|
|
||||||||
NEUROHUMORAL CONTROL OF CIRCULATION AND HYPERTENSION
Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
Submitted 11 September 2003 ; accepted in final form 22 February 2004
The present study sought to determine whether an acute increase in arterial blood pressure (ABP) reduces plasma vasopressin (VP) levels stimulated by ANG II or hyperosmolality. During an intravenous infusion of ANG II (100 ng·kg1·min1), attenuation of the ANG II-evoked increase in ABP with diazoxide or minoxidil did not further enhance plasma VP levels in rats. When VP secretion was stimulated by an infusion of hypertonic saline, coinfusion of the
-adrenergic agonist phenylephrine (PE) significantly increased ABP but did not reduce plasma VP levels. In fact, plasma VP levels were enhanced. The enhancement of plasma VP levels cannot be explained by a direct stimulatory action of PE, as plasma VP levels of isosmotic rats did not change during a similar infusion of PE. An infusion of endothelin-1 in hyperosmotic rats significantly raised ABP but did not reduce plasma VP levels; rather, VP levels increased as observed with PE. In
-chloralose-anesthetized rats infused with hypertonic saline, inflation of an aortic cuff to increase ABP and stimulate arterial baroreceptors did not reduce plasma VP levels. In each experiment, plasma oxytocin levels paralleled plasma VP levels. Collectively, the present findings suggest that an acute increase in ABP does not inhibit VP secretion.
baroreceptor; vasopressin; oxytocin
This article has been cited by other articles:
![]() |
C. J. Madden, S. D. Stocker, and A. F. Sved Attenuation of homeostatic responses to hypotension and glucoprivation after destruction of catecholaminergic rostral ventrolateral medulla neurons Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2006; 291(3): R751 - R759. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. J. Mueller, M. J. Sullivan, R. R. Grindstaff, J. T. Cunningham, and E. M. Hasser Regulation of plasma vasopressin and renin activity in conscious hindlimb-unloaded rats Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2006; 291(1): R46 - R52. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. D. Stocker, M. E. Wilson, C. J. Madden, U. Lone, and A. F. Sved Intravenous 6-hydroxydopamine attenuates vasopressin and oxytocin secretion stimulated by hemorrhage and hypotension but not hyperosmolality in rats Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2006; 291(1): R59 - R67. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. D Stocker and G. M Toney Median preoptic neurones projecting to the hypothalamic paraventricular nucleus respond to osmotic, circulating Ang II and baroreceptor input in the rat J. Physiol., October 15, 2005; 568(2): 599 - 615. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |