Uterine and renal renin release after ligation of the uterine arteries in the pregnant rabbit.

Uteroplacental ischemia is associated with uterine renin release in pregnant nephrectomized rabbits. In the present study, uterine and renal renin release after uteroplacental ischemia were investigated in 10 Australian white rabbits at 24 to 28 days' gestation. Pentobarbital was administered, and both uterine arteries were ligated close to their origins. Blood samples were taken for plasma renin activity (PRA) determinations from the femoral artery, uterine vein, and right renal vein before ligation and at 30 and 60 minutes after ligation. Mean arterial blood pressure (MAP) was monitored throughout. In five additional pregnant rabbits renal blood flow (RBF) was measured with an electromagnetic flowmeter. The preligation uterine vein-artery PRA difference was not significant (1.9 +/- 1.1 ng/ml/hr). Postligation uterine vein-artery PRA was 11.4 +/- 3.2 at 30 minutes and 6.6 +/- 1.9 ng/ml/hr at 90 minutes (p less than 0.02). Preligation renal vein-artery PRA was 32.3 +/- 10.5 ng/ml/hr (p less than 0.02) and did not change significantly after ligation. MAP remained stable and RBF was unchanged after uterine artery ligation. These observations confirm the finding that the kidney is the primary source of renin in the normal pregnant rabbit and demonstrate that following acute uteroplacental ischemia there is significant uterine renin release even when the kidneys are intact.