Verhoeven G, Cailleau J
Mol Cell Endocrinol. 1987 Feb;49(2-3):137-47. doi: 10.1016/0303-7207(87)90207-3.
It is demonstrated that tubular fragments derived from human testes and cultured in vitro produce a factor that stimulates the production of testosterone by human interstitial cells and by Percoll-purified Leydig cells from rat and mouse origin. The active principle in the conditioned media is a thermo-labile and trypsin-sensitive protein with an MW greater than 10,000. The factor is active in the presence as well as in the absence of maximally effective concentrations of LH and its activity is not accompanied by measurable changes in cAMP production. There are several points of analogy between this factor and a Leydig cell stimulatory protein produced by rat Sertoli cells. Molecular weight fractionation of spent media from human testicular tubules using an Amicon ultrafiltration system results in a 38- to 102-fold increase in Leydig cell stimulatory activity in a fraction corresponding to a molecular weight of 10,000 up to 30,000. These figures are comparable to those observed after molecular weight fractionation of spent media from rat Sertoli cells. Dose-response curves with partially purified preparations from human and rat origin yield parallel dose-response curves. In rat Sertoli cells as well as in human testicular tubules, the production of the active principle is stimulated by FSH and dibutyryl cAMP. Finally, maximally effective concentrations of the active principles of human and rat origin display no additive effects whereas additive effects are clearly evident with other Leydig cell stimulatory factors such as LHRHa and EGF. The hypothesis is advanced that the Leydig cell stimulatory factors from tubular origin may act as paracrine regulatory molecules responsible for the effects of FSH on Leydig cell function.
已证明，源自人类睾丸并在体外培养的管状片段产生一种因子，该因子可刺激人类间质细胞以及来自大鼠和小鼠的经Percoll纯化的Leydig细胞产生睾酮。条件培养基中的活性成分是一种热不稳定且对胰蛋白酶敏感的蛋白质，分子量大于10,000。该因子在存在或不存在最大有效浓度的LH时均具有活性，并且其活性不会伴随着cAMP产生的可测量变化。该因子与大鼠支持细胞产生的Leydig细胞刺激蛋白之间存在若干相似之处。使用Amicon超滤系统对人类睾丸小管的用过的培养基进行分子量分级分离，结果在分子量为10,000至30,000的级分中，Leydig细胞刺激活性增加了38至102倍。这些数字与大鼠支持细胞用过的培养基进行分子量分级分离后观察到的数字相当。来自人类和大鼠来源的部分纯化制剂的剂量反应曲线产生平行的剂量反应曲线。在大鼠支持细胞以及人类睾丸小管中，活性成分的产生受到FSH和二丁酰cAMP的刺激。最后，来自人类和大鼠来源的活性成分的最大有效浓度没有显示出相加作用，而与其他Leydig细胞刺激因子如LHRHa和EGF则明显存在相加作用。有人提出假说，认为来自管状来源的Leydig细胞刺激因子可能作为旁分泌调节分子，负责FSH对Leydig细胞功能的影响。
