EFFECT OF AN ALPHA-GLUCOSIDASE INHIBITOR ON GLOMERULAR-BASEMENT-MEMBRANE ANIONIC SITES IN STREPTOZOTOCIN-INDUCED MILDLY DIABETIC RATS

The present study was conducted in order to examine the effect of acar bose, a potent alpha-glucosidase inhibitor, on renal function in rats with mild streptozotocin-diabetes. Male Wistar rats were made mildly d iabetic by intravenous injection of streptozotocin (40 mg/kg) and were supplied a standard solid chow containing 0.1% acarbose for 8 weeks. Diabetic rats showed mild hyperglycemia under non-fasting condition an d their urine albumin excretion (UAE) rate was markedly increased comp ared to non-diabetic control rats, while acarbose treatment resulted i n a significant suppression of blood glucose level and UAE in diabetic rats. Examination by electronmicroscope revealed that the number of a nionic sites in the lamina rara externa per 1000 nm of glomerular base ment membrane (GBM) was significantly decreased in diabetic rats compa red to control value (15.7 +/- 0.9 vs. 20.9 +/- 0.3 P < 0.001), wherea s, significant recovery (19.6 +/- 0.6 P < 0.01) was observed after 8 w eeks of acarbose treatment. In conclusion, acarbose treatment suppress ed blood glucose level of mildly-insulin deficient animal model withou t insulin treatment and prevented from a reduction in the number of an ionic sites in GBM which might ameliorate an increased permeability of GBM leading to albuminuria. (C) 1997 Elsevier Science Ireland Ltd.