The formation of mercapturic acids. 3. N-Acetylation of S-substituted cysteines in the rabbit, rat and guinea pig

Abstract

Unlike the rabbit and the rat, the guinea pig did not excrete as mercapturic acid a large proportion of a dose of any of the 6 S-substituted cysteines administered. The extent of acetylation of S-(p-chlorobenzyl)cysteine and S-butylcysteine in vitro with liver slices was comparable with that obtained in vivo. p-Aminobenzene sulphonamide was readily acetylated by the guinea pig and by slices of guineapig liver. Failure of the guinea pig to excrete considerable amounts of mercapturic acid from precursors appears to be due to difficulty in N-acetylation of S-substituted cysteines.