerful synapse that even one afferent can fire interneurons, thereby driving feedforward inhibition. However, the spatial representation of this potent synapse on interneuron dendrites is poorly understood. Using Ca imaging and electron microscopy we show that an individual thalamic afferent forms multiple contacts with the interneuronal proximal dendritic arbor, preferentially near branch points. More contacts are correlated with larger amplitude synaptic responses. Each contact, consisting of a single bouton, can release up to seven vesicles simultaneously, resulting in graded and reliable Ca transients. Computational modeling indicates that the release of multiple vesicles at each contact minimally reduces the efficiency of the thalamic afferent in exciting the interneuron. This strategy preserves the spatial representation of thalamocortical inputs across the dendritic arbor over a wide range of release conditions.

  3. EFFECT OF ANGELICA SINENSIS ON AFFERENT DISCHARGE OF SINGLE MUSCLE SPINDLE IN TOADS

    Institute of Scientific and Technical Information of China (English)

    高云芳; 樊小力

    2004-01-01

    Objective In drugs for invigorating blood circulation, to find a herb that can stimulate afferent discharge of muscle spindle. Methods A single muscle spindle was isolated from sartorial muscle of toad. Using air-gap technique, afferent discharge of the muscle spindle was recorded. Effects of Angelica Sinensis, Salvia Miltiorrhiza, and Safflower on afferent discharge of the muscle spindle were observed. Results Angelica Sinensis could distinctly increase afferent discharge frequency of the muscle spindle, and this increase was dose-dependent. But Salvia Miltiorrhiza and Safflower had no this excitatory effect. Conclusion It is known that Angelica Sinensis can invigorate blood circulation, and we have found its excitatory effect on muscle spindle which makes it possible to serve people with muscle atrophy if more evidences from clinical experiments are available.

  4. Vagal afferent neurons in high fat diet-induced obesity; intestinal microflora, gut inflammation and cholecystokinin.

    Science.gov (United States)

    de Lartigue, Guillaume; de La Serre, Claire Barbier; Raybould, Helen E

    2011-11-30

    The vagal afferent pathway is the major neural pathway by which information about ingested nutrients reaches the CNS and influences both GI function and feeding behavior. Vagal afferent neurons (VAN) express receptors for many of the regulatory peptides and molecules released from the intestinal wall, pancreas, and adipocytes that influence GI function, glucose homeostasis, and regulate food intake and body weight. As such, they play a critical role in both physiology and pathophysiology, such as obesity, where there is evidence that vagal afferent function is altered. This review will summarize recent findings on changes in vagal afferent function in response to ingestion of high fat diets and explore the hypothesis that changes in gut microbiota and integrity of the epithelium may not only be important in inducing these changes but may be the initial events that lead to dysregulation of food intake and body weight in response to high fat, high energy diets.

  5. Mechanistic relationship between the vagal afferent pathway, central nervous system and peripheral organs in appetite regulation

    National Research Council Canada - National Science Library

    Ueno, Hiroaki; Nakazato, Masamitsu

    2016-01-01

    .... Of such peptides, gut peptides are known to bind to receptors at the vagal afferent pathway terminal that extend into the mucosal layer of the digestive tract, modulate the electrical activity...

  6. Interneurones in pathways from group II muscle afferents in sacral segments of the feline spinal cord.

    Science.gov (United States)

    Jankowska, E; Riddell, J S

    1994-03-15

    1. Properties of dorsal horn interneurones that process information from group II muscle afferents in the sacral segments of the spinal cord have been investigated in the cat using both intracellular and extracellular recording. 2. The interneurones were excited by group II muscle afferents and cutaneous afferents but not by group I muscle afferents. They were most effectively excited by group II afferents of the posterior biceps, semitendinosus, triceps surae and quadriceps muscle nerves and by cutaneous afferents running in the cutaneous femoris, pudendal and sural nerves. The earliest synaptic actions were evoked monosynaptically and were very tightly locked to the stimuli. 3. EPSPs evoked monosynaptically by group II muscle afferents and cutaneous afferents of the most effective nerves were often cut short by disynaptic IPSPs. As a consequence of this negative feedback the EPSPs gave rise to single or double spike potentials and only a minority of interneurones responded with repetitive discharges. However, the neurones that did respond repetitively did so at a very high frequency of discharges (0.8-1.2 ms intervals between the first 2-3 spikes). 4. Sacral dorsal horn group II interneurones do not appear to act directly upon motoneurones because: (i) these interneurones are located outside the area within which last order interneurones have previously been found and (ii) the latencies of PSPs evoked in motoneurones by stimulation of the posterior biceps and semitendinosus, cutaneous femoris and pudendal nerves (i.e. the main nerves providing input to sacral interneurones) are compatible with a tri- but not with a disynaptic coupling. Spatial facilitation of EPSPs and IPSPs following synchronous stimulation of group II and cutaneous afferents of these nerves shows, however, that sacral interneurones may induce excitation or inhibition of motoneurones via other interneurones. 5. Comparison of the properties of group II interneurones in the sacral segments with

  7. Computed tomographic features of afferent loop syndrome: pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Zissin, R. [Tel-Aviv Univ., Dept. of Diagnostic Imaging, Sapir Medical Center, Kfar Saba, Sackler Faculty of Medicine, Tel Aviv (Israel); Hertz, M. [Tel-Aviv Univ., Dept. of Diagnostic Imaging, Chaim Sheba Medical Center, Tel Hashomer, Tel Aviv (Israel); Paran, H. [Tel-Aviv Univ., Dept. of Diagnostic Imaging, Surgery ' A' , Sapir Medical Center, Kfar Saba, Sackler Faculty of Medicine, Tel Aviv (Israel); Osadchy, A. [Tel-Aviv Univ., Dept. of Diagnostic Imaging, Sapir Medical Center, Kfar Saba, Sackler Faculty of Medicine, Tel Aviv (Israel); Gayer, G. [Tel-Aviv Univ., Dept. of Diagnostic Imaging, Assaf Harofe Medical Center, Zrifin, Sackler Faculty of Medicine, Tel Aviv (Israel)

    2005-04-15

    This pictorial essay reviews the computed tomography (CT) findings of afferent loop syndrome (ALS) in various pathological conditions to demonstrate the contribution of a common imaging modality-that is, abdominal CT, used nowadays for various abdominal complaints-to the diagnosis of ALS. ALS is caused by obstruction of the duodenum and jejunum proximal to a gastrojejunostomy anastomosis. It is a rare complication after Billroth II subtotal gastrectomy and even more rare after total or subtotal gastrectomy with Roux-en-Y reconstruction. Although currently advanced medical treatment and endoscopic interventions have dramatically decreased the necessity of surgery for peptic ulcer disease, ALS may appear years after previously common operations. Alternatively, the use of surgical resection for early gastric cancer nowadays leads to an increasing rate of malignancy-related ALS. Clinically, ALS may be difficult to diagnose as its presentation may be vague and nonspecific, but it has a characteristic appearance on CT. Clinicians and radiologists should therefore be familiar with this rare complication. Prompt recognition and correct diagnosis of this syndrome and its probable etiology are important as a guide for treatment. This review illustrates the CT features of ALS in various conditions. (author)

  8. Dynamic GABAergic afferent modulation of AgRP neurons

    Science.gov (United States)

    Garfield, Alastair S; Shah, Bhavik P; Burgess, Christian R; Li, Monica M; Li, Chia; Steger, Jennifer S; Madara, Joseph C; Campbell, John N; Kroeger, Daniel; Scammell, Thomas E; Tannous, Bakhos A; Myers, Martin G; Andermann, Mark L; Krashes, Michael J; Lowell, Bradford B

    2017-01-01

    Agouti-related peptide (AgRP) neurons of the arcuate nucleus of the hypothalamus (ARC) promote homeostatic feeding at times of caloric insufficiency, yet they are rapidly suppressed by food-related sensory cues prior to ingestion. Here we identify a highly selective inhibitory afferent to AgRP neurons that serves as a neural determinant of this rapid modulation. Specifically, GABAergic projections arising from the ventral compartment of the dorsomedial nucleus of the hypothalamus (vDMH) contribute to the pre-consummatory modulation of ARCAgRP neurons. In a manner reciprocal to ARCAgRP neurons, ARC-projecting leptin receptor (LepR)-expressing GABAergic DMH neurons exhibit rapid activation upon availability of food that additionally reflects the relative value of the food. Thus, DMHLepR neurons form part of the sensory network that relays real-time information about the nature and availability of food to dynamically modulate ARCAgRP neuron activity and feeding behavior. PMID:27643429

  9. Hemispheric asymmetry and somatotopy of afferent inhibition in healthy humans.

    Science.gov (United States)

    Helmich, R C G; Bäumer, T; Siebner, H R; Bloem, B R; Münchau, A

    2005-11-01

    A conditioning electrical stimulus to a digital nerve can inhibit the motor-evoked potentials (MEPs) in adjacent hand muscles elicited by transcranial magnetic stimulation (TMS) to the contralateral primary motor cortex (M1) when given 25-50 ms before the TMS pulse. This is referred to as short-latency afferent inhibition (SAI). We studied inter-hemispheric differences (Experiment 1) and within-limb somatotopy (Experiment 2) of SAI in healthy right-handers. In Experiment 1, conditioning electrical pulses were applied to the right or left index finger (D2) and MEPs were recorded from relaxed first dorsal interosseus (FDI) and abductor digiti minimi (ADM) muscles ipsilateral to the conditioning stimulus. We found that SAI was more pronounced in right hand muscles. In Experiment 2, electrical stimulation was applied to the right D2 and MEPs were recorded from ipsilateral FDI, extensor digitorum communis (EDC) and biceps brachii (BB) muscles. The amount of SAI did not differ between FDI, EDC and BB muscles. These data demonstrate inter-hemispheric differences in the processing of cutaneous input from the hand, with stronger SAI in the dominant left hemisphere. We also found that SAI occurred not only in hand muscles adjacent to electrical digital stimulation, but also in distant hand and forearm and also proximal arm muscles. This suggests that SAI induced by electrical D2 stimulation is not focal and somatotopically specific, but a more widespread inhibitory phenomenon.

  10. Innervation of enteric mast cells by primary spinal afferents in guinea pig and human small intestine.

    Science.gov (United States)

    Wang, Guo-Du; Wang, Xi-Yu; Liu, Sumei; Qu, Meihua; Xia, Yun; Needleman, Bradley J; Mikami, Dean J; Wood, Jackie D

    2014-10-01

    Mast cells express the substance P (SP) neurokinin 1 receptor and the calcitonin gene-related peptide (CGRP) receptor in guinea pig and human small intestine. Enzyme-linked immunoassay showed that activation of intramural afferents by antidromic electrical stimulation or by capsaicin released SP and CGRP from human and guinea pig intestinal segments. Electrical stimulation of the afferents evoked slow excitatory postsynaptic potentials (EPSPs) in the enteric nervous system. The slow EPSPs were mediated by tachykinin neurokinin 1 and CGRP receptors. Capsaicin evoked slow EPSP-like responses that were suppressed by antagonists for protease-activated receptor 2. Afferent stimulation evoked slow EPSP-like excitation that was suppressed by mast cell-stabilizing drugs. Histamine and mast cell protease II were released by 1) exposure to SP or CGRP, 2) capsaicin, 3) compound 48/80, 4) elevation of mast cell Ca²⁺ by ionophore A23187, and 5) antidromic electrical stimulation of afferents. The mast cell stabilizers cromolyn and doxantrazole suppressed release of protease II and histamine when evoked by SP, CGRP, capsaicin, A23187, electrical stimulation of afferents, or compound 48/80. Neural blockade by tetrodotoxin prevented mast cell protease II release in response to antidromic electrical stimulation of mesenteric afferents. The results support a hypothesis that afferent innervation of enteric mast cells releases histamine and mast cell protease II, both of which are known to act in a diffuse paracrine manner to influence the behavior of enteric nervous system neurons and to elevate the sensitivity of spinal afferent terminals.

  11. Decreased contribution from afferent feedback to the soleus muscle during walking in patients with spastic stroke

    DEFF Research Database (Denmark)

    Mazzaro, Nazarena; Nielsen, Jørgen Feldbæk; Grey, Michael James

    2007-01-01

    We investigated the contribution of afferent feedback to the soleus (SOL) muscle activity during the stance phase of walking in patients with spastic stroke. A total of 24 patients with hemiparetic spastic stroke and age-matched healthy volunteers participated in the study. A robotic actuator...... by the Ashworth score. These results indicate that although the stretch reflex response is facilitated during spastic gait, the contribution of afferent feedback to the ongoing locomotor SOL activity is depressed in patients with spastic stroke....

  12. External QX-314 inhibits evoked cranial primary afferent synaptic transmission independent of TRPV1.

    Science.gov (United States)

    Hofmann, Mackenzie E; Largent-Milnes, Tally M; Fawley, Jessica A; Andresen, Michael C

    2014-12-01

    The cell-impermeant lidocaine derivative QX-314 blocks sodium channels via intracellular mechanisms. In somatosensory nociceptive neurons, open transient receptor potential vanilloid type 1 (TRPV1) receptors provide a transmembrane passageway for QX-314 to produce long-lasting analgesia. Many cranial primary afferents express TRPV1 at synapses on neurons in the nucleus of the solitary tract and caudal trigeminal nucleus (Vc). Here, we investigated whether QX-314 interrupts neurotransmission from primary afferents in rat brain-stem slices. Shocks to the solitary tract (ST) activated highly synchronous evoked excitatory postsynaptic currents (ST-EPSCs). Application of 300 μM QX-314 increased the ST-EPSC latency from TRPV1+ ST afferents, but, surprisingly, it had similar actions at TRPV1- ST afferents. Continued exposure to QX-314 blocked evoked ST-EPSCs at both afferent types. Neither the time to onset of latency changes nor the time to ST-EPSC failure differed between responses for TRPV1+ and TRPV1- inputs. Likewise, the TRPV1 antagonist capsazepine failed to prevent the actions of QX-314. Whereas QX-314 blocked ST-evoked release, the frequency and amplitude of spontaneous EPSCs remained unaltered. In neurons exposed to QX-314, intracellular current injection evoked action potentials suggesting a presynaptic site of action. QX-314 acted similarly at Vc neurons to increase latency and block EPSCs evoked from trigeminal tract afferents. Our results demonstrate that QX-314 blocked nerve conduction in cranial primary afferents without interrupting the glutamate release mechanism or generation of postsynaptic action potentials. The TRPV1 independence suggests that QX-314 either acted extracellularly or more likely entered these axons through an undetermined pathway common to all cranial primary afferents.

  13. Termination of electroreceptor and mechanical lateral line afferents in the mormyrid acousticolateral area.

    Science.gov (United States)

    Bell, C C; Russell, C J

    1978-12-01

    The projection regions of electroreceptor and mechanical lateral line afferents in electric fish of the mormyridae family are described. Electroreceptor afferents from the posterior dorsal skin run in the dorsal branch of the posterior lateral line nerve. Electroreceptor afferents from ventral skin and mechanical lateral line afferents and efferents run in the ventral branch of the nerve. Horseradish peroxidase (HRP) injections into each branch resulted in filling of its central terminals with the marker enzyme. The method yields a Golgi-like staining of afferent terminals, allowing some aspects of their morphology to be described. Comparison of results from dorsal and ventral branch injections shows the separate medullary regions to which electroreceptor and mechanical afferents project, and also demonstrates four separate somatotopic maps within the electroreceptor region. Mechanical afferents end predominantly ipsilaterally in nucleus anterior and eminentia granularis as has been suggested by others. Ipsilateral endings in nucleus octavius are also seen. Electroreceptor afferents end exclusively in the cortex and nucleus of posterior lateral line lobe (PLLL). Within the cortex there are three distinct maps of the skin surface which are separated from each other by discontinuities in the cellular layers. Somatotopic mapping is also present in the nucleus of PLLL though it is less precise than in the cortical zones. Large club endings of the cells of this nucleus are filled with HRP. Labeled cells are seen within a small midline nucleus located at the level of the eighth nerve just above the medial longitudinal fasciculus. These are probably the cell bodies of lateral line efferents.

  14. Can loss of muscle spindle afferents explain the ataxic gait in Riley–Day syndrome?

    OpenAIRE

    Macefield, Vaughan G.; Norcliffe-Kaufmann, Lucy; Gutiérrez, Joel; Axelrod, Felicia B.; Kaufmann, Horacio

    2011-01-01

    The Riley–Day syndrome is the most common of the hereditary sensory and autonomic neuropathies (Type III). Among the well-recognized clinical features are reduced pain and temperature sensation, absent deep tendon reflexes and a progressively ataxic gait. To explain the latter we tested the hypothesis that muscle spindles, or their afferents, are absent in hereditary sensory and autonomic neuropathy III by attempting to record from muscle spindle afferents from a nerve supplying the leg in 10...

  15. Input-output functions of vestibular afferent responses to air-conducted clicks in rats.

    Science.gov (United States)

    Zhu, Hong; Tang, Xuehui; Wei, Wei; Maklad, Adel; Mustain, William; Rabbitt, Richard; Highstein, Steve; Allison, Jerome; Zhou, Wu

    2014-02-01

    Sound-evoked vestibular myogenic potentials recorded from the sternocleidomastoid muscles (the cervical vestibular-evoked myogenic potential or cVEMP) and the extraocular muscles (the ocular VEMP or oVEMP) have proven useful in clinical assessment of vestibular function. VEMPs are commonly interpreted as a test of saccular function, based on neurophysiological evidence showing activation of saccular afferents by intense acoustic click stimuli. However, recent neurophysiological studies suggest that the clicks used in clinical VEMP tests activate vestibular end organs other than the saccule. To provide the neural basis for interpreting clinical VEMP testing results, the present study examined the extent to which air-conducted clicks differentially activate the various vestibular end organs at several intensities and durations in Sprague-Dawley rats. Single unit recordings were made from 562 vestibular afferents that innervated the otoliths [inferior branch otolith (IO) and superior branch otolith (SO)], the anterior canal (AC), the horizontal canal (HC), and the posterior canal (PC). Clicks higher than 60 dB SL (re-auditory brainstem response threshold) activated both semicircular canal and otolith organ afferents. Clicks at or below 60 dB SL, however, activated only otolith organ afferents. Longer duration clicks evoked larger responses in AC, HC, and SO afferents, but not in IO afferents. Intra-axonal recording and labeling confirmed that sound sensitive vestibular afferents innervated the horizontal and anterior canal cristae as well as the saccular and utricular maculae. Interestingly, all sound sensitive afferents are calyx-bearing fibers. These results demonstrate stimulus-dependent acoustic activation of both semicircular canals and otolith organs, and suggest that sound activation of vestibular end organs other than the saccule should not be ruled out when designing and interpreting clinical VEMP tests.

  16. The cottontail rabbits of Virginia

    Science.gov (United States)

    Llewellyn, L.M.; Handley, C.O.

    1945-01-01

    Five races of cottontail rabbits belonging to three species occur in Virginia. One of them, the Mearns cottontail (Sylvilagus floridanus mearnsi), is reported here for the first time. It occurs in six southwestern counties of the state, while the eastern cottontail (S. f. mallurus) occurs in the remainder of the state with the exception of Smith and Fishermans islands off the eastern coast of Cape Charles, where it is replaced by Hitchens cottontail (S. f. hitchensi). The New England cottontail (S. transitionalis) is found on the higher mountain peaks, above 3000 feet, and the swamp rabbit (S. palustris) occurs in the Dismal Swamp region of southeastern Virginia.....The height of the breeding season for the eastern cottontail in Virginia is March and April, but breeding continues through the entire year except in December and January. The average litter size based on embryo counts was 4.7. The sex ratio of 234 specimens from all parts of the state, taken mostly in the December to February period, was 53 males to 47 females. That of a group of 145 rabbits live-trapped at Blacksburg during February and Marchwas 58 males to 42 females. The figures show that males are more active than females during the winter months, and therefore are more easily taken then....In transplanting cottontails from one section of the state to another, it is recommended that only cottontails of the same race as those originally present in the region being restocked be released there....Tularemia is not a common disease among rabbits in Virginia, but the rabbit ticks are often carriers of the disease and may transmit it to rabbits. Rabbit ticks are also found to be carriers of Rocky Mountain fever and American Q. fever. After the ticks drop off the rabbits to hibernate in the ground, which is likely to occur during mid-winter in Virginia, there is relatively little danger of humans contracting tularemia by contact with rabbits. Present laws in Virginia which prohibit rabbit hunting until the

  17. Bilateral Renal Mass-Renal Disorder: Tuberculosis

    Directory of Open Access Journals (Sweden)

    Ozlem Tiryaki

    2013-01-01

    Full Text Available A 30-year-old woman has presented complaining of weakness and fatigue to her primary care physician. The renal sonography is a routine step in the evaluation of new onset renal failure. When the renal masses have been discovered by sonography in this setting, the functional imaging may be critical. We reported a case about bilateral renal masses in a young female patient with tuberculosis and renal insufficiency. Magnetic resonance (MR has revealed the bilateral renal masses in patient, and this patient has been referred to our hospital for further management. The patient’s past medical and surgical history was unremarkable.

  18. Distal renal tubular acidosis

    Science.gov (United States)

    Renal tubular acidosis - distal; Renal tubular acidosis type I; Type I RTA; RTA - distal; Classical RTA ... excreting it into the urine. Distal renal tubular acidosis (Type I RTA) is caused by a defect ...

  19. Proximal renal tubular acidosis

    Science.gov (United States)

    Renal tubular acidosis - proximal; Type II RTA; RTA - proximal; Renal tubular acidosis type II ... by alkaline substances, mainly bicarbonate. Proximal renal tubular acidosis (Type II RTA) occurs when bicarbonate is not ...

  20. Renal tuberculosis

    Directory of Open Access Journals (Sweden)

    Džamić Zoran

    2016-01-01

    Full Text Available Tuberculosis is still a significant health problem in the world, mostly in developing countries. The special significance lies in immunocompromised patients, particularly those suffering from the HIV. Urogenital tuberculosis is one of the most common forms of extrapulmonary tuberculosis, while the most commonly involved organ is the kidney. Renal tuberculosis occurs by hematogenous dissemination of mycobacterium tuberculosis from a primary tuberculosis foci in the body. Tuberculosis is characterized by the formation of pathognomonic lesions in the tissues - granulomata. These granulomata may heal spontaneously or remain stable for years. In certain circumstances in the body associated with immunosuppression, the disease may be activated. Central caseous necrosis occurs within tuberculoma, leading to formation of cavities that destroy renal parenchyma. The process may gain access to the collecting system, forming the caverns. In this way, infection can be spread distally to renal pelvis, ureter and bladder. Scaring of tissue by tuberculosis process may lead to development of strictures of the urinary tract. The clinical manifestations are presented by nonspecific symptoms and signs, so tuberculosis can often be overlooked. Sterile pyuria is characteristic for urinary tuberculosis. Dysuric complaints, flank pain or hematuria may be presented in patients. Constitutional symptoms of fever, weight loss and night sweats are presented in some severe cases. Diagnosis is made by isolation of mycobacterium tuberculosis in urine samples, by cultures carried out on standard solid media optimized for mycobacterial growth. Different imaging studies are used in diagnostics - IVU, CT and NMR are the most important. Medical therapy is the main modality of tuberculosis treatment. The first line anti-tuberculosis drugs include isoniazid, rifampicin, pyrazinamide and ethambutol. Surgical treatment is required in some cases, to remove severely damaged kidney, if

  1. Contribution of renal innervation to hypertension in rat autosomal dominant polycystic kidney disease.

    Science.gov (United States)

    Gattone, Vincent H; Siqueira, Tibério M; Powell, Charles R; Trambaugh, Chad M; Lingeman, James E; Shalhav, Arieh L

    2008-08-01

    The kidney has both afferent (sensory) and efferent (sympathetic) nerves that can influence renal function. Renal innervation has been shown to play a role in the pathogenesis of many forms of hypertension. Hypertension and flank pain are common clinical manifestations of autosomal dominant (AD) polycystic kidney disease (PKD). We hypothesize that renal innervation contributes to the hypertension and progression of cystic change in rodent PKD. In the present study, the contribution of renal innervation to hypertension and progression of renal histopathology and dysfunction was assessed in male Han:SPRD-Cy/+ rats with ADPKD. At 4 weeks of age, male offspring from crosses of heterozygotes (Cy/+) were randomized into either 1) bilateral surgical renal denervation, 2) surgical sham denervation control, or 3) nonoperated control groups. A midline laparotomy was performed to allow the renal denervation (i.e., physical stripping of the nerves and painting the artery with phenol/alcohol). Blood pressure (tail cuff method), renal function (BUN) and histology were assessed at 8 weeks of age. Bilateral renal denervation reduced the cystic kidney size, cyst volume density, systolic blood pressure, and improved renal function (BUN) as compared with nonoperated controls. Operated control cystic rats had kidney weights, cyst volume densities, systolic blood pressures, and plasma BUN levels that were intermediate between those in the denervated animals and the nonoperated controls. The denervated group had a reduced systolic blood pressure compared with the operated control animals, indicating that the renal innervations was a major contributor to the hypertension in this model of ADPKD. Renal denervation was efficacious in reducing some pathology, including hypertension, renal enlargement, and cystic pathology. However, sham operation also affected the cystic disease but to a lesser extent. We hypothesize that the amelioration of hypertension in Cy/+ rats was due to the effects

  2. Renale Osteopathie

    Directory of Open Access Journals (Sweden)

    Horn S

    2001-01-01

    Full Text Available Die renale Osteopathie umfaßt Erkrankungen des Knochens, die bei Patienten mit chronischen Nierenerkrankungen auftreten, wie den sekundären bzw. tertiären Hyperparathyreoidismus, die adynamische Knochenerkrankung und die Osteopathie nach Nierentransplantation. Durch die Identifikation des Kalzium-Sensing-Rezeptors bzw. des Vitamin D-Rezeptors hat sich unser Verständnis der Zusammenhänge in den letzten Jahren erheblich verbessert. Neue Medikamente versprechen effizientere Prophylaxe- und Therapiemöglichkeiten. Wir beeinflussen dadurch nicht nur die Morbidität und Lebensqualität, sondern auch die Mortalität unserer Patienten.

  3. Renal disease in pregnancy.

    Science.gov (United States)

    Thorsen, Martha S; Poole, Judith H

    2002-03-01

    Anatomic and physiologic adaptations within the renal system during pregnancy are significant. Alterations are seen in renal blood flow and glomerular filtration, resulting in changes in normal renal laboratory values. When these normal renal adaptations are coupled with pregnancy-induced complications or preexisting renal dysfunction, the woman may demonstrate a reduction of renal function leading to an increased risk of perinatal morbidity and mortality. This article will review normal pregnancy adaptations of the renal system and discuss common pregnancy-related renal complications.

  4. Raphe magnus and reticulospinal actions on primary afferent depolarization of group I muscle afferents in the cat.

    Science.gov (United States)

    Quevedo, J; Eguibar, J R; Jiménez, I; Rudomin, P

    1995-02-01

    1. In the anaesthetized cat, electrical stimulation of the bulbar reticular formation produced a short latency (2.1 +/- 0.3 ms) positive potential in the cord dorsum. In contrast, stimulation of the nucleus raphe magnus with strengths below 50 microA evoked a slow negative potential with a mean latency of 5.5 +/- 0.6 ms that persisted after sectioning the contralateral pyramid and was abolished by sectioning the ipsilateral dorsolateral funiculus. 2. The field potentials evoked by stimulation of the bulbar reticular formation and of the nucleus raphe magnus had a different intraspinal distribution, suggesting activation of different sets of segmental interneurones. 3. Stimulation of these two supraspinal nuclei produced primary afferent depolarization (PAD) in single Ib fibres and inhibited the PAD elicited by group I volleys in single Ia fibres. The inhibition of the PAD of Ia fibres produced by reticulospinal and raphespinal inputs appears to be exerted on different interneurones along the PAD pathway. 4. It is concluded that, although reticulospinal and raphespinal pathways have similar inhibitory effects on PAD of Ia fibres, and similar excitatory effects on the PAD of Ib fibres, their actions are conveyed by partly independent pathways. This would allow their separate involvement in the control of posture and movement.

  5. Remodeling of Afferent Arterioles From Mice With Oxidative Stress Does Not Account for Increased Contractility but Does Limit Excessive Wall Stress.

    Science.gov (United States)

    Li, Lingli; Feng, Di; Luo, Zaiming; Welch, William J; Wilcox, Christopher S; Lai, En Yin

    2015-09-01

    Because superoxide dismutase (SOD) knockout enhances arteriolar remodeling and contractility, we hypothesized that remodeling enhances contractility. In the isolated and perfused renal afferent arterioles from SOD wild type (+/+) and gene-deleted mice, contractility was assessed from reductions in luminal diameter with perfusion pressure from 40 to 80 mm Hg (myogenic responses) or angiotensin II (10(-6) mol/L), remodeling from media:lumen area ratio, superoxide (O2 (·-)) and hydrogen peroxide (H2O2) from fluorescence microscopy, and wall stress from wall tension/wall thickness. Compared with +/+ strains, arterioles from SOD1-/-, SOD2+/-, and SOD3-/- mice developed significantly (Premodeling. Although remodeling does not enhance contractility, it does prevent the potentially damaging effects of increased wall stress.

  6. Renal sinus hyperechogenicity in acute pyelonephritis: description and pathological correlation

    Energy Technology Data Exchange (ETDEWEB)

    Dacher, J.N.; Monroc, M.; Eurin, D.; Dosseur, P. le [Hopital Charles Nicolle, Rouen (France). Dept. of Pediatric Radiology; Avni, F.; Rypens, F. [Hopital Erasme, Brussels (Belgium). Dept. of Radiology; Francois, A. [Hopital Charles Nicolle, Rouen (France). Dept. of Pathology

    1999-03-01

    This paper reports on the association between renal sinus hyperechogenicity and acute pyelonephritis. The medical records and imaging studies of 18 children displaying this pattern were retrospectively studied. Thickening of the renal pelvis and renal enlargement were the most frequent associated sonographic abnormalities. Further subtle findings can be found on sonography and colour/power Doppler. Their identification can help in the diagnostic approach to acute pyelonephritis and may obviate the need for other imaging modalities such as enhanced CT or {sup 99} {sup m}Tc-DMSA scintigraphy. Renal sinus hyperechogenicity was also identified in a parallel study performed in female rabbits with experimental pyelonephritis and was shown, histologically, to be related to exudates of fibrin and polymorphonuclear leukocytes, interstitial oedema and micro-abscesses. (orig.) With 3 figs., 18 refs.

  7. Segmental and supraspinal control of synaptic effectiveness of functionally identified muscle afferents in the cat.

    Science.gov (United States)

    Enríquez, M; Jiménez, I; Rudomin, P

    1996-01-01

    The present investigation documents the patterns of primary afferent depolarization (PAD) of single, functionally identified muscle afferents from the medial gastrocnemius nerve in the intact, anesthetized cat. Classification of the impaled muscle afferents as from muscle spindles or from tendon organs was made according to several criteria, which comprised measurement of conduction velocity and electrical threshold of the peripheral axons, and the maximal frequency followed by the afferent fibers during vibration, as well as the changes in discharge frequency during longitudinal stretch, the projection of the afferent fiber to the motor pool, and, in unparalyzed preparations, the changes in afferent activity during a muscle twitch. In confirmation of a previous study, we found that most muscle spindle afferents (46.1-66.6%, depending on the combination of criteria utilized for receptor classification) had a type A PAD pattern. That is, they were depolarized by stimulation of group I fibers of the posterior biceps and semitendinosus (PBSt) nerve, but not by stimulation of cutaneous nerves (sural and superficial peroneus) or the bulbar reticular formation (RF), which in many cases inhibited the PBSt-induced PAD. In addition, we found a significant fraction of muscle spindle primaries that were depolarized by stimulation of group I PBSt fibers and also by stimulation of the bulbar RF. Stimulation of cutaneous nerves produced PAD in 9.1-31.2% of these fibers (type B PAD pattern) and no PAD in 8.2-15.4% (type C PAD pattern). In contrast to muscle spindle afferents, only the 7.7-15.4% of fibers from tendon organs had a type A PAD pattern, 23-46.1% had a type B and 50-61.5% a type C PAD pattern. These observations suggest that the neuronal circuitry involved in the control of the synaptic effectiveness of muscle spindles and tendon organs is subjected to excitatory as well as to inhibitory influences from cutaneous and reticulospinal fibers. As shown in the accompanying

  8. Identified proprioceptive afferents and motor rhythm entrainment in the crayfish walking system.

    Science.gov (United States)

    Elson, R C; Sillar, K T; Bush, B M

    1992-03-01

    1. In crayfish, Pacifastacus leniusculus, remotion of a walking leg stretches the thoraco-coxal (TC) muscle receptor organ (TCMRO), located at the leg's articulation with the thorax. In vitro, alternate stretch and release of the fourth leg's TCMRO entrained the centrally generated rhythmic motor output to that leg, with the remotor phase of the rhythm entraining to TCMRO stretch, the promoter phase to release. This coordination of motor bursts to afferent input corresponds to that of active, rhythmic movements in vivo. 2. Entrainment was rapid in onset (stable coordination resulting within the first or second stimulus cycle) and was relatively phase-constant (whatever the stimulus frequency, during 1:1 entrainment, remotor bursts began near the onset of stretch and promotor bursts began near the onset of release). Outside the range of 1:1 entrainment, 2:1, 1:2, and 1:3 coordination ratios (rhythm:stimulus) were encountered. Resetting by phasic stimulation of the TCMRO was complete and probabilistic: effective stimuli triggered rapid transitions between the two burst phases. 3. The TCMRO is innervated by two afferents, the nonspiking S and T fibers, which generate graded depolarizing receptor potentials in response to stretch. During proprioceptive entrainment, the more phasic T fiber depolarized and hyperpolarized more rapidly or in advance of the more tonic S fiber. These receptor potentials were modified differently in the two afferents by interaction with central synaptic inputs that were phase-locked to the entrained motor rhythm. 4. Injecting slow sinusoidal current into either afferent alone could entrain motor rhythms: promoter phase bursts were entrained to depolarization of the S fiber or hyperpolarization of the T fiber, whereas the converse response was obtained for remotor phase bursts. 5. During proprioceptive entrainment, tonic hyperpolarization of the S fiber weakened entrained promotor bursts and allowed remotor burst durations to increase

  9. Renal calculus

    CERN Document Server

    Pyrah, Leslie N

    1979-01-01

    Stone in the urinary tract has fascinated the medical profession from the earliest times and has played an important part in the development of surgery. The earliest major planned operations were for the removal of vesical calculus; renal and ureteric calculi provided the first stimulus for the radiological investigation of the viscera, and the biochemical investigation of the causes of calculus formation has been the training ground for surgeons interested in metabolic disorders. It is therefore no surprise that stone has been the subject of a number of monographs by eminent urologists, but the rapid development of knowledge has made it possible for each one of these authors to produce something new. There is still a technical challenge to the surgeon in the removal of renal calculi, and on this topic we are always glad to have the advice of a master craftsman; but inevitably much of the interest centres on the elucidation of the causes of stone formation and its prevention. Professor Pyrah has had a long an...

  10. [Expert consensus statement on interventional renal sympathetic denervation for hypertension treatment].

    Science.gov (United States)

    Mahfoud, F; Vonend, O; Bruck, H; Clasen, W; Eckert, S; Frye, B; Haller, H; Hausberg, M; Hoppe, U C; Hoyer, J; Hahn, K; Keller, T; Krämer, B K; Kreutz, R; Potthoff, S A; Reinecke, H; Schmieder, R; Schwenger, V; Kintscher, U; Böhm, M; Rump, L C

    2011-11-01

    This commentary summarizes the expert consensus and recommendations of the working group 'Herz und Niere' of the German Society of Cardiology (DGK), the German Society of Nephrology (DGfN) and the German Hypertension League (DHL) on renal denervation for antihypertensive treatment. Renal denervation is a new, interventional approach to selectively denervate renal afferent and efferent sympathetic fibers. Renal denervation has been demonstrated to reduce office systolic and diastolic blood pressure in patients with resistant hypertension, defined as systolic office blood pressure ≥ 160 mm Hg and ≥ 150 mm Hg in patients with diabetes type 2, which should currently be used as blood pressure thresholds for undergoing the procedure. Exclusion of secondary hypertension causes and optimized antihypertensive drug treatment is mandatory in every patient with resistant hypertension. In order to exclude pseudoresistance, 24-hour blood pressure measurements should be performed. Preserved renal function was an inclusion criterion in the Symplicity studies, therefore, renal denervation should be only considered in patients with a glomerular filtration rate > 45 ml/min. Adequate centre qualification in both, treatment of hypertension and interventional expertise are essential to ensure correct patient selection and procedural safety. Long-term follow-up after renal denervation and participation in the German Renal Denervation (GREAT) Registry are recommended to assess safety and efficacy after renal denervation over time.

  11. The action of knee joint afferents and the concomitant influence of cutaneous (sural) afferents on the discharge of triceps surae gamma-motoneurones in the cat.

    Science.gov (United States)

    Ellaway, P H; Davey, N J; Ferrell, W R; Baxendale, R H

    1996-01-01

    Electrical stimulation of group II joint afferents of the posterior articular nerve (PAN) to the knee evoked short-latency facilitation and/or inhibition of the background discharge of gastrocnemius-soleus (GS) gamma-motoneurones in decerebrated spinal cats. The latencies of these responses were consistent with mediation via segmental oligosynaptic spinal pathways. In addition, a longer-latency facilitation was frequently observed. Mechanical non-noxious stimulation of the skin within the field of innervation of the sural nerve, on the lateral aspect of the heel, suppressed the short-latency facilitation, but not the inhibition or long-latency facilitation. Brief mechanical indentation of the posterior aspect of the knee joint capsule could elicit facilitation or inhibition of gamma-motoneurones. Facilitation, but not inhibition, was blocked by anaesthesia or section of the PAN. Both actions could be suppressed by mechanical stimulation of the heel. We conclude that GS gamma-motoneurones receive both facilitatory and inhibitory segmental inputs from group II articular afferents arising in the knee joint. Cutaneous afferents from the sural field exert a selective inhibitory influence over the facilitation of fusimotor discharge by articular afferents.

  12. The White Rabbit Project

    CERN Document Server

    Serrano, J; Cattin, M; Garcia Cota, E; Lewis, J; Moreira, P; Wlostowski, T; Gaderer, G; Loschmidt, P; Dedic, J; Bär, R; Fleck, T; Kreider, M; Prados, C; Rauch, S

    2009-01-01

    Reliable, fast and deterministic transmission of control information in a network is a need formany distributed systems. One example is timing systems, where a reference frequency is used to accurately schedule time-critical messages. TheWhite Rabbit (WR) project is a multi-laboratory and multi-company effort to bring together the best of the data transfer and timing worlds in a completely open design. It takes advantage of the latest developments for improving timing over Ethernet, such as IEEE 1588 (Precision Time Protocol) and Synchronous Ethernet. The presented approach aims for a general purpose, fieldbus-like transmission system, which provides deterministic data and timing (sub-ns accuracy and ps jitter) to around 1000 stations. It automatically compensates for fiber lengths in the order of 10 km. This paper describes the WR design goals and the specification used for the project. It goes on to describe the central component of the WR system structure - the WR switch - with theoretical considerations a...

  13. Monitoring of renal hemodynamics during acute hemorrhagic shock with Doppler ultrasonic imaging: an experimental study

    Directory of Open Access Journals (Sweden)

    Rui-hong LIU

    2015-07-01

    Full Text Available Objective To evaluate the value of color Doppler flow imaging (CDFI and pulsed-wave Doppler (PWD in monitoring renal hemodynamics in rabbits with acute hemorrhagic shock. Methods The experimental model of acute hemorrhagic shock was reproduced in 16 normal New Zealand white rabbits by controlled exsanguination which was divided into 4 different grades: normal (100% MAP, mild (70% MAP, moderate (50% MAP, and severe (40% MAP. The right kidney of the experimental animal was examined by gray-scale ultrasound (2DUS, CDFI and PWD. The structure of the right kidney was observed with 2DUS. CDFI was used to monitor the change in right renal hemodynamics along with the progression of shock. The hemodynamic parameters of main renal artery (MRA, segmental renal artery (SRA and interlobar renal artery (IRA were measured by PWD, including the peak systolic velocity (Vmax, minimum diastolic velocity (Vmin and resistive index (RI. Results The animal model of hemorrhagic shock was successfully reproduced in 16 healthy New Zealand rabbits, of which 14 rabbits survived at the end of the experiment, and 2 died of severe shock. The mean arterial pressure (MAP declined, while the respiratory rate and heart rate increased as the circulation changed from normal to severe shock (P<0.05. Observation of the right renal structure by 2DUS revealed no obvious changes after bleeding in different degrees. CDFI showed a gradually reduced distribution of blood flow in renal hemodynamics along with the progression of hemorrhagic shock. Vmax and Vmin declined gradually, while RI intensity increased as the hemorrhagic shock progressed from minor to severe. There was statistically significant difference in RI intensity between different grades of shock (P<005. Conclusion CDFI and PWD can quantitatively assess the renal hemodynamics during acute hemorrhagic shock, so it can be used as a noninvasive monitoring tool in the diagnosis and treatment of hemorrhagic shock. DOI: 10

  14. Differential modulation of primary afferent depolarization of segmental and ascending intraspinal collaterals of single muscle afferents in the cat spinal cord.

    Science.gov (United States)

    Rudomin, P; Lomelí, J; Quevedo, J

    2004-06-01

    We examined primary afferent depolarization (PAD) in the anesthetized cat elicited in 109 pairs of intraspinal collaterals of single group I afferents from the gastrocnemius nerve, one of the pair ending in the L3 segment, around the Clarke's column nuclei, and the other in the L6 segment within the intermediate zone. Tests for refractoriness were made to assess whether the responses produced by intraspinal stimulation in the L3 and L6 segments were due to activation of collaterals of the same afferent fiber. PAD in each collateral was estimated by independent computer-controlled measurement of the intraspinal current required to maintain a constant probability of antidromic firing. In most fibers, stimulation of the ipsilateral posterior biceps and semitendinosus (PBSt) nerve with trains of pulses maximal for group I afferents had a qualitatively similar effect but produced a larger PAD in the L6 than in the L3 collaterals. Stimulation of cutaneous nerves (sural and superficial peroneus) with single pulses and of the posterior articular nerve, the ipsilateral reticular formation, nucleus raphe magnus and contralateral motor cortex with trains of pulses often had qualitatively different effects. They could produce PAD and/or facilitate the PBSt-induced PAD in one collateral, and produce PAH and/or inhibit the PAD in the other collateral. These patterns could be changed in a differential manner by sensory or supraspinal conditioning stimulation. In summary, the present investigation suggests that the segmental and ascending collaterals of individual afferents are not fixed routes for information transmission, but parts of dynamic systems in which information transmitted to segmental reflex pathways and to Clarke's column neurons by common sources can be decoupled by sensory and descending inputs and funneled to specific targets according to the motor tasks to be performed.

  15. Functional analysis of ultra high information rates conveyed by rat vibrissal primary afferents

    Directory of Open Access Journals (Sweden)

    André eMaia Chagas

    2013-12-01

    Full Text Available Sensory receptors determine the type and the quantity of information available for perception. Here, we quantified and characterized the information transferred by primary afferents in the rat whisker system using neural system identification. Quantification of ‘how much’ information is conveyed by primary afferents, using the direct method, a classical information theoretic tool, revealed that primary afferents transfer huge amounts of information (up to 529 bits/s. Information theoretic analysis of instantaneous spike-triggered kinematic stimulus features was used to gain functional insight on ‘what’ is coded by primary afferents. Amongst the kinematic variables tested - position, velocity, and acceleration - primary afferent spikes encoded velocity best. The other two variables contribute to information transfer, but only if combined with velocity. We further revealed three additional characteristics that play a role in information transfer by primary afferents. Firstly, primary afferent spikes show preference for well separated multiple stimuli (i.e. well separated sets of combinations of the three instantaneous kinematic variables. Secondly, spikes are sensitive to short strips of the stimulus trajectory (up to 10 ms pre-spike time, and thirdly, they show spike patterns (precise doublet and triplet spiking. In order to deal with these complexities, we used a flexible probabilistic neuron model fitting mixtures of Gaussians to the spike triggered stimulus distributions, which quantitatively captured the contribution of the mentioned features and allowed us to achieve a full functional analysis of the total information rate indicated by the direct method. We found that instantaneous position, velocity, and acceleration explained about 50% of the total information rate. Adding a 10 ms pre-spike interval of stimulus trajectory achieved 80-90%. The final 10-20% were found to be due to non-linear coding by spike bursts.

  16. Modulation of jaw muscle spindle afferent activity following intramuscular injections with hypertonic saline.

    Science.gov (United States)

    Ro, J Y; Capra, N F

    2001-05-01

    Transient noxious chemical stimulation of small diameter muscle afferents modulates jaw movement-related responses of caudal brainstem neurons. While it is likely that the effect is mediated from the spindle afferents in the mesencephalic nucleus (Vmes) via the caudally projecting Probst's tract, the mechanisms of pain induced modulations of jaw muscle spindle afferents is not known. In the present study, we tested the hypothesis that jaw muscle nociceptors gain access to muscle spindle afferents in the same muscle via central mechanisms and alter their sensitivity. Thirty-five neurons recorded from the Vmes were characterized as muscle spindle afferents based on their responses to passive jaw movements, muscle palpation, and electrical stimulation of the masseter nerve. Each cell was tested by injecting a small volume (250 microl) of either 5% hypertonic and/or isotonic saline into the receptor-bearing muscle. Twenty-nine units were tested with 5% hypertonic saline, of which 79% (23/29) showed significant modulation of mean firing rates (MFRs) during one or more phases of ramp-and-hold movements. Among the muscle spindle primary-like units (n = 12), MFRs of 4 units were facilitated, five reduced, two showed mixed responses and one unchanged. In secondary-like units (n = 17), MFRs of 9 were facilitated, three reduced and five unchanged. Thirteen units were tested with isotonic saline, of which 77% showed no significant changes of MFRs. Further analysis revealed that the hypertonic saline not only affected the overall output of muscle spindle afferents, but also increased the variability of firing and altered the relationship between afferent signal and muscle length. These results demonstrated that activation of muscle nociceptors significantly affects proprioceptive properties of jaw muscle spindles via central neural mechanisms. The changes can have deleterious effects on oral motor function as well as kinesthetic sensibility.

  17. The unsilent majority-TRPV1 drives "spontaneous" transmission of unmyelinated primary afferents within cardiorespiratory NTS.

    Science.gov (United States)

    Andresen, Michael C; Hofmann, Mackenzie E; Fawley, Jessica A

    2012-12-15

    Cranial primary afferent sensory neurons figure importantly in homeostatic control of visceral organ systems. Of the two broad classes of visceral afferents, the role of unmyelinated or C-type class remains poorly understood. This review contrasts key aspects of peripheral discharge properties of C-fiber afferents and their glutamate transmission mechanisms within the solitary tract nucleus (NTS). During normal prevailing conditions, most information arrives at the NTS through myelinated A-type nerves. However, most of visceral afferent axons (75-90%) in NTS are unmyelinated, C-type axons. Centrally, C-type solitary tract (ST) afferent terminals have presynaptic transient receptor potential vanilloid type 1 (TRPV1) receptors. Capsaicin activation of TRPV1 blocks phasic or synchronous release of glutamate but facilitates release of glutamate from a separate pool of vesicles. This TRPV1-operated pool of vesicles is active at normal temperatures and is responsible for actively driving a 10-fold higher release of glutamate at TRPV1 compared with TRPV1- terminals even in the absence of afferent action potentials. This novel TRPV1 mechanism is responsible for an additional asynchronous release of glutamate that is not present in myelinated terminals. The NTS is rich with presynaptic G protein-coupled receptors, and the implications of TRPV1-operated glutamate offer unique targets for signaling in C-type sensory afferent terminals from neuropeptides, inflammatory mediators, lipid metabolites, cytokines, and cannabinoids. From a homeostatic view, this combination could have broad implications for integration in chronic pathological disturbances in which the numeric dominance of C-type endings and TRPV1 would broadly disturb multisystem control mechanisms.

  18. Tanshinone ⅡA protects rabbits against LPS-induced disseminated intravascular coagulation (DIC)

    Institute of Scientific and Technical Information of China (English)

    Liang-cai WU; Xi LIN; Hao SUN

    2012-01-01

    Aim:To evaluate the effects of tanshinone ⅡA (Tan ⅡA),a lipophilic diterpene from the Chinese herb Salvia miltiorrhiza,on lipopolysaccharide (LPS)-induced disseminated intravascular coagulation (DIC) in rabbits.Methods:LPS-induced DIC model was made in adult male New Zealand rabbits by continuous intravenous infusion of LPS (0.5 mg/kg)via marginal ear vein for 6 h.The animals were simultaneously administered with Tan ⅡA (1,3 and 10 mg/kg) or heparin (500 000IU/kg) through continuous infusion via the contralateral marginal ear vein for 6 h.Before and 2 and 6 h after the start of LPS infusion,blood samples were taken for biochemical analyses.Results:Continuous infusion of LPS into the rabbits gradually impaired the hemostatic parameters,damaged renal and liver functions,increased the plasma TNF-α level,and led to a high mortality rate (80%).Treatment of the rabbits with Tan ⅡA dose-dependently attenuated the increase in activated partial thromboplastin time (APTT),prothrombin time (PT) and fibrin-fibrinogen degradation products (FDP); ameliorated the decrease in plasma levels of fibrinogen and platelets; and reversed the decline in activity of protein C and antithrombin Ⅲ.Meanwhile,the treatment significantly suppressed the increase in the plasma levels of aminotransferase,creatinine and TNF-α,and led to much lower mortality (46.7% and 26.7% for the medium- and high-dose groups).Treatment of the rabbits with the high dose of heparin also effectively improved the hemostatic parameters,ameliorated liver and renal injuries,and reduced the plasma level of TNF-α,and significantly reduced the mortality (33.3%).Conclusion:Tan ⅡA exerts a protective effect against DIC in rabbits.

  19. EFFECT OF FLUORIDE ON KIDNEY OF ALBINO RABBIT-AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Santosh K.

    2014-08-01

    Full Text Available BACKGROUND: Fluoride is present in environment in various forms and ingested by man from solid foods, drinks, drinking water and inhaled from the air. Out of these, fluoride is present in large quantities in dissolved state in many sources of drinking water producing toxicity in man. Fluoride, being excreted mainly through the kidneys, seems to damage it causing renal dysfunction. Kidneys are among the most sensitive body organs in their histopathological and functional responses to excessive amounts of fluoride. Trace elements are essential and beneficial to human being in minute concentrations. However, intake in large quantities produces adverse and toxic effects on our body. OBJECTIVE: The present study was designed to investigate the toxic effects (evaluated as histopathological changes of sodium fluoride on the kidney in albino rabbit. MATERIALS AND METHODS: Total 40 albino rabbits were used for this study, among them 8 rabbits were taken in the control group (Group A and16 rabbits each were taken in both group B and group C who were administered low and high dose of fluoride respectively. After 2 weeks interval, up to 16 weeks the histology of the kidney of each group of the rabbit was studied for histological analysis. RESULT: Histological changes in the kidneys of both Group B and Group C rabbits, following continuous daily exposure to sodium fluoride solutions in two different doses (0.5% solution for Group B and 3% solution for Group C for different durations of time were studied in detail and compared with those of the controls (Group A. CONCLUSION: It is concluded that Sodium Fluoride solution in high doses for prolonged period has a definite adverse effect on the renal parenchyma.

  20. Serotonin, Dopamine and Noradrenaline Adjust Actions of Myelinated Afferents via Modulation of Presynaptic Inhibition in the Mouse Spinal Cord

    OpenAIRE

    García-Ramírez, David L.; Calvo, Jorge R.; Shawn Hochman; Jorge N Quevedo

    2014-01-01

    Gain control of primary afferent neurotransmission at their intraspinal terminals occurs by several mechanisms including primary afferent depolarization (PAD). PAD produces presynaptic inhibition via a reduction in transmitter release. While it is known that descending monoaminergic pathways complexly regulate sensory processing, the extent these actions include modulation of afferent-evoked PAD remains uncertain. We investigated the effects of serotonin (5HT), dopamine (DA) and noradrenaline...

  1. Renal actinomycosis with concomitant renal vein thrombosis.

    Science.gov (United States)

    Chang, Dong-Suk; Jang, Won Ik; Jung, Ji Yoon; Chung, Sarah; Choi, Dae Eun; Na, Ki-Ryang; Lee, Kang Wook; Shin, Yong-Tai

    2012-02-01

    Renal actinomycosis is a rare infection caused by fungi of the genus Actinomyces. A 74-year-old male was admitted to our hospital because of gross hematuria with urinary symptoms and intermittent chills. Computed tomography of the abdomen showed thrombosis in the left renal vein and diffuse, heterogeneous enlargement of the left kidney. After nephrectomy, sulfur granules with chronic suppurative inflammation were seen microscopically, and the histopathological diagnosis was renal actinomycosis. Our case is the first report of renal actinomycosis with renal vein thrombosis.

  2. TRANSPLANTE RENAL

    Directory of Open Access Journals (Sweden)

    Soraia Geraldo Rozza Lopes

    2014-01-01

    Full Text Available El objetivo del estudio fue comprender el significado de espera del trasplante renal para las mujeres en hemodiálisis. Se trata de un estudio cualitativo-interpretativo, realizado con 12 mujeres en hemodiálisis en Florianópolis. Los datos fueron recolectados a través de entrevistas en profundidad en el domicilio. Fue utilizado el software Etnografh 6.0 para la pre-codificación y posterior al análisis interpretativo emergieron dos categorías: “las sombras del momento actual”, que mostró que las dificultades iniciales de la enfermedad están presentes, pero las mujeres pueden hacer frente mejor a la enfermedad y el tratamiento. La segunda categoría, “la luz del trasplante renal”, muestra la esperanza impulsada por la entrada en la lista de espera para un trasplante.

  3. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930564 Dwell times affect the local host de-fence mechanism of peritoneal dialysis patients.WANG Tao(汪涛),et al.Renal Instit,SunYatsen Med Univ,Guangzhou,510080.Chin JNephrol 1993;9(2):75—77.The effect of different intraperitoneal awelltimes on the local host defence in 6 peritonealdialysis patients was studied.A significant de-crease in the number of peritoneal cells,IgG con-centration and the phagoeytosis and bactericidalactivity of macrophages was determined when thedwell time decreased from 12 to 4 hs or form 4 to0.5hs,but the peroxidase activity in macrophagesincreased significantly.All variables,except theperoxidase activity in macrophages,showed nosignificant difference between patients of high or

  4. Traumatismo renal

    OpenAIRE

    Rocha, Sofia Rosa Moura Gomes da

    2009-01-01

    Introdução: A realização deste trabalho visa a elaboração de uma revisão sistematizada subordinada à temática da traumatologia renal. Objectivos: Os principais objectivos deste trabalho são: apurar a etiologia, definir a classificação, analisar o diagnóstico e expôr o tratamento e as complicações. Desenvolvimento: Os traumatismos são a principal causa de morte antes dos 40 anos. O rim é o órgão do aparelho génito-urinário mais frequentemente atingido. Os traumatismos renais são mais fre...

  5. Regulation of the renal sympathetic nerves in heart failure

    Directory of Open Access Journals (Sweden)

    Rohit eRamchandra

    2015-08-01

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

  6. Capsaicin-sensitive vagal afferent neurons contribute to the detection of pathogenic bacterial colonization in the gut.

    Science.gov (United States)

    Riley, T P; Neal-McKinney, J M; Buelow, D R; Konkel, M E; Simasko, S M

    2013-04-15

    Vagal activation can reduce inflammation and disease activity in various animal models of intestinal inflammation via the cholinergic anti-inflammatory pathway. In the current model of this pathway, activation of descending vagal efferents is dependent on a signal initiated by stimulation of vagal afferents. However, little is known about how vagal afferents are activated, especially in the context of subclinical or clinical pathogenic bacterial infection. To address this question, we first determined if selective lesions of capsaicin-sensitive vagal afferents altered c-Fos expression in the nucleus of the solitary tract (nTS) after mice were inoculated with either Campylobacter jejuni or Salmonella typhimurium. Our results demonstrate that the activation of nTS neurons by intraluminal pathogenic bacteria is dependent on intact, capsaicin sensitive vagal afferents. We next determined if inflammatory mediators could cause the observed increase in c-Fos expression in the nTS by a direct action on vagal afferents. This was tested by the use of single-cell calcium measurements in cultured vagal afferent neurons. We found that tumor necrosis factor alpha (TNFα) and lipopolysaccharide (LPS) directly activate cultured vagal afferent neurons and that almost all TNFα and LPS responsive neurons were sensitive to capsaicin. We conclude that activation of the afferent arm of the parasympathetic neuroimmune reflex by pathogenic bacteria in the gut is dependent on capsaicin sensitive vagal afferent neurons and that the release of inflammatory mediators into intestinal tissue can be directly sensed by these neurons.

  7. Origin and chemical coding of primary afferent neurones supplying the prostate of the dog.

    Science.gov (United States)

    Arciszewski, M B; Zacharko, A

    2004-12-01

    Retrograde tracing technique combined with the double-fluorescent immunohistochemistry were used to investigate the distribution and chemical coding of primary afferent neurones supplying the canine prostate. After the injection of Fast Blue (FB) into the prostatic tissue retrogradely-labelled (FB(+)) primary afferent neurones were localized in bilateral L(1)-Ca(1) dorsal root ganglia (DRG). Statistical analysis using anova test showed that there are two major sources of afferent prostate innervation. The vast majority of prostate-supplying primary afferent neurones were located in bilateral L(2)-L(4) DRG (56.9 +/- 0.6%). The second source of the afferent innervation of canine prostate were bilateral S(1)-Ca(1) DRG (40.6 +/- 1.0%). No statistically significant differences were found between average number of FB(+) neurones localized in the left and right DRG (49.5 +/- 1.7 and 50.5 +/- 1.7%, respectively). Immunohistochemistry revealed that FB(+) primary afferent neurones contain several neuropeptides in various combinations. In the prostate-supplying neurones of lumbar and sacro-caudal DRG the immunoreactivity to substance P (SP) and calcitonin gene-related peptide (CGRP) was found most frequently (50 +/- 3.7 and 37.3 +/- 1.9%, respectively). Both in the lumbar and sacro-caudal DRG, considerable population of FB(+) neurones immunoreactive neither to SP nor CGRP were also found (23 +/- 2.6 and 32.8 +/- 2.3%, respectively). In the lumbar DRG 10.7 +/- 1.1% of SP-immunoreactive FB(+) neurones also contained galanin (GAL). In 9.2 +/- 2.2% of the prostate-supplying primary afferent neurones located in the sacro-caudal DRG the co-localization of SP and GAL was also reported. Results of the retrograde tracing experiment demonstrated for the first time sources of afferent innervation of the canine prostate. Double immunohistochemistry revealed that many of the prostate-supplying primary afferent neurones express some of sensory neuropeptides which presumably may be involved

  8. Tonic and phasic differential GABAergic inhibition of synaptic actions of joint afferents in the cat.

    Science.gov (United States)

    Rudomin, P; Hernández, E; Lomelí, J

    2007-01-01

    The aim of this study was to examine the functional organization of the spinal neuronal networks activated by myelinated afferent fibers in the posterior articular nerve (PAN) of the anesthetized cat. Particular attention was given to the tonic and phasic GABAa inhibitory modulation of these networks. Changes in the synaptic effectiveness of the joint afferents were inferred from changes in the intraspinal focal potentials produced by electrical stimulation of the PAN. We found that conditioning stimulation of cutaneous nerves (sural, superficial peroneus and saphenous) and of the nucleus raphe magnus often inhibited, in a differential manner, the early and late components of the intraspinal focal potentials produced by stimulation of low and high threshold myelinated PAN afferents, respectively. The degree of the inhibition depended on the strength of both the conditioning and test stimuli and on the segmental level of recording. Conditioning stimulation of group I muscle afferents was less effective, but marked depression of the early and late focal potentials was produced by stimuli exceeding 5 xT. The i.v. injection of 1-2.5 mg/kg of picrotoxin, a GABAa blocker, had relatively minor effects on the early components of the PAN focal potentials, but was able to induce a significant increase of the late components. It also reduced the inhibitory effects of cutaneous and joint nerve conditioning on PAN focal responses. Conditioning autogenetic stimulation with high-frequency trains depressed the PAN focal potentials. The late components of the PAN responses remained depressed several minutes after discontinuing the conditioning train, even after picrotoxin administration. The present observations indicate that the neuronal networks activated by the low threshold PAN afferents show a relatively small post-activation depression and appear to be subjected to a minor tonic inhibitory GABAa control. In contrast, the pathways activated by stimulation of high threshold

  9. Radioactive chromium-ethylenediaminetetraacetic acid for determination of glomerular filtration rate in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Tvedegaard, E.; Kamstrup, O.

    1981-12-01

    Simultaneous determination of the glomerular filtration rate was made by the insulin clearance technique and by analysis of the plasma disappearance curve of radioactive chromium-ethylenediaminetetraacetic acid (/sup 51/Cr-EDTA) following an intravenous injection in 28 anaesthetized rabbits. In some rabbits, the renal function was reduced by previous surgery. The insulin clearances ranged from 2.7 to 17 ml/minute. By a double-exponential analysis of the plasma disappearance curve, the total plasma clearance of /sup 51/Cr-EDTA was found to exceed the inulin clearance by 12%. By the simpler slope-intercept analysis requiring only two blood samples, this value was 32%. The renal clearance of /sup 51/Cr-EDTA was 97% of inulin clearance. In nephrectomized rabbits, plasma clearance of /sup 51/Cr-EDTA was 0.7 ml/minute. At all levels of renal function, measurement of the plasma clearance rate of /sup 51/Cr-EDTA by the single injection technique allowed a fairly reliable estimate of the glomerular filtration rate.

  10. Is human muscle spindle afference dependent on perceived size of error in visual tracking?

    Science.gov (United States)

    Kakuda, N; Wessberg, J; Vallbo, A B

    1997-04-01

    Impulses of 16 muscle spindle afferents from finger extensor muscles were recorded from the radial nerve along with electromyographic (EMG) activity and kinematics of joint movement. Twelve units were classified as Ia and 4 as II spindle afferents. Subjects were requested to perform precision movements at a single metacarpophalangeal joint in an indirect visual tracking task. Similar movements were executed under two different conditions, i.e. with high and low error gain. The purpose was to explore whether different precision demands were associated with different spindle firing rates. With high error gain, a small but significantly higher impulse rate was found in pooled data from Ia afferents during lengthening movements but not during shortening movements, nor with II afferents. EMG was also significantly higher with high error gain in recordings with Ia afferents. When the effect of EMG was factored out, using partial correlation analysis, the significant difference in Ia firing rate vanished. The findings suggest that fusimotor drive as well as skeletomotor activity were both marginally higher when the precision demand was higher, whereas no indication of independent fusimotor adjustments was found. These results are discussed with respect to data from behaving animals and the role of fusimotor independence in various limb muscles proposed.

  11. Teratology studies in the rabbit.

    Science.gov (United States)

    Allais, Linda; Reynaud, Lucie

    2013-01-01

    The rabbit is generally the non-rodent species or second species after the rat recommended by the regulatory authorities and is part of the package of regulatory reproductive studies for the detection of potential embryotoxic and/or teratogenic effects of pharmaceuticals, chemicals, food additives, and other compounds, including vaccines (see Chapters 1-7).Its availability, practicality in housing and in mating as well as its large size makes the rabbit the preferred choice as a non-rodent species. The study protocols are essentially similar to those established for the rat (Chapter 9), with some particularities. The study designs are well defined in guidelines and are relatively standardized between testing laboratories across the world.As for the rat, large litter sizes and extensive background data in the rabbit are valuable criteria for an optimal assessment of in utero development of the embryo or fetus and for the detection of potential external or internal fetal malformations.

  12. [Review] Mary Toft's Rabbit Tale

    OpenAIRE

    Jones, Emrys

    2013-01-01

    Originally broadcast in April 2011 and aired again by BBC Radio 4 this November, Mary Toft’s Rabbit Tale is a radio drama retelling the story of its titular fraudster’s brief notoriety. With a high-profile cast – including singer Will Young as Toft’s husband and Rupert Graves as man-midwife, John Howard – the play explores a number of issues related to the alleged rabbit births of 1726 and their impact on public discourse of the time.

  13. An experimental study on vascular changes in renal biopsy injury

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jae Hoon; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1981-12-15

    An experimental study on the vascular alternations of the kidney following biopsy procedure was carried out in 47 kidneys from 28 rabbits to clarify their nature and frequency by renal arteriography and microangiography together with histopathologic investigation. Renal arteriography and microangiography were performed immediately 2 days, 1 week, and 2 weeks after percutaneous biopsy and the findings were correlated with histological nature. The results are summarized as follows: 1. Important biopsy injuries verified by renal arteriography and microangiography were arterial spasm, perfusion defect, arteriovenous fistula, injury to vasa rectae and renal tubules, intrarenal and extrarenal extravasation of contrast media, and arterial obstruction, in order of frequency. 2. Arterial spasm observed in majority of the cases were relieved during the period of 2 weeks. 3. Detectability of perfusion detect was 57% and 72% angiography and microangiography, respectively, and this perfusion defect seemed to be mostly caused by renal infraction due to vascular injury, such as arteriovenous fistula, arterial obstruction and other vascular injuries. 4. Arteriovenous fistula was detected in 28% by angiography and 50% by microangiography. Many of the arteriovenous fistulae appeared to be closed spontaneous within a week. Above findings suggest that renal biopsy procedure results in various degree of vascular injuries with their sequential modification, and that microangiography is assumed the most effective approach in analysis of biopsy injuries such as small arteriovenous fistula, perfusion defect, injury to vasa recta and renal tubules, overcoming the limitation of traditional angiography.

  14. Can focused US with a diagnostic US contrast agent favorably affect renal function?

    Science.gov (United States)

    Sica, Domenic A

    2009-12-01

    Focused ultrasonography (US) with simultaneous administration of a US microbubble contrast agent was used to transiently increase the glomerular filtration rate while altering the sieving properties of glomeruli in normal rabbits. In its current form, this process has very limited application potential to states of abnormal renal function.

  15. Management of afferent loop obstruction from recurrent metastatic pancreatic cancer using a venting gastrojejunostomy.

    Science.gov (United States)

    Bakes, Debbie; Cain, Christian; King, Michael; Dong, Xiang Da Eric

    2013-12-15

    Pancreatic cancer is an aggressive malignancy potentially curable with surgical intervention. Following pancreaticoduodenectomy for suspected pancreatic head malignancy, patients have a high risk for both immediate and delayed problems due to surgical complications and recurrent disease. We report here a patient with pancreatic cancer treated with pancreaticoduodenectomy who developed recurrent disease resulting in obstruction of the afferent limb. The patient developed biliary obstruction and cholangitis at presentation. Her biliary tree failed to dilate which precluded safe percutaneous biliary decompression. During surgical exploration, she was found to have a dilated afferent limb at the level of the transverse mesocolon. The patient underwent decompression of the afferent limb as well as the biliary tree using a venting gastrojejunostomy to the blind loop. This represents a novel surgical approach for management of this complicated and difficult problem.

  16. Monosynaptic connections between primary afferents and giant neurons in the turtle spinal dorsal horn

    DEFF Research Database (Denmark)

    Fernández, A; Radmilovich, M; Russo, R E

    1996-01-01

    This paper reports the occurrence of monosynaptic connections between dorsal root afferents and a distinct cell type-the giant neuron-deep in the dorsal horn of the turtle spinal cord. Light microscope studies combining Nissl stain and transganglionic HRP-labeling of the primary afferents have...... revealed the occurrence of axosomatic and axodendritic contacts between labeled boutons and giant neurons. The synaptic nature of these contacts has been confirmed by use of electron microscope procedures involving the partial three-dimensional reconstruction of identified giant neurons. Intracellular...... recording in spinal cord slices provided functional evidence indicating the monosynaptic connections between dorsal root afferents and giant neurons. The recorded neurons were morphologically identified by means of biocytin injection and with avidin conjugates. Electrical stimulation of the ipsilateral...

  17. Group Ia afferents contribute to short-latency interlimb reflexes in the human biceps femoris muscle

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Kamavuako, Ernest Nlandu; Geertsen, Svend Sparre

    2017-01-01

    and velocity of the iKnee rotations. Methods 11 seated participants (mean age: 25 ± 5 years) performed a voluntary isometric knee extension with the ipsilateral leg and contralateral knee flexion to 10% of maximum voluntary contraction (MVC). A mechanical actuator (MTS-Systems Corporation) imposed i...... amplitudes (4 vs. 8°) at the same 150°/s velocity (p’s > 0.08). Conclusion Because fast conducting group Ia muscle spindle afferents are sensitive to changes in muscle stretch velocity, while group II spindle afferents are sensitive to changes in amplitude (Grey et al., JPhysiol., 2001; Matthews, Trends...... Neurosci., 1991), group Ia velocity sensitive muscle spindle afferents likely contribute to the short-latency crossed spinal reflexes in the cBF muscle following iKnee joint rotations. This supports the findings for the short-latency crossed responses in the human soleus muscle (Stubbs & Mrachacz...

  18. Structure of the afferent terminals in terminal ganglion of a cricket and persistent homology.

    Directory of Open Access Journals (Sweden)

    Jacob Brown

    Full Text Available We use topological data analysis to investigate the three dimensional spatial structure of the locus of afferent neuron terminals in crickets Acheta domesticus. Each afferent neuron innervates a filiform hair positioned on a cercus: a protruding appendage at the rear of the animal. The hairs transduce air motion to the neuron signal that is used by a cricket to respond to the environment. We stratify the hairs (and the corresponding afferent terminals into classes depending on hair length, along with position. Our analysis uncovers significant structure in the relative position of these terminal classes and suggests the functional relevance of this structure. Our method is very robust to the presence of significant experimental and developmental noise. It can be used to analyze a wide range of other point cloud data sets.

  19. The Potential Role of Catheter-Based Renal Sympathetic Denervation in Chronic and End-Stage Kidney Disease.

    Science.gov (United States)

    Sata, Yusuke; Schlaich, Markus P

    2016-07-01

    Sympathetic activation is a hallmark of chronic and end-stage renal disease and adversely affects cardiovascular prognosis. Hypertension is present in the vast majority of these patients and plays a key role in the progressive deterioration of renal function and the high rate of cardiovascular events in this patient cohort. Augmentation of renin release, tubular sodium reabsorption, and renal vascular resistance are direct consequences of efferent renal sympathetic nerve stimulation and the major components of neural regulation of renal function. Renal afferent nerve activity directly influences sympathetic outflow to the kidneys and other highly innervated organs involved in blood pressure control via hypothalamic integration. Renal denervation of the kidney has been shown to reduce blood pressure in many experimental models of hypertension. Targeting the renal nerves directly may therefore be specifically useful in patients with chronic and end-stage renal disease. In this review, we will discuss the potential role of catheter-based renal denervation in patients with impaired kidney function and also reflect on the potential impact on other cardiovascular conditions commonly associated with chronic kidney disease such as heart failure and arrhythmias.

  20. Hydrogen sulfide activates the carotid body chemoreceptors in cat, rabbit and rat ex vivo preparations.

    Science.gov (United States)

    Jiao, Yingfu; Li, Qian; Sun, Biying; Zhang, Guohua; Rong, Weifang

    2015-03-01

    We and others previously reported experimental evidence suggesting an important role for hydrogen sulfide (H2S) in oxygen sensing in murine carotid body chemoreceptors. More recent data implicated abnormal H2S-mediated chemoreceptor signaling in pathological conditions such as chronic heart failure and hypertension. However, the idea of H2S as a mediator of oxygen-sensing in chemoreceptors has been challenged. In particular, it was shown that exogenous H2S inhibited the release of neurotransmitters (ACh and ATP) from the cat carotid body, raising the possibility that there exists significant species difference in H2S-mediated signaling in chemoreceptors. This study was designed specifically to determine the effect of H2S on chemoreceptors in different species. We conducted multiunit extracellular recordings of the sinus nerve in the ex vivo carotid body preparation taken from the rat, the cat and the rabbit. As observed in the mouse carotid body, H2S donors (NaHS or Na2S) evoked qualitatively similar excitatory responses of the afferent sinus nerves of the species studied here. The excitatory effects of the H2S donors were concentration-dependent and reversible. The sinus nerve responses to H2S donors were prevented by blockade of the transmission between type I cells and the afferent terminals, as was the response to hypoxia. These results demonstrate that exogenous H2S exerts qualitatively similar excitatory effects on chemoreceptor afferents of different species. The role of endogenous H2S-mediated signaling in carotid body function in different species awaits further investigation.

  1. Peptide and lipid modulation of glutamatergic afferent synaptic transmission in the solitary tract nucleus

    Directory of Open Access Journals (Sweden)

    Michael C. Andresen

    2013-01-01

    Full Text Available The brainstem nucleus of the solitary tract (NTS holds the first central neurons in major homeostatic reflex pathways. These homeostatic reflexes regulate and coordinate multiple organ systems from gastrointestinal to cardiopulmonary functions. The core of many of these pathways arise from cranial visceral afferent neurons that enter the brain as the solitary tract (ST with more than two-thirds arising from the gastrointestinal system. About one quarter of ST afferents have myelinated axons but the majority are classed as unmyelinated C-fibers. All ST afferents release the fast neurotransmitter glutamate with remarkably similar, high-probability release characteristics. Second order NTS neurons receive surprisingly limited primary afferent information with one or two individual inputs converging on single second order NTS neurons. A- and C-fiber afferents never mix at NTS second order neurons. Many transmitters modify the basic glutamatergic excitatory postsynaptic current (EPSC often by reducing glutamate release or interrupting terminal depolarization. Thus, a distinguishing feature of ST transmission is presynaptic expression of G-protein coupled receptors for peptides common to peripheral or forebrain (e.g. hypothalamus neuron sources. Presynaptic receptors for angiotensin (AT1, vasopressin (V1a, oxytocin (OT, opioid (MOR, ghrelin (GHSR1 and cholecystokinin (CCK differentially control glutamate release on particular subsets of neurons with most other ST afferents unaffected. Lastly, lipid-like signals are transduced by two key ST presynaptic receptors, the transient receptor potential vanilloid type 1 (TRPV1 and the cannabinoid receptor (CB1 that oppositely control glutamate release. Increasing evidence suggests that peripheral nervous signaling mechanisms are repurposed at central terminals to control excitation and are major sites of signal integration of peripheral and central inputs particularly from the hypothalamus.

  2. Differential action of (-)-baclofen on the primary afferent depolarization produced by segmental and descending inputs.

    Science.gov (United States)

    Quevedo, J; Eguibar, J R; Jiménez, I; Rudomin, P

    1992-01-01

    The purpose of the present series of experiments was to analyze, in anesthetized and paralyzed cats, the effects of (-)-baclofen and picrotoxin on the primary afferent depolarization (PAD) generated in single Ib afferent fibers by either intraspinal microstimulation or stimulation of the segmental and descending pathways. PAD was estimated by recording dorsal root potentials and by measuring the changes in the intraspinal activation threshold of single Ib muscle afferent fibers. The PAD elicited by stimulation of group I muscle or cutaneous afferents was readily depressed and often abolished 20-40 min after the intravenous injection of 1-2 mg/kg (-)-baclofen. In contrast, the same amounts of (-)-baclofen produced a relatively small depression of the PAD elicited by stimulation of the brainstem reticular formation (RF). The monosynaptic PAD produced in single Ib fibers by intraspinal microstimulation within the intermediate nucleus was depressed and sometimes abolished following the i.v. injections of 1-2 mg/kg (-)-baclofen. Twenty to forty minutes after the i.v. injection of picrotoxin (0.5-1 mg/kg), there was a strong depression of the PAD elicited by stimulation of muscle and cutaneous afferents as well as of the PAD produced by stimulation of the RF and the PAD produced by intraspinal microstimulation. The results obtained suggest that, in addition to its action on primary afferents, (-)-baclofen may depress impulse activity and/or transmitter release in a population of last-order GABAergic interneurons that mediate the PAD of Ib fibers. The existence of GABAb autoreceptors in last-order interneurons mediating the PAD may function as a self-limiting mechanism controlling the synaptic efficacy of these interneurons.

  3. Direct and indirect regulation of spinal cord Ia afferent terminal formation by the γ-Protocadherins

    Directory of Open Access Journals (Sweden)

    Tuhina ePrasad

    2011-12-01

    Full Text Available The Pcdh-γ gene cluster encodes 22 protocadherin adhesion molecules that interact as homophilic multimers and critically regulate synaptogenesis and apoptosis of interneurons in the developing spinal cord. Unlike interneurons, the two primary components of the monosynaptic stretch reflex circuit, dorsal root ganglion sensory neurons and ventral motor neurons, do not undergo excessive apoptosis in Pcdh-γdel/del null mutants, which die shortly after birth. However, as we show here, mutants exhibit severely disorganized Ia proprioceptive afferent terminals in the ventral horn. In contrast to the fine net-like pattern observed in wild-type mice, central Ia terminals in Pcdh-γ mutants are expanded, clumped, and fill the space between individual motor neurons; quantitative analysis shows a ~2.5 fold increase in the area of terminals. Concomitant with this, there is a 70% loss of the collaterals that Ia afferents extend to ventral interneurons, many of which undergo apoptosis in the mutants. The Ia afferent phenotype is ameliorated, though not entirely rescued, when apoptosis is blocked in Pcdh-γ null mice by introduction of a Bax null allele. This indicates that loss of ventral interneurons, which act as intermediate Ia afferent targets, contributes to the disorganization of terminals on motor pools. Restricted mutation of the Pcdh-γ cluster using conditional mutants and multiple Cre transgenic lines (Wnt1-Cre for sensory neurons; Pax2-Cre for ventral interneurons; Hb9-Cre for motor neurons also revealed a direct requirement for the γ-Pcdhs in Ia neurons and ventral interneurons, but not in motor neurons themselves. Together, these genetic manipulations indicate that the γ-Pcdhs are required for the formation of the Ia afferent circuit in two ways: First, they control the survival of ventral interneurons that act as intermediate Ia targets; and second, they provide a homophilic molecular cue between Ia afferents and target ventral interneurons.

  4. Botulinum toxin in migraine: Role of transport in trigemino-somatic and trigemino-vascular afferents.

    Science.gov (United States)

    Ramachandran, Roshni; Lam, Carmen; Yaksh, Tony L

    2015-07-01

    Migraine secondary to meningeal input is referred to extracranial regions innervated by somatic afferents that project to homologous regions in the trigeminal nucleus caudalis (TNC). Reported efficacy of extracranial botulinum toxin (BoNT) in treating migraine is surprising since a local extracranial effect of BoNT cannot account for its effect upon meningeal input. We hypothesize that intradermal BoNT acts through central transport in somatic afferents. Anesthetized C57Bl/6 mice (male) received unilateral supraorbital (SO) injections of BoNT-B (1.5 U/40 μl) or saline. 3 days later, mice received ipsilateral (ipsi)-SO capsaicin (20 μl of 0.5mM solution) or meningeal capsaicin (4 μl of 0.35 μM). Pre-treatment with ipsi-SO BoNT-B i) decreased nocicsponsive ipsilateral wiping behavior following ipsi-SO capsaicin; ii) produced cleavage of VAMP in the V1 region of ipsi-TG and in TG neurons showing WGA after SO injection; iii) reduced expression of c-fos in ipsi-TNC following ipsi-SO capsaicin; iv) reduced c-fos activation and NK-1 internalization in ipsi-TNC secondary to ipsi-meningeal capsaicin; and vi) SO WGA did not label dural afferents. We conclude that BoNT-B is taken up by peripheral afferents and transported to central terminals where it inhibits transmitter release resulting in decreased activation of second order neurons. Further, this study supports the hypothesis that SO BoNT exerts a trans-synaptic action on either the second order neuron (which receives convergent input from the meningeal afferent) or the terminal/TG of the converging meningeal afferent.

  5. Renal graft biopsy assists diagnosis and treatment of renal allograft dysfunction after kidney transplantation: a report of 106 cases.

    Science.gov (United States)

    Han, Yong; Guo, Hui; Cai, Ming; Xiao, Li; Wang, Qiang; Xu, Xiaoguang; Huang, Haiyan; Shi, Bingyi

    2015-01-01

    Acute antibody mediated rejection (AMR) is one of the most important complications after kidney transplantation. Renal graft biopsy is safe and reliable without adverse effects on the patients and transplanted kidneys, which was of great instructive significance in diagnosis and treatment of renal allograft dysfunction after renal transplantation. This paper reported a case series of 106 patients underwent renal allograft biopsies. All biopsies were evaluated according to the Banff 2007 schema. 52 examples were obtained within 1 month after transplantation, and there were another 20 examples in one to two months and other 34 examples in two to three months. Appropriate therapy was applied and clinical outcomes were observed. All patients received renal biopsies and anti-inflammatory and hemostasis treatment without complications. There were 2 cases of hyperacute rejection, and 15 cases of acute AMR. All Paraffin-embedded samples were stained by HE, periodic acid-Schiff (PAS), Masson, and immunohistochemistry (C4d, cd20, cd45RO, SV40). All samples were found C4d immunohistochemical staining positive. Patients with acute AMR were managed by steroid intravenous pulse therapy, Rabbit anti-thymocyte globulin intravenous pulse therapy, anti CD20 monoclonal antibody intravenous therapy and so on. Two cases of hyperacute rejection had renal failure, and received kidney excision; 12 cases in 15 cases of AMR recovered, another 2 cases did not recover with high-level creatine, and other 2 cases of renal allograft received excision.

  6. Multiphoton imaging of renal tissues in vitro.

    Science.gov (United States)

    Peti-Peterdi, János

    2005-06-01

    The highly inhomogeneous and light-scattering structure of living renal tissue makes the application of conventional imaging techniques more difficult compared with other parenchymal organs. On the other hand, key physiological processes of the kidney, such as regulation of glomerular filtration, hemodynamics, concentration, and dilution, involve complex interactions between multiple cell types and otherwise inaccessible structures that necessitate visual approaches. An ideal solution is multiphoton excitation fluorescence microscopy, a state-of-the-art imaging technique superior for deep optical sectioning of living tissue samples. Here, we review the basics and advantages of multiphoton microscopy and provide examples for its application in renal physiology using dissected cortical and medullary tissues in vitro. In combination with microperfusion techniques, the major functions of the juxtaglomerular apparatus, tubuloglomerular feedback and renin release, can be studied with high spatial and temporal resolution. Salt-dependent changes in macula densa cell volume, vasoconstriction of the afferent arteriole, and activity of an intraglomerular precapillary sphincter composed of renin granular cells are visualized in real time. Release and tissue activity of renin can be studied on the individual granule level. Imaging of the living inner medulla shows how interstitial cells interconnect cells of the vasa recta, loop of Henle, and collecting duct. In summary, multiphoton microscopy is an exciting new optical sectioning technique that has great potential for numerous future developments and is ideal for applications that require deep optical sectioning of living tissue samples.

  7. The organization of primary afferent depolarization in the isolated spinal cord of the frog

    Science.gov (United States)

    Carpenter, D. O.; Rudomin, P.

    1973-01-01

    1. The organization of primary afferent depolarization (PAD) produced by excitation of peripheral sensory and motor nerves was studied in the frog cord isolated with hind limb nerves. 2. Dorsal root potentials from sensory fibres (DR-DRPs) were evoked on stimulation of most sensory nerves, but were largest from cutaneous, joint and flexor muscle afferents. With single shock stimulation the largest cutaneous and joint afferent fibres gave DR-DRPs, but potentials from muscle nerves resulted from activation of sensory fibres with thresholds to electrical stimulation higher than 1·2-1·5 times the threshold of the most excitable fibres in the nerve. This suggests that PAD from muscle afferents is probably due to excitation of extrafusal receptors. 3. Dorsal root potentials produced by antidromic activation of motor fibres (VR-DRPs) were larger from extensor muscles and smaller or absent from flexor muscles. The VR-DRPs were produced by activation of the lowest threshold motor fibres. 4. Three types of interactions were found between test and conditioning DRPs from the same or different nerves. With maximal responses occlusion was usually pronounced. At submaximal levels linear summation occurred. Near threshold the conditioning stimulus frequently resulted in a large facilitation of the test DRP. All three types of interactions were found with two DR-DRPs, two VR-DRPs or one DR-DRP and one VR-DRP. 5. The excitability of sensory nerve terminals from most peripheral nerves was increased during the DR-DRP. The magnitude of the excitability increase varied roughly with the magnitude of the DR-DRP evoked by the conditioning stimulus. 6. There was a marked excitability increase of cutaneous and extensor muscle afferent terminals during the VR-DRP. Flexor muscle afferent terminals often showed no excitability changes to ventral root stimulation. In those experiments where afferent terminals from flexor muscles did show an excitability increase, the effects were smaller than

  8. Intracellular signalling pathways in the vasoconstrictor response of mouse afferent arterioles to adenosine

    DEFF Research Database (Denmark)

    Hansen, Pernille B. Lærkegaard; Friis, Ulla Glenert; Uhrenholt, Torben Rene

    2007-01-01

    AIMS: Adenosine causes vasoconstriction of afferent arterioles of the mouse kidney through activation of adenosine A(1) receptors and Gi-mediated stimulation of phospholipase C. In the present study, we further explored the signalling pathways by which adenosine causes arteriolar vasoconstriction....... METHODS AND RESULTS: Adenosine (10(-7) M) significantly increased the intracellular calcium concentration in mouse isolated afferent arterioles measured by fura-2 fluorescence. Pre-treatment with thapsigargin (2 microM) blocked the vasoconstrictor action of adenosine (10(-7) M) indicating that release...

  9. An Upgrade on the Rabbit Model of Anthracycline-Induced Cardiomyopathy: Shorter Protocol, Reduced Mortality, and Higher Incidence of Overt Dilated Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Jesús Talavera

    2015-01-01

    Full Text Available Current protocols of anthracycline-induced cardiomyopathy in rabbits present with high premature mortality and nephrotoxicity, thus rendering them unsuitable for studies requiring long-term functional evaluation of myocardial function (e.g., stem cell therapy. We compared two previously described protocols to an in-house developed protocol in three groups: Group DOX2 received doxorubicin 2 mg/kg/week (8 weeks; Group DAU3 received daunorubicin 3 mg/kg/week (10 weeks; and Group DAU4 received daunorubicin 4 mg/kg/week (6 weeks. A cohort of rabbits received saline (control. Results of blood tests, cardiac troponin I, echocardiography, and histopathology were analysed. Whilst DOX2 and DAU3 rabbits showed high premature mortality (50% and 33%, resp., DAU4 rabbits showed 7.6% premature mortality. None of DOX2 rabbits developed overt dilated cardiomyopathy; 66% of DAU3 rabbits developed overt dilated cardiomyopathy and quickly progressed to severe congestive heart failure. Interestingly, 92% of DAU4 rabbits showed overt dilated cardiomyopathy and 67% developed congestive heart failure exhibiting stable disease. DOX2 and DAU3 rabbits showed alterations of renal function, with DAU3 also exhibiting hepatic function compromise. Thus, a shortened protocol of anthracycline-induced cardiomyopathy as in DAU4 group results in high incidence of overt dilated cardiomyopathy, which insidiously progressed to congestive heart failure, associated to reduced systemic compromise and very low premature mortality.

  10. An Upgrade on the Rabbit Model of Anthracycline-Induced Cardiomyopathy: Shorter Protocol, Reduced Mortality, and Higher Incidence of Overt Dilated Cardiomyopathy.

    Science.gov (United States)

    Talavera, Jesús; Giraldo, Alejandro; Fernández-Del-Palacio, María Josefa; García-Nicolás, Obdulio; Seva, Juan; Brooks, Gavin; Moraleda, Jose M

    2015-01-01

    Current protocols of anthracycline-induced cardiomyopathy in rabbits present with high premature mortality and nephrotoxicity, thus rendering them unsuitable for studies requiring long-term functional evaluation of myocardial function (e.g., stem cell therapy). We compared two previously described protocols to an in-house developed protocol in three groups: Group DOX2 received doxorubicin 2 mg/kg/week (8 weeks); Group DAU3 received daunorubicin 3 mg/kg/week (10 weeks); and Group DAU4 received daunorubicin 4 mg/kg/week (6 weeks). A cohort of rabbits received saline (control). Results of blood tests, cardiac troponin I, echocardiography, and histopathology were analysed. Whilst DOX2 and DAU3 rabbits showed high premature mortality (50% and 33%, resp.), DAU4 rabbits showed 7.6% premature mortality. None of DOX2 rabbits developed overt dilated cardiomyopathy; 66% of DAU3 rabbits developed overt dilated cardiomyopathy and quickly progressed to severe congestive heart failure. Interestingly, 92% of DAU4 rabbits showed overt dilated cardiomyopathy and 67% developed congestive heart failure exhibiting stable disease. DOX2 and DAU3 rabbits showed alterations of renal function, with DAU3 also exhibiting hepatic function compromise. Thus, a shortened protocol of anthracycline-induced cardiomyopathy as in DAU4 group results in high incidence of overt dilated cardiomyopathy, which insidiously progressed to congestive heart failure, associated to reduced systemic compromise and very low premature mortality.

  11. An Upgrade on the Rabbit Model of Anthracycline-Induced Cardiomyopathy: Shorter Protocol, Reduced Mortality, and Higher Incidence of Overt Dilated Cardiomyopathy

    Science.gov (United States)

    Talavera, Jesús; Fernández-Del-Palacio, María Josefa; García-Nicolás, Obdulio; Seva, Juan; Brooks, Gavin; Moraleda, Jose M.

    2015-01-01

    Current protocols of anthracycline-induced cardiomyopathy in rabbits present with high premature mortality and nephrotoxicity, thus rendering them unsuitable for studies requiring long-term functional evaluation of myocardial function (e.g., stem cell therapy). We compared two previously described protocols to an in-house developed protocol in three groups: Group DOX2 received doxorubicin 2 mg/kg/week (8 weeks); Group DAU3 received daunorubicin 3 mg/kg/week (10 weeks); and Group DAU4 received daunorubicin 4 mg/kg/week (6 weeks). A cohort of rabbits received saline (control). Results of blood tests, cardiac troponin I, echocardiography, and histopathology were analysed. Whilst DOX2 and DAU3 rabbits showed high premature mortality (50% and 33%, resp.), DAU4 rabbits showed 7.6% premature mortality. None of DOX2 rabbits developed overt dilated cardiomyopathy; 66% of DAU3 rabbits developed overt dilated cardiomyopathy and quickly progressed to severe congestive heart failure. Interestingly, 92% of DAU4 rabbits showed overt dilated cardiomyopathy and 67% developed congestive heart failure exhibiting stable disease. DOX2 and DAU3 rabbits showed alterations of renal function, with DAU3 also exhibiting hepatic function compromise. Thus, a shortened protocol of anthracycline-induced cardiomyopathy as in DAU4 group results in high incidence of overt dilated cardiomyopathy, which insidiously progressed to congestive heart failure, associated to reduced systemic compromise and very low premature mortality. PMID:26788502

  12. Microbiological quality of rabbit meat.

    Science.gov (United States)

    Rodríguez-Calleja, Jose M; Santos, Jesús A; Otero, Andrés; García-López, María-Luisa

    2004-05-01

    World rabbit meat production is estimated to be over 1 million tons, and Spain is the third largest producer. Although rabbit meat is marketed and consumed worldwide, information on microbiological quality is very scarce. Here, we report indicator organisms, spoilage flora, sensory quality, and some physicochemical traits of 24 h postmortem chilled rabbit carcasses and prepackaged rabbit meat stored chilled in air for 0 to 3 days at the retail level. The mean total bacterial count (4.01 +/- 0.48 log CFU/g) for carcasses dressed at a small abattoir by a manual process was significantly lower (P Pseudomonas, lactic acid bacteria, and yeasts. These microorganisms and Brochothrix thermosphacta were dominant on carcasses from the large abattoir. On prepacked hind legs (pH 6.26 +/- 0.18) stored at -1 to +1 degree C (supermarket 1), mean aerobic mesophilic count was 5.87 +/- 1.03 log CFU/g, and the major microbial groups were Pseudomonas, yeasts, lactic acid bacteria, and B. thermosphacta. On prepacked whole carcasses (pH 6.37 +/- 0.18) displayed at -1 to +5 degrees C (supermarket 2), mean aerobic mesophilic count was 6.60 +/- 1.18 and the same microbial groups were dominant. Relative Escherichia coli incidence was supermarket 2 > large abattoir > supermarket 1 > small abattoir. Overall, low numbers of coliforms, Enterobacteriaceae, psychrotrophic clostridia, coagulase-positive staphylococci, and molds were found. Sensory scores, pH values, and L-lactic acid content differentiated fresh carcasses from retail samples. Data obtained suggest that the microflora of chilled rabbit meat are different from those found on the meat of other animals.

  13. RPR test for serological survey of rabbit syphilis in companion rabbits.

    Science.gov (United States)

    Saito, Kumiko; Tagawa, Masayo; Hasegawa, Atsuhiko

    2003-07-01

    Since the RPR (rapid plasma regain) test was found to be useful for the diagnosis of rabbit syphilis, serological survey by this test has been carried out in Japanese companion rabbits. A hundred virgin household rabbits kept alone and without signs and history of syphilis were examined by RPR test from April 2001 to March 2002, in Tokyo, Japan. The test was positive in 35 cases and negative in 65 cases. RPR negative rabbits should be selected for breeding to prevent the spread of rabbit syphilis in companion rabbits in Japan.

  14. Kidney (Renal) Failure

    Science.gov (United States)

    ... How is kidney failure treated? What is kidney (renal) failure? The kidneys are designed to maintain proper fluid ... marrow and strengthen the bones. The term kidney (renal) failure describes a situation in which the kidneys have ...

  15. Renal arteries (image)

    Science.gov (United States)

    A renal angiogram is a test used to examine the blood vessels of the kidneys. The test is performed ... main vessel of the pelvis, up to the renal artery that leads into the kidney. Contrast medium ...

  16. Functional analysis of ultra high information rates conveyed by rat vibrissal primary afferents

    NARCIS (Netherlands)

    A.M. Chagas (André); L. Theis (Lucas); B. Sengupta (Biswa); M.C. Stüttgen (Maik); M. Bethge (Matthias); C. Schwarz (Cornelius)

    2013-01-01

    textabstractSensory receptors determine the type and the quantity of information available for perception. Here, we quantified and characterized the information transferred by primary afferents in the rat whisker system using neural system identification. Quantification of "how much" information is

  17. Nesfatin-1 modulates murine gastric vagal afferent mechanosensitivity in a nutritional state dependent manner.

    Science.gov (United States)

    Kentish, Stephen J; Li, Hui; Frisby, Claudine L; Page, Amanda J

    2017-03-01

    Food intake is regulated by vagal afferent signals from the stomach. Nesfatin-1 is an anorexigenic peptide produced within the gastrointestinal tract and has well defined central effects. We aimed to determine if nesfatin-1 can modulate gastric vagal afferent signals in the periphery and further whether this is altered in different nutritional states. Female C57BL/6J mice were fed either a standard laboratory diet (SLD) or a high fat diet (HFD) for 12 weeks or fasted overnight. Plasma nucleobindin-2 (NUCB2; nesfatin-1 precursor)/nesfatin-1 levels were assayed, the expression of NUCB2 in the gastric mucosa and adipose tissue was assessed using real-time quantitative reverse-transcription polymerase chain reaction. An in vitro preparation was used to determine the effect of nesfatin-1 on gastric vagal afferent mechanosensitivity. HFD mice exhibited an increased body weight and adiposity. Plasma NUCB2/nesfatin-1 levels were unchanged between any of the groups of mice. NUCB2 mRNA was detected in the gastric mucosa and gonadal fat of SLD, HFD and fasted mice with no difference in mRNA abundance between groups in either tissue. In SLD and fasted mice nesfatin-1 potentiated mucosal receptor mechanosensitivity, an effect not observed in HFD mice. Tension receptor mechanosensitivity was unaffected by nesfatin-1 in SLD and fasted mice, but was inhibited in HFD mice. In conclusion, Nesfatin-1 modulates gastric vagal afferent mechanosensitivity in a nutritional state dependent manner.

  18. Afferent loop syndrome - a case report; Sindrome da alca aferente - relato de um caso

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Ana Karina Nascimento; Pinheiro, Marco Antonio Lopes; Galvao, Cristine Norwig [Fundacao Pio XII - Hospital do Cancer de Barretos, SP (Brazil)

    2000-02-01

    The afferent loop syndrome occurs in patients with previous gastric surgery for tumor, when there is anastomotic edema, use of inappropriate reconstruction technique for gastro jejunostomy or recurrent gastric cancer. Complaints such jaundice, intermittent abdominal distension associated with pain, and vomiting should be investigated in order to rule out this syndrome. (author)

  19. Ghrelin counteracts insulin-induced activation of vagal afferent neurons via growth hormone secretagogue receptor.

    Science.gov (United States)

    Iwasaki, Yusaku; Dezaki, Katsuya; Kumari, Parmila; Kakei, Masafumi; Yada, Toshihiko

    2015-08-01

    Vagal afferent nerves sense meal-related gastrointestinal and pancreatic hormones and convey their information to the brain, thereby regulating brain functions including feeding. We have recently demonstrated that postprandial insulin directly acts on the vagal afferent neurons. Plasma concentrations of orexigenic ghrelin and anorexigenic insulin show reciprocal dynamics before and after meals. The present study examined interactive effects of ghrelin and insulin on vagal afferent nerves. Cytosolic Ca(2+) concentration ([Ca(2+)]i) in isolated nodose ganglion (NG) neurons was measured to monitor their activity. Insulin at 10(-7)M increased [Ca(2+)]i in NG neurons, and the insulin-induced [Ca(2+)]i increase was inhibited by treatment with ghrelin at 10(-8)M. This inhibitory effect of ghrelin was attenuated by [D-Lys(3)]-GHRP-6, an antagonist of growth hormone-secretagogue receptor (GHSR). Des-acyl ghrelin had little effect on insulin-induced [Ca(2+)]i increases in NG neurons. Ghrelin did not affect [Ca(2+)]i increases in response to cholecystokinin (CCK), a hormone that inhibits feeding via vagal afferent neurons, indicating that ghrelin selectively counteracts the insulin action. These results demonstrate that ghrelin via GHSR suppresses insulin-induced activation of NG neurons. The action of ghrelin to counteract insulin effects on NG might serve to efficiently inform the brain of the systemic change between fasting-associated ghrelin-dominant and fed-associated insulin-dominant states for the homeostatic central regulation of feeding and metabolism.

  20. Role of primary afferents in the developmental regulation of motor axon synapse numbers on Renshaw cells.

    Science.gov (United States)

    Siembab, Valerie C; Gomez-Perez, Laura; Rotterman, Travis M; Shneider, Neil A; Alvarez, Francisco J

    2016-06-15

    Motor function in mammalian species depends on the maturation of spinal circuits formed by a large variety of interneurons that regulate motoneuron firing and motor output. Interneuron activity is in turn modulated by the organization of their synaptic inputs, but the principles governing the development of specific synaptic architectures unique to each premotor interneuron are unknown. For example, Renshaw cells receive, at least in the neonate, convergent inputs from sensory afferents (likely Ia) and motor axons, raising the question of whether they interact during Renshaw cell development. In other well-studied neurons, such as Purkinje cells, heterosynaptic competition between inputs from different sources shapes synaptic organization. To examine the possibility that sensory afferents modulate synaptic maturation on developing Renshaw cells, we used three animal models in which afferent inputs in the ventral horn are dramatically reduced (ER81(-/-) knockout), weakened (Egr3(-/-) knockout), or strengthened (mlcNT3(+/-) transgenic). We demonstrate that increasing the strength of sensory inputs on Renshaw cells prevents their deselection and reduces motor axon synaptic density, and, in contrast, absent or diminished sensory afferent inputs correlate with increased densities of motor axons synapses. No effects were observed on other glutamatergic inputs. We conclude that the early strength of Ia synapses influences their maintenance or weakening during later development and that heterosynaptic influences from sensory synapses during early development regulates the density and organization of motor inputs on mature Renshaw cells.

  1. Vagal afferents are essential for maximal resection-induced intestinal adaptive growth in orally fed rats

    DEFF Research Database (Denmark)

    Nelson, David W; Liu, Xiaowen; Holst, Jens Juul

    2006-01-01

    Small bowel resection stimulates intestinal adaptive growth by a neuroendocrine process thought to involve both sympathetic and parasympathetic innervation and enterotrophic hormones such as glucagon-like peptide-2 (GLP-2). We investigated whether capsaicin-sensitive vagal afferent neurons are es...

  2. Inhibitory mechanisms following electrical stimulation of tendon and cutaneous afferents in the lower limb.

    Science.gov (United States)

    Khan, Serajul I; Burne, John A

    2010-01-13

    Electrical stimulation of the Achilles tendon (TES) produced strong reflex depression (duration>250 ms) of a small background contraction in both heads of gastrocnemius (GA) via large diameter electrodes localized to the tendon. The inhibitory responses were produced without electrical (M wave) or mechanical (muscle twitch) signs of direct muscle stimulation. In this study, the contribution of presynaptic and postsynaptic mechanisms to the depression was investigated by studying conditioning effects of tendon afferent stimulation on the mechanical tendon reflex (TR) and magnetic motor evoked potential (MEP). TES completely inhibited the TR over an ISI of 300 ms that commenced before and continued during and after the period of voluntary EMG depression. Tendon afferent conditioning stimuli also partially inhibited the MEP, but over a short time course confined to the period of voluntary EMG depression. The strength and extended time course of tendon afferent conditioning of the TR and its failure to produce a similar depression of the MEP are consistent with a mechanism involving presynaptic inhibition of Ia terminals. Cutaneous (sural nerve) afferent conditioning partially inhibited the TR and MEP over a short time course (ISI voluntary EMG. This was consistent with the postsynaptic origin of cutaneous inhibition of the motoneurons.

  3. Chronic exposure to low dose bacterial lipopolysaccharide inhibits leptin signaling in vagal afferent neurons.

    Science.gov (United States)

    de La Serre, Claire B; de Lartigue, Guillaume; Raybould, Helen E

    2015-02-01

    Bacterially derived factors are implicated in the causation and persistence of obesity. Ingestion of a high fat diet in rodents and obesity in human subjects is associated with chronic elevation of low plasma levels of lipopolysaccharide (LPS), a breakdown product of Gram-negative bacteria. The terminals of vagal afferent neurons are positioned within the gut mucosa to convey information from the gut to the brain to regulate food intake and are responsive to LPS. We hypothesized that chronic elevation of LPS could alter vagal afferent signaling. We surgically implanted osmotic mini-pumps that delivered a constant, low-dose of LPS into the intraperitoneal cavity of rats (12.5 μg/kg/hr for 6 weeks). LPS-treated rats developed hyperphagia and showed marked changes in vagal afferent neuron function. Chronic LPS treatment reduced vagal afferent leptin signaling, characterized by a decrease in leptin-induced STAT3 phosphorylation. In addition, LPS treatment decreased cholecystokinin-induced satiety. There was no alteration in leptin signaling in the hypothalamus. These findings offer a mechanism by which a change in gut microflora can promote hyperphagia, possibly leading to obesity.

  4. Immobilization induces changes in presynaptic control of group Ia afferents in healthy humans

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye; Nielsen, Jens Bo

    2008-01-01

    maximal voluntary plantar- and dorsiflexion torque (MVC) was significantly reduced and the maximal SOL H-reflex amplitude increased with no changes in Mmax. Decreased presynaptic inhibition of the Ia afferents likely contributed to the increase of the H-reflex size, since we observed a significant...

  5. Synaptic transmission of baro- and chemoreceptors afferents in the NTS second order neurons.

    Science.gov (United States)

    Accorsi-Mendonça, Daniela; Machado, Benedito H

    2013-04-01

    Second order neurons in the nucleus tractus solitarius (NTS) process and integrate the afferent information from arterial baroreceptors with high fidelity and precise timing synaptic transmission. Since 2nd-order NTS neurons receiving baroreceptors inputs are relatively well characterized, their electrophysiological profile has been accepted as a general characteristic for all 2nd-order NTS neurons involved with the processing of different sensorial inputs. On the other hand, the synaptic properties of other afferent systems in NTS, such as the peripheral chemoreceptors, are not yet well understood. In this context, in previous studies we demonstrated that in response to repetitive afferents stimulation, the chemoreceptors 2nd-order NTS neurons also presented high fidelity of synaptic transmission, but with a large variability in the latency of evoked responses. This finding is different in relation to the precise timing transmission for baroreceptor 2nd-order NTS neurons, which was accepted as a general characteristic profile for all 2nd order neurons in the NTS. In this brief review we discuss this new concept as an index of complexity of the sensorial inputs to NTS with focus on the synaptic processing of baro- and chemoreceptor afferents.

  6. Afferent and Efferent Connections of the Optic Tectum in the Carp (Cyprinus carpio L.)

    NARCIS (Netherlands)

    Luiten, P.G.M.

    1981-01-01

    The afferent and efferent connections of the tectum opticum in the carp (Cyprinus carpio L.) were studied with the HRP method. Following iontophoretic peroxidase injections in several parts of the rectum anterograde transport of the enzyme revealed tectal projections to the lateral geniculate nucleu

  7. Tactile stimulation with kinesiology tape alleviates muscle weakness attributable to attenuation of Ia afferents.

    Science.gov (United States)

    Konishi, Yu

    2013-01-01

    Prolonged vibration stimulation to normal individuals could lead to muscle weakness attributable to attenuation of afferent feedback. This weakness is neurophysiologically similar to that seen in patients with knee injury. Theoretically, increasing input to gamma motor neurons could reverse this weakness. Sensory input to these neurons from skin could indirectly increase Ia afferent feedback. The present study examined the effect of this tactile stimulation in the form of Kinesiology tape on muscle weakness attributable to attenuation of afferent feedback. Randomized, crossover design. All participants were measured their eccentric maximal voluntary contractions under the 2 conditions (taping and non-taping). First, maximal voluntary contraction during eccentric contraction was measured as baseline. For the taping condition, Kinesiology tape was applied around each subject's knee joint during maximal voluntary contraction measurement after vibration. For the non-taping condition, tape was not applied during maximal voluntary contraction measurement after vibration. Mean percentage changes between pre- and post-vibration stimulation were compared between two conditions. Maximal voluntary contraction and average electromyography of taping condition was significantly larger than that of non-taping condition. Our results suggest that tactile stimulation in the form of Kinesiology tape inhibits the decline of both strength and electromyography. Alpha motor neuron activity attenuated by prolonged vibration would thus be partially rescued by tactile stimulation. These results indirectly suggest that stimulation of skin around the knee could counter quadriceps femoris weakness due to attenuated Ia afferent activity. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  8. Reversible anuric acute kidney injury secondary to acute renal autoregulatory dysfunction.

    Science.gov (United States)

    Imbriano, Louis J; Maesaka, John K; Drakakis, James; Mattana, Joseph

    2014-02-01

    Autoregulation of glomerular capillary pressure via regulation of the resistances at the afferent and efferent arterioles plays a critical role in maintaining the glomerular filtration rate over a wide range of mean arterial pressure. Angiotensin II and prostaglandins are among the agents which contribute to autoregulation and drugs which interfere with these agents may have a substantial impact on afferent and efferent arteriolar resistance. We describe a patient who suffered an episode of anuric acute kidney injury following exposure to a nonsteroidal anti-inflammatory agent while on two diuretics, an angiotensin-converting enzyme inhibitor, and an angiotensin receptor blocker. The episode completely resolved and we review some of the mechanisms by which these events may have taken place and suggest the term "acute renal autoregulatory dysfunction" to describe this syndrome.

  9. Afferent Innervation, Muscle Spindles, and Contractures Following Neonatal Brachial Plexus Injury in a Mouse Model.

    Science.gov (United States)

    Nikolaou, Sia; Hu, Liangjun; Cornwall, Roger

    2015-10-01

    We used an established mouse model of elbow flexion contracture after neonatal brachial plexus injury (NBPI) to test the hypothesis that preservation of afferent innervation protects against contractures and is associated with preservation of muscle spindles and ErbB signaling. A model of preganglionic C5 through C7 NBPI was first tested in mice with fluorescent axons using confocal imaging to confirm preserved afferent innervation of spindles despite motor end plate denervation. Preganglionic and postganglionic injuries were then created in wild-type mice. Four weeks later, we assessed total and afferent denervation of the elbow flexors by musculocutaneous nerve immunohistochemistry. Biceps muscle volume and cross-sectional area were measured by micro computed tomography. An observer who was blinded to the study protocol measured elbow flexion contractures. Biceps spindle and muscle fiber morphology and ErbB signaling pathway activity were assessed histologically and immunohistochemically. Preganglionic and postganglionic injuries caused similar total denervation and biceps muscle atrophy. However, after preganglionic injuries, afferent innervation was partially preserved and elbow flexion contractures were significantly less severe. Spindles degenerated after postganglionic injury but were preserved after preganglionic injury. ErbB signaling was inactivated in denervated spindles after postganglionic injury but ErbB signaling activity was preserved in spindles after preganglionic injury with retained afferent innervation. Preganglionic and postganglionic injuries were associated with upregulation of ErbB signaling in extrafusal muscle fibers. Contractures after NBPI are associated with muscle spindle degeneration and loss of spindle ErbB signaling activity. Preservation of afferent innervation maintained spindle development and ErbB signaling activity, and protected against contractures. Pharmacologic modulation of ErbB signaling, which is being investigated as a

  10. [Renal leiomyoma. Case report].

    Science.gov (United States)

    Joual, A; Guessous, H; Rabii, R; Benjelloun, M; Benlemlih, A; Skali, K; el Mrini, M; Benjelloun, S

    1999-01-01

    The authors report a case of renal leiomyoma observed in a 56-year-old man. This cyst presented in the from of loin pain. Computed tomography revealed a homogeneous renal tumor. Treatment consisted of radical nephrectomy. Histological examination of the specimen showed benign renal leiomyoma.

  11. Renal inflammatory myofibroblastic tumor

    DEFF Research Database (Denmark)

    Heerwagen, S T; Jensen, C; Bagi, P

    2007-01-01

    Renal inflammatory myofibroblastic tumor (IMT) is a rare soft-tissue tumor of controversial etiology with a potential for local recurrence after incomplete surgical resection. The radiological findings in renal IMT are not well described. We report two cases in adults with a renal mass treated...

  12. Renal denervation in the treatment of resistant hypertension: Dead, alive or surviving?

    Science.gov (United States)

    Al-Fakhouri, Ahmad; Efeovbokhan, Nephertiti; Nakhla, Rami; Khouzam, Rami N

    2016-10-01

    Hypertension is one of the most common chronic clinical problems encountered by physicians. The prevalence of resistant hypertension is estimated at 9% in the US. Patients with resistant hypertension have been shown to be at higher risk for adverse cardiovascular events, hence the need for greater efforts in improving the treatment of hypertension. The renal sympathetic nerves play an important role in the development of hypertension, mediated via sodium and water retention, increased renin release and alterations in renal blood flow. The proximity of the afferent and efferent renal sympathetic nerves to the adventitia of the renal arteries suggested the feasibility of an endovascular, selective, minimally invasive approach to renal denervation; a potential treatment option for resistant hypertension. While the RAPID, Reduce-HTN, EnligHTN, DENERHTN and Symplicity HTN-1 and -2 studies showed significant benefit of renal denervation in the treatment of resistant hypertension, the results of Oslo RDN, Prague-15 and Symplicity HTN-3 were not so favorable. Future well-designed clinical trials are needed to ascertain the benefits or otherwise of renal denervation in treatment-resistant hypertension.

  13. Immunosuppression abrogates resistance of young rabbits to Rabbit Haemorrhagic Disease (RHD).

    Science.gov (United States)

    Marques, Raquel M; Teixeira, Luzia; Aguas, Artur P; Ribeiro, Joana C; Costa-e-Silva, António; Ferreira, Paula G

    2014-02-04

    Rabbit Haemorrhagic Disease (RHD) is caused by a calicivirus (RHDV) that kills 90% of infected adult European rabbits within 3 days. Remarkably, young rabbits are resistant to RHD. We induced immunosuppression in young rabbits by treatment with methylprednisolone acetate (MPA) and challenged the animals with RHDV by intramuscular injection. All of these young rabbits died within 3 days of infection due to fulminant hepatitis, presenting a large number of RHDV-positive dead or apoptotic hepatocytes, and a significant seric increase in cytokines, features that are similar to those of naïve adult rabbits infected by RHDV. We conclude that MPA-induced immunosuppression abrogates the resistance of young rabbits to RHD, indicating that there are differences in the innate immune system between young and adult rabbits that contribute to their distinct resistance/susceptibility to RHDV infection.

  14. Spinal afferent neurons projecting to the rat lung and pleura express acid sensitive channels

    Directory of Open Access Journals (Sweden)

    Kummer Wolfgang

    2006-07-01

    Full Text Available Abstract Background The acid sensitive ion channels TRPV1 (transient receptor potential vanilloid receptor-1 and ASIC3 (acid sensing ion channel-3 respond to tissue acidification in the range that occurs during painful conditions such as inflammation and ischemia. Here, we investigated to which extent they are expressed by rat dorsal root ganglion neurons projecting to lung and pleura, respectively. Methods The tracer DiI was either injected into the left lung or applied to the costal pleura. Retrogradely labelled dorsal root ganglion neurons were subjected to triple-labelling immunohistochemistry using antisera against TRPV1, ASIC3 and neurofilament 68 (marker for myelinated neurons, and their soma diameter was measured. Results Whereas 22% of pulmonary spinal afferents contained neither channel-immunoreactivity, at least one is expressed by 97% of pleural afferents. TRPV1+/ASIC3- neurons with probably slow conduction velocity (small soma, neurofilament 68-negative were significantly more frequent among pleural (35% than pulmonary afferents (20%. TRPV1+/ASIC3+ neurons amounted to 14 and 10% respectively. TRPV1-/ASIC3+ neurons made up between 44% (lung and 48% (pleura of neurons, and half of them presumably conducted in the A-fibre range (larger soma, neurofilament 68-positive. Conclusion Rat pleural and pulmonary spinal afferents express at least two different acid-sensitive channels that make them suitable to monitor tissue acidification. Patterns of co-expression and structural markers define neuronal subgroups that can be inferred to subserve different functions and may initiate specific reflex responses. The higher prevalence of TRPV1+/ASIC3- neurons among pleural afferents probably reflects the high sensitivity of the parietal pleura to painful stimuli.

  15. Central distribution of octavolateral afferents and efferents in a teleost (Mormyridae).

    Science.gov (United States)

    Bell, C C

    1981-01-20

    The central distribution of afferents from individual eight nerve branches (N VIII) and mechanical lateral line end organs in mormyrid fish are described. Afferents were labeled with horseradish peroxidase (HRP) placed on the cut ends of the different N VIII branches and the anterior and posterior lateral line nerves. Descending, tangential, and magnocellular nuclei receive input almost exclusively from the utriculus and canals. Nucleus octavius receives afferents from the lateral line nerves and all N VIII branches, with one part receiving exclusive and bilateral input from the sacculus. Afferents from both lateral line nerves and all N VII branches, except the sacculus, end in eminentia granularis. Afferents from each of the two lateral line nerves and from each of three otolith branches of N VIII end in different regions of the anterior lateral line lobe, with some areas of overlap. Behavioral studies in other families of fish indicate that the utriculus and canals are critical for postural control, whereas the sacculus and possibly the lagena are concerned with hearing. Such findings, together with the results of this study, suggest that mormyrids and perhaps other fish possess separate auditory and vestibular centers within the octavolateral area. The HRP method also shows the cell bodies and axons of octavolateral efferents. N VIII and lateral line efferents arise from a common nucleus, and the central course of their axons parallels that of facial motoneurons. Axons of efferent cells divide to supply two or more branches of N VIII and some axons supply both lateral line and N VIII end organs.

  16. Identification of multisegmental nociceptive afferents that modulate locomotor circuits in the neonatal mouse spinal cord.

    Science.gov (United States)

    Mandadi, Sravan; Hong, Peter; Tran, Michelle A; Bráz, Joao M; Colarusso, Pina; Basbaum, Allan I; Whelan, Patrick J

    2013-08-15

    Compared to proprioceptive afferent collateral projections, less is known about the anatomical, neurochemical, and functional basis of nociceptive collateral projections modulating lumbar central pattern generators (CPG). Quick response times are critical to ensure rapid escape from aversive stimuli. Furthermore, sensitization of nociceptive afferent pathways can contribute to a pathological activation of motor circuits. We investigated the extent and role of collaterals of capsaicin-sensitive nociceptive sacrocaudal afferent (nSCA) nerves that directly ascend several spinal segments in Lissauer's tract and the dorsal column and regulate motor activity. Anterograde tracing demonstrated direct multisegmental projections of the sacral dorsal root 4 (S4) afferent collaterals in Lissauer's tract and in the dorsal column. Subsets of the traced S4 afferent collaterals expressed transient receptor potential vanilloid 1 (TRPV1), which transduces a nociceptive response to capsaicin. Electrophysiological data revealed that S4 dorsal root stimulation could evoke regular rhythmic bursting activity, and our data suggested that capsaicin-sensitive collaterals contribute to CPG activation across multiple segments. Capsaicin's effect on S4-evoked locomotor activity was potent until the lumbar 5 (L5) segments, and diminished in rostral segments. Using calcium imaging we found elevated calcium transients within Lissauer's tract and dorsal column at L5 segments when compared to the calcium transients only within the dorsal column at the lumbar 2 (L2) segments, which were desensitized by capsaicin. We conclude that lumbar locomotor networks in the neonatal mouse spinal cord are targets for modulation by direct multisegmental nSCA, subsets of which express TRPV1 in Lissauer's tract and the dorsal column. J. Comp. Neurol. 521:2870-2887, 2013. © 2013 Wiley Periodicals, Inc.

  17. Bicarbonate reabsorption by the kidney of the newborn rabbit.

    Science.gov (United States)

    van der Heijden, A J; Guignard, J P

    1989-01-01

    Bicarbonate reabsorption by the immature kidney in response to acute acid-base changes was assessed in 50 anesthetized newborn rabbits before the end of nephrogenesis. The normal newborn rabbit (age 5-12 days) is in a state of hypochloremic metabolic alkalosis (PHCO3-, 31.9 +/- 0.6 mmol/l; PCl-, 83.1 +/- 1.0) and excretes a hypertonic (Uosmol = 578 +/- 41 mosmol/kgH2O), alkaline (UpH = 7.40 +/- 0.15) urine containing 50 +/- 9 mmol/l Cl- and 13 +/- 4 mmol/l Na+. The alkalosis is probably generated by an alkaline load contained in the mother's milk and maintained by a state of chloride wasting and volume contraction. In this alkalotic model, bicarbonate reabsorption, expressed per milliliter glomerular filtration rate (GFR), correlates positively with arterial CO2 pressure (PaCO2). The ability of the immature kidney to reclaim filtered bicarbonate in response to an elevation of the plasma carbon dioxide tension remains unlimited up to PaCO2 of 110 mmHg (y = 20.7 + 0.15 x, r = 0.82, P less than 0.001). Hypercapnia is associated with a marked fall in GFR, so that the positive correlation between bicarbonate reabsorption and PaCO2 vanishes when the bicarbonate reabsorption rate is expressed in absolute terms. Bicarbonate reabsorption is strongly dependent on the filtered load during both acutely induced metabolic acidosis and alkalosis. The acid-base state of the newborn rabbit is in sharp contrast with that of most animal species, and the renal handling of bicarbonate as a function of GFR does not show signs of tubular immaturity.

  18. White Rabbit Status and Prospects

    CERN Document Server

    Serrano, J; Cattin, M; van der Bij, E; Wlostowski, T; Daniluk, G; Lipinski, M; Beck, D; Hoffmann, J; Kreider, M; Prados, C; Rauch, S; Terpstra, W W; Zweig, M

    2014-01-01

    The White Rabbit (WR) project started off to provide a sequencing and synchronisation solution for the needs of CERN and GSI. Since then, many other users have adopted it to solve problems in the domain of distributed hard realtime systems. The paper discusses the current performance of WR hardware, along with present and foreseen applications. It also describes current efforts to standardise WR under IEEE 1588 and recent developments on reliability of timely data distribution, finishing with an outline of future plans.

  19. Imaging features of gray-scale and contrast-enhanced color doppler US for the differentiation of transient renal arterial ischemia and arterial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byung Kwan; Kim Seung Hyup [Seoul National University Hospital, Seoul (Korea, Republic of); Moon, Min Hwan; Jung, Sung Il [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2005-09-15

    To characterize the imaging features on gray-scale and contrast-enhanced color Doppler US images which differentiate renal ischemia from renal infarction. The segmental renal arteries of eight healthy rabbits were surgically ligated. In four of these rabbits, the ligated renal artery was released 60 minutes after arterial occlusion to cause transient ischemia. In the remaining four rabbits, the arterial ligation was retained to cause a permanent infarction. The gray-scale and contrast-enhanced color Doppler US imaging features of the involved renal parenchymal of both ischemia and infarction groups were compared with respect to the presence or absence of parenchymal swelling, echogenicity changes, tissue loss and perfusion defects. Parenchyma swelling, echogenic changes, tissue loss and perfusion defects were found to be more extensive in the infarction than the ischemia group. The hyperechoic areas reperfused with blood flow recovered normal echogenicity and perfusion, whereas the hyperechoic areas without reperfusion became renal infarcts. Gray-scale and contrast-enhanced color Doppler US showed that the hyperechoic areas with reperfusion may reverse to normal parenchyma and allow the differentiation of renal ischemia from renal infarction.

  20. Doe productivity indices and sire effects of a heterogeneous rabbit ...

    African Journals Online (AJOL)

    IJAAAR

    Doe productivity indices are important in evaluating rabbit population since it influences the efficiency and profitability of rabbit ... Key words: Heterogeneous rabbit population, Doe productivity, Sire families). ..... Paris, France, 11-14. Cited in:.

  1. Cardiovascular physiology and diseases of the rabbit.

    Science.gov (United States)

    Pariaut, Romain

    2009-01-01

    This article reviews what is known about the diagnosis and management of cardiovascular diseases in the pet rabbit. Current knowledge is based on anecdotal reports, derived from research data using the rabbit as an animal model of human cardiovascular diseases, but most importantly canine and feline cardiology. It is likely that, as cardiovascular diseases are more often recognized, more specific information will soon become available for the treatment of the pet rabbit with cardiac disease.

  2. Welfare aspects in rabbit rearing and transport

    OpenAIRE

    Claudio Cavani; Massimiliano Petracci; Fabio Luzi; Marina Verga

    2010-01-01

    The review starts with the description of the rabbits’ (Oryctolagus cuniculus) main habits and the current situation concerning the rabbit husbandry and management systems, as well as their effects on the welfare of these animals. As far as the intensive rabbit husbandry systems are concerned, the main problems are related to the time since rabbits have been domesticated and their adaptive capacity and coping styles as respects the farming environment and management systems. Both these ...

  3. Rabbits' eye globe sonographic biometry.

    Science.gov (United States)

    Toni, Maria Carolina; Meirelles, Adriana Érica Wilkes Burton; Gava, Fábio Nelson; Camacho, Aparecido Antônio; Laus, José Luiz; Canola, Júlio Carlos

    2010-11-01

    To measure intraocular structures in New Zealand White breed rabbits (Oryctolagus cuniculus Linnaeus, 1758) using A-mode and B-mode ultrasound with a 20 MHz transducer. In this study, the eyes of 15 rabbits were evaluated for determination of intraocular measurements using an ophthalmic ultrasound unit able to operate in both A and B-modes. The distances from the cornea to the anterior capsule of the lens (D1), from the anterior capsule of the lens to the posterior capsule of the lens (D2), from the posterior capsule of the lens to the retina (D3) and the complete length of the eye, which corresponds to the distance from the cornea to the retina (D4) were taken. The mean values obtained were 2.70 mm (± 0.22 mm) for D1, 7.32 mm (± 0.40 mm) for D2, 7.10 mm (± 0.45 mm) for D3 and 17.12 mm (± 0.41 mm) for D4. Statistical analyses using the Student's t-test showed that there were no differences between the eyes. The study was feasible without the need of pharmacological restraint and yielded normal mean values for ocular sonographic biometry in rabbits. © 2010 American College of Veterinary Ophthalmologists.

  4. Postpartum renal vein thrombosis.

    Science.gov (United States)

    Rubens, D; Sterns, R H; Segal, A J

    1985-01-01

    Renal vein thrombosis in adults is usually a complication of the nephrotic syndrome. Rarely, it has been reported in nonnephrotic women postpartum. The thrombosis may be a complication of the hypercoagulable state associated with both the nephrotic syndrome and pregnancy. Two postpartum patients with renal vein thrombosis and no prior history of renal disease are reported here. Neither patient had heavy proteinuria. In both cases, pyelonephritis was suspected clinically and the diagnosis of renal vein thrombosis was first suggested and confirmed by radiologic examination. Renal vein thrombosis should be considered in women presenting postpartum with flank pain.

  5. Renal infarction resulting from traumatic renal artery dissection.

    Science.gov (United States)

    Kang, Kyung Pyo; Lee, Sik; Kim, Won; Jin, Gong Yong; Na, Ki Ryang; Yun, Il Yong; Park, Sung Kwang

    2008-06-01

    Renal artery dissection may be caused by iatrogenic injury, trauma, underlying arterial diseases such as fibromuscular disease, atherosclerotic disease, or connective tissue disease. Radiological imaging may be helpful in detecting renal artery pathology, such as renal artery dissection. For patients with acute, isolated renal artery dissection, surgical treatment, endovascular management, or medical treatment have been considered effective measures to preserve renal function. We report a case of renal infarction that came about as a consequence of renal artery dissection.

  6. THE ROLE OF NUCLEUS RAPHE MAGNUS IN THE ANTINOCICEPTIVE EFFECT OF MUSCLE SPINDLE AFFERENTS IN THE RAT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To investigate the role of NRM in the antinociceptive effect of muscle spindle afferents, the influence of NRM lesion on the inhibitory effect of muscle spindle afferents on the nociceptive responses of wide dynamic range (WDR) neurons and the effects of the muscle spindle afferents on the NRM neuronal activities were observed. Methods The single units of WDR neurons in the spinal dorsal horn were recorded extracellularly, and the inhibitory effects of activating muscle spindle afferents by intravenous administration of succinyicholine (SCH) on the C-fibers evoked responses (C-responses) of WDR neurons were tested before and after lesion of NRM. The ef- fects of the muscle spindle afferents activated by administrating SCH on the single NRM neurons were also examined. Results ①lt was found that the C-responses of WDR neurons were significantly inhibited by intravenously adminis- tration of SCH, and the inhibitory effect was reduced after lesion of NRM ;②The activities of most of the NRM neu- rons could be changed significantly by administrating SCH. According to their responses, NRM neurons could be classified into three types:excitatory, inhibitory and non-responsive neurons, and the responses were dose-depen- dent. Conclusion These results suggest that the muscle spindle afferents evoked by SCH may activate the NRM neu- rons, which plays an important role in the antinociception of muscle spindle afferents.

  7. Cerebral, subcortical, and cerebellar activation evoked by selective stimulation of muscle and cutaneous afferents: an fMRI study.

    Science.gov (United States)

    Wardman, Daniel L; Gandevia, Simon C; Colebatch, James G

    2014-01-01

    Abstract We compared the brain areas that showed significant flow changes induced by selective stimulation of muscle and cutaneous afferents using fMRI BOLD imaging. Afferents arising from the right hand were studied in eight volunteers with electrical stimulation of the digital nerve of the index finger and over the motor point of the FDI muscle. Both methods evoked areas of significant activation cortically, subcortically, and in the cerebellum. Selective muscle afferent stimulation caused significant activation in motor-related areas. It also caused significantly greater activation within the contralateral precentral gyrus, insula, and within the ipsilateral cerebellum as well as greater areas of reduced blood flow when compared to the cutaneous stimuli. We demonstrated separate precentral and postcentral foci of excitation with muscle afferent stimulation. We conclude, contrary to the findings with evoked potentials, that muscle afferents evoke more widespread cortical, subcortical, and cerebellar activation than do cutaneous afferents. This emphasizes the importance, for studies of movement, of matching the kinematic aspects in order to avoid the results being confounded by alterations in muscle afferent activation. The findings are consistent with clinical observations of the movement consequences of sensory loss and may also be the basis for the contribution of disturbed sensorimotor processing to disorders of movement.

  8. Expression of 5-HT3 receptors by extrinsic duodenal afferents contribute to intestinal inhibition of gastric emptying.

    Science.gov (United States)

    Raybould, Helen E; Glatzle, Jorg; Robin, Carla; Meyer, James H; Phan, Thomas; Wong, Helen; Sternini, Catia

    2003-03-01

    Intestinal perfusion with carbohydrates inhibits gastric emptying via vagal and spinal capsaicin-sensitive afferent pathways. The aim of the present study was to determine the role of 1) 5-hydroxytryptamine (5-HT)(3) receptors (5-HT(3)R) in mediating glucose-induced inhibition of gastric emptying and 2) 5-HT(3)R expression in vagal and spinal afferents in innervating the duodenum. In awake rats fitted with gastric and duodenal cannulas, perfusion of the duodenum with glucose (50 and 100 mg) inhibited gastric emptying. Intestinal perfusion of mannitol inhibited gastric emptying only at the highest concentration (990 mosm/kgH(2)O). Pretreatment with the 5-HT(3)R antagonist tropisetron abolished both glucose- and mannitol-induced inhibition of gastric emptying. Retrograde labeling of visceral afferents by injection of dextran-conjugated Texas Red into the duodenal wall was used to identify extrinsic primary afferents. Immunoreactivity for 5-HT(3)R, visualized with an antibody directed to the COOH terminus of the rat 5-HT(3)R, was found in >80% of duodenal vagal and spinal afferents. These results show that duodenal extrinsic afferents express 5-HT(3)R and that the receptor mediates specific glucose-induced inhibition of gastric emptying. These findings support the hypothesis that enterochromaffin cells in the intestinal mucosa release 5-HT in response to glucose, which activates 5-HT(3)R on afferent nerve terminals to evoke reflex changes in gastric motility. The primary glucose sensors of the intestine may be mucosal enterochromaffin cells.

  9. Isolation of TRPV1 independent mechanisms of spontaneous and asynchronous glutamate release at primary afferent to NTS synapses.

    Science.gov (United States)

    Fenwick, Axel J; Wu, Shaw-Wen; Peters, James H

    2014-01-01

    Cranial visceral afferents contained within the solitary tract (ST) contact second-order neurons in the nucleus of the solitary tract (NTS) and release the excitatory amino acid glutamate via three distinct exocytosis pathways; synchronous, asynchronous, and spontaneous release. The presence of TRPV1 in the central terminals of a majority of ST afferents conveys activity-dependent asynchronous glutamate release and provides a temperature sensitive calcium conductance which largely determines the rate of spontaneous vesicle fusion. TRPV1 is present in unmyelinated C-fiber afferents and these facilitated forms of glutamate release may underlie the relative strength of C-fibers in activating autonomic reflex pathways. However, pharmacological blockade of TRPV1 signaling eliminates only ~50% of the asynchronous profile and attenuates the temperature sensitivity of spontaneous release indicating additional thermosensitive calcium influx pathways may exist which mediate these forms of vesicle release. In the present study we isolate the contribution of TRPV1 independent forms of glutamate release at ST-NTS synapses. We found ST afferent innervation at NTS neurons and synchronous vesicle release from TRPV1 KO mice was not different to control animals; however, only half of TRPV1 KO ST afferents completely lacked asynchronous glutamate release. Further, temperature driven spontaneous rates of vesicle release were not different from 33 to 37°C between control and TRPV1 KO afferents. These findings suggest additional temperature dependent mechanisms controlling asynchronous and thermosensitive spontaneous release at physiological temperatures, possibly mediated by additional thermosensitive TRP channels in primary afferent terminals.

  10. Immunostimulant Effect of Egyptian Propolis in Rabbits

    National Research Council Canada - National Science Library

    Nassar, Somya A; Mohamed, Amira H; Soufy, Hamdy; Nasr, Soad M; Mahran, K. M

    2012-01-01

    The present experiment was conducted to study the effect of ethanolic extract of Egyptian propolis given alone or in combination with inactivated Pasteurella multocida vaccine on rabbits challenged...

  11. Encephalitozoon cuniculi: Grading the Histological Lesions in Brain, Kidney, and Liver during Primoinfection Outbreak in Rabbits

    Directory of Open Access Journals (Sweden)

    Luis E. Rodríguez-Tovar

    2016-01-01

    Full Text Available This is the first confirmed report of Encephalitozoon cuniculi (E. cuniculi in farm meat rabbits located in Northern Mexico. Eighty young rabbits exhibited clinical signs of this zoonotic emerging disease, like torticollis, ataxia, paresis, circling, and rolling. Samples of brain, kidney, and liver were examined for histology lesions. For the first time the lesions caused by E. cuniculi were graded according to their severity (I, II, and III and the size of the granulomas (Types A, B, and C. The main cerebral injuries were Grade III, coinciding with the presence of Type C granulomas. The cerebral lesions were located in the cortex, brain stem, and medulla. The renal lesions were also Grade III distributed throughout cortex and renal medulla, with no granuloma formation. The involvement of hypersensitivity Types III and IV is suggested. All of the rabbits were seropositive to E. cuniculi by CIA testing, suggesting that this zoonotic and emerging pathogen is widely distributed among animals intended for human consumption. We believe this work could be used as a guide when examining E. cuniculi and will provide direction to confirm the diagnosis of this pathogen.

  12. Encephalitozoon cuniculi: Grading the Histological Lesions in Brain, Kidney, and Liver during Primoinfection Outbreak in Rabbits

    Science.gov (United States)

    Rodríguez-Tovar, Luis E.; Nevárez-Garza, Alicia M.; Trejo-Chávez, Armando; Hernández-Martínez, Carlos A.; Zarate-Ramos, Juan J.; Castillo-Velázquez, Uziel

    2016-01-01

    This is the first confirmed report of Encephalitozoon cuniculi (E. cuniculi) in farm meat rabbits located in Northern Mexico. Eighty young rabbits exhibited clinical signs of this zoonotic emerging disease, like torticollis, ataxia, paresis, circling, and rolling. Samples of brain, kidney, and liver were examined for histology lesions. For the first time the lesions caused by E. cuniculi were graded according to their severity (I, II, and III) and the size of the granulomas (Types A, B, and C). The main cerebral injuries were Grade III, coinciding with the presence of Type C granulomas. The cerebral lesions were located in the cortex, brain stem, and medulla. The renal lesions were also Grade III distributed throughout cortex and renal medulla, with no granuloma formation. The involvement of hypersensitivity Types III and IV is suggested. All of the rabbits were seropositive to E. cuniculi by CIA testing, suggesting that this zoonotic and emerging pathogen is widely distributed among animals intended for human consumption. We believe this work could be used as a guide when examining E. cuniculi and will provide direction to confirm the diagnosis of this pathogen. PMID:27022485

  13. Different types of spinal afferent nerve endings in stomach and esophagus identified by anterograde tracing from dorsal root ganglia.

    Science.gov (United States)

    Spencer, Nick J; Kyloh, Melinda; Beckett, Elizabeth A; Brookes, Simon; Hibberd, Tim

    2016-10-15

    In visceral organs of mammals, most noxious (painful) stimuli as well as innocuous stimuli are detected by spinal afferent neurons, whose cell bodies lie in dorsal root ganglia (DRGs). One of the major unresolved questions is the location, morphology, and neurochemistry of the nerve endings of spinal afferents that actually detect these stimuli in the viscera. In the upper gastrointestinal (GI) tract, there have been many anterograde tracing studies of vagal afferent endings, but none on spinal afferent endings. Recently, we developed a technique that now provides selective labeling of only spinal afferents. We used this approach to identify spinal afferent nerve endings in the upper GI tract of mice. Animals were anesthetized, and injections of dextran-amine were made into thoracic DRGs (T8-T12). Seven days post surgery, mice were euthanized, and the stomach and esophagus were removed, fixed, and stained for calcitonin gene-related peptide (CGRP). Spinal afferent axons were identified that ramified extensively through many rows of myenteric ganglia and formed nerve endings in discrete anatomical layers. Most commonly, intraganglionic varicose endings (IGVEs) were identified in myenteric ganglia of the stomach and varicose simple-type endings in the circular muscle and mucosa. Less commonly, nerve endings were identified in internodal strands, blood vessels, submucosal ganglia, and longitudinal muscle. In the esophagus, only IGVEs were identified in myenteric ganglia. No intraganglionic lamellar endings (IGLEs) were identified in the stomach or esophagus. We present the first identification of spinal afferent endings in the upper GI tract. Eight distinct types of spinal afferent endings were identified in the stomach, and most of them were CGRP immunoreactive. J. Comp. Neurol. 524:3064-3083, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Serotonin, Dopamine and Noradrenaline Adjust Actions of Myelinated Afferents via Modulation of Presynaptic Inhibition in the Mouse Spinal Cord

    Science.gov (United States)

    García-Ramírez, David L.; Calvo, Jorge R.; Hochman, Shawn; Quevedo, Jorge N.

    2014-01-01

    Gain control of primary afferent neurotransmission at their intraspinal terminals occurs by several mechanisms including primary afferent depolarization (PAD). PAD produces presynaptic inhibition via a reduction in transmitter release. While it is known that descending monoaminergic pathways complexly regulate sensory processing, the extent these actions include modulation of afferent-evoked PAD remains uncertain. We investigated the effects of serotonin (5HT), dopamine (DA) and noradrenaline (NA) on afferent transmission and PAD. Responses were evoked by stimulation of myelinated hindlimb cutaneous and muscle afferents in the isolated neonatal mouse spinal cord. Monosynaptic responses were examined in the deep dorsal horn either as population excitatory synaptic responses (recorded as extracellular field potentials; EFPs) or intracellular excitatory postsynaptic currents (EPSCs). The magnitude of PAD generated intraspinally was estimated from electrotonically back-propagating dorsal root potentials (DRPs) recorded on lumbar dorsal roots. 5HT depressed the DRP by 76%. Monosynaptic actions were similarly depressed by 5HT (EFPs 54%; EPSCs 75%) but with a slower time course. This suggests that depression of monosynaptic EFPs and DRPs occurs by independent mechanisms. DA and NA had similar depressant actions on DRPs but weaker effects on EFPs. IC50 values for DRP depression were 0.6, 0.8 and 1.0 µM for 5HT, DA and NA, respectively. Depression of DRPs by monoamines was nearly-identical in both muscle and cutaneous afferent-evoked responses, supporting a global modulation of the multimodal afferents stimulated. 5HT, DA and NA produced no change in the compound antidromic potentials evoked by intraspinal microstimulation indicating that depression of the DRP is unrelated to direct changes in the excitability of intraspinal afferent fibers, but due to metabotropic receptor activation. In summary, both myelinated afferent-evoked DRPs and monosynaptic transmission in the

  15. Serotonin, dopamine and noradrenaline adjust actions of myelinated afferents via modulation of presynaptic inhibition in the mouse spinal cord.

    Directory of Open Access Journals (Sweden)

    David L García-Ramírez

    Full Text Available Gain control of primary afferent neurotransmission at their intraspinal terminals occurs by several mechanisms including primary afferent depolarization (PAD. PAD produces presynaptic inhibition via a reduction in transmitter release. While it is known that descending monoaminergic pathways complexly regulate sensory processing, the extent these actions include modulation of afferent-evoked PAD remains uncertain. We investigated the effects of serotonin (5HT, dopamine (DA and noradrenaline (NA on afferent transmission and PAD. Responses were evoked by stimulation of myelinated hindlimb cutaneous and muscle afferents in the isolated neonatal mouse spinal cord. Monosynaptic responses were examined in the deep dorsal horn either as population excitatory synaptic responses (recorded as extracellular field potentials; EFPs or intracellular excitatory postsynaptic currents (EPSCs. The magnitude of PAD generated intraspinally was estimated from electrotonically back-propagating dorsal root potentials (DRPs recorded on lumbar dorsal roots. 5HT depressed the DRP by 76%. Monosynaptic actions were similarly depressed by 5HT (EFPs 54%; EPSCs 75% but with a slower time course. This suggests that depression of monosynaptic EFPs and DRPs occurs by independent mechanisms. DA and NA had similar depressant actions on DRPs but weaker effects on EFPs. IC50 values for DRP depression were 0.6, 0.8 and 1.0 µM for 5HT, DA and NA, respectively. Depression of DRPs by monoamines was nearly-identical in both muscle and cutaneous afferent-evoked responses, supporting a global modulation of the multimodal afferents stimulated. 5HT, DA and NA produced no change in the compound antidromic potentials evoked by intraspinal microstimulation indicating that depression of the DRP is unrelated to direct changes in the excitability of intraspinal afferent fibers, but due to metabotropic receptor activation. In summary, both myelinated afferent-evoked DRPs and monosynaptic

  16. Is there a difference between hare syphilis and rabbit syphilis? Cross infection experiments between rabbits and hares

    NARCIS (Netherlands)

    Lumeij, J.T.; Mikalová, L.; Smajs, D.

    2013-01-01

    Abstract Cross infection of rabbits and hares with Treponema paraluiscuniculi from rabbits and the related microorganism from hares, which was provisionally named "Treponema paraluisleporis", revealed that T. paraluiscuniculi affects rabbits clinically, but only causes seroconversion in hares withou

  17. Specific and potassium components in the depolarization of the la afferents in the spinal cord of the cat.

    Science.gov (United States)

    Jiménez, I; Rudomin, P; Solodkin, M; Vyklicky, L

    1983-08-01

    In the cat spinal cord, primary afferent depolarization (PAD) of group Ia fibers of extensor muscles is produced by high-frequency stimulation (100 Hz) of group I muscle flexor afferents without significant increases in extracellular potassium. On the other hand, the PAD produced by stimulation of mixed and pure cutaneous nerves correlates well with increases in potassium ions. We conclude that the PAD produced by group I muscle afferents results from the activation of specific pathways making axo-axonic synapses with the Ia fiber terminals. The PAD of Ia fibers resulting from activation of cutaneous nerves involves instead unspecific accumulation of potassium ions.

  18. Rescue of neuronal function by cross-regeneration of cutaneous afferents into muscle in cats.

    Science.gov (United States)

    Nishimura, H; Johnson, R D; Munson, J B

    1993-07-01

    1. This study investigates the relation between the peripheral innervation of low-threshold cutaneous afferents and the postsynaptic potentials elicited by electrical stimulation of those afferents. 2. In cats deeply anesthetized with pentobarbital sodium, cord dorsum potentials (CDPs) and postsynaptic potentials (PSPs) in spinal motoneurons were elicited by stimulation of the caudal cutaneous sural nerve (CCS), the lateral cutaneous sural nerve (LCS), and the medial gastrocnemius (MG) muscle nerve. We tested 1) unoperated cats, and cats in which CCS has been 2) chronically axotomized and ligated, 3) cut and self-reunited, 4) cut and cross-united with LCS, or 5) cut and cross-united with the MG. Terminal experiments were performed 3-36 mo after initial surgery. 3. In cats in which the CCS had been self-reunited or cross-united distally with LCS, tactile stimulation of the hairy skin normally innervated by the distal nerve activated afferents in the CCS central to the coaptation, indicating that former CCS afferents had regenerated into native or foreign skin, respectively. 4. In cats in which the CCS had been cross-united distally with the MG, both stretch and contraction of the MG muscle activated the former CCS afferents. 5. In unoperated cats, CDPs elicited by stimulation of CCS and of LCS exhibited a low-threshold N1 wave and a higher-threshold N2 wave. These waves were greatly delayed and appeared to merge after chronic axotomy of CCS. Regeneration of CCS into itself, into LCS, or into MG restored the normal latencies and configurations of these potentials. 6. In unoperated cats, stimulation of CCS, of LCS, and of MG each produced PSPs of characteristic configurations in the various subpopulations of motoneurons of the triceps surae. CDPs and PSPs elicited by the CCS cross-regenerated into LCS or MG were typical of those generated by the normal CCS, i.e., there was no evidence of respecification of central synaptic connections to bring accord between center

  19. Cholecystokinin enhances visceral pain-related affective memory via vagal afferent pathway in rats

    Directory of Open Access Journals (Sweden)

    Cao Bing

    2012-06-01

    Full Text Available Abstract Background Pain contains both sensory and affective dimensions. Using a rodent visceral pain assay that combines the colorectal distension (CRD model with the conditioned place avoidance (CPA paradigms, we measured a learned behavior that directly reflects the affective component of visceral pain, and showed that perigenual anterior cingulate cortex (pACC activation is critical for memory processing involved in long-term visceral affective state and prediction of aversive stimuli by contextual cue. Progress has been made and suggested that activation of vagal afferents plays a role in the behavioral control nociception and memory storage processes. In human patients, electrical vagus nerve stimulation enhanced retention of verbal learning performance. Cholecystokinin-octapeptide (CCK, which is a gastrointestinal hormone released during feeding, has been shown to enhance memory retention. Mice access to food immediately after training session enhanced memory retention. It has been well demonstrated that CCK acting on vagal afferent fibers mediates various physiological functions. We hypothesize that CCK activation of vagal afferent enhances visceral pain-related affective memory. Results In the presented study, infusion of CCK-8 at physiological concentration combining with conditional training significantly increased the CRD-induced CPA scores, and enhanced the pain affective memory retention. In contrast, CCK had no effect on CPA induced by non-nociceptive aversive stimulus (U69,593. The physiological implications were further strengthened by the similar effects observed in the rats with duodenal infusion of 5% peptone, which has been shown to induce increases in plasma CCK levels. CCK-8 receptor antagonist CR-1409 or perivagal application of capsaicin abolished the effect of CCK on aversive visceral pain memory, which was consistent with the notion that vagal afferent modulates affective aspects of visceral pain. CCK does not change

  20. In pursuit of P2X3 antagonists: novel therapeutics for chronic pain and afferent sensitization.

    Science.gov (United States)

    Ford, Anthony P

    2012-02-01

    Treating pain by inhibiting ATP activation of P2X3-containing receptors heralds an exciting new approach to pain management, and Afferent's program marks the vanguard in a new class of drugs poised to explore this approach to meet the significant unmet needs in pain management. P2X3 receptor subunits are expressed predominately and selectively in so-called C- and Aδ-fiber primary afferent neurons in most tissues and organ systems, including skin, joints, and hollow organs, suggesting a high degree of specificity to the pain sensing system in the human body. P2X3 antagonists block the activation of these fibers by ATP and stand to offer an alternative approach to the management of pain and discomfort. In addition, P2X3 is expressed pre-synaptically at central terminals of C-fiber afferent neurons, where ATP further sensitizes transmission of painful signals. As a result of the selectivity of the expression of P2X3, there is a lower likelihood of adverse effects in the brain, gastrointestinal, or cardiovascular tissues, effects which remain limiting factors for many existing pain therapeutics. In the periphery, ATP (the factor that triggers P2X3 receptor activation) can be released from various cells as a result of tissue inflammation, injury or stress, as well as visceral organ distension, and stimulate these local nociceptors. The P2X3 receptor rationale has aroused a formidable level of investigation producing many reports that clarify the potential role of ATP as a pain mediator, in chronic sensitized states in particular, and has piqued the interest of pharmaceutical companies. P2X receptor-mediated afferent activation has been implicated in inflammatory, visceral, and neuropathic pain states, as well as in airways hyperreactivity, migraine, itch, and cancer pain. It is well appreciated that oftentimes new mechanisms translate poorly from models into clinical efficacy and effectiveness; however, the breadth of activity seen from P2X3 inhibition in models offers

  1. High fat diet induced changes in gastric vagal afferent response to adiponectin.

    Science.gov (United States)

    Kentish, Stephen J; Ratcliff, Kyle; Li, Hui; Wittert, Gary A; Page, Amanda J

    2015-12-01

    Food intake is regulated by vagal afferent signals from the stomach. Adiponectin, secreted primarily from adipocytes, also has a role in regulating food intake. However, the involvement of vagal afferents in this effect remains to be established. We aimed to determine if adiponectin can modulate gastric vagal afferent (GVA) satiety signals and further whether this is altered in high fat diet (HFD)-induced obesity. Female C57BL/6J mice were fed either a standard laboratory diet (SLD) or a HFD for 12weeks. Plasma adiponectin levels were assayed, and the expression of adiponectin in the gastric mucosa was assessed using real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The location of adiponectin protein within the gastric mucosa was determined by immunohistochemistry. To evaluate the direct effect of adiponectin on vagal afferent endings we determined adiponectin receptor expression in whole nodose ganglia (NDG) and also specifically in GVA neurons using retrograde tracing and qRT-PCR. An in vitro preparation was used to determine the effect of adiponectin on GVA response to mechanical stimulation. HFD mice exhibited an increased body weight and adiposity and showed delayed gastric emptying relative to SLD mice. Plasma adiponectin levels were not significantly different in HFD compared to SLD mice. Adiponectin mRNA was detected in the gastric mucosa of both SLD and HFD mice and presence of protein was confirmed immunohistochemically by the detection of adiponectin immunoreactive cells in the mucosal layer of the stomach. Adiponectin receptor 1 (ADIPOR1) and 2 (ADIPOR2) mRNA was present in both the SLD and HFD whole NDG and also specifically traced gastric mucosal and muscular neurons. There was a reduction in ADIPOR1 mRNA in the mucosal afferents of the HFD mice relative to the SLD mice. In HFD mice adiponectin potentiated gastric mucosal afferent responses to mucosal stroking, an effect not observed in SLD mice. Adiponectin reduced

  2. Refractory anemia leading to renal hemosiderosis and renal failure

    OpenAIRE

    Sujatha Siddappa; K M Mythri; Kowsalya, R.; Ashish Parekh

    2011-01-01

    Renal hemosiderosis is a rare cause of renal failure and, as a result, may not be diagnosed unless a detailed history, careful interpretation of blood parameters and renal biopsy with special staining is done. Here, we present a rare case of renal hemosiderosis presenting with renal failure.

  3. Refractory anemia leading to renal hemosiderosis and renal failure

    Directory of Open Access Journals (Sweden)

    Sujatha Siddappa

    2011-01-01

    Full Text Available Renal hemosiderosis is a rare cause of renal failure and, as a result, may not be diagnosed unless a detailed history, careful interpretation of blood parameters and renal biopsy with special staining is done. Here, we present a rare case of renal hemosiderosis presenting with renal failure.

  4. Renal replacement therapy for acute renal failure.

    Science.gov (United States)

    Macedo, E; Bouchard, J; Mehta, R L

    2009-09-01

    Renal replacement therapy became a common clinical tool to treat patients with severe acute kidney injury (AKI) since the 1960s. During this time dialytic options have expanded considerably; biocompatible membranes, bicarbonate dialysate and dialysis machines with volumetric ultrafiltration control have improved the treatment for acute kidney injury. Along with advances in methods of intermittent hemodialysis, continuous renal replacement therapies have gained widespread acceptance in the treatment of dialysis-requiring AKI. However, many of the fundamental aspects of the renal replacement treatment such as indication, timing of dialytic intervention, and choice of dialysis modality are still controversial and may influence AKI patient's outcomes. This review outlines current concepts in the use of dialysis techniques for AKI and suggests an approach for selecting the optimal method of renal replacement therapy.

  5. Renal function after renal artery stenting

    Institute of Scientific and Technical Information of China (English)

    George S. Hanzel; Mark Downes; Peter A. McCullough

    2005-01-01

    @@ Atherosclerotic renal artery stenosis (ARAS), a common clinical finding, is increasing in prevalence as the population ages. ARAS is seen in ~ 7% of persons over 65 years of age1 and in ~ 20% of patients at the time of coronary angiography.2 It is an important cause of chronic kidney disease and may result in 11-14% of cases of end stage renal disease.3

  6. Wavelet Packet Analysis for Angular Data Extraction from Muscle Afferent Cuff Electrode Signals

    Science.gov (United States)

    2001-10-25

    from rabbits. In order to estimate ankle flexion /extension angles, we recorded ENG signals from the left Tibial and Peroneal nerves, both during FES...study, angle predictions have yet to be assessed regarding inter-rabbit variability. Keywords – Natural sensors, neural prosthesis , implanted cuff...fixating the knee and ankle joints in place (see [3] for more details) . For extracting the ENG signals, tripolar cuff electrodes were implanted onto the

  7. Satin and their crossbred rabbit production

    Directory of Open Access Journals (Sweden)

    Bram Brahmantiyo

    2010-06-01

    Full Text Available Rabbit productivity in intensive management to be evaluated considering development in the rabbit farming were rapidly increased. Rex, Satin and their crossbred (Reza rabbits have been developed in Research Institute for Animal Production and productivity information of each breed can be used as basis for policy or model of cultivation and breeding in the community. Research conducted by evaluating the productivity of growth, carcass and the carcass proportion of the three strains of rabbit. Rex and satin growth were no different, and Reza was higher at 12-14 weeks of age. Carcass production comes from cutting the rabbit at the age of six months, this trait is strongly influenced by the weight of rabbits, and Reza gives the lowest performance compared to Rex and Satin. Rex, Satin and Reza were medium type rabbits with dual-purpose product (fur and meat. These rabbits showed the child's growth is good enough, to adapt the environment temperature and high food and have adequate carcass production.

  8. Congenital Transmission of Schistosoma japonicumin the Rabbit

    Institute of Scientific and Technical Information of China (English)

    QianBao-zhen; H.O.Bogh; M.V.Johansen; WangPeng-peng

    2005-01-01

    Fourteen pregnant rabbits were each infected with 300 cercariae of Schistosoma japonicum and divided into two groups.Group M (n =8)was infected during mid-gestation (the organogenetic stage)and group L (n=6)was infected during late-gestation (the post-organogenetic stage).Mother rabbits and rabbit kittens were killed 45-60 days after infection and perfused in order to obtain worm counts.Furthermore,faecal egg counts and tissue egg counts from livers were obtained from the mother rabbits as well as the rabbit kittens.All mother rabbits became infected harbouring 207.6+20.2 and 220.0+27.5 adult worms in group M and L,respectively.In groups M and L, 13.5%and 46.7% of the kittens were infected,respectively,In 12 of 14 litters at least one kitten was infected.Tne infected kittens harboured between one and three adult S.japonicum.The livers of the kittens infected with a worm pair displaced lesions,as a result of egg deposition.The results, therefore,show that congenital transmission of S.japonicum can occur in rabbits.The close anatomical resemblance between the rabbit and human placenta may be indicative of the presence of congenital transmssion of S.japomcum infection in humans.

  9. Viral skin diseases of the rabbit.

    Science.gov (United States)

    Meredith, Anna L

    2013-09-01

    This article describes the viral skin diseases affecting the domestic rabbit, the most important being myxomatosis. Transmission and pathogenesis, clinical signs, diagnosis, treatment, and control are described and the article will be of interest to veterinary practitioners who treat rabbits. Shope fibroma virus, Shope papilloma virus, and rabbitpox are also discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Rimonabant induced anorexia in rodents is not mediated by vagal or sympathetic gut afferents

    DEFF Research Database (Denmark)

    Madsen, Andreas Nygaard; Jelsing, Jacob; van de Wall, Esther H E M

    2009-01-01

    The selective CB1 receptor antagonist rimonabant is a novel weight control agent. Although CB1 receptors and binding sites are present in both the rodent central and peripheral nervous systems, including the afferent vagus nerve, the role of gut afferents in mediating anorexia following CB1R...... blockade is still debated. In the present study we examined rimonabant-induced anorexia in male C57BL/6J mice with subdiaphragmatic vagotomy (VGX) as well as in male Sprague-Dawley rats subjected to either subdiaphragmatic vagal deafferentation (SDA) alone or in combination with a complete celiac...... system, are required for rimonabant to inhibit food intake leading to the hypothesis that centrally located CB1 receptors are the prime mediators of rimonabant-induced anorexia....

  11. Blocking of periodontal afferents with anesthesia and its influence on elevator EMG activity.

    Science.gov (United States)

    Manns, A E; Garcia, C; Miralles, R; Bull, R; Rocabado, M

    1991-07-01

    The effect of anesthetic blocking of the periodontal afferents of the canine teeth was studied in order to determine its influence on any changes in the jaw elevation activity. Unilateral integrated EMG recordings were made of the masseter and anterior temporal muscles during maximal voluntary clenching in centric occlusion and laterotrusive position with canine contact. After anesthetic blocking of the periodontal afferents of one or both ipsilateral canines, a significant increase was observed of the EMG activity of both jaw elevator muscles studied, in centric occlusion as well as with canine contact. The elevator activity increase was of a greater magnitude when antagonistic canines were anesthetized. These findings thus support the hypothesis that high threshold periodontal receptors exert an inhibitory effect on jaw elevator muscular activity.

  12. Interaction and regulatory functions of μ- and δ-opioid receptors in nociceptive afferent neurons

    Institute of Scientific and Technical Information of China (English)

    Xu Zhang; Lan Bao

    2012-01-01

    μ-opioid receptor (MOR) agonists such as morphine are powerful analgesics used for pain therapy.However,the use of these drugs is limited by their side-effects,which include antinociceptive tolerance and dependence.Earlier studies reported that MOR analgesic tolerance is reduced by blockade of δ-opioid receptors (DORs) that interact with MORs.Recent studies show that the MOR/DOR interaction in nociceptive afferent neurons in the dorsal root ganglion may contribute to morphine analgesic tolerance.Further analysis of the mechanisms for regulating the trafficking of receptors,ion channels and signaling molecules in nociceptive afferent neurons would help to understand the nociceptive mechanisms and improve pain therapy.

  13. Activation of kinetically distinct synaptic conductances on inhibitory interneurons by electrotonically overlapping afferents.

    Science.gov (United States)

    Walker, Harrison C; Lawrence, J Josh; McBain, Chris J

    2002-07-03

    Mossy fiber (MF) and CA3 collateral (CL) axons activate common interneurons via synapses comprised of different AMPA receptors to provide feedforward and feedback inhibitory control of the CA3 hippocampal network. Because synapses potentially occur over variable electrotonic distances that distort somatically recorded synaptic currents, it is not known whether the underlying afferent-specific synaptic conductances are associated with different time courses. Using a somatic voltage jump technique to alter the driving force at the site of the synapse, we demonstrate that MF and CL synapses overlap in electrotonic location yet differ in conductance time course. Thus, afferent-specific conductance time courses allow single interneurons to differentially integrate feedforward and feedback information without the need to segregate distinct AMPA receptor subunits to different electrotonic domains.

  14. Somatic modulation of spinal reflex bladder activity mediated by nociceptive bladder afferent nerve fibers in cats.

    Science.gov (United States)

    Xiao, Zhiying; Rogers, Marc J; Shen, Bing; Wang, Jicheng; Schwen, Zeyad; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2014-09-15

    The goal of the present study was to determine if supraspinal pathways are necessary for inhibition of bladder reflex activity induced by activation of somatic afferents in the pudendal or tibial nerve. Cats anesthetized with α-chloralose were studied after acute spinal cord transection at the thoracic T9/T10 level. Dilute (0.25%) acetic acid was used to irritate the bladder, activate nociceptive afferent C-fibers, and trigger spinal reflex bladder contractions (amplitude: 19.3 ± 2.9 cmH2O). Hexamethonium (a ganglionic blocker, intravenously) significantly (P irritation. Understanding the sites of action for PNS or TNS inhibition is important for the clinical application of pudendal or tibial neuromodulation to treat bladder dysfunctions. Copyright © 2014 the American Physiological Society.

  15. A Experimental Study on Renal Injury Caused By Methyl Ethyl Ketone Peroxide Burns in Zelanian White Rabbits%过氧化甲乙酮烧伤对新西兰大白兔肾损伤的实验性研究

    Institute of Scientific and Technical Information of China (English)

    魏智艺; 李小毅; 程君涛; 刘丁井

    2016-01-01

    目的:观察过氧化甲乙酮( methyl ethyl ketone peroxide, MEKP)烧伤对新西兰大白兔肾功能的影响及肾组织的病理变化,探讨MEKP烧伤致肾损伤的机制。方法将30只新西兰大白兔随机分为普通火焰烧伤组( A组)、MEKP烧伤组( B组)及对照组,每组10只。分别于0、1、2、4 h采集血液,观察3组血清肌酐( Scr)、尿素( BUN)水平的变化情况及肾组织形态学变化。结果3组伤后0 h Scr和BUN比较差异无统计学意义(P>0.05)。伤后1、2、4 h A、B组Scr、BUN均高于对照组,且B组高于A组(P0. 05);at 1, 2 and 4 h after burning, the Scr and BUN levels in group A and B were significantly higher than those in control group, and the levels in group B were higher than those in group A (P<0. 05, P<0. 01). Pathological signs of renal tissues included epithelial cell degeneration and necrosis of kidney tubule ( especially proximal tubule) and structural damage of renal glomerulus in group B. Conclusion The kidney injury mechanisms after MEKP burns are tissue ischemia and hypoxia and reperfusion injury. Meanwhile, methyl ethyl ketone peroxide was absorbed into a large amount of free radicals and organic acids pro-duced by blood metabolism, and it can induce lipid peroxidation of renal tubular epithelial cell and glomerular basal cell membranes, cellular metabolism disorder, which can cause further damage to renal tubular epithelial cell and renal glomer-ulus.

  16. Imaging of renal osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Jevtic, V. E-mail: vladimir.jevtic@mf.uni-lj.si

    2003-05-01

    Chronic renal insufficiency, hemodialysis, peritoneal dialysis, renal transplantation and administration of different medications provoke complex biochemical disturbances of the calcium-phosphate metabolism with wide spectrum of bone and soft tissue abnormalities termed renal osteodystrophy. Clinically most important manifestation of renal bone disease includes secondary hyperparathyroidism, osteomalacia/rickets, osteoporosis, adynamic bone disease and soft tissue calcification. As a complication of long-term hemodialysis and renal transplantation amyloid deposition, destructive spondyloarthropathy, osteonecrosis, and musculoskeletal infections may occur. Due to more sophisticated diagnostic methods and more efficient treatment classical radiographic features of secondary hyperparathyroidism and osteomalacia/rickets are now less frequently seen. Radiological investigations play an important role in early diagnosis and follow-up of the renal bone disease. Although numerous new imaging modalities have been introduced in clinical practice (scintigraphy, CT, MRI, quantitative imaging), plain film radiography, especially fine quality hand radiograph, still represents most widely used examination.

  17. Receptor-mediated activation of gastric vagal afferents by glucagon-like peptide-1 in the rat

    DEFF Research Database (Denmark)

    Bucinskaite, V; Tolessa, T; Pedersen, J

    2009-01-01

    The vagus nerve plays a role in mediating effects of the two glucagon-like peptides GLP-1 and GLP-2 on gastrointestinal growth, functions and eating behaviour. To obtain electrophysiological and molecular evidence for the contribution of afferent pathways in chemoreception from the gastrointestinal...... tract, afferent mass activity in the ventral gastric branch of the vagus nerve and gene expression of GLP-1 receptors and GLP-2 receptors in the nodose ganglion were examined in Sprague-Dawley rats. Intravenous administration of GLP-1 (30-1000 pmol kg(-1)), reaching high physiological plasma...... afferent nerves mediate sensory input from the gastrointestinal tract or pancreas; either directly or indirectly via the release of another mediator. GLP-2 receptors appear not be functionally expressed on vagal afferents....

  18. Captopril attenuates hypertension and renal injury induced by the vascular endothelial growth factor inhibitor sorafenib

    Science.gov (United States)

    Nagasawa, Tasuku; Khan, Abdul Hye; Imig, John D

    2013-01-01

    SUMMARY Vascular endothelial growth factor inhibitors (VEGFi) are known to cause hypertension and renal injury that severely limits their use as an anticancer therapy. We hypothesized that the angiotensin-converting enzyme inhibitor captopril not only prevents hypertension, but also decreases renal injury caused by the VEGFi sorafenib.Rats were administered sorafenib (20 mg/kg per day) alone or in combination with captopril (40 mg/kg per day) for 4 weeks. Sorafenib administration increased blood pressure, which plateaued by day 10.Concurrent treatment with captopril for 4 weeks resulted in a 30 mmHg decrease in blood pressure compared with sorafenib alone (155 ± 5 vs 182 ± 6 mmHg, respectively; P captopril treatment reduced albuminuria by 50% compared with sorafenib alone (20 ± 8 vs 42 ± 9 mg/day, respectively; P captopril-treated rats administered sorafenib. Renal autoregulatory efficiency was determined by evaluating the afferent arteriolar constrictor response to ATP. Sorafenib administration attenuated the vasoconstriction to ATP, whereas concurrent captopril treatment improved ATP reactivity.In conclusion, captopril attenuated hypertension and renal injury and improved renal autoregulatory capacity in rats administered sorafenib. These findings indicate that captopril treatment, in addition to alleviating the detrimental side-effect of hypertension, decreases the renal injury associated with anticancer VEGFi therapies such as sorafenib. PMID:22443474

  19. Effect of elevated interstitial pressure on the renal cortical hemodynamics.

    Science.gov (United States)

    Källskog, O; Wolgast, M

    1975-12-01

    The influence of renal interstitial pressure on the resistance pattern within the superficial cortical vasculature has been investigated from determinations of 1) the glomerular blood flow eith a modified microsphere technique and 2) the intravascular hydrostatic pressures. Interstitial pressure was monitored via a 50 mum PVC-catheter placed into the subcapsular interstitial space. Two conditions were analyzed viz. a) elevation of uretheral pressure to 20 mm Hg and b) venous stasis to 10-15 mm Hg. Both conditions produced an increase in the interstitial pressure from 1-2 mm Hg to about 5 mm Hg as well as an increased hilar lymph flow and protein flow of about the same size. The vascular reactions were different, however. Uretheral stasis (but not the stasis of a single nephron) produced a decreased resistance in the afferent arteriolae with a concomitant increae in the pressures in the glomerular capillaries, and the peritobular capillary network. In contrast, venous stasis produced only small changes in the parameters studied but for the obvious rise in the peritubular capillary pressure. The results suggest that factors other than the interstitial pressure are governing the afferent vascular tone; the tubular wall tension might be one of these factors.

  20. Novel Calicivirus Identified in Rabbits, Michigan, USA

    Science.gov (United States)

    Wise, Annabel G.; Bolin, Steven R.; Mullaney, Thomas P.; Kiupel, Matti; Maes, Roger K.

    2009-01-01

    We report a disease outbreak in a Michigan rabbitry of a rabbit calicivirus distinct from the foreign animal disease agent, rabbit hemorrhagic disease virus (RHDV). The novel virus has been designated Michigan rabbit calicivirus (MRCV). Caliciviruses of the Lagovirus genus other than RHDV have not been described in US rabbit populations. The case-fatality rate was 32.5% (65/200). Clinical signs included hemorrhage and sudden death, with hepatic necrosis. Analysis of viral RNA sequence from >95% of the viral genome showed an average similarity of 79% with RHDV. Similarity of the predicted MRCV capsid amino acid sequence ranged from 89.8% to 91.3%, much lower than the 98% amino acid similarity between RHDV strains. Experimentally infected rabbits lacked clinical disease, but MRCV was detected in tissues by PCR. We propose that MRCV primarily causes subclinical infection but may induce overt RHD-like disease under certain field conditions. PMID:19961675

  1. Presynaptic α2-GABAA Receptors in Primary Afferent Depolarization and Spinal Pain Control

    OpenAIRE

    2011-01-01

    Spinal dorsal horn GABAA receptors are found both postsynaptically on central neurons and presynaptically on axons and/or terminals of primary sensory neurons, where they mediate primary afferent depolarization (PAD) and presynaptic inhibition. Both phenomena have been studied extensively on a cellular level, but their role in sensory processing in vivo has remained elusive, due to inherent difficulties to selectively interfere with presynaptic receptors. Here, we address the contribution of ...

  2. Presynaptic {alpha}2-GABAA receptors in primary afferent depolarization and spinal pain control

    OpenAIRE

    2011-01-01

    Spinal dorsal horn GABA(A) receptors are found both postsynaptically on central neurons and presynaptically on axons and/or terminals of primary sensory neurons, where they mediate primary afferent depolarization (PAD) and presynaptic inhibition. Both phenomena have been studied extensively on a cellular level, but their role in sensory processing in vivo has remained elusive, due to inherent difficulties to selectively interfere with presynaptic receptors. Here, we address the contribution o...

  3. Population coding of forelimb joint kinematics by peripheral afferents in monkeys.

    Directory of Open Access Journals (Sweden)

    Tatsuya Umeda

    Full Text Available Various peripheral receptors provide information concerning position and movement to the central nervous system to achieve complex and dexterous movements of forelimbs in primates. The response properties of single afferent receptors to movements at a single joint have been examined in detail, but the population coding of peripheral afferents remains poorly defined. In this study, we obtained multichannel recordings from dorsal root ganglion (DRG neurons in cervical segments of monkeys. We applied the sparse linear regression (SLiR algorithm to the recordings, which selects useful input signals to reconstruct movement kinematics. Multichannel recordings of peripheral afferents were performed by inserting multi-electrode arrays into the DRGs of lower cervical segments in two anesthetized monkeys. A total of 112 and 92 units were responsive to the passive joint movements or the skin stimulation with a painting brush in Monkey 1 and Monkey 2, respectively. Using the SLiR algorithm, we reconstructed the temporal changes of joint angle, angular velocity, and acceleration at the elbow, wrist, and finger joints from temporal firing patterns of the DRG neurons. By automatically selecting a subset of recorded units, the SLiR achieved superior generalization performance compared with a regularized linear regression algorithm. The SLiR selected not only putative muscle units that were responsive to only the passive movements, but also a number of putative cutaneous units responsive to the skin stimulation. These results suggested that an ensemble of peripheral primary afferents that contains both putative muscle and cutaneous units encode forelimb joint kinematics of non-human primates.

  4. Lack of central sprouting of primary afferent fibers after ricin deafferentation.

    Science.gov (United States)

    Pubols, L M; Bowen, D C

    1988-09-08

    A new deafferentation technique, the application of ricin to peripheral nerves, was used to test for collateral sprouting of undamaged primary afferent fibers within the adult mammalian spinal cord dorsal horn. The right sciatic nerves in rats were injected with ricin 14 to 57 days prior to bilateral labelling of dorsal rootlets with horseradish peroxidase. To equate the number of surviving dorsal root fibers on the two sides, the left sciatic nerves were injected 5 days prior to labelling. In each animal, horseradish peroxidase was applied to a bilateral pair of lumbar or low thoracic dorsal rootlets 18 hours prior to sacrifice to test for sprouting by labelling primary afferent fibers and terminals in the right (experimental) and left (control) dorsal horns. Although there is overlap of degenerated and intact primary afferent fields in this preparation, a postulated precondition for sprouting (Murray and Goldberger: J. Neurosci. 6:3205-3217, '86), we found no evidence for sprouting of undamaged, myelinated afferent fibers in the experimental dorsal horns. The pattern of labelling was symmetrical in all animals, and the density of labelling was not consistently greater on the experimental side. These results support the conclusions of Rodin et al. (J. Comp. Neurol. 215:187-198, '83) and Rodin and Kruger (Somatosens. Res. 2:171-192, '84), who also found no sprouting in the rat's dorsal horn after surgical deafferentation, and do not support the assertion that the difference between the results of those studies and earlier studies in cats was due to a lack of overlap of degenerated and intact dorsal roots in the rat.

  5. Selective activation of primary afferent fibers evaluated by sine-wave electrical stimulation

    OpenAIRE

    Katafuchi Toshihiko; Takaki Atsushi; Rashid Md Harunor; Furue Hidemasa; Koga Kohei; Yoshimura Megumu

    2005-01-01

    Abstract Transcutaneous sine-wave stimuli at frequencies of 2000, 250 and 5 Hz (Neurometer) are thought to selectively activate Aβ, Aδ and C afferent fibers, respectively. However, there are few reports to test the selectivity of these stimuli at the cellular level. In the present study, we analyzed action potentials (APs) generated by sine-wave stimuli applied to the dorsal root in acutely isolated rat dorsal root ganglion (DRG) preparations using intracellular recordings. We also measured e...

  6. Intercostal muscles and purring in the cat: the influence of afferent inputs.

    Science.gov (United States)

    Kirkwood, P A; Sears, T A; Stagg, D; Westgaard, R H

    1987-03-03

    Feline purring has previously been reported as originating in a central oscillator, independent of afferent inputs, and also as not involving expiratory muscles. Here we show, via electromyographic recordings from intercostal muscles, quantified by cross-correlation, that expiratory muscles can be involved and that even if the oscillator is central, reflex components nevertheless play a considerable part in the production of the periodic pattern of muscle activation seen during purring.

  7. Cholinergic modulation of primary afferent glutamatergic transmission in rat medullary dorsal horn neurons.

    Science.gov (United States)

    Jeong, Seok-Gwon; Choi, In-Sun; Cho, Jin-Hwa; Jang, Il-Sung

    2013-12-01

    Although muscarinic acetylcholine (mACh) receptors are expressed in trigeminal ganglia, it is still unknown whether mACh receptors modulate glutamatergic transmission from primary afferents onto medullary dorsal horn neurons. In this study, we have addressed the cholinergic modulation of primary afferent glutamatergic transmission using a conventional whole cell patch clamp technique. Glutamatergic excitatory postsynaptic currents (EPSCs) were evoked from primary afferents by electrical stimulation of trigeminal tract and monosynaptic EPSCs were recorded from medullary dorsal horn neurons of rat horizontal brain stem slices. Muscarine and ACh reversibly and concentration-dependently decreased the amplitude of glutamatergic EPSCs and increased the paired-pulse ratio. In addition, muscarine reduced the frequency of miniature EPSCs without affecting the current amplitude, suggesting that muscarine acts presynaptically to decrease the probability of glutamate release onto medullary dorsal horn neurons. The muscarine-induced decrease of glutamatergic EPSCs was significantly occluded by methoctramine or AF-DX116, M2 receptor antagonists, but not pirenzepine, J104129 and MT-3, selective M1, M3 and M4 receptor antagonists. The muscarine-induced decrease of glutamatergic EPSCs was highly dependent on the extracellular Ca2+ concentration. Physostigmine and clinically available acetylcholinesterase inhibitors, such as rivastigmine and donepezil, significantly shifted the concentration-inhibition relationship of ACh for glutamatergic EPSCs. These results suggest that muscarine acts on presynaptic M2 receptors to inhibit glutamatergic transmission by reducing the Ca2+ influx into primary afferent terminals, and that M2 receptor agonists and acetylcholinesterase inhibitors could be, at least, potential targets to reduce nociceptive transmission from orofacial tissues.

  8. Fine motor control of the jaw following alteration of orofacial afferent inputs.

    Science.gov (United States)

    Kumar, Abhishek; Castrillon, Eduardo; Trulsson, Mats; Svensson, Krister G; Svensson, Peter

    2017-03-01

    The study was designed to investigate if alteration of different orofacial afferent inputs would have different effects on oral fine motor control and to test the hypothesis that reduced afferent inputs will increase the variability of bite force values and jaw muscle activity, and repeated training with splitting of food morsel in conditions with reduced afferent inputs would decrease the variability and lead to optimization of bite force values and jaw muscle activity. Forty-five healthy volunteers participated in a single experimental session and were equally divided into incisal, mucosal, and block anesthesia groups. The participants performed six series (with ten trials) of a standardized hold and split task after the intervention with local anesthesia was made in the respective groups. The hold and split forces along with the corresponding jaw muscle activity were recorded and compared to a reference group. The hold force and the electromyographic (EMG) activity of the masseter muscles during the hold phase were significantly higher in the incisal and block anesthesia group, as compared to the reference group (P motor control. Further, inhibition of afferent inputs from the orofacial or periodontal mechanoreceptors did not increase the variability of bite force values and jaw muscle activity; indicating that the relative precision of the oral fine motor task was not compromised inspite of the anesthesia. The results also suggest the propensity of optimization of bite force values and jaw muscle activity due to repeated splitting of the food morsels, inspite of alteration of sensory inputs. Skill acquisition following a change in oral sensory environment is crucial for understanding how humans learn and re-learn oral motor behaviors and the kind of adaptation that takes place after successful oral rehabilitation procedures.

  9. Influence of locomotor muscle afferent inhibition on the ventilatory response to exercise in heart failure.

    Science.gov (United States)

    Olson, Thomas P; Joyner, Michael J; Eisenach, John H; Curry, Timothy B; Johnson, Bruce D

    2014-02-01

    What is the central question of this study? Patients with heart failure often develop ventilatory abnormalities at rest and during exercise, but the mechanisms underlying these abnormalities remain unclear. This study investigated the influence of inhibiting afferent neural feedback from locomotor muscles on the ventilatory response during exercise in heart failure patients. What is the main finding and its importance? Our results suggest that inhibiting afferent feedback from locomotor muscle via intrathecal opioid administration significantly reduces the ventilatory response to exercise in heart failure patients. Patients with heart failure (HF) develop ventilatory abnormalities at rest and during exercise, but the mechanism(s) underlying these abnormalities remain unclear. We examined whether the inhibition of afferent neural feedback from locomotor muscles during exercise reduces exercise ventilation in HF patients. In a randomized, placebo-controlled design, nine HF patients (age, 60 ± 2 years; ejection fraction, 27 ± 2%; New York Heart Association class 2 ± 1) and nine control subjects (age, 63 ± 2 years) underwent constant-work submaximal cycling (65% peak power) with intrathecal fentanyl (impairing the cephalad projection of opioid receptor-sensitive afferents) or sham injection. The hypercapnic ventilatory response was measured to determine whether cephalad migration of fentanyl occurred. There were no differences in hypercapnic ventilatory response within or between groups in either condition. Despite a lack of change in ventilation, tidal volume or respiratory rate, HF patients had a mild increase in arterial carbon dioxide (P(aCO(2)) and a decrease in oxygen (P(aO(2)); P rate at rest. In response to fentanyl during exercise, HF patients had a reduction in ventilation (63 ± 6 versus 44 ± 3 l min(-1), P rate (30 ± 1 versus 26 ± 2 breaths min(-1), P increased P(aCO(2)) (37.3 ± 0.9 versus 43.5 ± 1.1 mmHg, P exercise in HF patients.

  10. Afferent and Efferent Connections of the Cortex-Amygdala Transition Zone in Mice

    Science.gov (United States)

    Cádiz-Moretti, Bernardita; Abellán-Álvaro, María; Pardo-Bellver, Cecília; Martínez-García, Fernando; Lanuza, Enrique

    2016-01-01

    The transitional zone between the ventral part of the piriform cortex and the anterior cortical nucleus of the amygdala, named the cortex-amygdala transition zone (CxA), shows two differential features that allow its identification as a particular structure. First, it receives dense cholinergic and dopaminergic innervations as compared to the adjacent piriform cortex and amygdala, and second, it receives projections from the main and accessory olfactory bulbs. In this work we have studied the pattern of afferent and efferent projections of the CxA, which are mainly unknown, by using the retrograde tracer Fluorogold and the anterograde tracer biotinylated dextranamine. The results show that the CxA receives a relatively restricted set of intratelencephalic connections, originated mainly by the olfactory system and basal forebrain, with minor afferents from the amygdala. The only relevant extratelencephalic afference originates in the ventral tegmental area (VTA). The efferent projections of the CxA reciprocate the inputs from the piriform cortex and olfactory amygdala. In addition, the CxA projects densely to the basolateral amygdaloid nucleus and the olfactory tubercle. The extratelencephalic projections of the CxA are very scarce, and target mainly hypothalamic structures. The pattern of connections of the CxA suggests that it is indeed a transitional area between the piriform cortex and the cortical amygdala. Double labeling with choline acetyltransferase indicates that the afferent projection from the basal forebrain is the origin of its distinctive cholinergic innervation, and double labeling with dopamine transporter shows that the projection from the VTA is the source of dopaminergic innervation. These connectivity and neurochemical features, together with the fact that it receives vomeronasal in addition to olfactory information, suggest that the CxA may be involved in processing olfactory information endowed with relevant biological meaning, such as odors

  11. Unmyelinated afferents constitute a second system coding tactile stimuli of the human hairy skin.

    Science.gov (United States)

    Vallbo, A B; Olausson, H; Wessberg, J

    1999-06-01

    Impulses were recorded from unmyelinated afferents innervating the forearm skin of human subjects using the technique of microneurography. Units responding to innocuous skin deformation were selected. The sample (n = 38) was split into low-threshold units (n = 27) and high-threshold units (n = 11) on the basis of three distinctive features, i.e., thresholds to skin deformation, size of response to innocuous skin deformation, and differential response to sharp and blunt stimuli. The low-threshold units provisionally were denoted tactile afferents on the basis of their response properties, which strongly suggest that they are coding some feature of tactile stimuli. They exhibited, in many respects, similar functional properties as described for low-threshold C-mechanoreceptive units in other mammals. However, a delayed acceleration, not previously demonstrated, was observed in response to long-lasting innocuous indentations. It was concluded that human hairy skin is innervated by a system of highly sensitive mechanoreceptive units with unmyelinated afferents akin to the system previously described in other mammals. The confirmation that the system is present in the forearm skin and not only in the face area where it first was identified suggests a largely general distribution although there are indications that the tactile C afferents may be lacking in the very distal parts of the limbs. The functional role of the system remains to be assessed although physiological properties of the sense organs invite to speculations that the slow tactile system might have closer relations to limbic functions than to cognitive and motor functions.

  12. Is ATP a central synaptic mediator for certain primary afferent fibers from mammalian skin?

    OpenAIRE

    Fyffe, R E; Perl, E R

    1984-01-01

    The possibility that ATP acts as a synaptic mediator at the central terminals of primary afferent fibers was examined by applying it iontophoretically to neurons of the outer layers of the cat spinal cord in vivo. ATP proved to be selectively excitatory for a limited subset of spinal neurons. Those units consistently excited by ATP iontophoresis with very small currents (2-15 nA) responded to gentle mechanical stimulation of the skin and usually evidenced excitatory input from unmyelinated pr...

  13. Electron microscopic observations of terminals of functionally identified afferent fibers in cat spinal cord.

    Science.gov (United States)

    Egger, M D; Freeman, N C; Malamed, S; Masarachia, P; Proshansky, E

    1981-02-23

    Using the method of intra-axonal injection of horseradish peroxidase, functionally identified afferent fibers from three slowly adapting (Type I) receptors and one Pacinian corpuscle in the glabrous skin of the hind paw of the cat were stained. Electron microscopic observation of the terminals of these fibers revealed predominantly axodendritic asymmetric synapses containing round, clear vesicles. Multiple synapses on a single dendrite were observed, separated by as little as 900 mm from one another.

  14. Immune derived opioidergic inhibition of viscerosensory afferents is decreased in Irritable Bowel Syndrome patients.

    Science.gov (United States)

    Hughes, Patrick A; Moretta, Melissa; Lim, Amanda; Grasby, Dallas J; Bird, Daniel; Brierley, Stuart M; Liebregts, Tobias; Adam, Birgit; Blackshaw, L Ashley; Holtmann, Gerald; Bampton, Peter; Hoffmann, Peter; Andrews, Jane M; Zola, Heddy; Krumbiegel, Doreen

    2014-11-01

    Alterations in the neuro-immune axis contribute toward viscerosensory nerve sensitivity and symptoms in Irritable Bowel Syndrome (IBS). Inhibitory factors secreted from immune cells inhibit colo-rectal afferents in health, and loss of this inhibition may lead to hypersensitivity and symptoms. We aimed to determine the immune cell type(s) responsible for opioid secretion in humans and whether this is altered in patients with IBS. The β-endorphin content of specific immune cell lineages in peripheral blood and colonic mucosal biopsies were compared between healthy subjects (HS) and IBS patients. Peripheral blood mononuclear cell (PBMC) supernatants from HS and IBS patients were applied to colo-rectal sensory afferent endings in mice with post-inflammatory chronic visceral hypersensitivity (CVH). β-Endorphin was identified predominantly in monocyte/macrophages relative to T or B cells in human PBMC and colonic lamina propria. Monocyte derived β-endorphin levels and colonic macrophage numbers were lower in IBS patients than healthy subjects. PBMC supernatants from healthy subjects had greater inhibitory effects on colo-rectal afferent mechanosensitivity than those from IBS patients. The inhibitory effects of PBMC supernatants were more prominent in CVH mice compared to healthy mice due to an increase in μ-opioid receptor expression in dorsal root ganglia neurons in CVH mice. Monocyte/macrophages are the predominant immune cell type responsible for β-endorphin secretion in humans. IBS patients have lower monocyte derived β-endorphin levels than healthy subjects, causing less inhibition of colonic afferent endings. Consequently, altered immune function contributes toward visceral hypersensitivity in IBS.

  15. Stochastic resonance in the synaptic transmission between hair cells and vestibular primary afferents in development.

    Science.gov (United States)

    Flores, A; Manilla, S; Huidobro, N; De la Torre-Valdovinos, B; Kristeva, R; Mendez-Balbuena, I; Galindo, F; Treviño, M; Manjarrez, E

    2016-05-13

    The stochastic resonance (SR) is a phenomenon of nonlinear systems in which the addition of an intermediate level of noise improves the response of such system. Although SR has been studied in isolated hair cells and in the bullfrog sacculus, the occurrence of this phenomenon in the vestibular system in development is unknown. The purpose of the present study was to explore for the existence of SR via natural mechanical-stimulation in the hair cell-vestibular primary afferent transmission. In vitro experiments were performed on the posterior semicircular canal of the chicken inner ear during development. Our experiments showed that the signal-to-noise ratio of the afferent multiunit activity from E15 to P5 stages of development exhibited the SR phenomenon, which was characterized by an inverted U-like response as a function of the input noise level. The inverted U-like graphs of SR acquired their higher amplitude after the post-hatching stage of development. Blockage of the synaptic transmission with selective antagonists of the NMDA and AMPA/Kainate receptors abolished the SR of the afferent multiunit activity. Furthermore, computer simulations on a model of the hair cell - primary afferent synapse qualitatively reproduced this SR behavior and provided a possible explanation of how and where the SR could occur. These results demonstrate that a particular level of mechanical noise on the semicircular canals can improve the performance of the vestibular system in their peripheral sensory processing even during embryonic stages of development. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Modulation of synaptic transmission from segmental afferents by spontaneous activity of dorsal horn spinal neurones in the cat.

    Science.gov (United States)

    Manjarrez, E; Rojas-Piloni, J G; Jimenez, I; Rudomin, P

    2000-12-01

    We examined, in the anaesthetised cat, the influence of the neuronal ensembles producing spontaneous negative cord dorsum potentials (nCDPs) on segmental pathways mediating primary afferent depolarisation (PAD) of cutaneous and group I muscle afferents and on Ia monosynaptic activation of spinal motoneurones. The intraspinal distribution of the field potentials associated with the spontaneous nCDPs indicated that the neuronal ensembles involved in the generation of these potentials were located in the dorsal horn of lumbar segments, in the same region of termination of low-threshold cutaneous afferents. During the occurrence of spontaneous nCDPs, transmission from low-threshold cutaneous afferents to second order neurones in laminae III-VI, as well as transmission along pathways mediating PAD of cutaneous and Ib afferents, was facilitated. PAD of Ia afferents was instead inhibited. Monosynaptic reflexes of flexors and extensors were facilitated during the spontaneous nCDPs. The magnitude of the facilitation was proportional to the amplitude of the 'conditioning' spontaneous nCDPs. This led to a high positive correlation between amplitude fluctuations of spontaneous nCDPs and fluctuations of monosynaptic reflexes. Stimulation of low-threshold cutaneous afferents transiently reduced the probability of occurrence of spontaneous nCDPs as well as the fluctuations of monosynaptic reflexes. It is concluded that the spontaneous nCDPs were produced by the activation of a population of dorsal horn neurones that shared the same functional pathways and involved the same set of neurones as those responding monosynaptically to stimulation of large cutaneous afferents. The spontaneous activity of these neurones was probably the main cause of the fluctuations of the monosynaptic reflexes observed under anaesthesia and could provide a dynamic linkage between segmental sensory and motor pathways.

  17. Capsaicin-sensitive vagal afferent neurons contribute to the detection of pathogenic bacterial colonization in the gut

    OpenAIRE

    2013-01-01

    Vagal activation can reduce inflammation and disease activity in various animal models of intestinal inflammation via the cholinergic anti-inflammatory pathway. In the current model of this pathway, activation of descending vagal efferents is dependent on a signal initiated by stimulation of vagal afferents. However, little is known about how vagal afferents are activated, especially in the context of subclinical or clinical pathogenic bacterial infection. To address this question, we first d...

  18. An electron microscopic study of terminals of rapidly adapting mechanoreceptive afferent fibers in the cat spinal cord.

    Science.gov (United States)

    Semba, K; Masarachia, P; Malamed, S; Jacquin, M; Harris, S; Yang, G; Egger, M D

    1985-02-08

    The intra-axonal horseradish peroxidase technique was used to examine the central terminals of 7 A beta primary afferent fibers from rapidly adapting (RA) mechanoreceptors in the glabrous skin of the cat's hindpaw. At the light microscopic level, labelled collaterals were seen to bear occasional boutonlike swellings, mostly (75-82%) of the en passant type. These swellings were distributed more or less uniformly from lamina III to a dorsal part of lamina VI in the dorsal horn, over a maximum longitudinal extent of about 4 mm. At the electron microscopic level, we observed that labelled boutons of RA afferent fibers were 1.0 to 3.3 micrometers in longest sectional dimension, and contained clear, round synaptic vesicles. They frequently formed asymmetric axospinous and axodendritic synapses and commonly appeared to receive contacts from unlabelled structures containing flattened or pleomorphic vesicles plus occasional large dense-cored vesicles. The examination of synaptic connectivity over the entire surface of individual boutons indicated that RA afferent boutons each made contacts with an average of one spine and one dendrite and, in addition, appeared to be postsynaptic to an average of two unlabelled vesicle-containing structures. This synaptic organization was, in general, more complex than that we had seen previously in Pacinian corpuscle (PC) and slowly adapting (SA) type I mechanoreceptive afferent fibers. Our findings indicate that RA, SA, and PC afferent terminals, while displaying some differential synaptic organizations, have many morphological and synaptological characteristics in common. These afferent terminals, in turn, seem to be generally distinguishable from the terminals of muscle spindle Ia afferents or unmyelinated primary afferents.

  19. Psychoactive bacteria Lactobacillus rhamnosus (JB-1) elicits rapid frequency facilitation in vagal afferents.

    Science.gov (United States)

    Perez-Burgos, Azucena; Wang, Bingxian; Mao, Yu-Kang; Mistry, Bhavik; McVey Neufeld, Karen-Anne; Bienenstock, John; Kunze, Wolfgang

    2013-01-15

    Mounting evidence supports the influence of the gut microbiome on the local enteric nervous system and its effects on brain chemistry and relevant behavior. Vagal afferents are involved in some of these effects. We previously showed that ingestion of the probiotic bacterium Lactobacillus rhamnosus (JB-1) caused extensive neurochemical changes in the brain and behavior that were abrogated by prior vagotomy. Because information can be transmitted to the brain via primary afferents encoded as neuronal spike trains, our goal was to record those induced by JB-1 in vagal afferents in the mesenteric nerve bundle and thus determine the nature of the signals sent to the brain. Male Swiss Webster mice jejunal segments were cannulated ex vivo, and serosal and luminal compartments were perfused separately. Bacteria were added intraluminally. We found no evidence for translocation of labeled bacteria across the epithelium during the experiment. We recorded extracellular multi- and single-unit neuronal activity with glass suction pipettes. Within minutes of application, JB-1 increased the constitutive single- and multiunit firing rate of the mesenteric nerve bundle, but Lactobacillus salivarius (a negative control) or media alone were ineffective. JB-1 significantly augmented multiunit discharge responses to an intraluminal distension pressure of 31 hPa. Prior subdiaphragmatic vagotomy abolished all of the JB-1-evoked effects. This detailed exploration of the neuronal spike firing that encodes behavioral signaling to the brain may be useful to identify effective psychoactive bacteria and thereby offer an alternative new perspective in the field of psychiatry and comorbid conditions.

  20. A DSP for sensing the bladder volume through afferent neural pathways.

    Science.gov (United States)

    Mendez, Arnaldo; Belghith, Abrar; Sawan, Mohamad

    2014-08-01

    In this paper, we present a digital signal processor (DSP) capable of monitoring the urinary bladder volume through afferent neural pathways. The DSP carries out real-time detection and can discriminate extracellular action potentials, also known as on-the-fly spike sorting. Next, the DSP performs a decoding method to estimate either three qualitative levels of fullness or the bladder volume value, depending on the selected output mode. The proposed DSP was tested using both realistic synthetic signals with a known ground-truth, and real signals from bladder afferent nerves recorded during acute experiments with animal models. The spike sorting processing circuit yielded an average accuracy of 92% using signals with highly correlated spike waveforms and low signal-to-noise ratios. The volume estimation circuits, tested with real signals, reproduced accuracies achieved by offline simulations in Matlab, i.e., 94% and 97% for quantitative and qualitative estimations, respectively. To assess feasibility, the DSP was deployed in the Actel FPGA Igloo AGL1000V2, which showed a power consumption of 0.5 mW and a latency of 2.1 ms at a 333 kHz core frequency. These performance results demonstrate that an implantable bladder sensor that perform the detection, discrimination and decoding of afferent neural activity is feasible.

  1. Reflex control of locomotion as revealed by stimulation of cutaneous afferents in spontaneously walking premammillary cats.

    Science.gov (United States)

    Duysens, J

    1977-07-01

    1. Stimulation of different hindlimb nerves in spontaneously walking premammillary cats was used in order to examine the effects of sensory input on the rhythmic motor output. 2. Stimulation of the tibial or sural nerve at low intensities caused the burst of activity in the triceps surae or semimembranosus to be prolonged if stimuli were given during the extension phase. When applied during the flexion phase, the same stimuli shortened the burst of activity in the pretibial flexors and induced an early onset of the extensor activity, except if stimuli were given at the very beginning of the flexion phase, when flexor burst prolongations or rebounds were observed instead. 3. These effects were related to activation of large cutaneous afferents in these nerves since the results could be duplicated by low-intensity stimulation of the tibial nerve at the ankle or by direct stimulation of the pad. 4. In contrast, activation of smaller afferents by high-intensity stimulation resulted prolongations of the flexor burst and/or shortenings of the extensor burst for stimuli applied before or during these bursts, respectively. 5. It was concluded that the large and small cutaneous afferents make, respectively, inhibitory and excitatory connections with the central structure involved in the generation of flexion during walking.

  2. Comparison of the inhibitory response to tendon and cutaneous afferent stimulation in the human lower limb.

    Science.gov (United States)

    Rogasch, Nigel C; Burne, John A; Türker, Kemal S

    2012-01-01

    A powerful early inhibition is seen in triceps surae after transcutaneous electrical stimulation of the Achilles tendon [tendon electrical stimulation (TES)]. The aim of the present study was to confirm results from surface electromyogram (SEMG) recordings that the inhibition is not wholly or partly due to stimulation of cutaneous afferents that may lie within range of the tendon electrodes. Because of methodological limitations, SEMG does not reliably identify the time course of inhibitory and excitatory reflex components. This issue was revisited here with an analysis of changes in single motor unit (SMU) firing rate [peristimulus frequencygram (PSF)] and probability [peristimulus time histogram (PSTH)] to reexamine the time course of inhibitory SMU events that follow purely cutaneous (superficial sural) nerve stimulation. Results were then compared with similar data from TES. When compared with the reflex response to TES, sural nerve stimulation resulted in a longer onset latency of the primary inhibition and a weaker effect on SMU firing probability and rate. PSF also revealed that decreased SMU firing rates persisted during the excitation phase in SEMG, suggesting that the initial inhibition was more prolonged than previously reported. In a further study, the transcutaneous SEMG Achilles tendon response was compared with that from direct intratendon stimulation with insulated needle electrodes. This method should attenuate the SEMG response if it is wholly or partly dependent on cutaneous afferents. However, subcutaneous stimulation of the tendon produced similar components in the SEMG, confirming that cutaneous afferents made little or no contribution to the initial inhibition following TES.

  3. Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary

    Science.gov (United States)

    Gosselink, K. L.; Grindeland, R. E.; Roy, R. R.; Zhong, H.; Bigbee, A. J.; Grossman, E. J.; Edgerton, V. R.

    1998-01-01

    There are forms of growth hormone (GH) in the plasma and pituitary of the rat and in the plasma of humans that are undetected by presently available immunoassays (iGH) but can be measured by bioassay (bGH). Although the regulation of iGH release is well documented, the mechanism(s) of bGH release is unclear. On the basis of changes in bGH and iGH secretion in rats that had been exposed to microgravity conditions, we hypothesized that neural afferents play a role in regulating the release of these hormones. To examine whether bGH secretion can be modulated by afferent input from skeletal muscle, the proximal or distal ends of severed hindlimb fast muscle nerves were stimulated ( approximately 2 times threshold) in anesthetized rats. Plasma bGH increased approximately 250%, and pituitary bGH decreased approximately 60% after proximal nerve trunk stimulation. The bGH response was independent of muscle mass or whether the muscles were flexors or extensors. Distal nerve stimulation had little or no effect on plasma or pituitary bGH. Plasma iGH concentrations were unchanged after proximal nerve stimulation. Although there may be multiple regulatory mechanisms of bGH, the present results demonstrate that the activation of low-threshold afferents from fast skeletal muscles can play a regulatory role in the release of bGH, but not iGH, from the pituitary in anesthetized rats.

  4. The Organization of Submodality-Specific Touch Afferent Inputs in the Vibrissa Column

    Directory of Open Access Journals (Sweden)

    Katsuyasu Sakurai

    2013-10-01

    Full Text Available The rodent tactile vibrissae are innervated by several different types of touch sensory neurons. The central afferents of all touch neurons from one vibrissa collectively project to a columnar structure called a barrelette in the brainstem. Delineating how distinct types of sensors connect to second-order neurons within each barrelette is critical for understanding tactile information coding and processing. Using genetic and viral techniques, we labeled slowly adapting (SA mechanosensory neurons, rapidly adapting (RA mechanosensory neurons, afferent synapses, and second-order projection neurons with four different fluorescent markers to examine their connectivity. We discovered that within each vibrissa column, individual sensory neurons project collaterals to multiply distributed locations, inputs from SA and RA afferents are spatially intermixed without any discernible stereotypy or topography, and second-order projection neurons receive convergent SA and RA inputs. Our findings reveal a “one-to-many and many-to-one” connectivity scheme and the circuit architecture for tactile information processing at the first-order synapses.

  5. Peripheral relays in stress-induced activation of visceral afferents in the gut.

    Science.gov (United States)

    van den Wijngaard, René M; Klooker, Tamira K; de Jonge, Wouter J; Boeckxstaens, Guy E

    2010-02-16

    Multiple organs are targeted by the stress response, but the focus of this article is on stress-induced activation of visceral afferents in the gut. During recent years it became apparent that mast cells are pivotal in this response. Peripheral corticotrophin releasing factor (CRF) induces their degranulation whereupon mast cell mediators activate visceral afferents. In addition, these mediators are responsible for gut barrier dysfunction and subsequent influx of luminal antigens and bacteria. Some research groups have begun to investigate the possible importance of barrier dysfunction for enhanced visceral sensitivity. After reviewing the current knowledge on CRF-induced mast cell degranulation we will discuss these groundbreaking papers in a more elaborate way. They form the basis for a hypothesis in which not only CRF-induced but also antigen-mediated mast cell degranulation is relevant to stress-related afferent activation. Part of this hypothesis is certainly speculative and needs further investigation. At the end of this article we sum up some of the unanswered questions raised by others and during this review.

  6. Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary

    Science.gov (United States)

    Gosselink, K. L.; Grindeland, R. E.; Roy, R. R.; Zhong, H.; Bigbee, A. J.; Grossman, E. J.; Edgerton, V. R.

    1998-01-01

    There are forms of growth hormone (GH) in the plasma and pituitary of the rat and in the plasma of humans that are undetected by presently available immunoassays (iGH) but can be measured by bioassay (bGH). Although the regulation of iGH release is well documented, the mechanism(s) of bGH release is unclear. On the basis of changes in bGH and iGH secretion in rats that had been exposed to microgravity conditions, we hypothesized that neural afferents play a role in regulating the release of these hormones. To examine whether bGH secretion can be modulated by afferent input from skeletal muscle, the proximal or distal ends of severed hindlimb fast muscle nerves were stimulated ( approximately 2 times threshold) in anesthetized rats. Plasma bGH increased approximately 250%, and pituitary bGH decreased approximately 60% after proximal nerve trunk stimulation. The bGH response was independent of muscle mass or whether the muscles were flexors or extensors. Distal nerve stimulation had little or no effect on plasma or pituitary bGH. Plasma iGH concentrations were unchanged after proximal nerve stimulation. Although there may be multiple regulatory mechanisms of bGH, the present results demonstrate that the activation of low-threshold afferents from fast skeletal muscles can play a regulatory role in the release of bGH, but not iGH, from the pituitary in anesthetized rats.

  7. Incidental renal neoplasms

    DEFF Research Database (Denmark)

    Rabjerg, Maj; Mikkelsen, Minne Nedergaard; Walter, Steen;

    2014-01-01

    On the basis of associations between tumor size, pathological stage, histological subtype and tumor grade in incidentally detected renal cell carcinoma vs symptomatic renal cell carcinoma, we discussed the need for a screening program of renal cell carcinoma in Denmark. We analyzed a consecutive...... series of 204 patients with renal tumors in 2011 and 2012. The tumors were classified according to detection mode: symptomatic and incidental and compared to pathological parameters. Eighty-nine patients (44%) were symptomatic, 113 (55%) were incidental. Information was not available in two patients...

  8. Insuficiencia renal aguda.

    OpenAIRE

    Carlos Hernán Mejía

    2009-01-01

    Acute renal failure (ARF) is a clinic syndrome characterized by decline in renal function occurring over a short time period. Is a relatively common complication in hospitalized critically ill patients and is associated with high morbidity and mortality. ARF has often a multi-factorial etiology syndrome usually approached diagnostically as pre-renal, post-renal, or intrinsic ARF. Most intrinsic ARF is caused by ischemia or nephrotoxins and is classically associated with acute tubular necrosis...

  9. Integrin mobilizes intracellular Ca(2+) in renal vascular smooth muscle cells

    DEFF Research Database (Denmark)

    Chan, W L; Holstein-Rathlou, N H; Yip, K P

    2001-01-01

    Peptides with the Arg-Gly-Asp (RGD) motif induce vasoconstriction in rat afferent arterioles by increasing the intracellular Ca(2+) concentration ([Ca(2+)](i)) in vascular smooth muscle cells (VSMC). This finding suggests that occupancy of integrins on the plasma membrane of VSMC might affect...... vascular tone. The purpose of this study was to determine whether occupancy of integrins by exogenous RGD peptides initiates intracellular Ca(2+) signaling in cultured renal VSMC. When smooth muscle cells were exposed to 0.1 mM hexapeptide GRGDSP, [Ca(2+)](i) rapidly increased from 91 +/- 4 to 287 +/- 37 n...

  10. THE ROLE OF RED NUCLEUS IN THE MODULATION OF SPINAL NOCICEPTIVE TRANSMISSION AND IN NOCICEPTION ELICITED BY MUSCLE SPINDLE AFFERENTS

    Institute of Scientific and Technical Information of China (English)

    唐斌; 樊小力; 吴苏娣

    2003-01-01

    Objective To analyse the antinociceptive effect of red nucleus (RN) and its role in the antinociceptive effect of muscle spindle afferents. Methods The single units of RN or wide dynamic range (WDR) neuron in the spinal cord dorsal horn were extracelluarly recorded. The effects of RN stimulation on nociceptive responses (C-fibers-evoked responses, C-responses) of WDR neurons were observed. The influence of muscle spindle afferents elicited by intravenous administration of succinylcholine (Sch) on the spontaneous discharge of RN neurons and on C-responses of WDR neurons were observed. The effect of muscle spindle afferents on C-responses of WDR neurons after unilateral lesions of RN was also observed. Results Electrical stimulation of the RN produced a significantly inhibitory effect on the nociceptive responses of WDR neurons. RN neurons were excited by muscle spindle afferents. Muscle spindle afferents significantly inhibited C-response of WDR neurons and this inhibitory effect was reduced by lesions of RN. Conclusion RN neurons have a significant antinociceptive effect and might be involved in the antinociceptive effects elicited by muscle spindle afferents.

  11. THE ROLE OF BRAIN-STEM DISCENDING INHIBITORY SYSTEM IN THE ANTINOCICEPTIVE EFFECT ELICITED BY MUSCLE SPINDLE AFFERENTS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To analyse the antinociceptive effect of muscle spindle afferents and the involved mechanism.Methods The single unit of wide dynamic range(WDR) neurons in the spinal cord dorsal horn were recorded extracelluarly.The effects of muscle spindle afferents elicited by intravenous administration of succinylcholine (Sch) on nociceptive responses (C-fibres-evoked responses,C-responses) of WDR neurons were observed before and after bilateral lesions of ventrolateral periaqueduct gray (PAG).And the effects of muscle spindle afferents on the spontaneous discharge of the tail-flick related cell in the rostral ventro medial medulla (RVM) and on the spontaneous discharge of the PAG neurons were observed.Results The C-responses of WDR neurons were significantly inhibited by muscle spindle afferents,and the inhibitory effects were reduced by bilateral lesions of ventrolateral PAG.The spontaneous discharge of the off-cell in the RVM was excited while the on-cell was inhibited by intravenous administration of Sch.The spontaneous discharge of the PAG neurons were excited by muscle spindle afferents.Conclusion Muscle spindle afferents show a distinct effect of antinociception.PAG-RVM descending inhibitory system may play an important role in this nociceptive modulative mechanism.

  12. Isolated Renal Hydatidosis Presenting as Renal Mass: A Diagnostic Dilemma

    Directory of Open Access Journals (Sweden)

    Datteswar Hota

    2015-07-01

    Full Text Available Hydatid disease is a parasitic infestation by larval form of Echinococcus granulosus. Isolated renal involvement is extremely rare. There are no specific signs and symptoms of renal hydatidosis. However it may present as palpable mass, flank pain, hematuria, malaise, fever, and hydatiduria or as a complication of it such as infection, abscess, hemorrhage, necrosis and pelviureteric junction obstruction, renal failure etc. Except hydatiduria, none are pathognomonic for renal hydatidosis. There is no literature on renal hydatidosis presenting as renal mass we report 2 cases of isolated renal hydatidosis, which mimicked a renal mass on imaging study.

  13. Distal renal tubular acidosis in recurrent renal stone formers

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    (1.1%) had complete distal renal tubular acidosis and 14 (15.5%) incomplete distal renal tubular acidosis. Our results confirm that distal renal tubular acidification defects are associated with a more severe form of stone disease and make distal renal tubular acidosis one of the most frequent...... metabolic disturbances in renal stone formers. Distal renal tubular acidosis (dRTA) was relatively more common in female stone formers and most often found in patients with bilateral stone disease (36%). Since prophylactic treatment in renal stone formers with renal acidification defects is available...

  14. Renal pelvis or ureter cancer

    Science.gov (United States)

    Transitional cell cancer of the renal pelvis or ureter; Kidney cancer - renal pelvis; Ureter cancer ... Cancer can grow in the urine collection system, but it is uncommon. Renal pelvis and ureter cancers ...

  15. No apparent role for T-type Ca²⁺ channels in renal autoregulation.

    Science.gov (United States)

    Frandsen, Rasmus Hassing; Salomonsson, Max; Hansen, Pernille B L; Jensen, Lars J; Braunstein, Thomas Hartig; Holstein-Rathlou, Niels-Henrik; Sorensen, Charlotte Mehlin

    2016-04-01

    Renal autoregulation protects glomerular capillaries against increases in renal perfusion pressure (RPP). In the mesentery, both L- and T-type calcium channels are involved in autoregulation. L-type calcium channels participate in renal autoregulation, but the role of T-type channels is not fully elucidated due to lack of selective pharmacological inhibitors. The role of T- and L-type calcium channels in the response to acute increases in RPP in T-type channel knockout mice (CaV3.1) and normo- and hypertensive rats was examined. Changes in afferent arteriolar diameter in the kidneys from wild-type and CaV3.1 knockout mice were assessed. Autoregulation of renal blood flow was examined during acute increases in RPP in normo- and hypertensive rats under pharmacological blockade of T- and L-type calcium channels using mibefradil (0.1 μM) and nifedipine (1 μM). In contrast to the results from previous pharmacological studies, genetic deletion of T-type channels CaV3.1 did not affect renal autoregulation. Pharmacological blockade of T-type channels using concentrations of mibefradil which specifically blocks T-type channels also had no effect in wild-type or knockout mice. Blockade of L-type channels significantly attenuated renal autoregulation in both strains. These findings are supported by in vivo studies where blockade of T-type channels had no effect on changes in the renal vascular resistance after acute increases in RPP in normo- and hypertensive rats. These findings show that genetic deletion of T-type channels CaV3.1 or treatment with low concentrations of mibefradil does not affect renal autoregulation. Thus, T-type calcium channels are not involved in renal autoregulation in response to acute increases in RPP.

  16. Intra-Parenchymal Renal Resistive Index Variation (IRRIV) Describes Renal Functional Reserve (RFR): Pilot Study in Healthy Volunteers.

    Science.gov (United States)

    Samoni, Sara; Nalesso, Federico; Meola, Mario; Villa, Gianluca; De Cal, Massimo; De Rosa, Silvia; Petrucci, Ilaria; Brendolan, Alessandra; Rosner, Mitchell H; Ronco, Claudio

    2016-01-01

    An increase of glomerular filtration rate after protein load represents renal functional reserve (RFR) and is due to afferent arteriolar vasodilation. Lack of RFR may be a risk factor for acute kidney injury (AKI), but is cumbersome to measure. We sought to develop a non-invasive, bedside method that would indirectly measure RFR. Mechanical abdominal pressure, through compression of renal vessels, decreases blood flow and activates the auto-regulatory mechanism which can be measured by a fall in renal resistive index (RRI). The study aims at elucidating the relationship between intra-parenchymal renal resistive index variation (IRRIV) during abdominal pressure and RFR. In healthy volunteers, pressure was applied by a weight on the abdomen (fluid-bag 10% of subject's body weight) while RFR was measured through a protein loading test. We recorded RRI in an interlobular artery after application of pressure using ultrasound. The maximum percentage reduction of RRI from baseline was compared in the same subject to RFR. We enrolled 14 male and 16 female subjects (mean age 38 ± 14 years). Mean creatinine clearance was 106.2 ± 16.4 ml/min/1.73 m(2). RFR ranged between -1.9 and 59.7 with a mean value of 28.9 ± 13.1 ml/min/1.73 m(2). Mean baseline RRI was 0.61 ± 0.05, compared to 0.49 ± 0.06 during abdominal pressure; IRRIV was 19.6 ± 6.7%, ranging between 3.1% and 29.2%. Pearson's coefficient between RFR and IRRIV was 74.16% (p renal susceptibility to different exposures and the consequent risk for AKI.

  17. 9 CFR 354.124 - Quarantine of diseased rabbits.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Quarantine of diseased rabbits. 354... INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Inspection Procedures; Ante-Mortem Inspections § 354.124 Quarantine of diseased rabbits. If live rabbits, which...

  18. Clinical aspects of lagomorph dental anatomy: the rabbit (oryctolagus cuniculus).

    Science.gov (United States)

    Crossley, D A

    1995-12-01

    The lagomorphs most commonly encountered as pets are rabbits. There are many breeds of domestic rabbit, varying from dwarf varieties with an adult weight of under one kilogram to giants weighing 10 kg. This article provides a working knowledge of the dental anatomy and physiology of rabbits so that veterinarians can interpret clinical and radiographic findings when investigating rabbits with suspected dental disease.

  19. Autonomic control of the heart during exercise in humans: role of skeletal muscle afferents.

    Science.gov (United States)

    Fisher, James P

    2014-02-01

    What is the topic of this review? The autonomic nervous system plays a key role in bringing about the cardiovascular responses to exercise necessitated by the increased metabolic requirements of the active skeletal muscle. The complex interaction of central and peripheral neural control mechanisms evokes a decrease in parasympathetic activity and an increase sympathetic activity to the heart during exercise. What advances does it highlight? This review presents some of the recent insights provided by human studies into the role of mechanically and metabolically sensitive skeletal muscle afferents in the regulation of cardiac autonomic control during exercise. The autonomic responses to exercise are orchestrated by the interactions of several central and peripheral neural mechanisms. This report focuses on the role of peripheral feedback from skeletal muscle afferents in the autonomic control of the heart during exercise in humans. Heart rate responses to passive calf stretch are abolished with cardiac parasympathetic blockade, indicating that the activation of mechanically sensitive skeletal muscle afferents (muscle mechanoreceptors) can inhibit cardiac parasympathetic activity and is likely to contribute to the increase in heart rate at the onset of exercise. Recent experiments show that the partial restriction of blood flow to the exercising skeletal muscles, to augment the activation of metabolically sensitive skeletal muscle afferents (muscle metaboreceptors) in humans, evokes an increase in heart rate that is attenuated with β1-adrenergic blockade, thus suggesting that this response is principally mediated via an increase in cardiac sympathetic activity. Heart rate remains at resting levels during isolated activation of muscle metaboreceptors with postexercise ischaemia following hand grip, unless cardiac parasympathetic activity is inhibited, whereupon a sympathetically mediated increase in heart rate is unmasked. During postexercise ischaemia following leg

  20. Current radiological techniques used to evaluate unilateral partial ureteral obstruction: an experimental rabbit study.

    Science.gov (United States)

    Yazıcı, Mehmet; Celebi, Suleyman; Kuzdan, Özgür; Koçan, Hüseyin; Ayyıldız, Halil Suat; Bayrak, İlkay Koray; Bilgici, Meltem Ceyhan; Yapıcı, Oktay; Kefeli, Mehmet; Arıtürk, Ender

    2015-07-01

    The aim of this study was to evaluate functional and prognostic benefits of Doppler ultrasonography (DU), diuretic renal scintigraphy (DRS), and magnetic resonance urography (MRU) during diagnosis and follow-up of ureteropelvic junction obstruction (UPJO) and to examine apoptosis rates caused by UPJO in an experimental rabbit model. Twenty-four rabbits were divided randomly into two groups. The left kidneys of 15 rabbits from the first group underwent Ulm-Miller surgery to create UPJO, whereas the left kidneys of nine rabbits from the second group underwent sham surgery. A pressure flow study (Whitaker's test) was done during postoperative week 6. Based on the Whitaker test, the DU, DRS, and MRU findings were compared. The number of apoptotic renal cells was counted after death. The Whitaker test run during postoperative week 6 revealed obstructions in 15 rabbits from group 1; the nine rabbits of the sham group had no obstructions. Sensitivity and specificity of DRS were 93.3 and 88.8 %, respectively, and those of MRU were 93.3 and 88.8 %, respectively. The postoperative mean RI values were significantly higher than the preoperative values, associated with sensitivity of 86.6 % and specificity of 77.5 % for detecting UPJO. DRS, MRU, and RI could not predict UPJO in one (8 %), one (8 %), and two (16 %) kidneys, respectively. Likelihood ratio (LR) was 8.4 for MRU and scintigraphy, while for RI, LR was 3.9. Pathology specimens revealed that all kidneys with UPJO underwent apoptosis, and the number of apoptotic cells was significantly higher on the UPJO-created side than on the contralateral and in the sham group (p < 0.05). No test predicted all apoptosis related to UPJO. The RI, DRS, and DMRU results correlated with the pressure flow results for detecting UPJO. No single radiological technique predicted all initial UPJO-created kidneys that concluded with apoptosis. Further studies are required to seek with better methods for diagnosing an obstruction or to define a

  1. Tamarindus indica L. and Moringa oleifera M. extract administration ameliorates fluoride toxicity in rabbits.

    Science.gov (United States)

    Ranjan, R; Swarup, D; Patra, R C; Chandra, Vikas

    2009-11-01

    Aqueous extracts of T. indica fruit pulp (100 mg/kg body weight) and M. oleifera seeds (50 mg/kg body wight) orally once daily for 90 days lowered plasma fluoride concentrations in rabbits receiving fluorinated drinking water (200 mg NaF/ Liter water). Cortical indices and metaphysial width in animals receiving extracts also revealed beneficial effects of plant extracts. Changes in plasma biochemistry suggested less hepatic and renal damages in animals receiving plant extracts along with fluorinated water in comparison to that receiving fluorinated water alone. Preliminary results revealed these plant extracts have some potential to mitigate fluoride toxicity.

  2. Parasitic infections of wild rabbits and hares

    Directory of Open Access Journals (Sweden)

    Ilić Tamara

    2014-01-01

    Full Text Available The paper presents the most important parasitic infections of wild rabbits and hares, which harmful effect in this animal population is manifested as a gradual weakening of the immune system, reduction in fertility, weight loss and constant exhaustion. Order of Lagomorpha (hares or lagomorphs belongs to superorder of higher mammals which includes the family of rabbits (Leporidae which are represented in Europe as well as the family of whistleblowers (Ochotonidae which live only in North America and Northern regions of Asia. The most important representatives of Leporidae family are European hare (Lepus europeus and wild rabbit (Oryctolagus cuniculus. The most important endoparasitosis of hares and wild rabbits are: coccidiosis, encephalitozoonosis (nosemosis, toxoplasmosis, sarcocystosis, giardiasis, cryptosporidiosis, protostrongylosis, trichostrngylodosis, passalurosis, anoplocephalidosis, cysticercosis and fasciolosis. The most frequent ectoparasites of rabbits and wild hares are fleas, lice and ticks. Reduction in hare population, which is noticed in whole Europe including Serbia, is caused by changed living conditions, quantitatively and qualitatively insufficient nutrition, increased use of herbicides as well as various infectious diseases and the diseases of parasitic etiology. Since wild rabbits and hares pose a threat to health of domestic rabbits and people, knowledge of parasitic fauna of these wild animals is of extreme epizootiological and epidemiological importance.

  3. Welfare aspects in rabbit rearing and transport

    Directory of Open Access Journals (Sweden)

    Claudio Cavani

    2010-01-01

    Full Text Available The review starts with the description of the rabbits’ (Oryctolagus cuniculus main habits and the current situation concerning the rabbit husbandry and management systems, as well as their effects on the welfare of these animals. As far as the intensive rabbit husbandry systems are concerned, the main problems are related to the time since rabbits have been domesticated and their adaptive capacity and coping styles as respects the farming environment and management systems. Both these aspects have implications in the present and future of rabbit rearing for different purposes. Examples are given on the effects of different housing and management systems on rabbit welfare, as well as examples of the ethological, physiological and productive indicators used to evaluate these effects. Transportation and, more generally, preslaughter phases including catching, fasting and lairage at the abattoir are considered major stressors for farmed rabbits and might have deleterious effects on health, well-being, performance, and finally, product quality. A general statement of the recent scientific studies considering the effects of pre-slaughter factors on physiological and productive measurements are reported. Finally, some indications in order to improve rabbit welfare, already present at the European level, are also outlined, together with the European Food Safety Authority opinions.

  4. Ultrastructural changes of the peritoneum in a rabbit model of peritoneal dialysis

    Directory of Open Access Journals (Sweden)

    Jovanović Nataša

    2013-01-01

    Full Text Available Background/Aim. The number of patients with end-stage renal diseases treated with chronic dialysis is increasing over the last years. Long-term peritoneal dialysis is associated with progressive development of structural and functional alterations of peritoneal membrane. The aim of the study was to analyze ultrastructural alterations of mesothelial monolayer and submesothelial tissue in a modified nonuremic experimental model of peritoneal dialysis in rabbits. Methods. The study was performed on 5 healthy Chinchilla rabbits. Surgical procedures of implantation and removal of peritoneal catheter, prevention of catheter clothing, prevention of infection and dialysate instillation were performed according to previously described protocols. Peritoneal tissue samples were collected upon catheter placement and removal after a 5-week follow-up and processed for transmission electron microscopy (TEM examination. Results. The rabbits tolerated anesthesia, surgical procedure and the applied regimen of dialysate instillations well. The animals recovered completely and no adverse effects were noted. In the animals treated with peritoneal dialysis instillations, TEM revealed alterations of the mesothelial monolayer and submesothelial tissue. The mesothelial cells in direct contact with dialysis fluid were prone to shrinking. They lost the typical cobblestone morphology and assumed a flattened shape. The mesothelial cells were often detached from the basement membrane. These cells showed euchromatic nuclei, higher number of microvilli in their apical part and very numerous vesicles. A higher quantity of collagen fibers was noticed in the peritoneal lamina propria in close relation to the basement membrane of mesothelium. The nuclei of the fibroblasts were also euchromatic. Numerous mitochondria, granules and vesicles were present in their cytoplasm. Conclusion. The used rabbit model of peritoneal dialysis is simple, practical to perform, reproducible, not

  5. [Hemorrhagic bilateral renal angiomyolipoma].

    Science.gov (United States)

    Benjelloun, Mohamed; Rabii, Redouane; Mezzour, Mohamed Hicham; Joual, Abdenbi; Bennani, Saâd; el Mrini, Mohamed

    2003-09-01

    Renal angiomyolipoma is a rare benign tumour, often associated with congenital diseases especially de Bourneville's tuberous sclerosis. Bilateral angiomyolipoma is exceptional. The authors report a case of bilateral renal angiomyolipoma in a 33-year-old patient presenting with haemorrhagic shock. In the light of this case and a review of the literature, the authors discuss the diagnostic and therapeutic aspects of this disease.

  6. FARMACOFISIOLOGÍA RENAL

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    Musso CG

    2014-03-01

    Full Text Available Renal physiology plays a key role in the pharmacokinetics of many drugs. Knowledge of the particularities of each nephron function (filtration, secretion, reabsorption and excretion and each of renal tubular transport mechanisms (simple diffusion, facilitated diffusion, facilitated transport, active transport, endocytosis and pinocytosis is fundamental to achieve better management of drug prescriptions.

  7. Newer antipsychotics and the rabbit syndrome

    Directory of Open Access Journals (Sweden)

    Masalehdan Azadeh

    2007-06-01

    Full Text Available Abstract Background Rabbit syndrome is a movement disorder that is associated with long-term exposure to neuroleptic medications. Of particular interest and importance is the risk of rabbit syndrome with exposure to the newer atypical antipsychotics. Our recent experience with such a case brought to light the importance of exploring this risk. Methods MEDLINE and PubMed (1972–2006 databases were searched for English language articles using the keywords rabbit syndrome, tardive dyskinesia, antipsychotic, extrapyramidal symptoms and side effects. A recent case study is used to expand upon the literature available on newer antipsychotics and rabbit syndrome. Results We reviewed papers that addressed the following aspects of rabbit syndrome 1 the clinical manifestations 2 prevalence and risk factors, 3 etiopathogenesis 4 older antipsychotics and rabbit syndrome 5 newer antipsychotics, 6 treatment options. Moreover, we report a case of RS in a 50 year old white female, diagnosed with bipolar I disorder, that, after the discontinuation of risperidone, developed involuntary movements of the mouth that were fine, rhythmic and rapid, along the vertical axis, and without involvement of the tongue. After the re-introduction of risperidone, the symptoms decreased in a few hours and disappeared after 3 days. Conclusion Eleven cases of rabbit syndrome have been documented since the implementation of newer antipsychotics. Future research is needed to better understand the etiopathogenesis of rabbit syndrome in psychiatric populations treated with the atypical antipsychotics. Understanding the differences and similarities of rabbit syndrome and tardive dyskinesia is crucial to the creation of a successful treatment paradigm.

  8. Application of rabbits in biomedical research: a review.

    OpenAIRE

    Bosze, Zs.; Houdebine, L M

    2006-01-01

    The first transgenic rabbits were obtained two decades ago by pronuclear microinjection. Several characteristics of rabbit made it the first and classical model for the study of lipoproteins and atherosclerosis. Rabbit models include normal cholesterol-fed rabbits, spontaneous mutants for lipid metabolism and transgenic rabbits. Though most molecular investigations of the cardiovascular system have used transgenic mice, the small rodents do not accurately reflect crucial facets of human cardi...

  9. Primary renal hydatidosis

    Directory of Open Access Journals (Sweden)

    Johnsy Merla Joel

    2016-01-01

    Full Text Available Echinococcosis or hydatidosis caused by the tapeworm, Echinococcus granulosus, has the highest prevalence in endemic regions and sheep farming areas. The most common organ involved is the liver (50–75% followed by the lungs (15–20% and other organs (10–20%. Primary involvement of the kidney without the involvement of the liver and lungs, i.e., isolated renal hydatid disease is extremely rare even in endemic areas. The incidence of renal echinococcosis is 2–4%. Renal hydatid cysts usually remain asymptomatic for many years and are multiloculated. A 63-year-old male presented with left loin pain. Computed tomography scan abdomen revealed a presumptive diagnosis of renal hydatid disease. The nephrectomy specimen received in histopathology confirmed the diagnosis. We describe a rare case of primary renal hydatidosis.

  10. Expression of the transient receptor potential channels TRPV1, TRPA1 and TRPM8 in mouse trigeminal primary afferent neurons innervating the dura

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    Huang Dongyue

    2012-09-01

    Full Text Available Abstract Background Migraine and other headache disorders affect a large percentage of the population and cause debilitating pain. Activation and sensitization of the trigeminal primary afferent neurons innervating the dura and cerebral vessels is a crucial step in the “headache circuit”. Many dural afferent neurons respond to algesic and inflammatory agents. Given the clear role of the transient receptor potential (TRP family of channels in both sensing chemical stimulants and mediating inflammatory pain, we investigated the expression of TRP channels in dural afferent neurons. Methods We used two fluorescent tracers to retrogradely label dural afferent neurons in adult mice and quantified the abundance of peptidergic and non-peptidergic neuron populations using calcitonin gene-related peptide immunoreactivity (CGRP-ir and isolectin B4 (IB4 binding as markers, respectively. Using immunohistochemistry, we compared the expression of TRPV1 and TRPA1 channels in dural afferent neurons with the expression in total trigeminal ganglion (TG neurons. To examine the distribution of TRPM8 channels, we labeled dural afferent neurons in mice expressing farnesylated enhanced green fluorescent protein (EGFPf from a TRPM8 locus. We used nearest-neighbor measurement to predict the spatial association between dural afferent neurons and neurons expressing TRPA1 or TRPM8 channels in the TG. Results and conclusions We report that the size of dural afferent neurons is significantly larger than that of total TG neurons and facial skin afferents. Approximately 40% of dural afferent neurons exhibit IB4 binding. Surprisingly, the percentage of dural afferent neurons containing CGRP-ir is significantly lower than those of total TG neurons and facial skin afferents. Both TRPV1 and TRPA1 channels are expressed in dural afferent neurons. Furthermore, nearest-neighbor measurement indicates that TRPA1-expressing neurons are clustered around a subset of dural afferent

  11. Expression of the transient receptor potential channels TRPV1, TRPA1 and TRPM8 in mouse trigeminal primary afferent neurons innervating the dura

    Science.gov (United States)

    2012-01-01

    Background Migraine and other headache disorders affect a large percentage of the population and cause debilitating pain. Activation and sensitization of the trigeminal primary afferent neurons innervating the dura and cerebral vessels is a crucial step in the “headache circuit”. Many dural afferent neurons respond to algesic and inflammatory agents. Given the clear role of the transient receptor potential (TRP) family of channels in both sensing chemical stimulants and mediating inflammatory pain, we investigated the expression of TRP channels in dural afferent neurons. Methods We used two fluorescent tracers to retrogradely label dural afferent neurons in adult mice and quantified the abundance of peptidergic and non-peptidergic neuron populations using calcitonin gene-related peptide immunoreactivity (CGRP-ir) and isolectin B4 (IB4) binding as markers, respectively. Using immunohistochemistry, we compared the expression of TRPV1 and TRPA1 channels in dural afferent neurons with the expression in total trigeminal ganglion (TG) neurons. To examine the distribution of TRPM8 channels, we labeled dural afferent neurons in mice expressing farnesylated enhanced green fluorescent protein (EGFPf) from a TRPM8 locus. We used nearest-neighbor measurement to predict the spatial association between dural afferent neurons and neurons expressing TRPA1 or TRPM8 channels in the TG. Results and conclusions We report that the size of dural afferent neurons is significantly larger than that of total TG neurons and facial skin afferents. Approximately 40% of dural afferent neurons exhibit IB4 binding. Surprisingly, the percentage of dural afferent neurons containing CGRP-ir is significantly lower than those of total TG neurons and facial skin afferents. Both TRPV1 and TRPA1 channels are expressed in dural afferent neurons. Furthermore, nearest-neighbor measurement indicates that TRPA1-expressing neurons are clustered around a subset of dural afferent neurons. Interestingly, TRPM

  12. Bobcat attack on a cottontail rabbit

    Science.gov (United States)

    Biggins, D.E.; Biggins, D.M.

    2006-01-01

    We observed an attack by a bobcat (Lynx rufus) on a cottontail rabbit (Sylvilagus) that involved stealthy approach by the cat for >1 h, followed by a 12.3-s chase covering 116.0 m for the cat and 128.4 m for the rabbit. During the chase, the route of the cat from starting point to kill site was more direct than the semi-circular route of the rabbit. Stride lengths for the cat and total distance covered by the chase were longer than those previously reported for bobcats.

  13. Benign Rabbit Calicivirus in New Zealand.

    Science.gov (United States)

    Nicholson, Leila J; Mahar, Jackie E; Strive, Tanja; Zheng, Tao; Holmes, Edward C; Ward, Vernon K; Duckworth, Janine A

    2017-06-01

    The Czech v351 strain of rabbit hemorrhagic disease virus (RHDV1) is used in Australia and New Zealand as a biological control agent for rabbits, which are important and damaging introduced vertebrate pests in these countries. However, nonpathogenic rabbit caliciviruses (RCVs) can provide partial immunological cross-protection against lethal RHDV infection and thus interfere with effective rabbit biocontrol. Antibodies that cross-reacted against RHDV antigens were found in wild rabbits before the release of RHDV1 in New Zealand in 1997, suggesting that nonpathogenic RCVs were already present in New Zealand. The aim of this study was to confirm the presence of nonpathogenic RCV in New Zealand and describe its geographical distribution. RCV and RHDV antibody assays were used to screen serum samples from 350 wild rabbits from 14 locations in New Zealand. The serological survey indicated that both RCV and RHDV are widespread in New Zealand wild rabbits, with antibodies detected in 10 out of 14 and 12 out of 14 populations, respectively. Two closely related RCV strains were identified in the duodenal tissue from a New Zealand wild rabbit (RCV Gore-425A and RCV Gore-425B). Both variants are most closely related to Australian RCV strains, but with 88% nucleotide identity, they are genetically distinct. Phylogenetic analysis revealed that the New Zealand RCV strains fall within the genetic diversity of the Australian RCV isolates, indicating a relatively recent movement of RCVs between Australia and New Zealand.IMPORTANCE Wild rabbits are important and damaging introduced vertebrate pests in Australia and New Zealand. Although RHDV1 is used as a biological control agent, some nonpathogenic RCVs can provide partial immunological cross-protection against lethal RHDV infection and thus interfere with its effectiveness for rabbit control. The presence of nonpathogenic RCVs in New Zealand wild rabbits has been long hypothesized, but earlier attempts to isolate a New Zealand RCV

  14. Water transport by the renal Na(+)-dicarboxylate cotransporter

    DEFF Research Database (Denmark)

    Meinild, A K; Loo, D D; Pajor, A M;

    2000-01-01

    This study investigated the ability of the renal Na(+)-dicarboxylate cotransporter, NaDC-1, to transport water. Rabbit NaDC-1 was expressed in Xenopus laevis oocytes, cotransporter activity was measured as the inward current generated by substrate (citrate or succinate), and water transport...... was monitored by the changes in oocyte volume. In the absence of substrates, oocytes expressing NaDC-1 showed an increase in osmotic water permeability, which was directly correlated with the expression level of NaDC-1. When NaDC-1 was transporting substrates, there was a concomitant increase in oocyte volume....... This solute-coupled influx of water took place in the absence of, and even against, osmotic gradients. There was a strict stoichiometric relationship between Na(+), substrate, and water transport of 3 Na(+), 1 dicarboxylate, and 176 water molecules/transport cycle. These results indicate that the renal Na...

  15. The renal handling of hemoglobin. I. Glomerular filtration.

    Science.gov (United States)

    Bunn, H F; Esham, W T; Bull, R W

    1969-05-01

    The glomerular filtration of hemoglobin (alpha(2)beta(2)) was studied under conditions in which its dissociation into alphabeta dimers was experimentally altered. Rats receiving hemoglobin treated with the sulfhydryl reagent bis(N-maleimidomethyl) ether (BME) showed a much lower renal excretion and prolonged plasma survival as compared with animals injected with untreated hemoglobin. Plasma disappearance was also prolonged in dogs receiving BME hemoglobin. Gel filtration data indicated that under physiological conditions, BME hemoglobin had impaired subunit dissociation. In addition, BME hemoglobin showed a very high oxygen affinity and a decreased rate of auto-oxidation. Glomerular filtration was enhanced under conditions which favor the dissociation of hemoglobin into dimers. Cat hemoglobin, which forms subunits much more extensively than canine hemoglobin, was excreted more readily by the rat kidney. The renal uptake of (59)Fe hemoglobin injected intra-arterially into rabbits varied inversely with the concentration of the injected dose.

  16. Water transport by the renal Na(+)-dicarboxylate cotransporter

    DEFF Research Database (Denmark)

    Meinild, A K; Loo, D D; Pajor, A M

    2000-01-01

    was monitored by the changes in oocyte volume. In the absence of substrates, oocytes expressing NaDC-1 showed an increase in osmotic water permeability, which was directly correlated with the expression level of NaDC-1. When NaDC-1 was transporting substrates, there was a concomitant increase in oocyte volume....... This solute-coupled influx of water took place in the absence of, and even against, osmotic gradients. There was a strict stoichiometric relationship between Na(+), substrate, and water transport of 3 Na(+), 1 dicarboxylate, and 176 water molecules/transport cycle. These results indicate that the renal Na......This study investigated the ability of the renal Na(+)-dicarboxylate cotransporter, NaDC-1, to transport water. Rabbit NaDC-1 was expressed in Xenopus laevis oocytes, cotransporter activity was measured as the inward current generated by substrate (citrate or succinate), and water transport...

  17. Renal replacement therapy after cardiac surgery; renal function recovers

    DEFF Research Database (Denmark)

    Steinthorsdottir, Kristin Julia; Kandler, Kristian; Agerlin Windeløv, Nis

    2013-01-01

    To assess renal outcome in patients discharged from hospital following cardiac surgery-associated acute kidney injury (CSA-AKI) with need for renal replacement therapy.......To assess renal outcome in patients discharged from hospital following cardiac surgery-associated acute kidney injury (CSA-AKI) with need for renal replacement therapy....

  18. Towards a Guided Regeneration of Renal Tubules at a Polyester Interstitium

    Directory of Open Access Journals (Sweden)

    Will W. Minuth

    2010-03-01

    Full Text Available Stem/progenitor cells are promising candidates for a therapy of renal failure. However, sound knowledge about implantation and regeneration is lacking. Therefore, mechanisms leading from stem/progenitor cells into tubules are under research. Renal stem/progenitor cells were isolated from neonatal rabbit kidney and mounted between layers of polyester fleece. It creates an artificial interstitium and replaces coating by extracellular matrix proteins. Tubulogenic development is induced by aldosterone. Electron microscopy illuminates growth of tubules in close vicinity to polyester fibers. Tubules contain a differentiated epithelium. The spatial extension of tubules opens a new strategy for testing morphogenic drugs and biocompatible fleece materials.

  19. Firing patterns and functional roles of different classes of spinal afferents in rectal nerves during colonic migrating motor complexes in mouse colon.

    Science.gov (United States)

    Zagorodnyuk, Vladimir P; Kyloh, Melinda; Brookes, Simon J; Nicholas, Sarah J; Spencer, Nick J

    2012-08-01

    The functional role of the different classes of visceral afferents that innervate the large intestine is poorly understood. Recent evidence suggests that low-threshold, wide-dynamic-range rectal afferents play an important role in the detection and transmission of visceral pain induced by noxious colorectal distension in mice. However, it is not clear which classes of spinal afferents are activated during naturally occurring colonic motor patterns or during intense contractions of the gut smooth muscle. We developed an in vitro colorectum preparation to test how the major classes of rectal afferents are activated during spontaneous colonic migrating motor complex (CMMC) or pharmacologically induced contraction. During CMMCs, circular muscle contractions increased firing in low-threshold, wide-dynamic-range muscular afferents and muscular-mucosal afferents, which generated a mean firing rate of 1.53 ± 0.23 Hz (n = 8) under isotonic conditions and 2.52 ± 0.36 Hz (n = 17) under isometric conditions. These low-threshold rectal afferents were reliably activated by low levels of circumferential stretch induced by increases in length (1-2 mm) or load (1-3 g). In a small proportion of cases (5 of 34 units), some low-threshold muscular and muscular-mucosal afferents decreased their firing rate during the peak of the CMMC contractions. High-threshold afferents were never activated during spontaneous CMMC contractions or tonic contractions induced by bethanechol (100 μM). High-threshold rectal afferents were only activated by intense levels of circumferential stretch (10-20 g). These results show that, in the rectal nerves of mice, low-threshold, wide-dynamic-range muscular and muscular-mucosal afferents are excited during contraction of the circular muscle that occurs during spontaneous CMMCs. No activation of high-threshold rectal afferents was detected during CMMCs or intense contractile activity in naïve mouse colorectum.

  20. The Gomez' equations and renal hemodynamic function in kidney disease research.

    Science.gov (United States)

    Bjornstad, Petter; Škrtić, Marko; Lytvyn, Yuliya; Maahs, David M; Johnson, Richard J; Cherney, David Z I

    2016-09-07

    Diabetic kidney disease (DKD) remains the leading cause of end-stage renal disease. A major challenge in preventing DKD is the difficulty in identifying high-risk patients at an early, pre-clinical stage. Albuminuria and eGFR as measures of renal function in DKD research and clinical practice are limited by regression of one-third of patients with microalbuminuria to normoalbuminuria and eGFR is biased and imprecise in the normal-elevated range. Moreover, existing methods that are used to assess renal function do not give detailed insight into the location of the renal hemodynamic effects of pharmacological agents at the segmental level. To gain additional information about the intrarenal circulation in-vivo in humans, mathematical equations were developed by Gomez et al in the 1950s. These equations used measurements of GFR, renal blood flow (RBF), effective renal plasma flow (ERPF), renal vascular resistance (RVR), hematocrit and serum protein to calculate afferent and efferent arteriolar resistances, glomerular hydrostatic pressure and filtration pressure. Although indirect and based on physiological assumptions, these techniques have the potential to improve researchers' ability to identify early pre-clinical changes in renal hemodynamic function in patients with a variety of conditions including DKD, thereby offering tremendous potential in mechanistic human research studies. In this review, we focus on the application of Gomez' equations and summarize the potential and limitations of this technique in DKD research. We also summarize illustrative data derived from Gomez' equations in patients with type 1 (T1D) and type 2 diabetes (T2D) and hypertension.

  1. Renal neuroendocrine tumors

    Directory of Open Access Journals (Sweden)

    Brian R Lane

    2009-01-01

    Full Text Available Objectives: Neuroendocrine tumors (NETs are uncommon tumors that exhibit a wide range of neuroendocrine differentiation and biological behavior. Primary NETs of the kidney, including carcinoid tumor, small cell carcinoma (SCC, and large cell neuroendocrine carcinoma (LCNEC are exceedingly rare. Materials and Methods: The clinicopathologic features of renal NETs diagnosed at a single institution were reviewed along with all reported cases in the worldwide literature. Results: Eighty renal NETs have been described, including nine from our institution. Differentiation between renal NETs and the more common renal neoplasms (renal cell carcinoma, transitional cell carcinoma can be difficult since clinical, radiographic, and histopathologic features overlap. Immunohistochemical staining for neuroendocrine markers, such as synaptophysin and chromogranin, can be particularly helpful in this regard. Renal carcinoids are typically slow-growing, may secrete hormones, and pursue a variable clinical course. In contrast, SCC and LCNEC often present with locally advanced or metastatic disease and carry a poor prognosis. Nephrectomy can be curative for clinically localized NETs, but multimodality treatment is indicated for advanced disease. Conclusions: A spectrum of NETs can rarely occur in the kidney. Renal carcinoids have a variable clinical course; SCC and LCNEC are associated with poor clinical outcomes. Diagnosis of NETs, especially LCNEC, requires awareness of their rare occurrence and prudent use of immunohistochemical neuroendocrine markers.

  2. Pregnancy and renal transplantation.

    Science.gov (United States)

    Başaran, O; Emiroğlu, R; Seçme, S; Moray, G; Haberal, M

    2004-01-01

    Ovarian dysfunction, anovulatory vaginal bleeding, amenorrhea, high prolactin levels, and loss of libido are the causes of infertility in women with chronic renal failure. After renal transplantation, endocrine function generally improves after recovery of renal function. In this study we retrospectively evaluated the prepregnancy and postdelivery renal function, outcome of gestation, as well as maternal and fetal complications for eight pregnancies in eight renal transplant recipients between November 1975 and March 2003 of 1095 among 1425. Eight planned pregnancies occurred at a mean of 3.6 years posttransplant. Spontaneous abortion occured in the first trimester in one case. One intrauterine growth retardation was observed with a full-term pregnancy; one intrauterine growth retardation and preterm delivery; one preeclampsia with preterm delivery and urinary tract infection; and one preeclampsia with preterm delivery and oligohydramnios. The mean gestation period was 35.5 +/- 3.0 weeks (31.2 to 38.0). Pregnancy had no negative impact on renal function during a 2-year follow-up. No significant proteinuria or acute rejection episodes were observed. Among the seven deliveries, no congenital anomaly was documented and no postpartum problems for the child and the mother were observed. Our study suggests that successful pregnancy is possible in renal transplant recipients. In cases with good graft function and absence of severe proteinuria or hypertension, pregnancy does not affect graft function or patient survival; however, fetal problems are encountered such as intrauterine growth retardation, low birth weight, and preeclampsia.

  3. Renal autotransplantation: current perspectives.

    Science.gov (United States)

    Stewart, B H; Banowsky, L H; Hewitt, C B; Straffon, R A

    1976-01-01

    Autotransplantation, with or without an extracorporeal renal operation, has been done 39 times in 37 patients. Indications for the procedure included severe ureteral injury in 4 patients, failed supravesical diversion in 2, renal carcinoma in a solitary kidney in 1, renovascular hypertension in 1 and donor arterial reconstruction before renal transplantation in 29. Success was obtained in all but 2 procedures, both of which involved previously operated kidneys with severe inflammation and adhesions involving the renal pelvis and pedicle. Based on our experience and a review of currently available literature we believe that renal autotransplantation and extracorporeal reconstruction can provide the best solution for patients with severe renovascular and ureteral disease not correctable by conventional operative techniques. The technique can be of particular value in removing centrally located tumors in solitary kidneys and in preparing donor kidneys with abnormal arteries for renal transplantation. The role of autotransplantation in the management of advanced renal trauma and calculus disease is less clear. A long-term comparison of patients treated by extracorporeal nephrolithotomy versus conventional lithotomy techniques will be necessary before a conclusion is reached in these disease categories.

  4. Perioperative acute renal failure.

    LENUS (Irish Health Repository)

    Mahon, Padraig

    2012-02-03

    PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

  5. Fetotoxicity and teratogenesis of SWL treatment in the rabbit.

    Science.gov (United States)

    Frankenschmidt, A; Heisler, M

    1998-02-01

    The potential effects of extracorporeal application of shockwaves on an embryo or fetus were explored in an animal model. In experimental Series A, the fetuses of 30 gravid rabbits were exposed to piezoelectrically induced and sonographically guided shockwaves on Day 25 or 20 of gestation under technical conditions corresponding to extracorporeal lithotripsy in humans. Fetotoxicity was examined by abdominal section 24 hours or 9 days later, and immediate/intermediate damage was assessed (resorptions, viability, gross injuries, and microscopic lesions of the target and neighboring fetuses). In series B, the kidneys of an additional 28 gravid rabbits (including a control group) were exposed to the same shockwave treatment on Day 11 of gestation in order to investigate indirect embryotoxic effects, including teratogenic potency. One day before the expected birth, the maternal kidneys, uteri, and adjacent organs were examined for lesions, and the 156 offspring were assessed for embryolethal, embryonoxious, or teratogenic sequelae. Shockwave targeting of the cranium, thorax, abdomen, or placenta was usually lethal to the fetuses. When the uterine wall or the space between two fetuses was targeted, the fetuses suffered from superficial hematoma, as was found in the surrounding soft tissues within a radius of 1.5 cm. Fetuses outside this region were vital and free of lesions. Shockwave treatment of the maternal kidney resulted in renal petechial hemorrhage or subcapsular hematoma. However, statistically significant embryotoxic or teratogenetic effects could be demonstrated neither from maternal data (resorptions) nor from fetal findings (body measurements, vitality test, inner organs, skeletal deformities). When using a piezoelectric lithotripter with a small focus of high energy, lesions of a fetus are to be expected only when it is located in or close to the focus. It seems that embryotoxic or teratogenic sequelae do not occur when shockwaves are focused outside the

  6. Afferent roles in hindlimb wipe-reflex trajectories: free-limb kinematics and motor patterns.

    Science.gov (United States)

    Kargo, W J; Giszter, S F

    2000-03-01

    The hindlimb wiping reflex of the frog is an example of a targeted trajectory that is organized at the spinal level. In this paper, we examine this reflex in 45 spinal frogs to test the importance of proprioceptive afferents in trajectory formation at the spinal level. We tested hindlimb to hindlimb wiping, in which the wiping or effector limb and the target limb move together. Loss of afferent feedback from the wiping limb was produced by cutting dorsal roots 7-9. This caused altered initial trajectory direction, increased ankle path curvature, knee-joint velocity reversals, and overshooting misses of the target limb. We established that these kinematic and motor-pattern changes were due mainly to the loss of ipsilateral muscular and joint afferents. Loss of cutaneous afferents alone did not alter the initial trajectory up to target limb contact. However, there were cutaneous effects in later motor-pattern phases after the wiping and target limb had made contact: The knee extension or whisk phase of wiping was often lost. Finally, there was a minor and nonspecific excitatory effect of phasic contralateral feedback in the motor-pattern changes after deafferentation. Specific muscle groups were altered as a result of proprioceptive loss. These muscles also showed configuration-based regulation during wiping. Biceps, semitendinosus, and sartorius (all contributing knee flexor torques) all were regulated in amplitude based on the initial position of the limb. These muscles contributed to an initial electromyographic (EMG) burst in the motor pattern. Rectus internus and semimembranosus (contributing hip extensor torques) were regulated in onset but not in the time of peak EMG or in termination of EMG based on initial position. These two muscles contributed to a second EMG burst in the motor pattern. After deafferentation the initial burst was reduced and more synchronous with the second burst, and the second burst often was broadened in duration. Ankle path curvature

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

    Science.gov (United States)

    Kanai, Takashi; Krum, Henry

    2013-09-01

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

  8. Midterm renal functions following acute renal infarction

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    Sakir Ongun

    2015-10-01

    Full Text Available The aim of this study was to explore clinical features of renal infarction (RI that may have a role in diagnosis and treatment in our patient cohort and provide data on midterm renal functions. Medical records of patients with diagnosis of acute RI, established by contrast enhanced computed tomography (CT and at least 1 year follow-up data, who were hospitalized in our clinic between 1998 and 2012 were retrospectively reviewed; including descriptive data, clinical signs and symptoms, etiologic factors, laboratory findings, and prescribed treatments. Patients with solitary infarct were treated with acetylsalicylic acid (ASA only, whereas patients with atrial fibrillation (AF or multiple or global infarct were treated with anticoagulants. Estimated Glomerular Filtration Rate (eGFR referring to renal functions was determined by the Modification of Diet in Renal Disease (MDRD formula. Twenty-seven renal units of 23 patients with acute RI were identified. The mean age was 59.7 ± 15.7 years. Fourteen patients (60.8% with RI had atrial fibrillation (AF as an etiologic factor of which four had concomitant mesenteric ischemia at diagnosis. At presentation, 20 patients (86.9% had elevated serum lactate dehydrogenase (LDH, 18 patients (78.2% had leukocytosis, and 16 patients (69.5% had microscopic hematuria. Two patients with concomitant mesenteric ischemia and AF passed away during follow up. Mean eGFR was 70.8 ± 23.2 mL/min/1.73 m2 at admission and increased to 82.3 ± 23.4 mL/min/1.73 m2 at 1 year follow up. RI should be considered in patients with persistent flank or abdominal pain, particularly if they are at high risk of thromboembolism. Antiplatelet and/or anticoagulant drugs are both effective treatment options according to the amplitude of the infarct for preserving kidney functions.

  9. Midterm renal functions following acute renal infarction.

    Science.gov (United States)

    Ongun, Sakir; Bozkurt, Ozan; Demir, Omer; Cimen, Sertac; Aslan, Guven

    2015-10-01

    The aim of this study was to explore clinical features of renal infarction (RI) that may have a role in diagnosis and treatment in our patient cohort and provide data on midterm renal functions. Medical records of patients with diagnosis of acute RI, established by contrast enhanced computed tomography (CT) and at least 1 year follow-up data, who were hospitalized in our clinic between 1998 and 2012 were retrospectively reviewed; including descriptive data, clinical signs and symptoms, etiologic factors, laboratory findings, and prescribed treatments. Patients with solitary infarct were treated with acetylsalicylic acid (ASA) only, whereas patients with atrial fibrillation (AF) or multiple or global infarct were treated with anticoagulants. Estimated Glomerular Filtration Rate (eGFR) referring to renal functions was determined by the Modification of Diet in Renal Disease (MDRD) formula. Twenty-seven renal units of 23 patients with acute RI were identified. The mean age was 59.7 ± 15.7 years. Fourteen patients (60.8%) with RI had atrial fibrillation (AF) as an etiologic factor of which four had concomitant mesenteric ischemia at diagnosis. At presentation, 20 patients (86.9%) had elevated serum lactate dehydrogenase (LDH), 18 patients (78.2%) had leukocytosis, and 16 patients (69.5%) had microscopic hematuria. Two patients with concomitant mesenteric ischemia and AF passed away during follow up. Mean eGFR was 70.8 ± 23.2 mL/min/1.73 m(2) at admission and increased to 82.3 ± 23.4 mL/min/1.73 m(2) at 1 year follow up. RI should be considered in patients with persistent flank or abdominal pain, particularly if they are at high risk of thromboembolism. Antiplatelet and/or anticoagulant drugs are both effective treatment options according to the amplitude of the infarct for preserving kidney functions.

  10. Identification of Rabbit Myostatin Gene Polymorphisms

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    T. I. Amalianingsih

    2015-08-01

    Full Text Available The existence of selection on the rabbits with potential for meat has only been seen from phenotypic aspects including performance and productivity, while the molecular genetic studies are still very rare. One of the candidate genes for meat production traits in rabbit is myostatin. Totally 50 blood samples of male rabbits from Rex, Satin, Reza (crossing from Rex and Satin, Flemish Giant and FZ3 (crossing from Flemish Giant and Reza breed were used at Indonesian Research Institute for Animal Production (IRIAP. Genetic polymorphism by Polymerase Chain Reaction – Restriction Fragment Length Polymorphism (PCR-RFLP method used FspBI restriction enzyme. PCR-RFLP data were analyzed by calculating allele and genotype frequencies. Sequencing was performed in rabbit with different genotypes which represents each of the samples. Genotype of AT had two cut points of the FspBI restriction enzyme at the base position of 508 bp and 444 bp. The cut point at the base position of 446 bp was site mutation base T became A. Genotype of TT had one cut point at the base position of 508 bp and no mutation site. Allele T had higher frequency than allele A and just Rex and Reza rabbit breeds had two alleles. The other rabbits (Satin, Flemish Giant and FZ3 only had one allele i.e., allele T. PCR - RFLP analysis of the MSTN|FspBI gene segments was polymorphic in Rex and Reza rabbit breeds. All of rabbit breeds in this study did not have AA genotype.

  11. Organophosphorus poisoning in two Rex rabbits.

    Science.gov (United States)

    Jones, J M

    1984-01-01

    A case of organophosphorus (OP) poisoning in two Rex rabbits is described. Three animals were diagnosed as having dermatitis characterised by pruritus and alopecia due to infestation with Cheyletiella parasitivorax. Two of the animals were dipped in 2% malathion solution: one died within 15 hours post-dipping, the other was euthanased subsequent to the onset of convulsions. A procedure for the future dipping of rabbits is suggested, and a recommendation is made for a lower concentration of malathion to be used.

  12. INFECTIOUS MYXOMATOSIS (SANARELLI) IN PREGNANT RABBITS

    Science.gov (United States)

    Sprunt, Douglas H.

    1932-01-01

    Pregnancy in rabbits alters the reactivity of the tissues to the virus of infectious myxomatosis. The livers of pregnant animals with the myxoma have a central acidophilic necrosis. Secondary lesions in the lungs are much more numerous and larger in the pregnant than in the non-gravid animals. In like manner the lesions in the spleen are more extensive in the pregnant rabbit. On the other hand the skin lesions of the pregnant animal are decreased in size. PMID:19870088

  13. Gastric relaxation induced by hyperglycemia is mediated by vagal afferent pathways in the rat.

    Science.gov (United States)

    Zhou, Shi-Yi; Lu, Yuan-Xu; Owyang, Chung

    2008-05-01

    Hyperglycemia has a profound effect on gastric motility. However, little is known about the site and mechanism that sense alteration in blood glucose level. The identification of glucose-sensing neurons in the nodose ganglia led us to hypothesize that hyperglycemia acts through vagal afferent pathways to inhibit gastric motility. With the use of a glucose-clamp rat model, we showed that glucose decreased intragastric pressure in a dose-dependent manner. In contrast to intravenous infusion of glucose, intracisternal injection of glucose at 250 and 500 mg/dl had little effect on intragastric pressure. Pretreatment with hexamethonium, as well as truncal vagotomy, abolished the gastric motor responses to hyperglycemia (250 mg/dl), and perivagal and gastroduodenal applications of capsaicin significantly reduced the gastric responses to hyperglycemia. In contrast, hyperglycemia had no effect on the gastric contraction induced by electrical field stimulation or carbachol (10(-5) M). To rule out involvement of serotonergic pathways, we showed that neither granisetron (5-HT(3) antagonist, 0.5 g/kg) nor pharmacological depletion of 5-HT using p-chlorophenylalanine (5-HT synthesis inhibitor) affected gastric relaxation induced by hyperglycemia. Lastly, N(G)-nitro-L-arginine methyl ester (L-NAME) and a VIP antagonist each partially reduced gastric relaxation induced by hyperglycemia and, in combination, completely abolished gastric responses. In conclusion, hyperglycemia inhibits gastric motility through a capsaicin-sensitive vagal afferent pathway originating from the gastroduodenal mucosa. Hyperglycemia stimulates vagal afferents, which, in turn, activate vagal efferent cholinergic pathways synapsing with intragastric nitric oxide- and VIP-containing neurons to mediate gastric relaxation.

  14. Increasing cutaneous afferent feedback improves proprioceptive accuracy at the knee in patients with sensory ataxia.

    Science.gov (United States)

    Macefield, Vaughan G; Norcliffe-Kaufmann, Lucy; Goulding, Niamh; Palma, Jose-Alberto; Fuente Mora, Cristina; Kaufmann, Horacio

    2016-02-01

    Hereditary sensory and autonomic neuropathy type III (HSAN III) features disturbed proprioception and a marked ataxic gait. We recently showed that joint angle matching error at the knee is positively correlated with the degree of ataxia. Using intraneural microelectrodes, we also documented that these patients lack functional muscle spindle afferents but have preserved large-diameter cutaneous afferents, suggesting that patients with better proprioception may be relying more on proprioceptive cues provided by tactile afferents. We tested the hypothesis that enhancing cutaneous sensory feedback by stretching the skin at the knee joint using unidirectional elasticity tape could improve proprioceptive accuracy in patients with a congenital absence of functional muscle spindles. Passive joint angle matching at the knee was used to assess proprioceptive accuracy in 25 patients with HSAN III and 9 age-matched control subjects, with and without taping. Angles of the reference and indicator knees were recorded with digital inclinometers and the absolute error, gradient, and correlation coefficient between the two sides calculated. Patients with HSAN III performed poorly on the joint angle matching test [mean matching error 8.0 ± 0.8° (±SE); controls 3.0 ± 0.3°]. Following application of tape bilaterally to the knee in an X-shaped pattern, proprioceptive performance improved significantly in the patients (mean error 5.4 ± 0.7°) but not in the controls (3.0 ± 0.2°). Across patients, but not controls, significant increases in gradient and correlation coefficient were also apparent following taping. We conclude that taping improves proprioception at the knee in HSAN III, presumably via enhanced sensory feedback from the skin.

  15. BDNF released during neuropathic pain potentiates NMDA receptors in primary afferent terminals.

    Science.gov (United States)

    Chen, Wenling; Walwyn, Wendy; Ennes, Helena S; Kim, Hyeyoung; McRoberts, James A; Marvizón, Juan Carlos G

    2014-05-01

    NMDA receptors in primary afferent terminals can contribute to hyperalgesia by increasing neurotransmitter release. In rats and mice, we found that the ability of intrathecal NMDA to induce neurokinin 1 receptor (NK1R) internalization (a measure of substance P release) required a previous injection of BDNF. Selective knock-down of NMDA receptors in primary afferents decreased NMDA-induced NK1R internalization, confirming the presynaptic location of these receptors. The effect of BDNF was mediated by tropomyosin-related kinase B (trkB) receptors and not p75 neurotrophin receptors (p75(NTR) ), because it was not produced by proBDNF and was inhibited by the trkB antagonist ANA-12 but not by the p75(NTR) inhibitor TAT-Pep5. These effects are probably mediated through the truncated form of the trkB receptor as there is little expression of full-length trkB in dorsal root ganglion (DRG) neurons. Src family kinase inhibitors blocked the effect of BDNF, suggesting that trkB receptors promote the activation of these NMDA receptors by Src family kinase phosphorylation. Western blots of cultured DRG neurons revealed that BDNF increased Tyr(1472) phosphorylation of the NR2B subunit of the NMDA receptor, known to have a potentiating effect. Patch-clamp recordings showed that BDNF, but not proBDNF, increased NMDA receptor currents in cultured DRG neurons. NMDA-induced NK1R internalization was also enabled in a neuropathic pain model or by activating dorsal horn microglia with lipopolysaccharide. These effects were decreased by a BDNF scavenger, a trkB receptor antagonist and a Src family kinase inhibitor, indicating that BDNF released by microglia potentiates NMDA receptors in primary afferents during neuropathic pain. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  16. Biochemical evidence that L-glutamate is a neurotransmitter of primary vagal afferent nerve fibers

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    Perrone, M.H. (Cornell Univ., New York (USA). Medical Coll.)

    1981-12-28

    To determine in rat if vagal afferent fibers projecting into the intermediate one third of the nucleus tractus solitarius (NTS), the site of termination of baroafferents, utilize glutamate as a neurotransmitter, the high-affinity uptake of (/sup 3/H)L-glutamate and content of glutamate were analyzed in micropunches of rat brain stem. The intermediate NTS contains a high-affinity synaptosomal uptake system for (/sup 3/H)L-glutamate that is greater in capacity than that in areas adjacent to the NTS; it is almost two-fold higher than uptake in medial septum and nucleus accumbens and equal to that of hippocampal regions purportedly containing a rich glutamatergic innervation. Unilateral ablation of the nodose ganglion (i.e. cells of origin of vagal afferents) resulted, within 24 h in a prolonged significant reduction, to 56% of control, of (/sup 3/H)L-glutamate uptake, bilaterally in the NTS. The reduction of Na/sup +/-dependent synaptosomal uptake of (/sup 3/H)L-glutamate, resulted from a decrease in Vsub(max) without change in the Ksub(m) of the process, was anatomically restricted to the intermediate NTS, and was not associated with changes in (/sup 3/H)GABA uptake. The content of glutamate in the NTS was significantly (P < 0.01) decreased by 30% 7 days following unilateral extirpation of the nodose ganglion without changes in the concentrations of aspartate, glycine, glutamine, or GABA. A population of vagal afferent fibers projecting to NTS are glutamatergic. The results are consistent with the hypothesis obtained by physiological and pharmacological techniques that glutamate is a neurotransmitter of baroafferents.

  17. Contributions of skin and muscle afferent input to movement sense in the human hand.

    Science.gov (United States)

    Cordo, Paul J; Horn, Jean-Louis; Künster, Daniela; Cherry, Anne; Bratt, Alex; Gurfinkel, Victor

    2011-04-01

    In the stationary hand, static joint-position sense originates from multimodal somatosensory input (e.g., joint, skin, and muscle). In the moving hand, however, it is uncertain how movement sense arises from these different submodalities of proprioceptors. In contrast to static-position sense, movement sense includes multiple parameters such as motion detection, direction, joint angle, and velocity. Because movement sense is both multimodal and multiparametric, it is not known how different movement parameters are represented by different afferent submodalities. In theory, each submodality could redundantly represent all movement parameters, or, alternatively, different afferent submodalities could be tuned to distinctly different movement parameters. The study described in this paper investigated how skin input and muscle input each contributes to movement sense of the hand, in particular, to the movement parameters dynamic position and velocity. Healthy adult subjects were instructed to indicate with the left hand when they sensed the unseen fingers of the right hand being passively flexed at the metacarpophalangeal (MCP) joint through a previously learned target angle. The experimental approach was to suppress input from skin and/or muscle: skin input by anesthetizing the hand, and muscle input by unexpectedly extending the wrist to prevent MCP flexion from stretching the finger extensor muscle. Input from joint afferents was assumed not to play a significant role because the task was carried out with the MCP joints near their neutral positions. We found that, during passive finger movement near the neutral position in healthy adult humans, both skin and muscle receptors contribute to movement sense but qualitatively differently. Whereas skin input contributes to both dynamic position and velocity sense, muscle input may contribute only to velocity sense.

  18. Vagal afferents are essential for maximal resection-induced intestinal adaptive growth in orally fed rats.

    Science.gov (United States)

    Nelson, David W; Liu, Xiaowen; Holst, Jens J; Raybould, Helen E; Ney, Denise M

    2006-11-01

    Small bowel resection stimulates intestinal adaptive growth by a neuroendocrine process thought to involve both sympathetic and parasympathetic innervation and enterotrophic hormones such as glucagon-like peptide-2 (GLP-2). We investigated whether capsaicin-sensitive vagal afferent neurons are essential for maximal resection-induced intestinal growth. Rats received systemic or perivagal capsaicin or ganglionectomy before 70% midjejunoileal resection or transection and were fed orally or by total parenteral nutrition (TPN) for 7 days after surgery. Growth of residual bowel was assessed by changes in mucosal mass, protein, DNA, and histology. Both systemic and perivagal capsaicin significantly attenuated by 48-100% resection-induced increases in ileal mucosal mass, protein, and DNA in rats fed orally. Villus height was significantly reduced in resected rats given capsaicin compared with vehicle. Sucrase specific activity in jejunal mucosa was not significantly different; ileal mucosal sucrase specific activity was significantly increased by resection in capsaicin-treated rats. Capsaicin did not alter the 57% increase in ileal proglucagon mRNA or the 150% increase in plasma concentration of bioactive GLP-2 resulting from resection in orally fed rats. Ablation of spinal/splanchnic innervation by ganglionectomy failed to attenuate resection-induced adaptive growth. In TPN rats, capsaicin did not attenuate resection-induced mucosal growth. We conclude that vagal afferents are not essential for GLP-2 secretion when the ileum has direct contact with luminal nutrients after resection. In summary, vagal afferent neurons are essential for maximal resection-induced intestinal adaptation through a mechanism that appears to involve stimulation by luminal nutrients.

  19. Decoding of the spike timing of primary afferents during voluntary arm movements in monkeys

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    Tatsuya eUmeda

    2014-05-01

    Full Text Available Understanding the mechanisms of encoding forelimb kinematics in the activity of peripheral afferents is essential for determining the optimal parameters of afferent stimulation to transmit proprioceptive signals in neuroprosthetics. To investigate whether the spike timing of dorsal root ganglion (DRG neurons could be estimated from the forelimb kinematics of behaving monkeys, we implanted two multi-electrode arrays chronically in the DRGs at the level of the cervical segments in two monkeys. Neuronal activity during voluntary reach-to-grasp movements were recorded simultaneously with the trajectories of hand/arm movements, which were tracked in three-dimensional space using a motion capture system. Sixteen and 13 neurons, including muscle spindles, skin receptors, and tendon organ afferents, were recorded in the two monkeys, respectively. We were able to reconstruct forelimb joint kinematics from the temporal firing pattern of a subset of DRG neurons using sparse linear regression (SLiR analysis, suggesting that DRG neuronal ensembles encoded information about joint kinematics. Furthermore, we estimated the spike timing of the DRG neuronal ensembles from joint kinematics using an integrate-and-fire model (IF incorporating the SLiR algorithm. The temporal change of firing frequency of a subpopulation of neurons was reconstructed precisely from forelimb kinematics using the SLiR. The spike timing of the DRG neurons was calculated using an IF model, in which a spike occurs if the cumulative sum of the firing frequency value exceeded a constant threshold. The estimated firing pattern of the DRG neuronal ensembles encoded forelimb joint angles and velocities as precisely as the originally recorded neuronal activity. These results suggest that the simple model can be used to generate an accurate estimate of the spike timing of DRG neuronal ensembles from forelimb joint kinematics, and is useful for designing a proprioceptive decoder in a brain machine

  20. Lactulose and renal failure.

    Science.gov (United States)

    Vogt, B; Frey, F J

    1997-01-01

    The introduction of lactulose as a new therapeutic agent for treatment of hepatic encephalopathy was a major breakthrough in this field. It was hypothesized that lactulose might prevent postoperative renal impairment after biliary surgery in patients with obstructive jaundice. The presumable mechanism purported was the diminished endotoxinemia by lactulose. Unfortunately, such a reno-protective effect has not been shown conclusively until now in clinical studies. In chronic renal failure lactulose is known to promote fecal excretion of water, sodium, potassium, amonium, urea, creatinine and protons. Thus, lactulose could be useful for the treatment of chronic renal failure. However, compliance to the therapy represents a major problem.

  1. Renal tubule cell repair following acute renal injury.

    Science.gov (United States)

    Humes, H D; Lake, E W; Liu, S

    1995-01-01

    Experimental data suggests the recovery of renal function after ischemic or nephrotoxic acute renal failure is due to a replicative repair process dependent upon predominantly paracrine release of growth factors. These growth factors promote renal proximal tubule cell proliferation and a differentiation phase dependent on the interaction between tubule cells and basement membrane. These insights identify the molecular basis of renal repair and ischemic and nephrotoxic acute renal failure, and may lead to potential therapeutic modalities that accelerate renal repair and lessen the morbidity and mortality associated with these renal disease processes. In this regard, there is a prominent vasoconstrictor response of the renal vasculature during the postischemic period of developing acute renal failure. The intravenous administration of pharmacologic doses of atrial natriuretic factor (ANF) in the postischemic period have proven efficacious by altering renal vascular resistance, so that renal blood flow and glomerular filtration rate improve. ANF also appears to protect renal tubular epithelial integrity and holds significant promise as a therapeutic agent in acute renal failure. Of equal or greater promise are the therapeutic interventions targeting the proliferative reparative zone during the postischemic period. The exogenous administration of epidermal growth factor or insulin-like growth factor-1 in the postischemic period have effectively decreased the degree of renal insufficiency as measured by the peak serum creatinine and has hastened renal recovery as measured by the duration of time required to return the baseline serum creatinine values. A similarly efficacious role for hepatocyte growth factor has also been recently demonstrated.

  2. Light colour preference of growing rabbits

    Directory of Open Access Journals (Sweden)

    Zsolt Szendrő

    2010-01-01

    Full Text Available The objective of the experiment was to evaluate the light colour preference of growing rabbits placed in a free-choice cage. The experiment was carried out on 128 Pannon White growing rabbits weaned at the age of 5 weeks and placed into blocks (2m2 of four cages. The rabbits could move freely among the four cages (0.5m2 each through swing doors. The cages differed only in the colour of the light applied (white, yellow, green or blue. The lighting schedule was 16L: 8D. From 6 until 10 weeks of age, infrared video recording was performed once a week (24 hours. The number of rabbits in each cage was counted every 15 minutes. Feed consumption was measured weekly. Between 6 and 10 weeks of age the rabbits significantly preferred white light (28.0%. The preference order was the following: yellow (26.3%, blue (23.4% and green (22.3% (P<0.001. No significant differences were recorded in the feed consumption among the cages. In conclusion, the cage preference of the rabbits was slightly affected by the light colour.

  3. PAD patterns of physiologically identified afferent fibres from the medial gastrocnemius muscle.

    Science.gov (United States)

    Jiménez, I; Rudomin, P; Solodkin, M

    1988-01-01

    Intracellular recordings were made in the barbiturate-anesthetized cat from single afferent fibres left in continuity with the medial gastrocnemius muscle to document the transmembrane potential changes produced in functionally identified fibres by stimulation of sensory nerves and of the contralateral red nucleus (RN). Fifty five fibres from muscle spindles had conduction velocities above 70 m/s and were considered as from group Ia. Stimulation of group I afferent fibres of the posterior biceps and semitendinosus nerve (PBSt) produced primary afferent depolarization (PAD) in 30 (54%) Ia fibres. Stimulation of the sural (SU) nerve produced no transmembrane potential changes in 39 (71%) group Ia fibres and dorsal root reflex-like activity (DRRs) in 16 (29%) fibres. In 17 out of 28 group Ia fibres (60.7%) SU conditioning inhibited the PAD generated by stimulation of the PBSt nerve. Facilitation of the PBSt-induced PAD by SU conditioning was not seen. Repetitive stimulation of the RN had mixed effects: it produced PAD in 1 out of 8 fibres and inhibited the PAD induced by PBSt stimulation in 2 other fibres. Nine fibres connected to muscle spindles had conduction velocities below 70 m/s and were considered to be group II afferents. No PAD was produced in these fibres by SU stimulation but DRRs were generated in 5 of them. In 23 out of 31 fibres identified as from tendon organs group I PBSt volleys produced PAD. However, stimulation of the SU nerve produced PAD only in 3 out of 34 fibres, no transmembrane potential changes in 30 fibres and DRRs in 1 fibre. The effects of SU conditioning on the PAD produced by PBSt stimulation were tested in 19 Ib fibres and were inhibitory in 12 of them. In 9 of these fibres SU alone produced no transmembrane potential changes. Repetitive stimulation of the RN produced PAD in 3 out of 9 Ib fibres. SU conditioning inhibited the RN-induced PAD. The present findings support the existence of an alternative inhibitory pathway from cutaneous

  4. Cutaneous neurturin overexpression alters mechanical, thermal, and cold responsiveness in physiologically identified primary afferents.

    Science.gov (United States)

    Jankowski, Michael P; Baumbauer, Kyle M; Wang, Ting; Albers, Kathryn M; Davis, Brian M; Koerber, H Richard

    2017-03-01

    Neurotrophic factors play an important role in the regulation of functional properties of sensory neurons under normal and pathological conditions. The GDNF family member neurturin is one such factor that has been linked to modulating responsiveness to peripheral stimuli. Neurturin binds to the GFRα2 receptor, a receptor found primarily in isolectin B4-expressing polymodal cutaneous nociceptors. Previous work has shown that knockout of GFRα2 alters heat, but not mechanical, responses in dissociated sensory neurons and reduces pain-related behaviors during the second phase of the formalin test. Research has also shown that overexpression of neurturin in basal keratinocytes increases behavioral responsiveness to mechanical stimulation and innocuous cooling of the skin without affecting noxious heat responses. Here we directly examined the impact of neurturin overexpression on cutaneous afferent function. We compared physiological responses of individual sensory neurons to mechanical and thermal stimulation of the skin, using an ex vivo skin-nerve-dorsal root ganglion-spinal cord preparation produced from neurturin-overexpressing (NRTN/OE) mice and wild-type littermate controls. We found that neurturin overexpression increases responsiveness to innocuous mechanical stimuli in A-fiber nociceptors, alters thermal responses in the polymodal subpopulation of C-fiber sensory neurons, and changes the relative numbers of mechanically sensitive but thermally insensitive C-fiber afferents. These results demonstrate the potential roles of different functional groups of sensory neurons in the behavioral changes observed in mice overexpressing cutaneous neurturin and highlight the importance of neurturin in regulating cutaneous afferent response properties.NEW & NOTEWORTHY GDNF family neurotrophic factors regulate the development and function of primary sensory neurons. Of these, neurturin has been shown to modulate mechanical and cooling sensitivity behaviorally. Here we show

  5. Contribution of afferent feedback to the soleus muscle activity during human locomotion

    DEFF Research Database (Denmark)

    Mazzaro, Nazarena; Grey, Michael James; Sinkjær, Thomas

    2005-01-01

    During the stance phase of the human step cycle, the ankle undergoes a natural dorsiflexion that stretches the soleus muscle. The afferent feedback resulting from this stretch enhances the locomotor drive. In this study a robotic actuator was used to slightly enhance or reduce the natural ankle...... dorsiflexion, in essence, mimicking the small variations in the ankle dorsiflexion movement that take place during the stance phase of the step cycle. The soleus (SOL) and tibialis anterior EMG were analyzed in response to the ankle trajectory modifications. The dorsiflexion enhancements and reductions...

  6. High-Fat Diet-Induced Obesity Ablates Gastric Vagal Afferent Circadian Rhythms.

    Science.gov (United States)

    Kentish, Stephen J; Vincent, Andrew D; Kennaway, David J; Wittert, Gary A; Page, Amanda J

    2016-03-16

    Rats with high-fat diet (HFD)-induced obesity increase daytime eating, suggesting an alteration in circadian food intake mechanisms. Gastric vagal afferents (GVAs) respond to mechanical stimuli to initiate satiety. These signals are dampened in HFD mice and exhibit circadian variations inversely with food intake in lean mice. Furthermore, leptin shows circadian variation in its circulating level and is able to modulate GVA mechanosensitivity. However, whether leptin's ability to modulate GVAs occurs in a circadian manner is unknown. Therefore, we investigated whether changes in the circadian intake of food in HFD-induced obesity is associated with a disruption in GVA circadian rhythms. Eight-week-old male C57BL/6 mice were fed a standard laboratory diet (SLD) or a HFD for 12 weeks. A subgroup of SLD and HFD mice were housed in metabolic cages. After 12 weeks, ex vivo GVA recordings were taken at 3 h intervals starting at zeitgeber time 0 (ZT0) and stomach content was measured. After 12 weeks, HFD mice consumed more food during the light phase through larger and more frequent meals compared with SLD mice. SLD mice exhibited circadian fluctuation in stomach content, which peaked at ZT18 and reached a nadir at ZT9. At these time points, both tension and mucosal receptor mechanosensitivity were the lowest and highest, respectively. HFD mice exhibited little circadian variation in stomach content or GVA mechanosensitivity. Leptin potentiated mucosal receptor mechanosensitivity only in SLD mice and with reduced potency during the dark phase. In conclusion, loss of circadian variation in GVA signaling may underpin changes in eating behavior in HFD-induced obesity. Appropriate circadian control of food intake is vital for maintaining metabolic health. Diet-induced obesity is associated with strong circadian changes in food intake, but the contributing mechanisms have yet to be determined. Vagal afferents are involved in regulation of feeding behavior, particularly meal

  7. Prostaglandin potentiates 5-HT responses in stomach and ileum innervating visceral afferent sensory neurons

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sojin; Jin, Zhenhua; Lee, Goeun [Department of Physiology, School of Medicine, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Park, Yong Seek; Park, Cheung-Seog [Department of Microbiology, School of Medicine, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Jin, Young-Ho, E-mail: jinyh@khu.ac.kr [Department of Physiology, School of Medicine, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

    2015-01-02

    Highlights: • Prostaglandin E2 (PGE{sub 2}) effect was tested on visceral afferent neurons. • PGE{sub 2} did not evoke response but potentiated serotonin (5-HT) currents up to 167%. • PGE{sub 2}-induced potentiation was blocked by E-prostanoid type 4 receptors antagonist. • PGE{sub 2} effect on 5-HT response was also blocked by protein kinase A inhibitor KT5720. • Thus, PGE{sub 2} modulate visceral afferent neurons via synergistic signaling with 5-HT. - Abstract: Gastrointestinal disorder is a common symptom induced by diverse pathophysiological conditions that include food tolerance, chemotherapy, and irradiation for therapy. Prostaglandin E{sub 2} (PGE{sub 2}) level increase was often reported during gastrointestinal disorder and prostaglandin synthetase inhibitors has been used for ameliorate the symptoms. Exogenous administration of PGE{sub 2} induces gastrointestinal disorder, however, the mechanism of action is not known. Therefore, we tested PGE{sub 2} effect on visceral afferent sensory neurons of the rat. Interestingly, PGE{sub 2} itself did not evoked any response but enhanced serotonin (5-HT)-evoked currents up to 167% of the control level. The augmented 5-HT responses were completely inhibited by a 5-HT type 3 receptor antagonist, ondansetron. The PGE{sub 2}-induced potentiation were blocked by a selective E-prostanoid type4 (EP{sub 4}) receptors antagonist, L-161,982, but type1 and 2 receptor antagonist AH6809 has no effect. A membrane permeable protein kinase A (PKA) inhibitor, KT5720 also inhibited PGE{sub 2} effects. PGE{sub 2} induced 5-HT current augmentation was observed on 15% and 21% of the stomach and ileum projecting neurons, respectively. Current results suggest a synergistic signaling in visceral afferent neurons underlying gastrointestinal disorder involving PGE{sub 2} potentiation of 5-HT currents. Our findings may open a possibility for screen a new type drugs with lower side effects than currently using steroidal prostaglandin

  8. Movement and afferent representations in human motor areas: a simultaneous neuroimaging and transcranial magnetic/peripheral nerve-stimulation study

    Directory of Open Access Journals (Sweden)

    Hitoshi eShitara

    2013-09-01

    Full Text Available Neuroimaging combined with transcranial magnetic stimulation (TMS to primary motor cortex (M1 is an emerging technique that can examine motor-system functionality through evoked activity. However, because sensory afferents from twitching muscles are widely represented in motor areas the amount of evoked activity directly resulting from TMS remains unclear. We delivered suprathreshold TMS to left M1 or electrically stimulated the right median nerve (MNS in 18 healthy volunteers while simultaneously conducting functional magnetic resonance imaging and monitoring with electromyography (EMG. We examined in detail the localization of TMS-, muscle afferent- and superficial afferent-induced activity in M1 subdivisions. Muscle afferent- and TMS-evoked activity occurred mainly in rostral M1, while superficial afferents generated a slightly different activation distribution. In 12 participants who yielded quantifiable EMG, differences in brain activity ascribed to differences in movement-size were adjusted using integrated information from the EMGs. Sensory components only explained 10-20% of the suprathreshold TMS-induced activity, indicating that locally and remotely evoked activity in motor areas mostly resulted from the recruitment of neural and synaptic activity. The present study appears to justify the use of fMRI combined with suprathreshold TMS to M1 for evoked motor network imaging.

  9. Protective Effect of Morocco Carob Honey Against Lead-Induced Anemia and Hepato-Renal Toxicity

    Directory of Open Access Journals (Sweden)

    Aicha Fassi Fihri

    2016-06-01

    Full Text Available Background/Aims: Natural honey has many biological activities including protective effect against toxic materials. The aim of this study was to evaluate the protective effect of carob honey against lead-induced hepato-renal toxicity and lead-induced anemia in rabbits. Methods: Twenty four male rabbits were allocated into four groups six rabbits each; group 1: control group, received distilled water (0.1 ml / kg.b.wt /daily; group 2: received oral lead acetate (2 g/kg.b.wt/daily; group 3: treated with oral honey (1g /kg.b.wt/daily and oral lead (2 g/kg.b.wt/daily, and group 4: received oral honey (1 g/kg.b.wt/daily. Honey and lead were given daily during 24 days of experimentation. Laboratory tests and histopathological evaluations of kidneys were done. Results: Oral administration of lead induced hepatic and kidney injury and caused anemia during three weeks of the exposure. Treatment with honey prevented hepato-renal lead toxicity and ameliorated lead-induced anemia when honey was given to animals during lead exposure. Conclusion: It might be concluded that honey has a protective effect against lead-induced blood, hepatic and renal toxic effects.

  10. Renal scintigraphy in veterinary medicine.

    Science.gov (United States)

    Tyson, Reid; Daniel, Gregory B

    2014-01-01

    Renal scintigraphy is performed commonly in dogs and cats and has been used in a variety of other species. In a 2012 survey of the members of the Society of Veterinary Nuclear Medicine, 95% of the respondents indicated they perform renal scintigraphy in their practice. Renal scintigraphy is primarily used to assess renal function and to evaluate postrenal obstruction. This article reviews how renal scintigraphy is used in veterinary medicine and describes the methods of analysis. Species variation is also discussed.

  11. Primary renal synovial sarcoma

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    Girish D. Bakhshi

    2012-03-01

    Full Text Available Primary Renal Sarcoma is rare tumor comprising only 1% of all renal tumours. Synovial sarcomas are generally deep-seated tumors arising in the proximity of large joints of adolescents and young adults and account for 5-10% of all soft tissue tumours. Primary synovial sarcoma of kidney is rare and has poor prognosis. It can only be diagnosed by immunohistochemistry. It should be considered as a differential in sarcomatoid and spindle cell tumours. We present a case of 33-year-old female, who underwent left sided radical nephrectomy for renal tumour. Histopathology and genetic analysis diagnosed it to be primary renal synovial sarcoma. Patient underwent radiation therapy and 2 years follow up is uneventful. A brief case report with review of literature is presented.

  12. Renal protection in diabetes

    DEFF Research Database (Denmark)

    Parving, H H; Tarnow, L; Rossing, P

    1996-01-01

    BACKGROUND: The combination of diabetes and hypertension increases the chances of progressive renal disorder and, ultimately, renal failure. Roughly 40% of all diabetics, whether insulin-dependent or not, develop diabetic nephropathy. Diabetic nephropathy is the single most important cause of end......-stage renal disease in the Western world and accounts for more than a quarter of all end-stage renal diseases. Diabetic nephropathy is a major cause of increased morbidity and mortality in diabetic patients. Increased arterial blood pressure is an early and common phenomenon in incipient and overt diabetic...... nephropathy. The relationship between arterial blood pressure and diabetic nephropathy is a complex one, with diabetic nephropathy increasing blood pressure and blood pressure accelerating the course of nephropathy. OVERVIEW: Calcium antagonists antagonize preglomerular vasoconstriction. Additional putative...

  13. Renal primitive neuroectodermal tumors.

    Science.gov (United States)

    Bartholow, Tanner; Parwani, Anil

    2012-06-01

    Primitive neuroectodermal tumors exist as a part of the Ewing sarcoma/primitive neuroectodermal tumor family. These tumors most commonly arise in the chest wall and paraspinal regions; cases with a renal origin are rare entities, but have become increasingly reported in recent years. Although such cases occur across a wide age distribution, the average age for a patient with a renal primitive neuroectodermal tumor is the mid- to late 20s, with both males and females susceptible. Histologically, these tumors are characterized by pseudorosettes. Immunohistochemically, CD99 is an important diagnostic marker. Clinically, these are aggressive tumors, with an average 5-year disease-free survival rate of only 45% to 55%. Given that renal primitive neuroectodermal tumor bears many similarities to other renal tumors, it is important to review the histologic features, immunostaining profile, and genetic abnormalities that can be used for its correct diagnosis.

  14. Renal vein thrombosis

    Science.gov (United States)

    ... Saunders; 2012:chap 34. Read More Acute kidney failure Arteriogram Blood clots Dehydration Nephrotic syndrome Pulmonary embolus Renal Tumor Review Date 5/19/2015 Updated by: Charles Silberberg, ...

  15. Eligibility for renal denervation

    DEFF Research Database (Denmark)

    Persu, Alexandre; Jin, Yu; Baelen, Marie;

    2014-01-01

    -resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure-lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according......Based on the SYMPLICITY studies and CE (Conformité Européenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after...... undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility...

  16. Adult rabbits acquire resistance to lethal calicivirus infection by adoptive transfer of sera from infected young rabbits.

    Science.gov (United States)

    Ferreira, P G; Dinís, M; Costa-E-Silva, A; Aguas, A P

    2008-02-15

    Calicivirus infection of adult rabbits induces the so-called rabbit haemorrhagic disease (RHD) that kills 90% or more of the infected animals; in contrast, young rabbits (up to 8-week-old animals) are resistant to the same infectious agent. We report that calicivirus inoculation of young rabbits induced moderate titres of antiviral antibodies. When these rabbits reached adulthood, a second calicivirus inoculation resulted in resistance to RHD and boosting of antibody titres in half of the rabbits. Adoptive transfer of sera from calicivirus-infected young rabbits to naïve adult rabbits conferred resistance to RHD. We conclude that calicivirus infection of young rabbits induces specific anti-calicivirus antibodies that will protect them from RHD when they reach adulthood.

  17. Nephroprotective effect of Corn Silk extract on oxalic acid-induced nephrocalcinosis in rabbit model

    Directory of Open Access Journals (Sweden)

    Faruk Hassan Al-Jawad

    2012-04-01

    Full Text Available ABSTRACT Background : Nephrocalcinosis is a state of deposition of calcium phosphate or oxalate in the renal parenchyma. It may occur in patients with renal tubular acidosis, vitamin D intoxication, and hyperparathyroidism. Corn silk was used in traditional Chinese medicine to relieve renal pains. Aim: To evaluate the effect of Corn silk aqueous extract in reducing calcium deposits from renal parenchyma in oxalic acid-induced nephrocalcinosis model. Materials and methods: Fourteen healthy rabbits were allocated to two groups. Two hours before induction of nephrocalcinosis, one group received water and the other received aqueous extract of corn silk and continued feeding for ten days. Blood samples were collected for biochemical analysis before induction and in the fifth and tenth post-induction day. Urine samples were taken to estimate urinary ca+2 levels and crystals. The histopathological examination was carried to check for crystal deposits in renal tissues. Results: Corn silk aqueous extract produced a significant reduction of blood urea nitrogen(5.2+/-0.08 vs 7.3+/-0.2 mmol/l, serum creatinine (85.9+/-0.2 vs 97.3+/-0.5 mmol/l and serum Na+ levels (137+/-0.2 vs 142.16+/-0.7 mmol/l with non-significant reduction in serum K+ (4.0+/-0.02 vs 4.2+/-0.05. There is a significant reduction in calcium deposition in renal parenchyma in comparison to the control group after ten days of treatment. Conclusion: Corn silk had a significant diuretic effect that accelerates the excretion of urinary calcium. [J Intercult Ethnopharmacol 2012; 1(2.000: 75-78

  18. Rabbit haemorrhagic disease: advantages of cELISA in assessing immunity in wild rabbits (Oryctolagus cuniculus).

    Science.gov (United States)

    Zheng, Tao; Parkes, John P

    2011-12-15

    Rabbit haemorrhagic disease (RHD) is an acute fatal disease of domestic and wild European rabbits (Oryctolagus cuniculus) caused by RHD virus (RHDV). Accurate assessment of immunity is of great importance for the conservation and control of wild rabbits. We evaluated a competitive ELISA (cELISA) against isotype ELISAs for assessing the protective immunity against the disease by challenging 50 wild-caught rabbits with a lethal dose of RHDV. Death or survival to the challenge was used as a criterion to determine the performance characteristics of the assay for the assessment of immunity in rabbits. At 1:10 dilution, a serum exhibiting ≥ 25% inhibition (1:10(25)) was regarded as the presence of RHDV-specific antibodies. Eleven of 16 (68.8%) rabbits with antibodies at 1:10(25) (rabbit calicivirus, which interfered with isotype ELISAs, had little impact on the specificity of the cELISA for the diagnosis of RHDV infection. The presence of RHDV-specific antibody at 1:10(50) by the cELISA is a reliable indicator for the protective immunity. In contrast to isotype ELISAs, the cELISA is a valuable specific tool for monitoring the herd immunity to RHD for the conservation and management of wild rabbits in the field.

  19. Complete renal recovery from severe acute renal failure after thrombolysis of bilateral renal vein thrombosis.

    Science.gov (United States)

    Ramadoss, Suresh; Jones, Robert G; Foggensteiner, Lukas; Willis, Andrew P; Duddy, Martin J

    2012-10-01

    A previously healthy young man presented with acute renal failure due to extensive spontaneous deep vein thrombosis, including the inferior vena cava (IVC) and both renal veins. The patient was treated with selectively delivered thrombolytic therapy over a 7-day-period, which resulted in renal vein patency and complete recovery of renal function. A stent was placed over a segment stenosis of the IVC. No thrombophilic factors were identified. Bilateral renal vein thrombosis in young fit individuals is an unusual cause of acute renal failure. Thrombolytic therapy, even with delay, can completely restore renal function.

  20. OBSTETRIC RENAL FAILURE

    Directory of Open Access Journals (Sweden)

    Rajeshwari

    2015-11-01

    Full Text Available Renal failure in obstetrics is rare but important complication, associated with significant mortality and long term morbidity.1,2 It includes acute renal failure due to obstetrical complications or due to deterioration of existing renal disease. AIMS AND OBJECTIVES: To evaluate the etiology and outcome of renal failure in obstetric patients. METHODS: We prospectively analyzed 30 pregnant and puerperal women with acute renal failure or pre-existing renal disease developing renal failure during pregnancy between November 2007 to sep-2009. Patients who presented/developed ARF during the hospital stay were included in this study. RESULTS: Among 30 patients, mean age was 23 years and 33 years age group. 12 cases (40% patients were primigravidae and 9(30% patients were multigravidae and 9 cases (30% presented in post-partum period. Eighteen cases (60% with ARF were seen in third trimester, followed by in postpartum period 9 cases (30%. Most common contributing factors to ARF were Pre-eclampsia, eclampsia and HELLP syndrome 60%, sepsis 56.6%, post abortal ARF 10%. DIC 40%. Haemorrhage as the aetiology for ARF was present 46%, APH in 20% and PPH in 26.6%. The type of ARF was renal in (63% and prerenal (36%; Oliguric seen in 10 patients (33% and high mortality (30%. Among the 20 pregnant patients with ARF, The average period of gestation was 33±2 weeks (30 -36 weeks, 5 cases (25% presented with intrauterine fetal demise and 18 cases (66% had preterm vaginal delivery and 2 cases (10% had induced abortion. And the average birth weight was 2±0.5 kg (1.5 kg. Eight cases (26% required dialysis. 80% of patients recovered completely of renal functions. 63% patients recovered without renal replacement therapy whereas 17% required dialysis. the maternal mortality was 20%, the main reason for mortality was septic shock and multi organ dysfunction (66%. CONCLUSION: ARF related pregnancy was seen commonly in the primigravidae and in the third trimester, the most

  1. Renal papillary necrosis

    Directory of Open Access Journals (Sweden)

    Stephen A. Geller

    2013-12-01

    Full Text Available In 1877, Dr. Nikolaus Friedreich (1825-1882; student of Virchow who became Professor of Pathology at Heidelberg and who also described Friedreich’s ataxia first described renal papillary necrosis (RPN in patients with prostatic hypertrophy and secondary hydronephrosis. Thereafter in 1937, Froboese and Günther emphasized the association of this entity with diabetes mellitus. These authors also observed renal papillary necrosis in cases of urinary tract obstruction even in the absence of diabetes mellitus.

  2. [Hyperuricemia and renal risk].

    Science.gov (United States)

    Viazzi, Francesca; Bonino, Barbara; Ratto, Elena; Desideri, Giovambattista; Pontremoli, Roberto

    2015-01-01

    Recent studies have revealed an association between elevated levels of uric acid and conditions correlated to chronic kidney diseases such as hypertension, cardiovascular and cerebral disease, insulin resistance. Several pathogenetic mechanisms at cellular and tissue levels could justify a direct correlation between serum uric acid levels and renal damage. Growing evidence indicating a correlation between urate lowering therapy and renal morbidity could encourage the use of urate lowering therapy in primary or secondary prevention in chronic kidney disease.

  3. Scintigraphic imaging with {sup 99m}Tc- exorphin C in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Ertay, T. [Department of Nuclear Medicine, Medical School, Dokuz Eyluel University, Inciralti (Turkey)]. E-mail: turkan.ertay@deu.edu.tr; Uenak, P. [Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Bornova (Turkey); Tasci, C. [Department of Nuclear Medicine, Medical School, Dokuz Eyluel University, Inciralti (Turkey); Zihnioglu, F. [Department of Biochemistry, Faculty of Sciences, Ege University, Bornova, Izmir (Turkey); Durak, H. [Department of Nuclear Medicine, Medical School, Dokuz Eyluel University, Inciralti (Turkey)

    2005-06-01

    Exorphin C is a peptide with five amino acids [(Tyr-Pro-Ile-Ser-Leu) Trifluoroacetate salt] (Sigma) that has an affinity to opioid receptor-expressing tissues and tumors. Exorphin-C was labeled with {sup 99m}Tc using glucoheptonate (GH) as bifunctional chelating agent. Then, we investigated its radiopharmaceutical potential as opioid receptor-expressing tissue on rabbits. Quality controls were performed by ITLC, paper electrophoresis and HPLC. Labeling efficiency was higher than 98%. The compound was stable for at least 5 h at room temperature. Scintigraphic imaging with {sup 99m}Tc-GH-exorphin C ({sup 99m}Tc-GE) was performed on male Albino rabbits. Static images were obtained from anterior projection using a Camstar XR/T gamma camera at several time intervals. Although a significant amount of activity was seen in the brain, less activity was seen on receptor saturation studies at 30 min. Slight hepatobiliary excretion was seen, though the main excretion route was renal. After saturating, the receptor hepatobiliary excretion was not seen; the only excretion route was renal.

  4. Beta 2-microglobulin levels in serum and urine of cadmium exposed rabbits.

    Science.gov (United States)

    Piscator, M; Björck, L; Nordberg, M

    1981-07-01

    Male rabbits were exposed to cadmium during 16 weeks by subcutaneous injections of either 0.25 mg or 0.5 md Cd as cadmium chloride per kg body weight 3 times per week. beta 2-microglobulin (beta 2-m) and creatinine in serum, cadmium in blood, as well as total protein, creatinine, beta 2-m and cadmium in urine were determined before exposure and after 3 and 7 weeks of exposure. Measurements were also made at 19 weeks, 3 weeks after the last exposure. During exposure, there was a slight increase in the serum beta 2-m/creatinine ratio among rabbits with the highest exposure, while no effect of the cadmium burden could be observed once exposure had ceased. Urinary excretion of beta 2-m was related to urinary pH, which appeared to be the case also for excretion of total protein. In the high exposure group, a significant increase in urinary beta 2-m excretion, indicative of renal tubular dysfunction was seen after 7 weeks of exposure. This was, however, not related to serum beta 2-m levels. It was concluded that before renal damage has occurred even heavy cadmium exposure has very little influence on serum beta 2-m levels.

  5. Effect of cation-anion balance in feed on urine pH in rabbits in comparison with other species.

    Science.gov (United States)

    Heer, F; Dobenecker, B; Kienzle, E

    2017-03-16

    In the present investigation, the impact of diet composition on urine pH in rabbits was compared with previous studies on rabbits, cats, dogs, pigs and horses. A total of 13 dwarf rabbits were fed six different diets with a cation-anion balance (CAB) between -39 and +320 mmol/kg dry matter (DM) using ammonium chloride (NH4 Cl) as an acidifier. CAB was calculated as follows: CAB (mmol/kg DM) = 49.9*Ca + 82.3*Mg +43.5*Na + 25.6*K - 59*P - 62.4*S - 28.2*Cl; minerals in g/kg DM. Urine, faeces and blood were collected. Urine pH ranged from 5.26 ± 0.22 at a CAB of -39 mmol/kg DM to 8.56 ± 0.24 at a CAB of +320 mmol/kg DM. A low CAB in the feed reduced blood pH and blood base excess significantly. Renal excretion of Ca, P, Na and Mg and water was significantly higher in rabbits eating acidifying diets. In comparison with other species, rabbits reacted to acidifying diets in a similar way as cats, dogs and pigs. Rabbits on a mildly alkalizing diet, however, had a trend to higher urine pH than other monogastric species on such diets (cats, dogs, pigs, horses).

  6. Detection of parenchymal abnormalities in experimentally induced acute pyelonephritis in rabbits using contrast-enhanced ultrasonography, CT, and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jeong Ah; Kim, Bo Hyun; Kim, Seung Kwon; Seo, Jin Won [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Jong Sung [Laboratory Animal Research Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2016-12-15

    We evaluated the efficacy of contrast-enhanced ultrasonography (CEUS) in detecting acute pyelonephritis (APN) using the rabbit kidney model and compared it with CT and MRI. This study was approved by the Institutional Review Board. In a total of 20 New Zealand White rabbits, APN was induced experimentally. CEUS, CT, and MRI were performed on the first, third, and seventh postoperative days. After imaging studies, the subjects were sacrificed and the pathological diagnosis of APN was confirmed in each animal by a pathologist. Imaging studies were obtained in eight animals, including eight CEUS, four computed tomography (CT), and four magnetic resonance imaging (MRI) images. CEUS depicted diffuse renal enlargement (7), diffuse heterogeneous parenchymal enhancement (6), and focal areas of decreased parenchymal enhancement (6). These findings were well correlated with the CT and MRI findings in five cases in which these studies were available. CT and MRI showed diffuse renal enlargement, diffuse heterogeneous parenchymal enhancement, focal areas of decreased parenchymal enhancement, focal contour bulging, and the finding of perinephric spread of infection. In a rabbit model, CEUS could depict the parenchymal lesions of APN similar to CT or MRI; however, it was limited in depicting the perinephric extension of inflammation.

  7. Laparoscopic Renal Cryoablation

    Science.gov (United States)

    Schiffman, Marc; Moshfegh, Amiel; Talenfeld, Adam; Del Pizzo, Joseph J.

    2014-01-01

    In light of evidence linking radical nephrectomy and consequent suboptimal renal function to adverse cardiovascular events and increased mortality, research into nephron-sparing techniques for renal masses widely expanded in the past two decades. The American Urological Association (AUA) guidelines now explicitly list partial nephrectomy as the standard of care for the management of T1a renal tumors. Because of the increasing utilization of cross-sectional imaging, up to 70% of newly detected renal masses are stage T1a, making them more amenable to minimally invasive nephron-sparing therapies including laparoscopic and robotic partial nephrectomy and ablative therapies. Cryosurgery has emerged as a leading option for renal ablation, and compared with surgical techniques it offers benefits in preserving renal function with fewer complications, shorter hospitalization times, and allows for quicker convalescence. A mature dataset exists at this time, with intermediate and long-term follow-up data available. Cryosurgical recommendations as a first-line therapy are made at this time in limited populations, including elderly patients, patients with multiple comorbidities, and those with a solitary kidney. As more data emerge on oncologic efficacy, and technical experience and the technology continue to improve, the application of this modality will likely be extended in future treatment guidelines. PMID:24596441

  8. Neonatal renal vein thrombosis.

    Science.gov (United States)

    Brandão, Leonardo R; Simpson, Ewurabena A; Lau, Keith K

    2011-12-01

    Neonatal renal vein thrombosis (RVT) continues to pose significant challenges for pediatric hematologists and nephrologists. The precise mechanism for the onset and propagation of renal thrombosis within the neonatal population is unclear, but there is suggestion that acquired and/or inherited thrombophilia traits may increase the risk for renal thromboembolic disease during the newborn period. This review summarizes the most recent studies of neonatal RVT, examining its most common features, the prevalence of acquired and inherited prothrombotic risk factors among these patients, and evaluates their short and long term renal and thrombotic outcomes as they may relate to these risk factors. Although there is some consensus regarding the management of neonatal RVT, the most recent antithrombotic therapy guidelines for the management of childhood thrombosis do not provide a risk-based algorithm for the acute management of RVT among newborns with hereditary prothrombotic disorders. Whereas neonatal RVT is not a condition associated with a high mortality rate, it is associated with significant morbidity due to renal impairment. Recent evidence to evaluate the effects of heparin-based anticoagulation and thrombolytic therapy on the long term renal function of these patients has yielded conflicting results. Long term cohort studies and randomized trials may be helpful to clarify the impact of acute versus prolonged antithrombotic therapy for reducing the morbidity that is associated with neonatal RVT.

  9. Myelinated Afferents Are Involved in Pathology of the Spontaneous Electrical Activity and Mechanical Hyperalgesia of Myofascial Trigger Spots in Rats

    Directory of Open Access Journals (Sweden)

    Fei Meng

    2015-01-01

    Full Text Available Myofascial trigger points (MTrPs are common causes for chronic pain. Myelinated afferents were considered to be related with muscular pain, and our clinical researches indicated they might participate in the pathology of MTrPs. Here, we applied myofascial trigger spots (MTrSs, equal to MTrPs in human of rats to further investigate role of myelinated afferents. Modified pyridine-silver staining revealed more nerve endings at MTrSs than non-MTrSs (P0.05. 30 min after the injection, MPTs at MTrSs were significantly lower than those of non-MTrSs (P<0.01. Therefore, we concluded that proliferated myelinated afferents existed at MTrSs, which were closely related to pathology of SEA and mechanical hyperalgesia of MTrSs.

  10. Afferent projections from the brainstem to the area hypothalamica dorsalis: a horseradish peroxidase study in the cat.

    Science.gov (United States)

    Aguirre, J A; Coveñas, R; Alonso, J R; Lara, J M; Aijón, J

    1989-06-01

    Experiments using the retrograde transport of horseradish peroxidase were performed in order to identify the cells of origin the ascending projections from different brainstem regions to the area hypothalamica dorsalis (aHd) in the cat. The afferent inputs to this area originate mainly from the midbrain and medulla oblongata regions. The main afferent source of the area hypothalamica dorsalis arises from the substantia grisea centralis, where a large number of labeled cells were observed bilaterally, although more abundant on the ipsilateral side. Substantial afferents reach the aHd from the nuclei vestibularis medialis and inferior and the formatio reticularis mesencephali. A modest number of peroxidase-labeled neurons were observed in the nuclei ruber, interpeduncularis, substantia nigra, reticularis gigantocellularis, vestibularis lateralis, cuneatus and gracilis. From the pons, the nucleus raphe magnus sends a weak projection to the aHd. These anatomical data suggest that such area could be involved in visceral, sexual, nociceptive somatosensorial, sleep-waking and motor mechanisms.

  11. The urodelean Mauthner cell. Morphology of the afferent synapses to the M-cell of larval Salamandra salamandra

    Energy Technology Data Exchange (ETDEWEB)

    Cioni, C.; De Palma, F.; De Vito, L.; Stefanelli, A. [Rome, Univ. (Italy). Dipt. di Biologia Animale e dell`Uomo

    1997-12-31

    In the present work the fine morphology and the distribution of the afferent synapses to the Mauthner cell of larval Salamandra salamandra are described. The aim of the study is to characterize the synaptic bed in the larvae of this terrestrial salamander in order to compare it with that of larval axolotl and larval anurans. Four main types of afferent endings have been identified: myelinated club endings, round-vesicle end bulbs, flattened-vesicle end bulbs and spiral fibers endings. The M-cell afferent synaptology of larval stages of terrestrial amphibians is quite similar to that previously observed in larval stages of aquatic species. This fact can be related to the fundamental similarities between the larval lifestyles.

  12. An in vitro method for recording single unit afferent activity from mesenteric nerves innervating isolated segments of rat ileum.

    Science.gov (United States)

    Sharkey, K A; Cervero, F

    1986-04-01

    A technique has been developed for recording single unit afferent activity from mesenteric nerves in isolated segments of rat distal ileum in vitro. The preparation consists of a 3-cm segment of ileum, containing a single neurovascular bundle, held horizontally in an organ bath. One end of the segment is attached to a tension transducer to record changes in longitudinal tension of the gut muscle and the other is connected to a pressure transducer to record changes in intra-luminal pressure. Electromyographic activity of the smooth muscle is recorded using glass-insulated tungsten microelectrodes inserted in the wall of the gut. Afferent nerve activity is recorded with a monopolar platinum wire electrode from filaments of the mesenteric nerves that run between the artery and vein supplying the segment. This preparation permits the detailed analysis of the electrical activity of intestinal afferent nerve fibres correlated with mechanical and chemical events occurring naturally in the gut or imposed experimentally on it.

  13. Group II muscle afferents probably contribute to the medium latency soleus stretch reflex during walking in humans

    DEFF Research Database (Denmark)

    Grey, Michael James; Ladouceur, Michel; Andersen, Jacob B.

    2001-01-01

    1. The objective of this study was to determine which afferents contribute to the medium latency response of the soleus stretch reflex resulting from an unexpected perturbation during human walking. 2. Fourteen healthy subjects walked on a treadmill at approximately 3.5 km h(-1) with the left ankle...... component (P = 0.004), whereas the medium latency component was unchanged (P = 0.437). 6. Two hours after the ingestion of tizanidine, an alpha(2)-adrenergic receptor agonist known to selectively depress the transmission in the group II afferent pathway, the medium latency reflex was strongly depressed (P...... = 0.007), whereas the short latency component was unchanged (P = 0.653). 7. An ankle block with lidocaine hydrochloride was performed to suppress the cutaneous afferents of the foot and ankle. Neither the short (P = 0.453) nor medium (P = 0.310) latency reflexes were changed. 8. Our results support...

  14. The cough reflex is upregulated by lisinopril microinjected into the caudal nucleus tractus solitarii of the rabbit.

    Science.gov (United States)

    Cinelli, Elenia; Bongianni, Fulvia; Pantaleo, Tito; Mutolo, Donatella

    2015-12-01

    We have previously shown that cough potentiation induced by intravenous administration of the AT1 receptor antagonist losartan is lower than that induced by the ACE inhibitor lisinopril in anesthetized and awake rabbits. Since losartan and lisinopril cross the blood-brain barrier, their central action on the cough reflex can be hypothesized. Mechanical stimulation of the tracheobronchial tree and citric acid inhalation were used to induce cough reflex responses in pentobarbital sodium-anesthetized, spontaneously breathing rabbits. Bilateral microinjections (30-50 nl) of losartan (5mM), lisinopril (1mM), bradykinin (0.05 mM), HOE-140 (0.2mM, a bradykinin B2 receptor antagonist) and CP-99,994 (1mM, an NK1 receptor antagonist) were performed into the caudal nucleus tractus solitarii, the predominant site of termination of cough-related afferents. Lisinopril, but not losartan increased the cough number. This effect was reverted by HOE-140 or CP-99,994. Cough potentiation was also induced by bradykinin. The results support for the first time a central protussive action of lisinopril mediated by an accumulation of bradykinin and substance P.

  15. Targeting Strategies for Renal Cell Carcinoma: From Renal Cancer Cells to Renal Cancer Stem Cells

    OpenAIRE

    Zhi-xiang Yuan; Jingxin Mo; Guixian Zhao; Gang Shu; Hua-lin Fu; Wei Zhao

    2016-01-01

    Renal cell carcinoma (RCC) is a common form of urologic tumor that originates from the highly heterogeneous epithelium of renal tubules. Over the last decade, targeting therapies to renal cancer cells have transformed clinical care for RCC. Recently, it was proposed that renal cancer stem cells (CSCs) isolated from renal carcinomas were responsible for driving tumor growth and resistance to conventional chemotherapy and radiotherapy, according to the theory of CSCs; this has provided the rati...

  16. RENAL MALIGNANT NEOPLASMS: RENAL CELL CARCINOMA

    Directory of Open Access Journals (Sweden)

    Elisangela Giachini

    2017-06-01

    Full Text Available The aim of this study is to evaluate the incidence and prevalence of malignant kidney tumors, to contribute to identifying factors which the diagnosis of renal cell carcinomas. Through this study, we understand that kidney disease over the years had higher incidence rates, especially in adults in the sixth decade of life. The renal cell carcinoma (RCC is the third most common malignancy of the genitourinary tract, affecting 2% to 3% of the population. There are numerous ways of diagnosis; however, the most important are ultrasonography, magnetic resonance imaging and computed tomography. In general most of the patients affected by the CCR, have a good prognosis when diagnosed early and subjected to an effective treatment. This study conducted a literature review about the CCR, through this it was possible to understand the development needs of the imaging methods used for precise diagnosis and classification of RCC through the TNM system.

  17. Gentamicin induced nitric oxide-related oxidative damages on vestibular afferents in the guinea pig.

    Science.gov (United States)

    Hong, Sung Hwa; Park, Sook Kyung; Cho, Yang-Sun; Lee, Hyun-Seok; Kim, Ki Ryung; Kim, Myung Gu; Chung, Won-Ho

    2006-01-01

    Gentamicin is a well-known ototoxic aminoglycoside. However, the mechanism underlying this ototoxicity remains unclear. One of the mechanisms which may be responsible for this ototoxicity is excitotoxic damage to hair cells. The overstimulation of the N-methyl-d-aspartate (NMDA) receptors increases the production of nitric oxide (NO), which induces oxidative stress on hair cells. In order to determine the mechanism underlying this excitotoxicity, we treated guinea pigs with gentamicin by placing gentamicin (0.5 mg) pellets into a round window niche. After the sacrifice of the animals, which occurred at 3, 7 and 14 days after the treatment, the numbers of hair cells in the animals were counted with a scanning electron microscope. We then performed immunostaining using neuronal nitric oxide synthase (nNOS), inducible NOS (iNOS) and nitrotyrosine antibodies. The number of hair cells in the animals was found to decrease significantly after 7 days. nNOS and iNOS expression levels were observed to have increased 3 days after treatment. Nitrotyrosine was expressed primarily at the calyceal afferents of the type I hair cells 3 days after treatment. Terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining revealed positive hair cells 3 days after treatment. Our results suggest that inner ear treatment with gentamicin may upregulate nNOS and iNOS to induce oxidative stress in the calyceal afferents of type I hair cells, via nitric oxide overproduction.

  18. Physiological recruitment of motor units by high-frequency electrical stimulation of afferent pathways.

    Science.gov (United States)

    Dideriksen, Jakob L; Muceli, Silvia; Dosen, Strahinja; Laine, Christopher M; Farina, Dario

    2015-02-01

    Neuromuscular electrical stimulation (NMES) is commonly used in rehabilitation, but electrically evoked muscle activation is in several ways different from voluntary muscle contractions. These differences lead to challenges in the use of NMES for restoring muscle function. We investigated the use of low-current, high-frequency nerve stimulation to activate the muscle via the spinal motoneuron (MN) pool to achieve more natural activation patterns. Using a novel stimulation protocol, the H-reflex responses to individual stimuli in a train of stimulation pulses at 100 Hz were reliably estimated with surface EMG during low-level contractions. Furthermore, single motor unit recruitment by afferent stimulation was analyzed with intramuscular EMG. The results showed that substantially elevated H-reflex responses were obtained during 100-Hz stimulation with respect to a lower stimulation frequency. Furthermore, motor unit recruitment using 100-Hz stimulation was not fully synchronized, as it occurs in classic NMES, and the discharge rates differed among motor units because each unit was activated only after a specific number of stimuli. The most likely mechanism behind these observations is the temporal summation of subthreshold excitatory postsynaptic potentials from Ia fibers to the MNs. These findings and their interpretation were also verified by a realistic simulation model of afferent stimulation of a MN population. These results suggest that the proposed stimulation strategy may allow generation of considerable levels of muscle activation by motor u