Renal hypertrophy in streptozotocin-diabetic rats

1. Kidney weight and content of protein, RNA and DNA were measured in rats with streptozotocin diabetes of varying duration. 2. Diabetic rats had larger kidneys than control rats: after 3 days of diabetes the weight increase was 15 per cent and after 42 days of diabetes it was 90 per cent. The protein content rose in parallel to the weight. 3 RNA content was already increased after 36 h of glycosuria, whereas DNA content was unchanged for the first 3 days of diabetes, and increased thereafter. The protein/DNA ratio increased rapidly during the first 3 days but remained constant thereafter. 4. Insulin treatment decreased the renal weight gain by about 67 per cent during the first 8 days of diabetes, but did not prevent the increase in DNA. When insulin was started after 25 days of diabetes there was only a slight regression of kidney growth.