Verhoeven G, Cailleau J
J Steroid Biochem. 1986 Sep;25(3):393-402. doi: 10.1016/0022-4731(86)90252-9.
There is increasing evidence that factors derived from the seminiferous tubules influence Leydig cell function in a paracrine way. In previous experiments we demonstrated that conditioned media from Sertoli cell-enriched cultures contain a protein with stimulatory activity on prepubertal rat Leydig cells. In this paper we further studied the specificity of this factor. In addition we describe a simple but efficient partial purification procedure. It is demonstrated that Sertoli cell conditioned media contain a factor that stimulates the testosterone output from prepubertal and adult Leydig cells. The effects are evident within the first hour of incubation and can be observed in the presence as well as in the absence of LH. Peritubular cells do not produce a similar factor but enhance the production of the Leydig cell stimulating factor when cocultured with Sertoli cells. The Sertoli cell factor acts on rat as well as on mouse Leydig cells. It barely influences the adrenostenedione output of ovarian stromal cells or the corticosterone output of adrenal cells. The production of this factor is enhanced by dbcAMP, FSH, L-isoproterenol and glucagon but is not affected by androgens. The characteristics of the Sertoli cell factor have been compared with those of a Leydig cell stimulating factor in the medium from an established rabbit kidney cell line: RK13. It is shown that the active principle in RK13 conditioned medium is also a thermolabile trypsin-sensitive protein with a mol. wt of more than 10,000. Nonetheless, the RK13 and Sertoli cell derived factors act by different mechanisms since at maximally effective concentrations their effects are additive. Finally it is demonstrated that molecular weight fractionation of Sertoli cell conditioned medium using an Amicon ultrafiltration system results in a 50- to 130-fold increase in Sertoli cell factor activity in a fraction corresponding to a mol. wt of 10,000 up to 30,000.
越来越多的证据表明，来自生精小管的因子以旁分泌方式影响睾丸间质细胞的功能。在先前的实验中，我们证明富含支持细胞的培养物的条件培养基含有一种对青春期前大鼠睾丸间质细胞具有刺激活性的蛋白质。在本文中，我们进一步研究了该因子的特异性。此外，我们描述了一种简单而有效的部分纯化程序。结果表明，支持细胞条件培养基含有一种刺激青春期前和成年睾丸间质细胞睾酮分泌的因子。在孵育的第一小时内效果明显，并且在有或没有促黄体生成素（LH）的情况下都可以观察到。睾丸周细胞不产生类似的因子，但与支持细胞共培养时会增强睾丸间质细胞刺激因子的产生。支持细胞因子对大鼠和小鼠的睾丸间质细胞均起作用。它几乎不影响卵巢基质细胞的肾上腺雄烯二酮分泌或肾上腺细胞的皮质酮分泌。二丁酰环磷腺苷（dbcAMP）、促卵泡激素（FSH）、L-异丙肾上腺素和胰高血糖素可增强该因子的产生，但雄激素对其没有影响。已将支持细胞因子的特性与来自已建立的兔肾细胞系RK13培养基中的睾丸间质细胞刺激因子的特性进行了比较。结果表明，RK13条件培养基中的活性成分也是一种分子量超过10,000的热不稳定、对胰蛋白酶敏感的蛋白质。尽管如此，RK13和支持细胞衍生的因子作用机制不同，因为在最大有效浓度下它们的作用是相加的。最后证明，使用Amicon超滤系统对支持细胞条件培养基进行分子量分级分离，会使分子量在10,000至30,000之间的部分中支持细胞因子活性增加50至130倍。
