Inhibition of the adrenalectomy-induced increase in plasma renin concentration by vasoconstrictor agents in rats.

Plasma renin concentrations in rats increase after bilateral adrenalectomy without sodium substitution. The effects of i.v. infused (asp1-beta-amid, val5)-angiotensin II (1 mug/kg min), felypressin (phen2, lys8-vasopressin) (40 mU/kg min) and phenylephrine (30 mug/kg min) were investigated on the increase in plasma renin concentration. These effects of the agents were compared with their actions on blood pressure, heart rate and renal hemodynamics. In rats with destroyed macula densa cells the effect of bilateral adrenalectomy without sodium substitution was also studied. Adrenalectomy still increased the plasma renin concentration. Angiotensin II and felypressin, also depressed under these conditions the elevation of plasma renin concentration caused by adrenalectomy. The mechanism of the adrenalectomy-induced renin release and its suppression by vasoconstrictor agents is discussed.