Gregoraszczuk E L, Piekło R
Department of Animal Physiology, Jagiellonian University, Krakow, Poland.
J Physiol Pharmacol. 1998 Sep;49(3):467-75.
In the present study hydroxylated cholesterol derivatives were used to monitor P450scc activity as an effect of triiodothyronine. Luteal cells isolated from mid-developing and mature corpora lutea were plated into 24-well plates by 18 h incubation with M199 supplemented with 5% of alf serum. After that time the plates were washed with fresh M199 and hydroxylated cholesterol derivatives (25-, 20-, and 22-hydroxylated cholesterol) were added to the control (not-T3-treated) and T3-treated cells. Two hours later, all cultures were terminated and the media were frozen until further progesterone analysis. Triiodotyronine added to the culture medium of cells isolated from mature corpora lutea increased both basal and hydroxylated cholesterol derivative-stimulated cells. Aminoglutethimide, a P450scc enzyme inhibitor, added to the culture medium in all doses used, had no effect on basal progesterone secretion while added to the T3-treated cells reduced progesterone production. This study strongly supports the hypothesis of a direct effect of thyroid hormone on mitochondrial cytochrome P450scc--catalysing side-chain cleavage of cholesterol enzyme in luteal cells.
在本研究中，使用羟基化胆固醇衍生物来监测作为三碘甲状腺原氨酸作用结果的P450scc活性。从发育中期和成熟黄体中分离出的黄体细胞，在补充有5%胎牛血清的M199中孵育18小时后接种到24孔板中。在该时间之后，用新鲜的M199洗涤平板，并将羟基化胆固醇衍生物（25-、20-和22-羟基化胆固醇）添加到对照（未用T3处理）和T3处理的细胞中。两小时后，终止所有培养物，并将培养基冷冻直至进一步进行孕酮分析。添加到从成熟黄体中分离出的细胞培养基中的三碘甲状腺原氨酸增加了基础和羟基化胆固醇衍生物刺激的细胞。氨基导眠能，一种P450scc酶抑制剂，以所有使用的剂量添加到培养基中，对基础孕酮分泌没有影响，而添加到T3处理的细胞中则降低了孕酮的产生。本研究有力地支持了甲状腺激素对黄体细胞中线粒体细胞色素P450scc（催化胆固醇侧链裂解的酶）有直接作用这一假说。
