title: Hepatic enzyme induction and acute endocrine effects of 2,3,3',4',6-pentachlorobiphenyl in prepubertal female rats.
abstract: Polychlorinated biphenyls (PCBs) with the labile 2,3,6-substitution are important components of atmospheric and certain food chain exposures, but little is known about their biological activities. Chlorobiphenyl 110 (2,3,3',4',6-pentaCB) was investigated in weanling female rats dosed ip on days 21 and 22 and killed on day 23 of age. The initial preparation of CB 110 markedly induced 7-ethoxyresorufin O-dealkylase (EROD) activity and was found to be contaminated with coplanar 3,3',4,4',5-pentaCB (CB 126). The contaminated preparation (CB 110C) was purified with activated charcoal (CB 110P). The CB 110P induced pentoxyresorufin O-dealkylase (PROD), was weakly uterotropic and a modest depleter of serum thyroxine (T4). CB 110C caused increased liver weight, induced EROD, PROD, and UDP glucuronyl transferase activities and caused a greater depletion of serum T4; on the other hand, it suppressed the PROD induction and the uterotropic effect of CB 110P. Hepatic residues of CB 110 were a constant 2-3% of the dose while those of CB 126 (from CB 110C) increased with increasing dose to as much as 50% of the dose.
authors.affiliation: Department of Geography, National Taiwan University, Taipei, Taiwan, Republic of China.
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: C
authors.initials: C
authors.lastname: Rhine
authors.forename: L G
authors.initials: LG
authors.lastname: Hansen
mesh_terms: D000818:Animals; D001822:Body Burden; D019362:Cytochrome P-450 CYP2B1 / Q000096:biosynthesis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004703:Endocrine System / Q000187:drug effects*; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D007274:Injections, Intraperitoneal; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D011078:Polychlorinated Biphenyls / Q000008:administration & dosage / Q000097:blood / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013974:Thyroxine / Q000097:blood / Q000187:drug effects; D014018:Tissue Distribution; D014599:Uterus / Q000187:drug effects
chemical_list: C032903:2,3,3',4',6-pentachlorobiphenyl; D011078:Polychlorinated Biphenyls; D019362:Cytochrome P-450 CYP2B1; D013974:Thyroxine