Tekmal R R, Burns W N, Rao D V, Montoya I A, Chang P L, Stoica G, Schenken R S
Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio 78284-7836, USA.
Am J Obstet Gynecol. 1996 Aug;175(2):420-7. doi: 10.1016/s0002-9378(96)70156-4.
Our purpose was to assess the effects of follicle-stimulating hormone, luteinizing hormone, forskolin (an adenylyl cyclase activator), estradiol, and progesterone on alpha-inhibin promoter activity in an in vitro fusion gene-transfection system.
A fusion gene consisting of the alpha-inhibin 5' flanking and promoter regions linked to the chloramphenicol acetyl transferase reporter gene was constructed. A granulosa cell line originally derived from an inbred strain of Berlin Duckrey rats was transiently transfected with the fusion gene. Fusion gene activity was determined by measuring chloramphenicol acetyl transferase activity in transfected cells.
Both follicle-stimulating hormone and luteinizing hormone activated the alpha-inhibin promoter. Activity in response to combined luteinizing hormone-forskolin treatment was greater than the summation of the activities of the two treatments individually, suggesting that the effects of luteinizing hormone might be partially mediated by second messengers other than cyclic adenosine monophosphate. Gonadotropin-stimulated activity was diminished by estradiol and combined estradiol-progesterone treatments.
The stimulatory effects of follicle-stimulating hormone and luteinizing hormone on alpha-inhibin production are mediated at least in part by stimulation of the alpha-inhibin promoter. The stimulatory effects are blunted by estradiol-progesterone. These observations may partially explain how alpha-inhibin is down-regulated in vivo in response to the preovulatory luteinizing hormone surge.
我们的目的是在体外融合基因转染系统中评估促卵泡激素、促黄体生成素、福斯高林（一种腺苷酸环化酶激活剂）、雌二醇和孕酮对α-抑制素启动子活性的影响。
构建了一个由α-抑制素5'侧翼和启动子区域与氯霉素乙酰转移酶报告基因相连的融合基因。将最初源自柏林杜克雷大鼠近交系的颗粒细胞系用该融合基因进行瞬时转染。通过测量转染细胞中的氯霉素乙酰转移酶活性来确定融合基因活性。
促卵泡激素和促黄体生成素均激活α-抑制素启动子。联合促黄体生成素-福斯高林处理后的活性大于两种处理单独活性之和，这表明促黄体生成素的作用可能部分由环磷酸腺苷以外的第二信使介导。促性腺激素刺激的活性因雌二醇和雌二醇-孕酮联合处理而降低。
促卵泡激素和促黄体生成素对α-抑制素产生的刺激作用至少部分是通过刺激α-抑制素启动子介导的。雌二醇-孕酮会减弱这种刺激作用。这些观察结果可能部分解释了在体内α-抑制素如何响应排卵前促黄体生成素激增而下调。
