Norepinephrine-induced diuresis in chronically ethanol-treated rats.

Previous research from this laboratory indicated that noradrenergic mechanisms mediate ethanol diuresis. Experiments described here examined changes in sensitivity of these noradrenergic mechanisms in animals chronically treated with ethanol. Norepinephrine hydrochloride (0-12 micrograms intraventricularly) produced dose-dependent diuresis in control (dextrin maltose)- and ethanol (8-11 g/kg/day)-treated rats on the first day of treatment. Tolerance to ethanol diuresis was present after 10 days of ethanol treatment. Lack of responsiveness to norepinephrine-induced diuresis was evident only on the 20th day of treatment in both ethanol and dextrin-maltose groups of rats. These results suggest that norepinephrine does not play a primary role in the development of tolerance to the diuretic action of ethanol.