The effects of cyproheptadine on glucose tolerance and pancreatic islets in rats.

The effects of cyprohepatadine (CPH) on plasma levels, of glucose, insulin and glucagon were studied in rats in order to clarify the diabetogenicity of this compound. CPH was given to the rats at a daily dose of 45 mg per kg body weight via gastric intubation for up to 20 days. Glucose intolerance appeared after 5 days of CPH treatment without significant increase in fasting glucose level. Plasma insulin response to glucose loading was depressed in the early phase of the glucose tolerance test in groups treated for 10 and 20 days. In these groups the insulinogenic index was significantly lowered. Pancreatic insulin content decreased rapidly after single dose of CPH. Plasma level and pancreatic content of glucagon were not changed by this compound. These results suggested that chronic treatment with CPH caused glucose intolerance in rats through its direct influence on pancreatic B-cell function.