Enhancement of 45Ca2+ binding to acidic lipids by barbiturates, diphenylhydantoin, and ethanol.

Effects of barbiturates, diphenylhydantoin, and ethanol on 45Ca2+ binding to acidic lipids have been examined in an organic, solvent-aqueous partition system. Hexobarbital, pentobarbital, and phenobarbital, at concentrations of 0.3 and/or 0.6 mM, enhanced the binding of 45Ca2+ to phosphatidic acid, phosphatidylserine, and sulfatide but not to phosphatidylinositol or cardiolipin. Diphenylhydantoin, 0.3 mM, enhanced 45Ca2+ binding to phosphatidic acid and phosphatidylserine but not to sulfatide. Ethanol at 80 mM did not enhance 45Ca2+ binding to phosphatidic acid, but ethanol decreased the binding to cardiolipin and increased it to sulfatide.