EVIDENCE THAT DIAZEPAM ELICITS ALTERATIONS ON RAT RENAL-FUNCTION

The effects of diazepam on rat renal function were investigated by mea ns of clearance techniques in conscious animals. Different intravenous doses of diazepam were tested: 0.1, 0.3 and 10 mg/Kg body weight A ma rked increase in fractional water, sodium and potassium excretion was found in every group studied. This alteration was associated with a ur ine-to-plasma osmolality ratio diminution. On the other hand, no modif ications in glomerular filtration rate or p-aminohippuric acid clearan ce were observed. The reabsorption of water in collecting tubule in di azepam treated rats was decreased as compared with control rats. To as sess diazepam-effects on collecting tubule response to vasopressin, th e effects of desmopressin on concentrating ability in control and diaz epam-treated rats were tested. Desmopressin-treatment promoted a signi ficantly lower free water reabsorption in diazepam-treated group as re fered to control rats. This results indicate that diazepam may promote impairments on renal tubular ions reabsorption and that it modifies t he collecting tubule response to desmopressin.