The development of hepatic drug-metabolizing enzymes in perinatal guinea pigs: a biochemical and morphological study

The development of four functionally diverse, hepatic enzymes (p-nitroanisole O-demethylase, aniline hydroxylase, carboxyleterase, and glucuronyltransferase (with alpha-naphthol as the aglycone acceptor)) was studied in perinatal Hartley guinea pigs from 8 days prepartum to 28 days postpartum. A good correlation was observed between the activities measured in resuspended Ca2+-aggregated microsomes and the quantities of hepatic smooth endoplasmic reticulum visible by electron microscopic examination at the different stages of development. The study demonstrated that, postnatally, the guinea pig developed competent enzymatic systems as rapidly as did other laboratory species but that, prenatally, these same enzyme(s) systems were much further advanced than those in other species.