Failure of alpha-adrenergic stimulation by phenylephrine to enhance renin secretion in the isolated rat kidney.

The intrarenal effect of the alpha-receptor agonist phenylephrine on renin secretion was examined in the isolated rat kidney. Infusion of phenylephrine in non-vasoconstrictor doses resulted in secretion rates which were not significantly different from control values. Similarly no change in renin secretion was found when phenylephrine was infused at a dose that clearly caused renal vasoconstriction and increased vascular resistance. These results do not support the hypothesis of a role for the alpha-receptor in the stimulation of renin secretion by adrenergic activity.