钙对培养的人滋养层细胞芳香化作用的双重影响。

The dual effect of calcium on aromatization by cultured human trophoblast.

作者信息

Hochberg Z, Bick T, Perlman R, Brandes J M, Barzilai D

出版信息

J Steroid Biochem. 1986 Jun;24(6):1217-9. doi: 10.1016/0022-4731(86)90386-9.

Abstract

To study the effect of calcium ion on aromatization of an androgenic precursor to estradiol by the placenta, cultured term trophoblasts were used as a model system. Secretion of estradiol into the culture medium was regarded as indicating aromatization, since cells cultured with no androgenic precursors produced only insignificant amounts of estradiol. EGTA, verapamil and ionophore A23187 inhibited aromatization, while trifluoperazine, an inhibitor of the calcium-calmodulin complex, interfered with the stimulatory effect of cyclic AMP on aromatization. We conclude that calcium ion has an essential role in the aromatization of 4-androstene-3,17-dione to estradiol. The calcium-calmodulin complex is required for activation of aromatase by cyclic AMP. However, when flooded with calcium by ionophore A23187, the trophoblast is unable to effectively buffer calcium, and aromatization is inhibited.

摘要

为研究钙离子对胎盘将雄激素前体转化为雌二醇的芳香化作用的影响，将培养的足月滋养层细胞用作模型系统。由于在无雄激素前体的情况下培养的细胞仅产生微量的雌二醇，因此将雌二醇分泌到培养基中视为芳香化作用的指标。乙二醇双（2-氨基乙基醚）四乙酸（EGTA）、维拉帕米和离子载体A23187抑制芳香化作用，而钙调蛋白复合物抑制剂三氟拉嗪则干扰环磷酸腺苷（cAMP）对芳香化作用的刺激效应。我们得出结论，钙离子在4-雄烯-3,17-二酮转化为雌二醇的芳香化作用中起重要作用。钙调蛋白复合物是cAMP激活芳香化酶所必需的。然而，当通过离子载体A23187使细胞内钙超载时，滋养层细胞无法有效缓冲钙离子，芳香化作用受到抑制。