Glucose homeostasis in rats acutely and chronically treated with chloroquine

Glucose homeostasis of normal rats was studied after chronic or acute administration of chloroquine. Male rats received, in drinking water, a daily dose of 5-20 mg chloroquine/kg, for 20 weeks. The high dose caused a slight decrease in food intake and weight gain. In these animals, plasma glucose levels were somewhat lower than in controls after an overnight fast and after oral administration of glucose or intravenous administration of insulin, but not after intravenous administration of glucose. Their insulin response to oral or intravenous glucose was normal. The insulin content of their pancreas was decreased by about 15%. Electron microscopy revealed the presence of myeloid bodies and numerous lysosomes in B cells. Acute intraperitoneal administration of chloroquine was without effect on glucose tolerance and insulin release. This study shows that chloroquine, at plasma concentrations similar to those reached in treated patients, does not impair glucose homeostasis in normal rats.