AJP - Regulatory, Integrative and Comparative Physiology, Vol 250, Issue 4 633-R637, Copyright © 1986 by American Physiological Society
Suppression of renin release by antagonism of endogenous opiates in the dog
J. E. Szilagyi, J. Chelly and M. F. Doursout
The influence of blockade of endogenous opioids on the release of renin due
to partial renal arterial constriction was determined acutely and
chronically in unilaterally nephrectomized dogs. In acute preparations
changes in plasma renin activity, arterial blood pressure, and heart rate
were determined after 15 min of 60% renal arterial constriction before and
after administration of either a saline vehicle, the opiate antagonist
naloxone (0.05 mg/kg), or morphine (2 mg/kg). Acute antagonism of
endogenous opiates abolished the increase in plasma renin activity and mean
arterial pressure associated with renal arterial constriction. Repeated
renal arterial constrictions in saline- or morphine-treated animals did not
alter the humoral or hemodynamic responses. In chronic preparations
long-term naloxone infusion attenuated the development of renovascular
hypertension and diminished the increase in plasma renin activity. These
data suggest that endogenous opioid peptides are modulators in the control
of renin release and may be important participants in the pathogenesis of
hypertension.
