Intralobular localization of different cytochrome P-450 form dependent monooxygenase activities in the liver of normal and inducer-treated rats.
1. Isolated periportal (PP) and perivenous (PV) hepatocytes from normal and inducer-treated rat livers were used to examine the following: intralobular localization of cytochrome P-450IA, P-450IIB, P-450IIE and P-450IIIA dependent monooxygenase activities and effects of phenobarbital (PB), beta-naphthoflavone (BNF) and pregnenolone-16 alpha-carbonitrile (PCN) on the zonal induction of these monooxygenases. 2. 7-Ethoxyresorufin O-deethylase (7EROD), 7-pentoxyresorufin O-dealkylase (7PROD) and N-nitrosodimethylamine N-demethylase (NAND) activities of PP hepatocytes were not significantly different from those of PV hepatocytes. 3. Ethylmorphine N-demethylase (EMND) activity was significantly higher in PV hepatocytes than in PP hepatocytes of normal rats. 4. EMND activity was induced by PCN and PB treatments. The response of EMND activity to PCN treatment was higher in PP hepatocytes than that in PV hepatocytes, and as a result the PV dominance disappeared following PCN treatment. 5. Extents of the response of this activity to PB treatment were similar in PP and PV hepatocytes, and PV dominance remained unchanged even after induction.
Serasinghe
P
P
Department of Pharmacology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
Yamazaki
H
H
Nishiguchi
K
K
Serasinghe
S
S
Nakanishi
S
S
D000818:Animals; D001571:Benzoflavones / Q000494:pharmacology; D002478:Cells, Cultured; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000378:metabolism*; D004790:Enzyme Induction; D008099:Liver / Q000166:cytology / Q000201:enzymology*; D008297:Male; D010105:Oxygenases / Q000096:biosynthesis / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology; D011285:Pregnenolone Carbonitrile / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D019324:beta-Naphthoflavone
D001571:Benzoflavones; D011285:Pregnenolone Carbonitrile; D019324:beta-Naphthoflavone; D003577:Cytochrome P-450 Enzyme System; D010105:Oxygenases; D010634:Phenobarbital