Montgomery Rice V, Limback S D, Roby K F, Terranova P F
Center for Reproductive Sciences, Department of Obstetrics and Gynecology, University of Kansas Medical Center, Kansas City 66160-7401, USA.
Endocrine. 1999 Feb;10(1):19-23. doi: 10.1385/ENDO:10:1:19.
Tumor necrosis factor alpha (TNF) inhibits follicle-stimulating hormone- (FSH)induced estradiol secretion by granulosa cells in several species, including humans. One major inhibitory effect of TNF in rat granulosa cells is at the level of stimulatable adenylyl cyclase, resulting in reduced cAMP concentrations. The purpose of the present study was to investigate whether a reduction in cAMP secretion could account for the inhibitory effects of TNF on FSH-induced estradiol in human granulosa cells. Granulosa cells were taken from ovaries of premenopausal women undergoing oophorectomy for reasons unrelated to ovarian pathology. Women in this study were in various stages of the menstrual cycle or exhibited irregular cycles. Granulosa cells from follicles ranging from 5 to 10 mm diameter were subjected to culture for 48 and 96 h. Granulosa cells were cultured with human FSH (2 ng/mL) and testosterone (1 microM) in the presence and absence of human TNF (20 ng/mL). Media were collected at 48 h, fresh media and hormones added, and cultures continued for an additional 48 h. Accumulation of cAMP, progesterone, and estradiol in media were determined by radioimmunoassay (RIA). FSH induced significant increases in cAMP, progesterone, and estradiol by 96 h of culture. TNF inhibited the secretion of estradiol at 96 h without reducing the accumulation of cAMP and progesterone in media. Similar results were observed in the presence of 0.1 mM isobutylmethylxanthine (D3MX), a phosphodiesterase inhibitor that would prevent metabolism of cAMP to AMP. To determine whether TNF would inhibit the ability of cAMP to induce estradiol and progesterone secretion, granulosa cells were incubated with 0.1 mM cAMP in the presence and absence of TNF. TNF consistently inhibited the ability of cAMP to increase estradiol secretion. These results indicate that a pathway for TNF inhibition of FSH- or cAMP-induced estradiol secretion in human granulosa cells is at post-cAMP sites rather than inhibition of FSH-stimulatable adenylyl cyclase.
肿瘤坏死因子α（TNF）可抑制包括人类在内的多种物种的颗粒细胞中促卵泡激素（FSH）诱导的雌二醇分泌。TNF对大鼠颗粒细胞的一个主要抑制作用是在可刺激的腺苷酸环化酶水平，导致细胞内cAMP浓度降低。本研究的目的是探讨cAMP分泌减少是否可以解释TNF对人颗粒细胞中FSH诱导的雌二醇的抑制作用。颗粒细胞取自因与卵巢病变无关的原因而接受卵巢切除术的绝经前妇女的卵巢。本研究中的妇女处于月经周期的不同阶段或月经周期不规律。直径为5至10毫米卵泡的颗粒细胞进行48小时和96小时的培养。颗粒细胞在有和没有人TNF（20 ng/mL）的情况下，与人FSH（2 ng/mL）和睾酮（1 microM）一起培养。在48小时时收集培养基，添加新鲜培养基和激素，并将培养再持续48小时。通过放射免疫测定法（RIA）测定培养基中cAMP、孕酮和雌二醇的积累量。培养96小时后，FSH显著增加了cAMP、孕酮和雌二醇的含量。TNF在96小时时抑制了雌二醇的分泌，但没有降低培养基中cAMP和孕酮的积累量。在存在0.1 mM异丁基甲基黄嘌呤（D3MX）（一种磷酸二酯酶抑制剂，可防止cAMP代谢为AMP）的情况下，观察到了类似的结果。为了确定TNF是否会抑制cAMP诱导雌二醇和孕酮分泌的能力，颗粒细胞在有和没有TNF的情况下与0.1 mM cAMP一起孵育。TNF持续抑制cAMP增加雌二醇分泌的能力。这些结果表明，TNF抑制人颗粒细胞中FSH或cAMP诱导的雌二醇分泌的途径是在cAMP产生后的位点，而不是抑制FSH可刺激的腺苷酸环化酶。
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