Release of active and inactive renin from hog renal cortical slices in vitro.

Both inactive and active renin were released from renal cortical slices of the hog. Isoproterenol, prostaglandin E1, and dibutyryl cAMP stimulated the release of both inactive and active renin. Renal kallikrein caused selective stimulation of the release of active renin and suppressed the release of inactive renin. Bradykinin and kallidin did not stimulate renin release. The effect of kallikrein was abolished by aprotinin but not by indomethacin. These observations indicate that the effect of kallikrein is not mediated via kinin formation or prostaglandin generation. The data suggest that there may be at least two types of mechanism for renin release from hog kidney. One is of the nonselective type by which both active and inactive renin are released, as in the case of beta-adrenergic or prostaglandin stimulation. The other is a selective mechanism by which only active renin is preferentially released, as in the case of urinary or renal kallikrein stimulation.