title: The decrease in level of serum thyroxine by 2,2',4,5,5'-pentachlorobiphenyl in rats and mice: no correlation with formation of methylsulfonyl metabolites.
abstract: A relationship between formation of methylsulfonyl (MeSO2) metabolites of 2,2',4,5,5'-pentachlorobiphenyl (PentaCB) and decrease in serum thyroxine (T4) level was examined in the rats and mice after a single i.p. injection of PentaCB (342 micromol/kg body weight). In either rats or mice, levels of the 3- and 4-MeSO2 metabolites of PentaCB in the liver and feces increased in a time-dependent fashion up to 8 days after PentaCB-treatment. However, there was a marked difference between rats and mice in the amount of the metabolites formed, and the cumulative amount of the either MeSO2 metabolite for 8 days after PentaCB treatment in the liver was 4 to 15 times higher in mice than in rats. On the other hand, a 40 to 60% decrease in level of serum total T4 occurred in both rats and mice at 1 day after PentaCB treatment, and the decrease was retained up to 8 days after PentaCB treatment. Thus, there was a marked difference between rats and mice in the formation of MeSO2 metabolites from PentaCB but not a significant difference between rats and mice in PentaCB-induced decrease in the level of serum total T4, indicating that PentaCB-induced decrease in the level of serum total T4 is not necessarily dependent on the MeSO2 metabolites formed.
authors.affiliation: School of Pharmaceutical Sciences, University of Shizuoka, hizuoka, Japan. kato@ys7.u-shizuoka-ken.ac.jp
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Kato
authors.forename: Koichi
authors.initials: K
authors.lastname: Haraguchi
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Ryohei
authors.initials: R
authors.lastname: Kimura
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Koga
authors.forename: Shizuo
authors.initials: S
authors.lastname: Yamada
authors.forename: Masakuni
authors.initials: M
authors.lastname: Degawa
mesh_terms: D000818:Animals; D005243:Feces / Q000737:chemistry; D014453:Glucuronosyltransferase / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008297:Male; D051379:Mice; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D010416:Pentachlorophenol / Q000031:analogs & derivatives / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000493:pharmacokinetics / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013045:Species Specificity; D013450:Sulfones / Q000378:metabolism; D013974:Thyroxine / Q000097:blood*; D013997:Time Factors; D000099237:UDP-Galactose Translocators; D000099148:UGT1A1 Enzyme
chemical_list: D014453:Glucuronosyltransferase; D009004:Monosaccharide Transport Proteins; D010416:Pentachlorophenol; D011078:Polychlorinated Biphenyls; D013450:Sulfones; D013974:Thyroxine; D000099237:UDP-Galactose Translocators; C499946:Ugt1a1 protein, rat; D000099148:UGT1A1 Enzyme; C009828:2,4,5,2',5'-pentachlorobiphenyl; C033124:methylsulfonylpentachlorobenzene