Gunasegaram R, Loganath A, Peh K L, Ng S C, Karim S M, Ratnam S S
Acta Endocrinol (Copenh). 1983 Feb;102(2):288-91. doi: 10.1530/acta.0.1020288.
With a view to establish the hitherto undescribed role of cholesterol in foetal-membranous steroidogenesis, homogenates of term chorion pars reflexa and amnion pars reflexa and pars placentaris collected from 6 women after spontaneous labour at term (38 to 41 weeks gestation) were incubated with [26-14C]cholesterol. Using reverse-isotope dilution analysis, [14C]isocaproic acid was isolated and characterized. This conversion constitutes strong evidence that C-20, 22-desmolase activity, normally present in the adrenal, gonadal and placental tissues, is present in the homogenates of both membranes. The efficiency of the enzymic conversion suggests that the chorion possesses a more active desmolase system compared to that of the amnion.
为确定胆固醇在胎膜甾体激素生成中迄今未被描述的作用，从6名足月（妊娠38至41周）自然分娩后的妇女收集的足月绒毛膜反折部、羊膜反折部和胎盘部的匀浆，与[26-¹⁴C]胆固醇一起孵育。采用反向同位素稀释分析法，分离并鉴定了[¹⁴C]异己酸。这种转化构成了强有力的证据，表明通常存在于肾上腺、性腺和胎盘组织中的C-20、22-碳链裂解酶活性也存在于这两种膜的匀浆中。酶促转化的效率表明，与羊膜相比，绒毛膜拥有更活跃的碳链裂解酶系统。
