Neuropeptide Y lowers plasma renin activity in the anaesthetised cat

The effect of intravenously administered neuropeptide Y (NPY) on circulating renin activity has been investigated in the anaesthetized cat. Bolus pressor doses of NPY (100, 300, 1000 and 3000 pmol/kg) produced a dose-related fall in renal conductance and a parallel reduction of plasma renin activity. Low dose infusions of NPY (12.5, 50 and 200 pmol/kg/min) for consecutive 20 min periods had no effect on mean arterial blood pressure or renal conductance, but still produced a concentration dependent fall in plasma renin activity. At the end of the infusion plasma renin activity increased rapidly as the circulating concentration of NPY declined. The infusion study suggests that NPY has a direct inhibitory action on renin secretion.