A new mouse model of spontaneous diabetes derived from ddY strain

By the selective breeding of obese male mice of the ddY strain and using in dices of the heavy body weight and appearance of urinary glucose, we establ ished two inbred strains in 1992: one with obesity and urinary glucose (Tsu mura, Suzuki, Obese Diabetes: TSOD) and the other without them (Tsumura, Su zuki, Non Obesity: TSNO). The male TSOD mice constantly showed signs of obe sity and urinary glucose with increases in food and water intake, body weig ht and some fat weight. The body mass index (BMI) clearly showed moderate o besity. Increases in the levels of diabetic blood parameters (glucose, insu lin and lipids) were also found in males, in which the levels of blood gluc ose and insulin were high to the ages past the growth peak. In the histolog ical studies, pancreatic islets of the TSOD males were found hypertrophic w ithout any signs of insulitis or fibrous formation. Among these diabetic ch aracteristics, some of which were similar to the reported models of non-ins ulin-dependent diabetes mellitus (NIDDM), the stable appearances of the hyp erglycemia, the hyperinsulinemia and the hypertrophy of pancreatic islets t o the ages past the growth peak were the prominent features. In these respe ct the TSOD mouse may be a useful model for researching the mechanisms of h uman diabetes and ifs complications.