Bhavnani B R, Martin L J, Baker R D
Endocrinology. 1975 Apr;96(4):1009-17. doi: 10.1210/endo-96-4-1009.
A mixture of 1-14C-isopentenylpyrophosphate and 3H-dehydroisoandrosterone was injected into a horse fetus intramuscularly during laparotomy, after which maternal urine was collected for 4 days. Steroid conjugates in the urine were extracted with Amberlite XAD-2 resin, hydrolysed and separated into phenolic and neutral fractions. From the phenolic fraction estrone, 17alpha-estradiol, equilin and equilenin were isolated. Only estrone and 17alpha-estradiol contained both 3H and 14C, while the ring B unsaturated estrogens contained only 14C. From the neutral fraction 14C-labeled 3beta-hydroxy-5alpha-pregnan-20-one, 5alpha-pregnane-3beta,20beta-diol and 5alpha-pregnan-3beta, 20alpha-diol were isolated. These results demonstrate that the route of biosynthesis of both the ring B saturated and unsaturated estrogens is the same up to the stage of isopentenylpyrophosphate. Thus, the bifurcation in the classical pathway of steroid biosynthesis reported previously by us is occurring at a point after the formation of isopentenylpyrophosphate and prior to the formation of squalene.
在剖腹手术期间，将1-¹⁴C-异戊烯基焦磷酸酯和³H-脱氢异雄酮的混合物经肌肉注射到一匹马胎儿体内，之后收集母马尿液4天。尿液中的类固醇结合物用Amberlite XAD-2树脂提取，水解并分离为酚类和中性部分。从酚类部分中分离出雌酮、17α-雌二醇、马萘雌酮和马萘雌酚。只有雌酮和17α-雌二醇同时含有³H和¹⁴C，而B环不饱和雌激素只含有¹⁴C。从中性部分中分离出¹⁴C标记的3β-羟基-5α-孕烷-20-酮、5α-孕烷-3β,20β-二醇和5α-孕烷-3β,20α-二醇。这些结果表明，在异戊烯基焦磷酸酯阶段之前，B环饱和和不饱和雌激素的生物合成途径是相同的。因此，我们之前报道的类固醇生物合成经典途径中的分支发生在异戊烯基焦磷酸酯形成之后、角鲨烯形成之前的某个点。
