Nedvídková J, Schreiber V, Stárka L
Institute of Endocrinology, Prague, Czech Republic.
J Endocrinol Invest. 1997 Apr;20(4):225-9. doi: 10.1007/BF03346908.
The aim of this study was to find out whether mifepristone, known mainly as a substance with an antiprogesterone and antiglucocorticoid effect, also has an in vivo antiestrogenic activity on the adenohypophysis of the rat. Male Wistar rats were given chronically either estradiol-benzoate (EB, 1 mg s.c. twice a week) for a period of 12 days, or the non steroidal antiestrogen tamoxifen (1 mg/day/rat), or mifepristone (1 mg/day/rat), or EB together with mifepristone or tamoxifen. The hypertrophic effect of the EB on the weight of the adenohypophysis (AP) was significantly suppressed both by tamoxifen and by mifepristone. Mifepristone and tamoxifen reduced the increased content of PRL in the estrogenized adenohypophysis. Mifepristone but not tamoxifen significantly increased the content of the LH in the adenohypophysis of estrogen treated rats. Mifepristone and tamoxifen suppressed the increased concentration of cyclic nucleotides cAMP and cGMP in the estrogenized adenohypophysis. Mifepristone given alone increased serum levels of corticosterone, but when given together with EB deepened inhibiting effect EB on them. The results of our preliminary study show that mifepristone exerts a weak antiestrogenic activity on the level of hypophysis, however the pharmacology is not identical to tamoxifen.
本研究的目的是查明主要作为一种具有抗孕激素和抗糖皮质激素作用的物质的米非司酮，对大鼠腺垂体是否也具有体内抗雌激素活性。雄性Wistar大鼠被长期给予以下处理：每周两次皮下注射1 mg苯甲酸雌二醇（EB），持续12天；或给予非甾体抗雌激素他莫昔芬（1 mg/天/只大鼠）；或给予米非司酮（1 mg/天/只大鼠）；或同时给予EB与米非司酮或他莫昔芬。他莫昔芬和米非司酮均显著抑制了EB对腺垂体（AP）重量的肥大效应。米非司酮和他莫昔芬降低了雌激素化腺垂体中催乳素（PRL）含量的增加。米非司酮显著增加了雌激素处理大鼠腺垂体中促黄体生成素（LH）的含量，而他莫昔芬则无此作用。米非司酮和他莫昔芬抑制了雌激素化腺垂体中环状核苷酸cAMP和cGMP浓度的增加。单独给予米非司酮可增加血清皮质酮水平，但与EB同时给予时，会加深EB对其的抑制作用。我们初步研究的结果表明，米非司酮在垂体水平发挥微弱的抗雌激素活性，但其药理学作用与他莫昔芬不同。
