[Animal sensitivity to the diabetogenic action of alloxan during cold adaptation].

During cold adaptation, the rats demonstrate a significant decrease in plasma immunoreactive insulin (IRI), with glucose concentration remaining invariable. Injection of alloxan (170 mg/kg bw) to control rats causes death of 58% of animals. Survived rats show stable hyperglycemia and a considerable fall of plasma IRI. The insular apparatus of the pancreas undergoes considerable destructive changes. Relative density of the endocrine section decreases dramatically. This is conditioned by the reduction of both the number and size of Langerhans islets. Injection of alloxan to animals after cold adaptation results in the death of 28% of rats. Normoglycemia with invariable plasma IRI level was noticed in survived animals. The changes in the endocrine section of the pancreas were less significant in these animals. The relative volume of islets was almost twice as large as that in control animals after alloxan injection.