The effect of ascorbic acid on the conjugation of 4-hydroxybiphenyl in rat isolated hepatocytes.

Ascorbic acid at high non-physiological levels inhibited the sulphation of 4-hydroxybiphenyl by rat isolated hepatocytes. Glucuronylation of 4-hydroxybiphenyl, formed from 4-methoxybiphenyl, was increased at ascorbic acid levels which inhibited sulphation. The glucuronylation of 4-hydroxybiphenyl added directly to the cells was enhanced at concentrations of ascorbic acid which did not inhibit sulphation. Ascorbic acid did not influence the cytochrome P-450-dependent O-demethylation of 4-methoxybiphenyl or the level of cellular lipid peroxidation.