The effect of -naphthoflavone Ž-NF. on several catalytic activities of cytochrome P450 ŽCYP. and phase II enzymes putatively controlled by Ah-receptor activation in the liver, heart and kidney of gilthead seabream, was investigated. In the liver, -NF treatment intraperitoneal injection Ži.p.. 50 mgkg resulted in an increase of CYP content, immunoreactive CYP 1A and methoxyresorufin-O-demethylase ŽMEROD., pentoxyresorufin O-depentylase ŽPROD. and ethoxyresorufin-O-deethylase ŽEROD. activities. However, -NF had no effect on any of the hepatic phase II enzymes examined Žbenzaldehyde dehydrogenase, propionaldehyde dehydrogenase, glutathione S-transferase, UDP-glucuronyl- transferase, DT-diaphorase.. Single i.p. injection of 10 mgkg -NF showed a maximal induction of CYP 1A-like protein and EROD activity after 37 days. CYP 1A and EROD returned to control levels 18-days post-treatment. -NF injection also caused a rapid increase of a single band size of mRNA recognized by a CYP 1A1 cDNA fragment from sea bass ŽDicentrarchus labrax.. Expression of mRNA preceded the increase of EROD activity and declined rapidly by 96 h. Doseresponse experiments demonstrated that EROD was significantly enhanced in liver by a single injection of 0.3 mgkg -NF and was the most sensitive measurement for CYP 1A-like induction. -NF treatments also increased the expression of CYP 1A-like protein, mRNA and EROD, but not MEROD and PROD activities in heart and kidney.
EFFECTS OF B-NAPHTHOFLAVONE ON THE CYTOCHROME P450 SYSTEM AND PHASE II ENZYMES IN GILTHEAD SEABREAM (SPARUS AURATA)
PRETTI, CARLO;SALVETTI, ALESSANDRA;GIORGI, MARIO;
2001-01-01
Abstract
The effect of -naphthoflavone Ž-NF. on several catalytic activities of cytochrome P450 ŽCYP. and phase II enzymes putatively controlled by Ah-receptor activation in the liver, heart and kidney of gilthead seabream, was investigated. In the liver, -NF treatment intraperitoneal injection Ži.p.. 50 mgkg resulted in an increase of CYP content, immunoreactive CYP 1A and methoxyresorufin-O-demethylase ŽMEROD., pentoxyresorufin O-depentylase ŽPROD. and ethoxyresorufin-O-deethylase ŽEROD. activities. However, -NF had no effect on any of the hepatic phase II enzymes examined Žbenzaldehyde dehydrogenase, propionaldehyde dehydrogenase, glutathione S-transferase, UDP-glucuronyl- transferase, DT-diaphorase.. Single i.p. injection of 10 mgkg -NF showed a maximal induction of CYP 1A-like protein and EROD activity after 37 days. CYP 1A and EROD returned to control levels 18-days post-treatment. -NF injection also caused a rapid increase of a single band size of mRNA recognized by a CYP 1A1 cDNA fragment from sea bass ŽDicentrarchus labrax.. Expression of mRNA preceded the increase of EROD activity and declined rapidly by 96 h. Doseresponse experiments demonstrated that EROD was significantly enhanced in liver by a single injection of 0.3 mgkg -NF and was the most sensitive measurement for CYP 1A-like induction. -NF treatments also increased the expression of CYP 1A-like protein, mRNA and EROD, but not MEROD and PROD activities in heart and kidney.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
