In the present study we have determined for the first time the hepatic activities of several microsomal P-450 dependent monooxygenases including the testosterone hydroxylase and the Ah-receptor gene battery-related phase II enzymes [UDP-glucuronyl transferase (UDP-GT), DT-diaphorase, glutathione S-transferase, aldehyde dehydrogenases] in adult sea bass (300-400 g). We also investigated the effect of beta-naphtoflavone (beta-NF) on these enzymes to assess their potential as biomarkers of polycyclic aromatic hydrocarbon exposure. beta-NF. administered to fish with a single i.p. injection at various doses, resulted in an induction in the liver of the P-450 1A, as immunodetected by anti rat P-450 1A1 antibodies, P-450 1A-linked ethoxyresorufin-O-deethylase (EROD) and methoxyresorufin-O-demethylase (MEROD) activities. Among the phase II enzymes only the phenol UDP-GT was induced in liver by beta-NF. The time course of these inductions exhibited different patterns. EROD and MEROD activities reached a peak value 3 days post-injection and maintained values significantly above the corresponding control activities over the 30 days of the experiment, the phenol UDP-GT activity peaked at dap 8 and afterwards declined rapidly achieving the control value 18 days post-injection. A treatment of 80 mg kg(-1) beta-NF increased the immunodetectable P-450 1A apoprotein and EROD, but not MEROD, activity in extrahepatic tissues such as, gill, kidney and olfactory rosettes. Taken overall, the results indicate that MEROD. EROD and phenol UDP-GT activities may be useful biomarkers for the exposure of adult sea bass to polycyclic aromatic hydrocarbons. (C) 1998 Elsevier Science B.V. All rights reserved.
Biotransformation enzymes and their induction by beta-naphthoflavone in adult sea bass (Dicentrarchus labrax)
PRETTI, CARLO;
1998-01-01
Abstract
In the present study we have determined for the first time the hepatic activities of several microsomal P-450 dependent monooxygenases including the testosterone hydroxylase and the Ah-receptor gene battery-related phase II enzymes [UDP-glucuronyl transferase (UDP-GT), DT-diaphorase, glutathione S-transferase, aldehyde dehydrogenases] in adult sea bass (300-400 g). We also investigated the effect of beta-naphtoflavone (beta-NF) on these enzymes to assess their potential as biomarkers of polycyclic aromatic hydrocarbon exposure. beta-NF. administered to fish with a single i.p. injection at various doses, resulted in an induction in the liver of the P-450 1A, as immunodetected by anti rat P-450 1A1 antibodies, P-450 1A-linked ethoxyresorufin-O-deethylase (EROD) and methoxyresorufin-O-demethylase (MEROD) activities. Among the phase II enzymes only the phenol UDP-GT was induced in liver by beta-NF. The time course of these inductions exhibited different patterns. EROD and MEROD activities reached a peak value 3 days post-injection and maintained values significantly above the corresponding control activities over the 30 days of the experiment, the phenol UDP-GT activity peaked at dap 8 and afterwards declined rapidly achieving the control value 18 days post-injection. A treatment of 80 mg kg(-1) beta-NF increased the immunodetectable P-450 1A apoprotein and EROD, but not MEROD, activity in extrahepatic tissues such as, gill, kidney and olfactory rosettes. Taken overall, the results indicate that MEROD. EROD and phenol UDP-GT activities may be useful biomarkers for the exposure of adult sea bass to polycyclic aromatic hydrocarbons. (C) 1998 Elsevier Science B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
