Effects of Hormonally Active Agents on Steroid Hormone Receptor Expression and Cell Proliferation in the Myometrium of Ovariectomized Macaques

Autor: Darlene Dixon, Elizabeth Ney, J. Mark Cline, Georgette D. Hill, Grace E. Kissling, Norris D. Flagler, Alicia B. Moore
Rok vydání: 2011
Předmět:
Zdroj: Toxicologic Pathology. 39:508-515
ISSN: 1533-1601
0192-6233
Popis: Hormone replacement therapy and selective estrogen receptor modulators have been controversial treatment options for postmenopausal women because of their potential health benefits and/or risks. In this study, we determine the effects of the hormonally active compounds, conjugated equine estrogens (CEE), medroxyprogesterone acetate (MPA), CEE + MPA, and tamoxifen (TAM) on the myometrium of ovariectomized macaques. Immunoexpression of estrogen receptor-α (ERα), progesterone receptor (PR), and Ki-67 in the myometrium is assessed. We found no significant difference in ERα myometrial expression in the CEE, MPA, and CEE + MPA treatment groups, but there was a significant decrease in expression in animals administered TAM versus controls. Conjugated equine estrogen–, TAM–, and CEE + MPA-treated animals had significantly increased expression of PR in myometrial cells and there was no difference in PR expression in cells from MPA-treated animals versus control animals. Myometrial cell proliferation did not significantly differ between the controls and any of the treatment groups, although normalized Ki-67 values were somewhat higher in the CEE and TAM groups. These data suggest that ERα and PR expression in the myometrium is influenced by treatment with hormonally active agents.
Databáze: OpenAIRE