Byers S W
J Reprod Fertil. 1984 May;71(1):17-21. doi: 10.1530/jrf.0.0710017.
Testosterone production in testis tissue taken from rams that had been scrotally insulated for 28 days and from control animals was compared in the presence and absence of pregnenolone and LH. The absolute content of testosterone, but not its concentration was reduced in scrotally insulated rams. Tissue from treated animals was able to synthesize testosterone from exogenous pregnenolone as effectively as tissue from control rams, whilst LH and pregnenolone together had little additive effect. The addition of LH alone stimulated greater testosterone production by testis tissue from treated rams than from control testes. The addition of pregnenolone was followed by a rise in testosterone production within 1 h of incubation, whilst the LH stimulation of testosterone production was not evident until after 4 h of incubation. This suggests that the major action of LH in this system may be to simulate the conversion of pregnenolone precursors to pregnenolone. It is suggested that an accumulation of pregnenolone precursors occurs in the scrotally insulated testes and that these may be mobilized and cleaved after incubation with LH in vitro.
比较了取自阴囊保温28天的公羊以及对照动物的睾丸组织在有和没有孕烯醇酮及促黄体生成素（LH）存在的情况下的睾酮生成情况。阴囊保温的公羊中睾酮的绝对含量降低了，但其浓度未降低。与对照公羊的组织一样，处理过的动物的组织能够有效地从外源性孕烯醇酮合成睾酮，而LH和孕烯醇酮共同作用时几乎没有相加效应。单独添加LH时，处理过的公羊的睾丸组织比对照睾丸刺激产生更多的睾酮。添加孕烯醇酮后，孵育1小时内睾酮生成增加，而LH对睾酮生成的刺激直到孵育4小时后才明显。这表明在该系统中LH的主要作用可能是模拟孕烯醇酮前体向孕烯醇酮的转化。有人提出，在阴囊保温的睾丸中会发生孕烯醇酮前体的积累，并且在体外与LH孵育后这些前体可能会被动员并裂解。
