ABILITY OF MOLAR TROPHOBLASTS TO SPLIT THE SIDE-CHAIN OF [26-14C]CHOLESTEROL IN VITRO

Abstract

University Department of Obstetrics and Gynaecology, Kandang Kerbau Hospital for Women, Singapore 8, Republic of Singapore (Revised manuscript received 1 September 1978) Evidence from various laboratories indicates that molar trophoblasts may be biosynthetically very active in vitro and capable of bringing about several steroidal transformations (Van Leusden & Siemerink, 1969; Coutts & MacNaughton, 1971). However, a lack of incorporation of labelled acetate into pregnenolone and progesterone by molar vesicles has been observed by Van Leusden (1971) and Van Leusden & Villee (1966). Van Leusden (1971) also failed to demonstrate the conversion of [5-3H]mevalonate into sterols, cholesterol and steroids by these vesicles. These observations could be interpreted as indicating that the molar vesicles lack or possess only a very limited capacity to biosynthesize cholesterol from acetate and mevalonate. There also remains the distinct possibility that the vesicles are deficient in the C-20,22-desmolase complex that cleaves the sterol molecule into pregnenolone and