| Abstract: | Effects of intrarenal infusions of prazosin (0.7 microgram/kg/min), yohimbine (1 microgram/kg/min), propranolol (4 micrograms/kg/min) and sulpiride (20 micrograms/kg/min) on renal prostaglandin (PG) E2 and renin release in response to renal nerve stimulation (RNS) were examined in anesthetized dogs. RNS (2.5-5 Hz, for 10 min) decreased renal blood flow and increased both PGE2 and renin secretion rates. The blood flow response was inhibited by prazosin but not by other antagonists. Prazosin and propranolol, but not yohimbine or sulpiride, attenuated the renin response. However, none of these antagonists affected the PGE2 response. The results suggest that the RNS-induced renin release is mediated by alpha adrenoceptors, which seem to be alpha-1 type, and beta adrenoceptors, but the RNS-induced PGE2 release is not mediated by these adrenoceptors. Renal dopaminergic component may play no significant role in the RNS-induced PGE2 or renin release. |
