Effect of prostacyclin infusion on active and inactive renin release in the isolated perfused kidney

The effect of prostacyclin infusion into the renal artery of the isolated perfused hog kidney on the release of active and inactive renin was investigated. Infusion of prostacyclin at a rate of 0.1 microgram/min resulted in a significant increase (p less than 0.01) in active renin and a significant fall (p less than 0.01) in inactive renin. Prostacyclin also increased urinary kallikrein excretion (p less than 0.05). The results indicate that the kidney secretes not only active renin but also inactive renin, and suggest that prostacyclin stimulates the conversion of inactive renin to the active form through the activation of the renal kallikrein system.