Evidence that diazepam elicits alterations on rat renal function.

The effects of diazepam on rat renal function were investigated by means of clearance techniques in conscious animals. Different intravenous doses of diazepam were tested: 0.1, 0.3 and 10 mg/Kg body weight A marked increase in fractional water, sodium and potassium excretion was found in every group studied. This alteration was associated with a urine-to-plasma osmolality ratio diminution. On the other hand, no modifications in glomerular filtration rate or p-aminohippuric acid clearance were observed. The reabsorption of water in collecting tubule in diazepam treated rats was decreased as compared with control rats. To assess diazepam-effects on collecting tubule response to vasopressin, the effects of desmopressin on concentrating ability in control and diazepam-treated rats were tested. Desmopressin-treatment promoted a significantly lower free water reabsorption in diazepam-treated group as referred to control rats. This results indicate that diazepam may promote impairments on renal tubular ions reabsorption and that it modifies the collecting tubule response to desmopressin.