Enhancement of gamma-aminobutyric acid (GABA) receptor binding by lipophilic antioxidants.

Treatment of synaptic membrane preparations from rat brain with various lipophilic antioxidants invariably resulted in a significant enhancement of the binding of [3H]muscimol and [3H]gamma-aminobutyric acid with a concomitant facilitation of superoxide anion formation, whereas treatment with hydrophilic antioxidants exhibited no significant alterations in the binding and the formation of superoxide anion. These results suggest that the superoxide anion may play a modulatory role in the binding of gamma-aminobutyric acid to its relevant synaptic receptor.