Hypertension, Vol 3, 615-621, Copyright © 1981 by American Heart Association
CR Ayers, RE Katholi, RM Carey, MR Yancey and CL Morton
The effect of continuous intrarenal infusion of norepinephrine,
isoproterenol, and methoxamine on renin release was studied in the
uninephrectomized conscious dog. Chronic intrarenal infusion of
norepinephrine produced a biphasic curve of plasma renin activity (PRA) and
a sustained 25 mm Hg increase in mean arterial pressure (MAP). The initial
increase in PRA peaked at 3 hours, after which PRA returned to control
levels. Alpha- or beta-adrenergic antagonists did not attenuate the initial
rise in PRA. The PRA increased again after 48 hours of chronic intrarenal
norepinephrine infusion and remained elevated thereafter. The second rise
in PRA was increased by 30% with alpha- adrenergic blockade. Chronic
intrarenal isoproterenol administration produced a similar increase in PRA,
which peaked at 3-5 hours and then returned to control levels. In contrast
to norepinephrine, chronic isoproterenol administration did not result in a
second increase in PRA. At the end of the chronic isoproterenol infusion
period, beta- adrenergic receptor refractoriness was demonstrated, as PRA
did not increase significantly in response to a fourfold increase in the
dose of isoproterenol. An increase in PRA was produced by acute intrarenal
infusion of methoxamine. This increase in PRA was blocked by phentolamine,
suggesting a vascular alpha-adrenergic receptor-mediated release of renin.
ARTICLES
Acute and chronic intrarenal alpha- and beta- adrenergic receptor stimulation of renin release in the conscious dog
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