Experimental pancreas transplantation: the consequences of the portocaval shunt on the blood glucose, plasma insulin, and glucagon

Abstract

The consequences of the bypass of the portal venous effluent into the systemic circulation on the blood glucose, plasma insulin, and glucagon in immediate postoperative period of rats submitted to pancreas transplantation were studied. Forty outbred male Wistar rats were randomly assigned to two experimental groups: group NC included 20 non-diabetic control rats, submitted to simulated operating (sham-operated), and group PT included 20 diabetic rats that received heterotopic pancreas transplantation from normal donor Wistar rats. For 7 days prior and 1, 3, 6, 12, 24, 48, 72 and 96 hours after transplantation blood glucose, plasma insulin, and glucagon were recorded. These parameters were also concurrently recorded for NC rats. Diabetes was induced by i.v. alloxan administration; PT rats were immunosuppressed with cyclosporin A. NC rats presented normal values of blood glucose, plasma insulin, and glucagon over the course of experiment. A marked hyperinsulinemia was found in peripheral venous blood of PT rats, being plasma insulin significantly higher than that for NC rats (P<0.01) beginning 72- h after transplant. The plasma glucagon, elevated in pre-transplant period, did not change after transplant. Despite hyperinsulinemia and hyperglucagonemia, the blood glucose levels were elevated up to 6- h after transplant, but were within normal levels following this period. Beginning at 12- h after transplant the blood glucose levels observed in PT rats did not differ significantly to NC rats until the sacrifice.