Effects of ethanol on plasma chloroquine, arginine vasopressin (AVP) concentrations and renal hydro-electrolyte handling in the rat.

Current evidence in literature suggests that acute effects of either chloroquine or ethanol on kidney function partly depend on influencing plasma concentrations of arginine vasopressin (AVP). Therefore, the goal of the current study was to explore the effects of chloroquine and/or various doses of ethanol on plasma AVP levels and associated effects on renal hydro-electrolyte handling. Separate groups of male anaesthetized Sprague-Dawley rats were placed on a continuous jugular infusion of 0.077 M NaCl at 150 microL/min(-1). After 3 h equilibration period, consecutive 20 min urine collections were made over the subsequent 4 h of 1 h control, 1 h 20 min treatment and 1 h 40 min postequilibration periods for measurements of urine flow and Na+ and K+ excretion rates. Chloroquine (0.06 microg/min(-1)) and/or ethanol at either 2.4, 6, 18 or 24 microg/min(-1) were added to the infusate during the treatment period. Trunk blood was collected after the treatment period from parallel groups for AVP, ethanol and chloroquine measurements. Vehicle infused animals acted as control animals. Infusion of ethanol at low rate of 2.4 microg/min(-1) increased Na+ excretion rates, but high rates (6-24 microg/min(-1)) did not elicit such effects. Plasma ethanol concentrations were undetectable following administration of ethanol alone at 2.4 or 6 microg/min(-1). However, ethanols were measurable following co-infusion of chloroquine and ethanol at 6 microg/min(-1) (6+/-1 mg/dL(-1)). Concurrent chloroquine and ethanol (24 microg/min(-1)) administration elevated plasma ethanol concentrations by 26% by comparison with that of ethanol alone at the same dose. Chloroquine and ethanol infusion at all doses significantly (p < 0.01) increased plasma chloroquine concentrations. Intravenous infusion of ethanol increased plasma AVP concentrations in a dose-dependent manner. The observations of this study suggest that acute ethanol increases plasma AVP levels in a dose-dependent manner to affect hydro-electrolyte balance.