title: Enzymatic O-methylation of catechol estrogens in red blood cells: differences in animal species and strains.
abstract: Enzymatic O-methylation of catechol estrogens in red blood cells has been investigated with respect to species difference. In the presence of S-adenosylmethionine, 2- or 4-hydroxyestradiol (2-OHE2 or 4-OHE2) was incubated with blood lysate obtained from rats (five strains), guinea pigs, mice, rabbits, dogs, monkeys, and humans, respectively. The yielded guaiacols and unchanged substrate were determined by gas chromatography/mass spectrometry in a selected ion monitoring mode employing the corresponding 2H4-labeled compounds as internal standards. The total amounts of guaiacols formed from 2-OHE2 and 4-OHE2 were different, being the highest (79.6% and 38.1%) in monkeys and the lowest (5.1% and 1.9%) in humans. The ratios of isomeric guaiacols formed from 4-OHE2 (4Me/3Me) were 7.6-71, while those from 2-OHE2 (2Me/3Me) were 1.4-3.2. Thus, marked differences in O-methylation of catechol estrogens were observed among animal species, but no significant strain difference was detected in rats.
authors.affiliation: Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Saegusa
authors.forename: T
authors.initials: T
authors.lastname: Anjo
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuki
authors.forename: T
authors.initials: T
authors.lastname: Nambara
mesh_terms: D000328:Adult; D000818:Animals; D004285:Dogs; D004912:Erythrocytes / Q000201:enzymology*; D004958:Estradiol / Q000031:analogs & derivatives / Q000378:metabolism; D002393:Estrogens, Catechol / Q000097:blood*; D006168:Guinea Pigs; D006801:Humans; D008252:Macaca fascicularis; D008745:Methylation; D051379:Mice; D008813:Mice, Inbred ICR; D051381:Rats; D011916:Rats, Inbred F344; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012436:S-Adenosylmethionine / Q000378:metabolism; D013045:Species Specificity
chemical_list: D002393:Estrogens, Catechol; D004958:Estradiol; D012436:S-Adenosylmethionine; C001390:2-hydroxyestradiol; C014036:4-hydroxyestradiol