Correction of decreased guanylate cyclase activity in diabetic rats by pancreatic islet transplantation.

We have previously demonstrated that streptozotocin-induced diabetic rats have decreased guanylate cyclase (EC 4.6.1.2) activity in liver and other tissues which was returned to normal by the administration of exogenous insulin. Since successful pancreatic islet transplants have been shown to lower basal hepatic glucose output, gluconeogenesis, and urea production, pancreatic islet transplants seemed to be a more physiological model to test the in vivo effects of insulin on guanylate cyclase activity in diabetic animals. The present investigation demonstrates that pancreatic islet transplants into two different species of streptozotocin-induced diabetic rats increased the lowered activity of guanylate cyclase activity found in diabetic animals to the level of guanylate cyclase activity present in control animals.