title: Preparation and characterization of subcellular fractions from the head kidney of the Northern pike (Esox lucius), with particular emphasis on xenobiotic-metabolizing enzymes.
abstract: The present study was designed to prepare and characterize subcellular fractions from the head 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 cell components was determined using both enzyme markers and morphological criteria. 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 microsomal fraction prepared here from the pike head kidney seems well-suited for studies of drug metabolism.
authors.forename: L
authors.initials: L
authors.lastname: Balk
authors.forename: S
authors.initials: S
authors.lastname: Månér
authors.forename: A
authors.initials: A
authors.lastname: Bergstrand
authors.forename: W
authors.initials: W
authors.lastname: Birberg
authors.forename: A
authors.initials: A
authors.lastname: Pilotti
authors.forename: J W
authors.initials: JW
authors.lastname: DePierre
mesh_terms: D000818:Animals; D004247:DNA / Q000032:analysis; D004721:Endoplasmic Reticulum / Q000201:enzymology; D005260:Female; D005399:Fishes / Q000378:metabolism*; D005952:Glucose-6-Phosphatase / Q000032:analysis; D007668:Kidney / Q000201:enzymology* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009251:NADPH-Ferrihemoprotein Reductase / Q000032:analysis; D004364:Pharmaceutical Preparations / Q000378:metabolism*
chemical_list: D004364:Pharmaceutical Preparations; D004247:DNA; D009251:NADPH-Ferrihemoprotein Reductase; D005952:Glucose-6-Phosphatase