Renal function and hemodynamics in recent onset type 1 diabetes mellitus in sprague dawley rats

The present study investigated the renal functional and hemodynamic changes in rats with very recent onset of type I diabetes mellitus (DM). Male Sprague Dawley rats were induced with experimental DM by an i.p. injection of 55 mg/kg streptozotocin (STZ). The diabetic state in rats was confirmed by hyperglycemia, polyuria, polydipsia and reduction in the body mass. Acute clearance and hemodynamic experiments were performed 7 d after the onset of DM. During the acute study, diabetic rats showed no marked alteration (all P>0.05 vs. control) in the urine flow rate (UFR). Both absolute (U_NaV) and fractional (FE_Na) sodium excretions were significantly lower (all P<0.05 vs. control) in diabetic rats. Kidney glomerular filtration rate (GFR), plasma sodium (P_Na) and plasma creatinine (P_Cr) were significantly higher in diabetics (all P<0.05 vs. control). Mean arterial pressure (MAP) and renal blood flow (RBF) were slightly higher while renal vascular resistance (RVR) was slightly lower; however, these changes were not significantly different from the control (all P>0.05). Kidney weight was only slightly higher in diabetic rats (P>0.05 vs. control) but no observable changes in renal histology were detected. These results suggest that acute renal insufficiency of a prerenal cause seems to accompany recent onset type I DM. The changes in kidney function, at least in part, are likely to be due to the associated volume depletion.