Enzymatic O-methylation of catechol estrogens in red blood cells: differences in animal species and strains

Steroids. 1993 Nov;58(11):540-6. doi: 10.1016/0039-128x(93)90032-i.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Dogs
  • Erythrocytes / enzymology*
  • Estradiol / analogs & derivatives
  • Estradiol / metabolism
  • Estrogens, Catechol / blood*
  • Guinea Pigs
  • Humans
  • Macaca fascicularis
  • Methylation
  • Mice
  • Mice, Inbred ICR
  • Rats
  • Rats, Inbred F344
  • Rats, Inbred SHR
  • Rats, Sprague-Dawley
  • Rats, Wistar
  • S-Adenosylmethionine / metabolism
  • Species Specificity


  • Estrogens, Catechol
  • Estradiol
  • S-Adenosylmethionine
  • 2-hydroxyestradiol
  • 4-hydroxyestradiol