Comparison of Portal and Peripheral Insulin Delivery on Lipid Metabolism in Streptozocin-diabetic Rats

Severely diabetic (150 mg/kg streptozocin, STZ) rats were transplanted with fetal pancreatic islets: (1) under the renal capsule to model peripheral insulin delivery, and (2) into the splenic pulp to model portal delivery. In both groups of transplanted animals, weight gainand blood glucose levels were normal as were peripheral plasma insulin levels. Plasma nonesterified fatty acids, glycerol, acetoacetate, 3-hydroxybutyrate, triglyceride, and cholesterol levels were normal in the two groups of transplanted animals as were VLDL-triglyceride turnover and totalketone body turnover. Adipose tissue lipoprotein lipase activity was also normal in both the fed and fasting states. The findings indicate that consistent normoglycemia and normalization of manyaspects of lipid metabolism can be achieved in the rat with peripheral insulin delivery without associated hyperinsulinemia.