RT Journal Article
SR Electronic
T1 An Investigation of the Relationship Between Estrogen, Estrogen Metabolites and Blood Cholesterol Levels in Ovariectomized Rats
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 561
OP 568
VO 286
IS 1
A1 Dongfang Liu
A1 Kenneth A. Bachmann
YR 1998
UL http://jpet.aspetjournals.org/content/286/1/561.abstract
AB 17β-Estradiol (E2) has long been known for protecting against coronary heart disease by lowering cholesterol levels in premenopausal women. A recent study in our laboratory suggested that two hydroxylated metabolites of E2 possess similar hypocholesterolemic effects in male rats. This effect has been further investigated with additional estrogen metabolites in ovariectomized rats with a view toward mimicking the true postmenopausal situation in humans. Their effects in reproductive tissues were also evaluated histologically. Fundamentally, the following issues were addressed: (1) Do oxidized metabolites of estradiol lower total cholesterol levels? (2) Can a hypocholesterolemic effect be achieved without eliciting estrogenic activities on reproductive tissues? The results of this investigation showed that a number of oxygenated metabolites of estradiol can lower cholesterol levels. Among them, 4-hydroxyestradiol (4-OHE2) produced a striking hypocholesterolemic effect and a substantial uterotropic effect. 2-Hydroxyestradiol (2-OHE2), 2-methoxyestradiol (2-meoE2) and 2-methoxyestrone (2-meoE1) produced a significant decrease in cholesterol levels at doses that did not produce significant uterotropic effects. The American Society for Pharmacology and Experimental Therapeutics