Tseng J K, Sun B, Tseng L
Department of Obstetrics and Gynecology, School of Medicine, State University of New York, Stony Brook 11794.
J Steroid Biochem. 1988 Jan;29(1):9-13. doi: 10.1016/0022-4731(88)90369-x.
The ability of rabbit endometrium to synthesize estrogen was investigated. Aromatase activity was measured by incubating the viable tissue fragments with [3H] testosterone at 37 degrees C and quantitated the [3H]estrogens at the end of 6 h incubation. The activity was not detectable in endometrium and myometrium of non-pregnant rabbits. In pregnant rabbit, the activity increased from 2 to 12 fmol/h/g of tissue in endometrium obtained from both gravid and nongravid uterine horns 4-8 days after mating. Aromatase activity in endometrium at implanted sites on the 8th day after mating reached up to 550 fmol/h/g of tissue. Hormonal regulation of the aromatase activity was studied directly in cultured rabbit endometrial stromal cells. Both progesterone and medroxyprogesterone acetate stimulated the activity with 2- to 25-fold increase over the control values (0.2-1 fmol/h/mg protein). The stimulation of aromatase activity by progestin was found to be both time- and dose-dependent. Estrogen, Bu2cAMP, forskolin, HCG or relaxin had no effect on the activity. Aromatase activity in glandular epithelial cells was neither detectable nor affected by progestin. These results indicate that aromatase activity in rabbit endometrium is concentrated in stromal cells and progestin stimulates the activity. However, estrogen, forskolin and relaxin which enhanced the stimulation of the activity by progestin in human endometrium had no effect on aromatase in rabbit endometrium. The increase of aromatase activity observed after the onset of conception may be physiologically important to increase the local estrogen content for decidualization of the endometrium.
研究了兔子宫内膜合成雌激素的能力。通过将活组织碎片与[3H]睾酮在37℃下孵育来测量芳香化酶活性，并在孵育6小时结束时对[3H]雌激素进行定量。在未孕兔的子宫内膜和子宫肌层中未检测到该活性。在孕兔中，交配后4 - 8天，从妊娠和非妊娠子宫角获得的子宫内膜中，该活性从2 fmol/h/g组织增加到12 fmol/h/g组织。交配后第8天着床部位的子宫内膜中芳香化酶活性高达550 fmol/h/g组织。直接在培养的兔子宫内膜基质细胞中研究了芳香化酶活性的激素调节。孕酮和醋酸甲羟孕酮均刺激该活性，比对照值（0.2 - 1 fmol/h/mg蛋白质）增加2至25倍。发现孕激素对芳香化酶活性的刺激具有时间和剂量依赖性。雌激素、双丁酰环磷腺苷、福斯高林、人绒毛膜促性腺激素或松弛素对该活性无影响。腺上皮细胞中的芳香化酶活性既未检测到，也不受孕激素影响。这些结果表明，兔子宫内膜中的芳香化酶活性集中在基质细胞中，孕激素刺激该活性。然而，在人子宫内膜中增强孕激素对该活性刺激作用的雌激素、福斯高林和松弛素对兔子宫内膜中的芳香化酶没有影响。受孕后观察到的芳香化酶活性增加对于增加局部雌激素含量以促进子宫内膜蜕膜化可能具有重要的生理意义。
