title: Hepatic drug metabolizing enzyme activity in the channel catfish, Ictalurus punctatus.
abstract: 1. Several pathways of drug metabolizing enzymic activity were measured in hepatic fractions of the channel catfish and rat using model substrates. The pathways examined included the O-demethylation of p-nitroanisole, microsomal ester hydrolysis of procaine and glucuronidation of p-nitrophenol, and the cytosolic acetylation of sulfamethazine and sulfation of 2-naphthol. Catfish liver preparations were incubated at both 25 degrees C and 37 degrees C. 2. The oxidative metabolism of p-nitrophenol was only one-eighth that of the rat at 37 degrees C and one-twelfth that of the rat at 25 degrees C. 3. Procaine ester hydrolysis was negligible in catfish microsomal preparations. 4. At 37 degrees C, p-nitrophenol glucuronidation was equivalent in catfish and rat microsomes. 5. Catfish cytosolic preparations exhibited N-acetyltransferase and arylsulfotransferase nearly comparable to those of the rat. 6. Rates of glucuronidation and sulfation were higher at 37 degrees C than at 25 degrees C in hepatic fractions of catfish.
mesh_terms: D000818:Animals; D002397:Catfishes / Q000378:metabolism*; D007059:Ictaluridae / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D004364:Pharmaceutical Preparations / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D013045:Species Specificity
chemical_list: D007527:Isoenzymes; D004364:Pharmaceutical Preparations; D006899:Mixed Function Oxygenases