Uptake of labelled-n-nitrosomethylurea in the pancreatic islets.

Labelled N-nitrosomethylurea was injected intravenously into mice (C57/BI strain) and Chinese hamsters. In whole-body autoradiograms the isotope was found to accumulate heavily in the islet tissue of the Chinese hamsters but not in that of the mice. The selective uptake in the islet of Chinese hamsters was most pronounced after one hour. A dose of 50 mg/kg body weight of non-labelled N-nitrosomethylurea caused hyperglycemia in the Chinese hamsters while no hyperglycemia occurred in the mice at a dose of 150 mg/kg in the Chines hamsters while no hyperglycemia occurred in the mice at a dose of 150 mg/kg body weight. The results indicated that the diabetogenic effect of N-nitrosomethylurea is related to the ability of this substance, or a metabolite of it, to accumulate in the pancreatic islets.