Differential effect of guanethidine on dopamine and norepinephrine in rat peripheral tissues

Favre-Maurice, R.; Haut, Mitchell; Dalmaz, Y.; Peyrin, L

doi:10.1007/bf01244817

Cited by 8 publications

(5 citation statements)

References 36 publications

(26 reference statements)

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“…In the present study, we observed a Ͼ10-fold decrease in NE and Epi levels in the heart atria from the guanethidine-treated animals compared with the control group. This result is in line with heart catecholamine levels in sympathectomized and control rats reported by other investigators (17,27,38,39) and, along with the BP reduction displayed by guanethidine-treated rats used for this study, is consistent with having achieved an almost total chemical sympathectomy.…”

Section: Discussionsupporting

confidence: 78%

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Calcitonin gene-related peptide and substance P contribute to reduced blood pressure in sympathectomized rats

Supowit¹,

Ethridge²,

Zhao³

et al. 2005

American Journal of Physiology-Heart and Circulatory Physiology

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DiPette. Calcitonin gene-related peptide and substance P contribute to reduced blood pressure in sympathectomized rats. Am J Physiol Heart Circ Physiol 289: H1169 -H1175, 2005. First published May 6, 2005; doi:10.1152/ajpheart.00973.2004.-CGRP and substance P (SP) are produced in dorsal root ganglia (DRG) sensory neurons and modulate vascular tone. Sympathetic and sensory nerves compete for NGF, a potent stimulator of CGRP and SP, and it has been suggested that sympathetic hyperinnervation in spontaneously hypertensive rats may reduce the availability of NGF to sensory nerves, thus reducing CGRP and SP. The purpose of this study was to determine whether destruction of peripheral sympathetic nerves in normal rats would increase the availability of NGF for sensory neurons and enhance expression of CGRP and SP. Sympathectomy was produced in rats by guanethidine sulfate administration. Control rats received saline. Sympathectomized rats displayed reductions in blood pressure (BP) and atria norepinephrine levels, whereas NGF levels in the DRG, spleen, and ventricles were increased. Sympathectomy also enhanced CGRP and SP mRNA and peptide content in DRG. Administration of CGRP and SP receptor antagonists increased the BP in sympathectomized rats but not in the controls. Thus sympathectomy enhances sensory neuron CGRP and SP expression that contributes to the BP reduction.guanethidine; blood pressure; peripheral nervous system; nerve growth factor CALCITONIN GENE-RELAXED PEPTIDE (CGRP) and substance P (SP) are potent vasodilator neuropeptides that have been implicated in the regulation of regional organ blood flows and blood pressure (BP), both under normal physiological conditions and in hypertension (6,7,9,10,15,16,36,43,54). Immunoreactive CGRP (iCGRP), SP (iSP), and their receptors are widely distributed in the nervous and cardiovascular systems (6,7,9,10,15,16,23,54). A prominent site of CGRP and SP production is the dorsal root ganglia (DRG) that contain the cell bodies of sensory nerves that terminate peripherally in blood vessels and in other tissues innervated by the sensory nervous system and that terminate centrally in the dorsal horn of the spinal cord. A dense perivascular CGRP and SP neural network is seen around the blood vessels in all vascular beds. In these vessels, CGRP and SP containing nerves are found at the junction of the adventia and the media passing into the muscle layer (6,9,10,15,16,23,54). Indeed, these peptides are often colocalized in the same peripheral nerve terminals. CGRP and SP are released tonically and circulate normally in humans and animals (6,9,15,25,26,54). Plasma CGRP is largely derived from perivascular nerve terminals and is thought to represent a spillover phenomenon related to the release of these peptides to promote vasodilation or other functions. Plasma SP also comes from these perivascular nerve terminals as well as the intestine. Receptors for CGRP have been identified in the endothelial layer, media, and intima of resistance vessels, whereas SP receptors [neurokini...

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Section: Discussionsupporting

confidence: 78%

“…Chemical sympathectomy with guanethidine selectively destroys the postganglionic noradrenergic neurons, whereas dopaminergic fibers and nonneural catecholamine-secreting cells are spared (17,27,38,39). This destruction of peripheral sympathetic nerves occurs through an immune system-mediated response.…”

Section: Discussionmentioning

confidence: 99%

Calcitonin gene-related peptide and substance P contribute to reduced blood pressure in sympathectomized rats

Supowit¹,

Ethridge²,

Zhao³

et al. 2005

American Journal of Physiology-Heart and Circulatory Physiology

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“…Denervation, using a combination of vagotomy, surgical and chemical sympathectomy, eliminated 97% of norepinephrine and adrenaline, but only reduced DA to 40% [16, 24]. These results and those of other groups [25, 26] together indicate the existence of a nonneuronal DA source in the gastrointestinal tract.…”

Section: Introductionsupporting

confidence: 61%

Dopamine Produced by the Stomach May Act as a Paracrine/ Autocrine Hormone in the Rat

Mezey¹,

Eisenhofer

Hansson

et al. 1998

Neuroendocrinology

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Dopamine (DA) has been suggested to be a protective factor in the gastrointestinal tract but neither a source of DA nor its exact targets of action have been identified. In this study, we demonstrate high levels of DA (and DOPA) which persist after chemical sympathectomy in the gastric juice of rats. Immunostaining and in situ hybridization histochemistry reveal the presence of tyrosine hydroxylase (TH), DA transporter and vesicular monamine transporters in the acid-producing parietal cells. Like DA, TH enzyme activity remains after chemical sympathectomy. We also demonstrate active reuptake and storage of DA that indicates a regulated release of this neurohormone from parietal cells. DA D1b receptor mRNA is the most abundant DA receptor subtype in gastric and duodenal epithelium. Therefore, we suggest that selective DA D1b receptor agonists may be useful adjuncts in the treatment of duodenal and gastric ulcers. Gastric epithelia possess the hallmarks of functional DA neuroendocrine cells, suggesting that DA has an important role in self-protective mechanisms of the gastrointestinal tract. These findings should allow elucidation of DA role in normal and disease states in the stomach and duodenum.

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“…Rats had free access to water throughout the study. At the end of the experiment, rats received an intravenous overdose of pentobarbital sodium, and both kidneys were removed, weighed, and frozen for subsequent determination of norepinephrine concentration (9).…”

Section: Methodsmentioning

confidence: 99%

Spontaneous renal blood flow autoregulation curves in conscious sinoaortic baroreceptor-denervated rats

Pires

Julien

Chapuis

et al. 2002

American Journal of Physiology-Renal Physiology

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Pires, Silene L. S., Claude Julien, Bruno Chapuis, Jean Sassard, and Christian Barrè s. Spontaneous renal blood flow autoregulation curves in conscious sinoaortic baroreceptor-denervated rats. Am J Physiol Renal Physiol 282: F51-F58, 2002. First published August 8, 2001 10.1152/ajprenal.00186.2001.-These experiments examined whether the conscious sinoaortic baroreceptor-denervated (SAD) rat, owing to its high spontaneous arterial pressure (AP) variability, might represent a model for renal blood flow (RBF) autoregulation studies. In eight SAD and six baroreceptor-intact rats, AP and RBF were recorded (1-h periods) before and after furosemide (10 mg/kg followed by 10 mg ⅐ kg Ϫ1 ⅐ h Ϫ1 iv) administration. In control conditions, AP variability was markedly enhanced in SAD rats (coefficient of variation: 16.0 Ϯ 1.2 vs. 5.4 Ϯ 0.5% in intact rats), whereas RBF variability was only slightly increased (8.7 Ϯ 0.6 vs. 6.1 Ϯ 0.5% in intact rats), suggesting buffering by autoregulatory mechanisms. In SAD rats, but not in intact rats, the AP-RBF relationships could be modeled with a four-parameter sigmoid Weibull equation (r 2 ϭ 0.24 Ϯ 0.07, 3,600 data pairs/rat), allowing for estimation of an autoregulatory plateau (10.1 Ϯ 0.7 ml/min) and a lower limit of RBF autoregulation (PLL ϭ 93 Ϯ 6 mmHg, defined as AP at RBF 5% below the plateau). After furosemide treatment, autoregulation curves (r 2 ϭ 0.49 Ϯ 0.07) in SAD rats were shifted downward (plateau ϭ 8.6 Ϯ 0.8 ml/min) and rightward (PLL ϭ 102 Ϯ 5 mmHg). In five of six intact rats, PLL became measurable (104 Ϯ 1 mmHg), albeit with limited accuracy (r 2 ϭ 0.09 Ϯ 0.03). In conclusion, the conscious SAD rat offers the possibility of describing RBF autoregulation curves under dynamic, unforced conditions. The tubuloglomerular feedback and myogenic mechanisms cooperate in setting PLL and thus in stabilizing RBF during spontaneous depressor episodes.arterial pressure variability; furosemide; modeling AUTOREGULATION OF TOTAL RENAL blood flow (RBF) is usually explored by measuring RBF responses to externally induced stepwise reductions of arterial pressure (AP) in both anesthetized (6,8,11,13,17,21,22) and conscious (2,4,16,18,(24)(25)(26) animals. Steady-state levels of RBF are plotted as a function of AP, which allows the drawing of autoregulation curves from which the plateau and lower pressure limit of RBF autoregulation (P LL ) are estimated. It is not known whether such information can be gained under spontaneous unforced conditions, i.e., using RBF responses to naturally occurring AP fluctuations.The conscious sinoaortic baroreceptor-denervated (SAD) rat is a well-recognized model of exaggerated AP variability, which is characterized by the spontaneous occurrence of pressor and depressor episodes of occasionally large amplitude (3,28). Recently, we have investigated in conscious SAD rats the relationships between AP variability and RBF variability (20). Although AP variability was markedly increased, RBF variability was only slightly increased, suggesting a powerful participa...

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Differential effect of guanethidine on dopamine and norepinephrine in rat peripheral tissues

Cited by 8 publications

References 36 publications

Calcitonin gene-related peptide and substance P contribute to reduced blood pressure in sympathectomized rats

Calcitonin gene-related peptide and substance P contribute to reduced blood pressure in sympathectomized rats

Dopamine Produced by the Stomach May Act as a Paracrine/ Autocrine Hormone in the Rat

Spontaneous renal blood flow autoregulation curves in conscious sinoaortic baroreceptor-denervated rats

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