Loganath A, Peh K L, Wong Y C, Ng S C
University Department of Obstetrics and Gynaecology, National University Hospital, Singapore.
Horm Res. 2000;53(3):125-8. doi: 10.1159/000023560.
The cholesterol biosynthetic activity was assessed using [2-(14)C]-acetate as substrate in the homogenates of amnion and chorion obtained from women (n = 6, age 26-39 years) after spontaneous labour at term (37-40 weeks of gestation) having uncomplicated pregnancies. Reverse-isotope dilution analysis gave positive identification of [(14)C]-cholesterol acetate in all incubations of viable tissues. This metabolite was not evident in heat-denatured homogenates which served as controls. The extent of enzymic conversion for amnion at 2.6 x 10(-3) to 0.19% was persistently higher than that of the chorion at 1.7 x 10(-3) to 9.0 x 10(-3)%. The results indicate that human term fetal membranes possess the full complement of enzymes to catalyze the transformation of acetate to cholesterol. This study provides evidence that fetal membranes possess the capacity for de novo cholesterol biosynthesis, the sterol being essential for steroidogenesis as well as in embryo viability during pregnancy.
采用[2-(14)C]-乙酸盐作为底物，对妊娠37 - 40周足月自然分娩且妊娠过程无并发症的女性（n = 6，年龄26 - 39岁）的羊膜和绒毛膜匀浆进行胆固醇生物合成活性评估。反向同位素稀释分析在所有活组织孵育中均阳性鉴定出[(14)C]-胆固醇乙酸酯。作为对照的热变性匀浆中未发现这种代谢物。羊膜的酶促转化率在2.6×10(-3)至0.19%之间，持续高于绒毛膜的1.7×10(-3)至9.0×10(-3)%。结果表明，足月人胎膜具备将乙酸盐转化为胆固醇所需的全套酶。本研究提供了证据，证明胎膜具有从头合成胆固醇的能力，这种甾醇对类固醇生成以及孕期胚胎存活至关重要。
