Autoregulation of Renal Blood Flow in Streptozocin-Induced Diabetic Rats

Autoregulation of renal blood flow (RBF) was studied in male Wistar rats. We studied 11 control rats, 11 rats with severe streptozocin (STZ)-induced hyperglycemia (diabetic group), and 10 moderately hyperglycemie rats made diabetic by injection of STZ but given 2–8 U s.c. insulin daily (insulin-treated group). RBF was measured by an electromagnetic flowmeter during stepwise reduction of renal perfusion pressure 4–8 wk after injection of STZ (older group). RBF autoregulation of the diabetic group was impaired compared with the control group. In the insulin-treated group, autoregulatory capability was less attenuated than in the diabetic group. The average autoregulatory index (ARI) of the diabetic group (0.61 ± 0.05) was greater than that of the control (0.24 ± 0.02, P P P