Mechanism of renin inhibition by beta adrenergic blocking agents. Effects of dl-, d-, l-propranolol and pindolol on renin release.

In order to reveal the mechanism of renin inhibition by beta adrenergic blocking agents, the effects of dl-, d-, l-propranolol and pindolol on renin release were studied. This was done by injecting them intraperitoneally or by using an in vitro system of rat kidney slices. In the in vivo study, dl-, d-, and l-propranolol inhibited plasma renin activity and renal renin content significantly in normal rats. Furthermore, in the in vitro study, the basal levels of renin in the media and that in the kidney were significantly inhibited by these agents. Pindolol also inhibited renin release, but its effects were significantly less than those of other agents. The finding that d-propranolol which has little beta adrenergic blocking action inhibited renin release, and that the effects of pindolol which displays strong beta adrenergic blocking action but little membrane stabilizing action, were less than those of other agents, may suggest that the inhibitory effects of beta adrenergic blocking agents on renin release are dependent mainly on the membrane stabilizing action rather than the beta adrenergic blocking action.