Mono-(2-ethylhexyl) phthalate suppresses aromatase transcript levels and estradiol production in cultured rat granulosa cells
Mono-(2-ethylhexyl) phthalate suppresses aromatase transcript levels and estradiol production in cultured rat granulosa cells
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DOI：
10.1006/taap.2001.9156
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发表时间：
2001-05-01
影响因子：
3.8
通讯作者：
Davis, BJ
中科院分区：
文献类型：
--
作者：
Lovekamp, TN;Davis, BJ
邻苯二甲酸二（2-乙基己基）酯及其活性代谢物邻苯二甲酸单（2-乙基己基）酯（MEHP）的雌性生殖毒性归因于卵巢颗粒细胞雌二醇产生的抑制。在这些研究中，几种结构相关的邻苯二甲酸酯（0-200 μ M）和Wy-14，643比较了MEHP（0-100 μ M）与MEHP对颗粒细胞雌二醇产生和细胞色素P450酶β 19（也称为芳香酶）转录水平的影响（P450 arom），雄激素转化为雌激素的限速酶。从28日龄的Fisher 344大鼠获得颗粒细胞并培养48小时，在培养时加入测试化学品或DMSO，沿着睾酮作为芳香酶的底物。通过标准放射免疫测定法测量17 β-雌二醇的产生，通过荧光RT-PCR测量mRNA，通过Western印迹分析测量蛋白质。在邻苯二甲酸酯中，MEHP在降低雌二醇产生的能力方面是独特的，而Wy-14，643在100 μ M MEHP下具有与MEHP相似的作用，并且Wy-14，643还显著降低芳香酶mRNA水平。mRNA的减少是浓度依赖性的，并且被芳香化酶蛋白的减少所抵消。MEHP没有改变胆固醇侧链裂解酶（P450 SCC）的水平。在MEHP（100至200 μ M）存在下，用cAMP类似物处理增加了P450 SCC的表达，而芳香化酶的减少保持不变。因此，这些研究表明MEHP与几种结构相关的邻苯二甲酸酯不同，但在对颗粒细胞雌二醇产生的作用方面与过氧化物酶体增殖剂Wy-14，643相似。此外，MEHP对雌二醇的抑制可能是通过其对芳香酶转录水平的作用介导的，而不依赖于cAMP刺激的调节。(C)北京：科学出版社.
The female reproductive toxicity of di-(2-ethylhexyl) phthalate and its active metabolite mono-(2-ethylhexyl) phthalate (MEHP) is attributed to suppression of ovarian granulosa cell estradiol production. In these studies, several structurally related phthalates (0-200 muM) and Wy-14,643 (0-100 muM) were compared to MEHP for their effects on granulosa cell estradiol production and transcript levels of cytochrome P450 enzyme CYP 19, also known as aromatase (P450arom), the rate-limiting enzyme in the conversion of androgens to estrogens, Granulosa cells were obtained from 28-day-old Fisher 344 rats and were cultured for 48 h, Test chemical or DMSO was added at the time of culture, along with testosterone as a substrate for aromatase. 17 beta -Estradiol production was measured by standard radioimmunoassay, mRNA was measured by fluorescent RT-PCR, and protein was measured by Western blot analysis. MEHP was unique among the phthalates in its ability to decrease estradiol production, while Wy-14,643 had effects similar to MEHP at 100 muM MEHP and Wy-14,643 also significantly decreased aromatase mRNA levels. The decrease in mRNA was concentration dependent and was paralleled by a decrease in aromatase protein. MEHP did not alter levels of CYP 11A1, the cholesterol side-chain cleavage enzyme (P450scc). Treatment with a cAMP analogue increased expression of P450scc in the presence of MEHP (100 to 200 muM) while the decrease in aromatase remained. Thus, these studies suggest that MEHP is distinct from several structurally related phthalates but similar to the peroxisome proliferator Wy-14,643 in its action on granulosa cell estradiol production. Moreover, the suppression of estradiol by MEHP is likely mediated through its action on aromatase transcript levels independent of cAMP-stimulated regulation. (C) 2001 Academic Press.