title: Correlation of placental microsomal activities with protein detected by antibodies to rabbit cytochrome P-450 isozyme 6 in preparations from humans exposed to polychlorinated biphenyls, quaterphenyls, and dibenzofurans.
abstract: Placental tissues were obtained from Chinese women in Taiwan who had been exposed to contaminated rice oils containing polychlorinated biphenyls and their thermal degradative products. Exposure via the diet occurred 4-5 years prior to pregnancy. Placental microsomal fractions from eight of the nine exposed subjects studied showed marked elevation of benzo(a)pyrene hydroxylation and 7-ethoxyresorufin O-deethylation activities related to control subjects. Placental microsomes from exposed subjects were found to contain a protein that cross-reacted with antibodies raised to rabbit cytochrome P-450 isozyme 6, an isozyme induced by polycyclic aromatic hydrocarbons. This protein was not observed with microsomal samples from control subjects. A significant correlation was found between the relative amounts of the immunoreactive protein and benzo(a)-pyrene hydroxylation and 7-ethoxyresorufin O-deethylation activities. The 7-ethoxyresorufin O-deethylation activities were inhibited by alpha-naphthoflavone, a compound known to inhibit activities of rabbit cytochrome P-450, isozyme 6.
authors.forename: T K
authors.initials: TK
authors.lastname: Wong
authors.forename: B A
authors.initials: BA
authors.lastname: Domin
authors.forename: P E
authors.initials: PE
authors.lastname: Bent
authors.forename: T E
authors.initials: TE
authors.lastname: Blanton
authors.forename: M W
authors.initials: MW
authors.lastname: Anderson
authors.forename: R M
authors.initials: RM
authors.lastname: Philpot
mesh_terms: D001564:Benzo(a)pyrene / Q000378:metabolism; D001579:Benzopyrene Hydroxylase / Q000378:metabolism; D001724:Birth Weight; D019363:Cytochrome P-450 CYP1A1; D003577:Cytochrome P-450 Enzyme System / Q000276:immunology / Q000378:metabolism*; D005260:Female; D005506:Food Contamination; D006801:Humans; D007163:Immunosorbent Techniques; D007527:Isoenzymes / Q000276:immunology / Q000378:metabolism; D008861:Microsomes / Q000201:enzymology; D009821:Oils / Q000009:adverse effects*; D010078:Oxazines / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D010920:Placenta / Q000201:enzymology*; D011078:Polychlorinated Biphenyls / Q000009:adverse effects*; D011247:Pregnancy; D013624:Taiwan
chemical_list: D007527:Isoenzymes; D009821:Oils; D010078:Oxazines; D001564:Benzo(a)pyrene; C007649:ethoxyresorufin; D003577:Cytochrome P-450 Enzyme System; D011078:Polychlorinated Biphenyls; D010088:Oxidoreductases; D001579:Benzopyrene Hydroxylase; D019363:Cytochrome P-450 CYP1A1