N. S. Y. mouse is a new strain of congenital diabetic mice derived from the I.C.R. strain which possesses abnormal findings on small vessels of the glomerulus and is considered to be a useful model for human diabetes. According to the osmotic theory, intracellular accumulation of sorbitol has been implicated in the initiation of the cataract and the neuropathy resulting from diabetes. The present study was conducted to estimate the role of sorbitol on the development of renal disease in the N. S. Y. mice. In result, the concentrations of glucose and sorbitol were simillar in the kidney of N. S. Y. mice and age-matched nondiabetic controls. This result suggests that the activity of aldose reductase is low in the kidney of N. S. Y. mice and sorbitol does not play a main role in the appearance of renal disease in the N. S. Y. mice.
In 5 cases of insulin-treated diabetics, glucose infusion tests were performed to examine the biological effect of insulin in vivo which was injected subcutaneously twice a day as usual. Intravenous infusion of 10% glucose solution was begun soon after the subcutaneous injection of insulin. The glucose infusion rate was determined according to the levels of blood glucose, which were measured every 30 min. The amounts of glucose infused to prevent falls in blood glucose reflected the insulin effect. During the test, the blood glucose was kept in a narrow range. The maximum effect of semilente insulin injected to 3 cases in the morning was detected at 4.5, 6.5, and 7hr after the injection, respectively. The maximum effect of insulin injected in the evening tended to appear earlier than that of the same kinds of insulin injected in the morning. These results suggest that the biological effect of insulin differs from patient to patient and according to the time of injection.