AJP - Regulatory, Integrative and Comparative Physiology, Vol 255, Issue 5 768-R773, Copyright © 1988 by American Physiological Society

ARTICLES

Effects of chronic sinoaortic denervation on central vasopressin and catecholamine systems

N. Alexander and M. Morris
Department of Medicine, University of Southern California School of Medicine, Los Angeles 90033.

The objective of this study was to determine whether chronic arterial baroreceptor deficit induces time-related changes in central vasopressin (AVP) and catecholamine systems. Groups of sinoaortic-denervated (SAD) and sham-operated (SO) rats were studied 1, 3, 4, 7, and 14 days after surgery. Supraoptic (SON), paraventricular (PVN) and arcuate (ARC) nuclei, median eminence (ME) region, and A1 region of medulla were obtained by micropunch from frozen brain sections and assayed for AVP, tyrosine hydroxylase (TH) activity, catecholamines, and their metabolites, dihydroxyphenylethyleneglycol (DOPEG) and 2,5-dihydroxyphenylacetic acid (DOPAC). AVP concentration in SON and PVN was increased in 1-day-SAD rats, reduced in 3- and 4-day-SAD rats, equal and above control values in 7- and 14-day-SAD rats, respectively. TH activity was increased in SON and reduced in ME and ARC of 1- and 7-day-SAD rats. In SON, DOPEG was increased, whereas in ME all catecholamines and DOPEG and DOPAC were reduced in 1-day-SAD rats. ME catecholamines returned toward control levels in 3- to 4-day-SAD rats. These studies show that the chronic absence of arterial baroreceptor input produces time-related, regionally specific central changes of vasopressin and regionally associated catecholamines.

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				D. L. Dufloth, M. Morris, and L. C. Michelini Modulation of exercise tachycardia by vasopressin in the nucleus tractus solitarii Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1997; 273(4): R1271 - R1282. [Abstract] [Full Text] [PDF]