Portal versus peripheral venous drainage in segmental pancreatic transplantation in diabetic rats

The effect of the site of venous drainage in segmental pancreatic transplantation was investigated in diabetic rats with two surgical procedures anastomosing the superior mesenteric vein either on the vena cava (systemic drainage) or on the superior mesenteric vein (portal drainage). Both procedures corrected polyuria, glycosuria, and blood glucose concentration, and resulted in similar peripheral hyperinsulinemia. Intravenous glucose tolerance tests were performed 8 weeks after transplantation. In portal-grafted rats, glucose tolerance was strictly normalized, with a plasma insulin profile similar to that observed in normal rats. In caval-grafted rats, a delayed plasma insulin peak was observed with slight abnormalities in the plasma glucose profile, the late plasma glucose concentrations being higher than in portal-grafted animals. The extent of fibrosis was similar under both conditions. This study, performed in rats, of the influence of venous drainage on the metabolic outcome of segmental transplantation, demonstrating an abnormal plasma insulin profile during a glucose challenge in case of caval drainage, is consistent with other studies suggesting that the site of drainage might be important in case of reduced grafted mass.