[Importance of db gene for the development of low dose streptozotocin diabetes in C57BL/KsJ mice].

The paper is concerned with some data on the effect of the diabetic gene (db) on mouse sensitivity to streptozotocin (SC). Male mice aged 2-3 mos. of mutant C57BL/KsJ strain (genotypes: m+/+m, db+/+m, db+/+db) were used for investigation. Insulin-dependent diabetes mellitus was induced by intraperitoneal injections of streptozotocin at a daily dose of 40 mg/kg for 5 days. The structure and function of the insular apparatus were histologically assessed as well as by the blood level of insulin and glucose within 15 days after the start of the experiment. The earliest hyperglycemic reaction to SC was typical of mice, homozygous by the diabetic gene; they had normoglycemia at the time of treatment. In mice, heterozygous by the diabetic gene, a hyperglycemic reaction developed later after treatment. However by the end of the investigation it reached values which were typical of mice, homozygous by the diabetic gene, with basal normoglycemia. Mice, not carrying the diabetic gene, as well as homozygotes by this gene with basal hyperglycemia, possessed lesser sensitivity to SC. The expression of hyperglycemic reactions showed correlation with a degree of dystrophic changes and the development of lymphocellular infiltration in the pancreatic islets of mice with basal normoglycemia in low dose streptozotocin diabetes. The development of spontaneous hyperglycemia in homozygotes by the diabetic gene lowered their sensitivity to SC diabetogenic effects.