Carpenter A M, Lukyanenko Y O, Lee V H, Hutson J C
Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock 79430, USA.
J Androl. 1998 Jul-Aug;19(4):420-7.
We have previously demonstrated that conditioned medium from testicular macrophages stimulates testosterone production by Leydig cells. It was also reported that conditioned medium from macrophages treated with follicle-stimulating hormone (FSH) had an even greater amount of Leydig cell-stimulating activity than medium from untreated macrophages, indicating that this factor is under the regulation of FSH. However, most other laboratories have been unable to reproduce this effect of FSH. We have recently purified and partially characterized the stimulatory factor from macrophage-conditioned medium that stimulates Leydig cells. The purpose of the present investigation was to reinvestigate the effect of FSH by determining whether it regulates the production of this purified factor and by determining whether macrophages have mRNA for the FSH receptor. Testicular macrophages were isolated from adult rats and incubated 24 hours with human recombinant FSH (20 units/ml), ovine FSH (200 ng/ml), fetal bovine serum (2%), or dibutyryl cyclic adenosine monophosphate (1 mM). The macrophage-derived factor (MDF) was then purified from conditioned medium of the various treatment groups and added to Leydig cells. The concentration of testosterone in the Leydig cell medium was then measured after 16 hours. It was found that serum significantly stimulated production of the MDF. However, FSH had no effect on production of the MDF in the presence or absence of serum. Dibutyryl cyclic adenosine monophosphate exerted a slight inhibitory effect on production of the macrophage-derived factor. Most importantly, testicular macrophages did not express detectable levels of FSH receptor mRNA, either in vivo or in vitro, when evaluated using either in situ hybridization or northern analysis, under identical conditions that clearly demonstrated FSH receptor mRNA in Sertoli cells. We conclude that testicular macrophages are not a direct target for FSH.
我们之前已经证明，睾丸巨噬细胞的条件培养基可刺激睾丸间质细胞产生睾酮。也有报道称，用促卵泡激素（FSH）处理过的巨噬细胞的条件培养基比未处理巨噬细胞的培养基具有更强的刺激睾丸间质细胞的活性，这表明该因子受FSH调控。然而，其他大多数实验室都无法重现FSH的这种作用。我们最近从刺激睾丸间质细胞的巨噬细胞条件培养基中纯化并部分鉴定了该刺激因子。本研究的目的是通过确定FSH是否调节这种纯化因子的产生以及巨噬细胞是否具有FSH受体的mRNA，来重新研究FSH的作用。从成年大鼠分离出睾丸巨噬细胞，并用重组人FSH（20单位/毫升）、绵羊FSH（200纳克/毫升）、胎牛血清（2%）或二丁酰环磷酸腺苷（1毫摩尔）孵育24小时。然后从各个处理组的条件培养基中纯化巨噬细胞衍生因子（MDF），并将其添加到睾丸间质细胞中。16小时后测量睾丸间质细胞培养基中睾酮的浓度。发现血清显著刺激了MDF的产生。然而，无论有无血清，FSH对MDF的产生均无影响。二丁酰环磷酸腺苷对巨噬细胞衍生因子的产生有轻微抑制作用。最重要的是，当在与清楚显示支持细胞中FSH受体mRNA相同的条件下，使用原位杂交或Northern分析进行评估时，无论是在体内还是体外，睾丸巨噬细胞均未表达可检测水平的FSH受体mRNA。我们得出结论，睾丸巨噬细胞不是FSH的直接靶细胞。
