title: Preparation and characterization of subcellular fractions suitable for studies of drug metabolism from the trunk kidney of the Northern pike (Esox lucius) and assay of certain enzymes of xenobiotic metabolism in these subfractions.
abstract: The present study was designed to prepare and characterize subcellular fractions from the trunk kidney of the Northern pike (Esox lucius), with special emphasis on the preparation of a microsomal fraction suitable for studying xenobiotic metabolism. The purity of the different fractions obtained by differential centrifugation, as well as the recovery of different organelles, was determined using both enzyme markers and morphological examination with the electron microscope. Finally, the subcellular distributions of several drug-metabolizing enzymes (NADPH-cytochrome c reductase, NADH-ferricyanide reductase, glutathione transferase, epoxide hydrolase) were determined. With the exception of NADPH-cytochrome c reductase, the subcellular distributions obtained here for drug metabolizing and marker enzymes closely resembled those reported for rat liver. NADPH-cytochrome c reductase was apparently partially solubilized here from microsomal vesicles by an endogenous protease, which reduced its usefulness as a marker enzyme and raises questions concerning the measurement of activities catalyzed by the cytochrome P-450 system in these subfractions. In other respects the microsomes and supernatant fraction prepared here from the trunk kidney of the pike seem to be as well suited for investigations of drug metabolism as are the corresponding fractions from rat and pike liver.
mesh_terms: D000818:Animals; D002458:Cell Fractionation / Q000379:methods; D004247:DNA / Q000032:analysis; D004721:Endoplasmic Reticulum / Q000201:enzymology; D005260:Female; D005399:Fishes / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology* / Q000648:ultrastructure; D008297:Male; D009251:NADPH-Ferrihemoprotein Reductase / Q000032:analysis; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000201:enzymology* / Q000648:ultrastructure
chemical_list: D004364:Pharmaceutical Preparations; D004247:DNA; D009251:NADPH-Ferrihemoprotein Reductase