Acute, but not repeated, cocaine administration decreases renin secretion in the conscious male rat

The effects of cocaine on renin secretion have been addressed and a previously unreported inhibitory effect has been identified on this neuroendocrine system in the conscious male rat. Acute intraperitoneal administration of cocaine dose-dependently (1.5, 7.5, 15, and 30 mg/kg; at 15 min) produced a significant decrease in both plasma renin activity (PRA) and plasma renin concentration (PRC). The time course of inhibition by cocaine in PRA and PRC revealed maximal effect at 15 min following a 15 mg/kg dose. In contrast, the long term administration of cocaine for 1, 7, or 30 days (15 mg/kg, twice daily, i.p.) did not produce changes in PRC.