Interaction between 1,4-butanediol and ethanol on operant responding and the cardiovascular system.

The current studies characterized the rate-decreasing and cardiovascular responses produced by 1,4-butanediol administered alone and in combination with ethanol to test the hypothesis that these effects resulted from the degradation of 1,4-butanediol to gamma-hydroxybutyrate. One group of rats responded under a fixed-ratio 20 schedule of food presentation; ethanol and 1,4-butanediol dose-dependently decreased response rates. Ethanol administered in combination with 1,4-butanediol attenuated the rate-decreasing effects of 1,4-butanediol without altering the potency of ethanol. In separate groups of conscious rats, radio telemetry was used to record mean arterial pressure and heart rate. In contrast to its depressant effects on schedule-controlled responding, 1,4-butanediol increased mean arterial pressure and heart rate; these increases were attenuated by ethanol. Thus, the behavioral and cardiovascular actions of 1,4-butanediol are similar to those elicited by gamma-hydroxybutyrate. The ability of ethanol to attenuate the behavioral and cardiovascular effects of 1,4-butanediol indicates that these effects require the conversion of 1,4-butanediol to gamma-hydroxybutyrate.