Reiter E, McNamara M, Closset J, Hennen G
Biochemistry and Laboratory of Endocrinology, University of Liège, Belgium.
Endocrinology. 1995 Mar;136(3):917-23. doi: 10.1210/endo.136.3.7867600.
In addition to androgens that are essential for maintenance of prostate growth and function, nonandrogenic hormones must also be considered to explain some regulatory events occurring in the prostate. The detection of LH/CG receptor (LH/CG-R) gene expression in some nongonadal tissues, has led us to consider LH as a potential regulatory factor of prostatic development and function. In this study, we have demonstrated by RT-nested polymerase chain reaction and Northern blotting that the rat prostate contains the same LH/CG-R transcript as the gonads. Western immunoblotting, ligand blotting, and binding analysis have shown that rat prostate also contains a 93-kDa receptor protein that is able to bind [125I]hCG specifically and with a high affinity (6.0 x 10(9) M-1). Our results also indicated that the concentration of binding sites was lower in the prostate than in the gonads. LH/CG-R sites of expression have been localized in the prostate by immunohistochemistry: specific staining was observed in all the epithelial cells of the gland, but the ventral lobes are much more immunoreactive than the lateral and dorsal lobes. Finally, the ability of this prostatic LH/CG-R to induce a physiological response was evaluated in an explant culture system. A time course experiment was carried out, and we observed a significant dose-dependent stimulation of cAMP production after 3 h of treatment: 3.0 +/- 0.4, 4.2 +/- 0.4, and 5.0 +/- 0.5 pmol/ml of cAMP for 0, 100, and 500 ng/ml of LH, respectively. In conclusion, LH is able to act directly on the prostatic gland through specific receptors that are structurally and functionally very similar to those expressed in the gonads and are mainly localized in the ventral lobe of the organ. These data suggest that LH plays a significant physiological role in the prostate.
除了对维持前列腺生长和功能至关重要的雄激素外，还必须考虑非雄激素激素来解释前列腺中发生的一些调节事件。在一些非性腺组织中检测到促黄体生成素/绒毛膜促性腺激素受体（LH/CG-R）基因表达，这使我们将LH视为前列腺发育和功能的潜在调节因子。在本研究中，我们通过逆转录巢式聚合酶链反应和Northern印迹法证明，大鼠前列腺含有与性腺相同的LH/CG-R转录本。蛋白质免疫印迹、配体印迹和结合分析表明，大鼠前列腺还含有一种93 kDa的受体蛋白，该蛋白能够特异性且高亲和力（6.0×10⁹ M⁻¹）地结合[¹²⁵I]hCG。我们的结果还表明，前列腺中结合位点的浓度低于性腺。通过免疫组织化学将LH/CG-R的表达位点定位在前列腺中：在腺体的所有上皮细胞中均观察到特异性染色，但腹侧叶的免疫反应性比外侧叶和背侧叶强得多。最后，在器官外植体培养系统中评估了这种前列腺LH/CG-R诱导生理反应的能力。进行了一项时间进程实验，我们观察到处理3小时后cAMP产生有显著的剂量依赖性刺激：分别给予0、100和500 ng/ml LH时，cAMP的浓度分别为3.0±0.4、4.2±0.4和5.0±0.5 pmol/ml。总之，LH能够通过与性腺中表达的受体在结构和功能上非常相似且主要定位于器官腹侧叶的特异性受体直接作用于前列腺。这些数据表明LH在前列腺中发挥着重要的生理作用。
