The present study was undertaken to examine the possible augmentation of clonidine on the control of renal sympathetic nerve activity by Bezold-Jarisch reflex in anesthetized cats. Veratrine (3-20 micrograms/kg) produced dose-dependent decreases in arterial blood pressure (BP), heart rate (HR) and renal sympathetic nerve activity (RNA). Clonidine (3 micrograms/kg) resulted in decreases in BP, HR and RNA. Clonidine significantly potentiated the influence of Bezold-Jarisch reflex on RNA, but did not potentiate the influence of Bezold-Jarisch reflex on BP and HR. Bezold-Jarisch reflex gain calculated as percent inhibition of renal sympathetic nerve activity divided by decreases in mean blood pressure was significantly higher after the administration of clonidine.