Direct inhibitory effect of atriopeptin III on renin release in primate kidney

Patterns of in vitro renal renin release and the ability of atriopeptin to directly inhibit renin release have been examined in the rat, rabbit, and dog, but have been unstudied in the primate kidney. Accordingly, we examined renin release from superficial renal cortical slices of the squirrel monkey (Samiri sciuresus). The average age of the 5 animals was 10.2±2.5 yr at the time of study. Renin release was stimulated significantly by the β-adrenergic agonist isoproterenol in concentrations of 10^-5M (1.67-fold) and 10^-4M (1.84-fold). Isoproterenol-induced renin release was inhibited by atriopeptin III (ANP, 2×10^-8M) and the adenylate cyclase inhibitor dideoxadenosine (DDA, 10^-5M). Similarly, the incubation of the superficial cortical slices with arachidonic acid (10^-3M) resulted in a 4-fold increase in tissue renin release which was blocked by the calcium ionophore A23187 (17×10^-6M) and ANP; interestingly, DDA did not block arachidonic acid-induced renin release. These results suggest that ANP exerts a direct inhibitory effect on B-adrenergic and arachidonic acid-induced renin release in the primate kidney. Further, the inhibitory action of A23187 on renin release suggests, as in other species, an integral role for intracellular calcium in the renin release process. These patterns of renin release in primate kidney are similar to those observed in the rodent kidney in vitro.