New experimental congenital diabetic mice (N.S.Y. mice).

New experimental congenital diabetic mice were obtained in the descendants of streptozotocin-induced diabetic mice. Diabetes was developed by the administration of strepotozotocin in normal adult I.C.R. mice, and then these mice were mated to obtain the F1 mice. The F1 mice with impaired glucose tolerance were mated within the siblings. The same process was repeated over several generations. The diabetic features of the spontaneously diabetic mice thus obtained were as follows: 1) The mice did not show a tendency toward obesity. 2) Glucose tolerance of these mice, especially after the F6 generation, was remarkably impaired. However, the elevation of the fasting blood glucose level was slight throughout the generations. We propose to designate the congenital diabetic mice as the N.S.Y. (Nagoya, Shibata, Yasuda) mice. The N.S.Y. mice are considered to be useful models for human diabetes.