In vitro effects of various metabolic inhibitors on the formation of inactive renin and the loss of renin in rabbit uterine tissue.

A pronounced formation of renin occurs during incubation of non-pregnant uterine tissue slices in vitro. The synthesized renin appears in an enzymatically inactive form, which can be activated by acidification. Prior to incubation only a small fraction of inactive renin is present. The formation of inactive renin is blocked by puromycin and by inhibition of energy metabolism, indicating a de novo synthesis. A similar pattern of inhibition prevails the modest formation of inactive renin in post-partum uterus. The marked loss of active renin seen during incubation of post-partum uterine tissue is partly prevented by an inhibition of energy metabolism. Potent inhibitors are iodoacetate and chloroquine. These findings are in accordance with lysosomal engagement in the inactivation of renin. Incubated kidney cortex tissue shows only a minor loss of renin during incubation. This loss is uninfluenced by attempts to block it.