Glycemic control in diabetic dogs treated with pancreatic autotransplants and insulin pumps

The restoration of metabolic control in diabetes mellitus is predicated upon the uniform achievement of fasting euglycemia. In the absence of fasting normoglycemia, metabolic control is fundamentally compromised. We asked whether the currently experimental methods of treating experimental diabetes are capable of achieving normality in this regard. We therefore examined fasting plasma glycemia prospectively in a group of normal animals. This important index of metabolic homeostasis was remarkably tightly controlled with a mean +/- SD of 94 +/- 5 mg/dl. As a model of diabetes, we pancreatectomized a similar but larger group of animals. Some received grafts of their own pancreas while some received exogenous insulin by continuous intravenous infusion using an external pump. Half of this infused group received the insulin portally while the other half received it peripherally. Although our findings were globally similar to what has been reported previously, we elucidated subtle differences which heretofore have not been considered. Fist of all, the mean +/- SD fasting plasma glucose (FPG) concentration in the group of transplanted animals was 103 +/- 16 mg/dl, significantly higher than normal (p less than 0.001). It was, however, similar to the supra-normal levels we observed in the peripherally infused animals (100 +/- 25 mg/dl). Only the portally infused dogs had FPG levels of 95 +/- 27 mg/dl entirely similar to the normal controls. Most remarkably, all treatment methods resulted in variations in FPG levels which were significantly greater than normal (p less than 0.001), with coefficients of variation 3-5 times normal. Whether in the autotransplanted animals this variability represented the peripheral route of endogenous insulin replacement or the aneural nature of the transplanted gland was not clarified.(ABSTRACT TRUNCATED AT 250 WORDS)