Acute and chronic renal effects of radiocontrast in diabetic rats. Role of anesthesia and risk factors.

The acute and chronic renal effects of the intravenous injection of meglumine diatrizoate sodium 76% (CM), 5 mL/kg body weight were studied in diabetic (DM) and age-matched normal (C) female Sprague-Dawley rats. In acute studies, the effect of anesthesia was assessed for 2 hours. Although anesthesia decreased 14C-inulin clearance (Cin) in both DM and C rats (P less than .001 vs. conscious values), there was no impairment of Cin in either group after administration of CM. In chronic studies, creatinine clearance (Ccr) was followed for 3-4 days after CM administration. Four protocols to assess risk factors in DM and C were used: adult rats with normal hydration (2A); old dehydrated rats with DM of long duration (2B); rats with prior decreased Ccr (remnant kidney, 2C); and DM rats treated with insulin (2D). No clear-cut nephrotoxicity was apparent in these studies, except that proteinuria increased with CM in Study 2C. A greater severity of renal dysfunction, renal disease, or the association of multiple risk factors may be necessary to induce CM-related nephrotoxicity in the experimental animal. The rat, diabetic or not, may have an inherent resistance to CM-induced renal injury.