Differential effect of chronic ethanol treatment on barbiturate and steroid modulation of muscimol-binding to rat brain cortex.

We report the differential alterations produced by chronic ethanol treatment on the modulation, by the barbiturate thiopental and the steroid 5 beta-pregnan-3 alpha-ol-20-one, of the binding of [3H]muscimol to membrane preparations from rat brain cortex. We found a clear barbiturate- and steroid-promoted enhancement of muscimol-binding to membranes in both control and ethanol-treated animals. However, the enhancements were higher in control animals, using the barbiturate, and in ethanol-treated rats, using the steroid, Bmax and Kd values were also differentially affected in control and ethanol-treated animals by the presence of the barbiturate or the steroid.