Inhibition of renal sympathetic nerve activity of anesthetized rats by intracerebroventricular administration of angiotensin II.

Effects of intracerebroventricular (i. c. v.) administration of angiotensin II (AII) on renal sympathetic nerve activity (RSNA), arterial pressure, and heart rate were examined in rats anesthetized with a mixture of urethane and alpha-chloralose. Administration of AII evoked an increase in arterial pressure and a decrease in RSNA with no significant change in heart rate. Prior i. c. v. administration of an AII antagonist, saralasin, greatly attenuated the pressor response and inhibition of RSNA induced by i. c. v. AII. Rats with sinoaortic denervation showed the same magnitude pressor response and decrease in RSNA as intact animals. The result suggests that central AII directly inhibits RSNA via AII specific receptors.