Comparison of xenobiotic biotransformation enzymes in kidney and liver of rainbow trout (Salmo gairdneri).
The microsomal cytochrome P-450 content in kidney of rainbow trout (Salmo gairdneri) was approximately 5-fold lower than the content in liver. The renal ethoxycoumarin- and ethoxyresorufin-O-deethylase activities calculated on a per-cytochrome P-450 basis were, however, found to be about 10-fold higher than the hepatic activities. The patterns of time-dependent increase and subsequent decrease of microsomal cytochrome P-450-dependent monooxygenase activities after a single injection of beta-naphthoflavone (BNF) were similar in the kidney and liver. The microsomal ethoxyresorufin- and ethoxycoumarin-O-deethylase activities were maximally induced in liver (120- and 10-fold, respectively) by a single BNF injection (50 mg/kg body wt), whereas in kidney the maximal levels of induction (135- and 21-fold, respectively) were reached after three injections with BNF. The induction of cytochrome P-450 systems was associated with synthesis of a new microsomal protein of 58,000 Da in both kidney and liver. UDP-glucuronosyl transferase activity toward p-nitrophenol was about 8-fold lower in kidney than in liver. A significant 2.5-fold elevation in microsomal UDP-glucuronosyltransferase activity was found in the kidney 14 days after a single injection with BNF (50 mg/kg). In the liver, a 2-fold increase of this activity was seen 3 days after the treatment. The results indicate that the rainbow trout kidney in addition to the liver is of great importance in biotransformation of lipophilic xenobiotics.
D015660:7-Alkoxycoumarin O-Dealkylase; D000818:Animals; D001571:Benzoflavones / Q000494:pharmacology; D001711:Biotransformation; D019363:Cytochrome P-450 CYP1A1; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction; D014453:Glucuronosyltransferase / Q000096:biosynthesis / Q000378:metabolism; D007668:Kidney / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D008861:Microsomes / Q000201:enzymology; D008862:Microsomes, Liver / Q000201:enzymology; D010088:Oxidoreductases / Q000096:biosynthesis / Q000378:metabolism; D010105:Oxygenases / Q000096:biosynthesis / Q000378:metabolism; D012487:Salmonidae / Q000378:metabolism*; D014337:Trout / Q000378:metabolism*; D019324:beta-Naphthoflavone
D001571:Benzoflavones; D019324:beta-Naphthoflavone; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D010105:Oxygenases; D015660:7-Alkoxycoumarin O-Dealkylase; D019363:Cytochrome P-450 CYP1A1; D014453:Glucuronosyltransferase