Comparison of cytochrome P-450 content and conjugative enzymes in livers of camels (Camelus dromedarius), guinea-pigs (Cavia porcellus) and rats (Rattus norvegicus).

The activities of the conjugative enzymes, glutathione S-transferase and UDP-glucuronyl-transferase, have been measured in vitro in the livers of camels, guinea-pigs and rats. Some sex differences were observed in the levels of these conjugative enzymes. In rats and guinea-pigs, females had higher UDP-glucuronyltransferase activity than males. In camels, females had higher glutathione S-transferase activity than males. In these species, the cytochrome P-450 isozymes observed between the 50,000 and 60,000 mol. wt regions have been separated and characterized by SDS-polyacrylamide gel electrophoresis. Camels showed lower levels of all types of cytochrome P-450 isozymes, while guinea-pigs showed higher levels of most of these isozymes. In general, camels seemed to have the lowest drug-metabolizing enzyme activity when compared to rats and guinea-pigs.