title: Estrogen regulates bcl-x expression in rat hippocampus.
abstract: In this study, we examined whether experimental alterations of circulating estrogen levels are associated with changes in the expression of bcl-x, an inhibitor of apoptosis. We report that bcl-x mRNA expression in rat hippocampus significantly decreases after reduction of estrogen levels resulting from ovariectomy. Exposure of ovariectomized rats to 17beta-estradiol for either 5 or 28 days restored bcl-x mRNA expression to levels at or above those observed in sham-ovariectomized control animals. These data demonstrate that physiological levels of estrogen regulate hippocampal expression of bcl-x, an important modulator of neuronal apoptosis. Estrogen-mediated regulation of bcl-x may be relevant to the maintenance of neuronal viability and may contribute to the mechanism of estrogen neuroprotection.
authors.affiliation: Andrus Gerontology Center, University of Southern California, 3715 McClintock Avenue, Los Angeles, CA 90089-0191, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Stoltzner
authors.forename: N C
authors.initials: NC
authors.lastname: Berchtold
authors.forename: C W
authors.initials: CW
authors.lastname: Cotman
authors.forename: C J
authors.initials: CJ
authors.lastname: Pike
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004958:Estradiol / Q000097:blood* / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009410:Nerve Degeneration / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D009474:Neurons / Q000378:metabolism*; D018696:Neuroprotective Agents / Q000378:metabolism / Q000494:pharmacology; D010052:Ovariectomy; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D051020:bcl-X Protein
chemical_list: C494813:Bcl2l1 protein, rat; D018696:Neuroprotective Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051020:bcl-X Protein; D004958:Estradiol