Grizard G
Laboratoire de Biologie de la Reproduction, Faculté de Médecine, Clermont-Ferrand.
Contracept Fertil Sex. 1994 Sep;22(9):551-5.
Many in vitro and in vivo studies have demonstrated a presence of IGF-I in the testis. Testicular production of IGF-I and its mRNA is stimulated largely by gonadotropins; FSH acts on Sertoli cells while LH acts on Leydig cells. A regulation by local factors is also demonstrated; the role of GH remains unclear. In the testis, IGF-I has various effects but we only focussed this review on Leydig cells. Specific receptors have been characterized on these cells. They are up-regulated by LH/hCG (at the transcriptional level) and down regulated by IGF-I. The effect of GH is depend on the experimental models used. In addition in this paper, we have shown in adult rats that the IGF-I level in the testicular interstitial fluid and the IGF-I receptors on Leydig cells are modified by fasting. Both in vivo and in vitro, IGF-I increased LH/hCG receptors and the steroïdogenic response to hCG by a mechanism which is poorly understood yet.
许多体外和体内研究都已证实在睾丸中存在胰岛素样生长因子-I（IGF-I）。睾丸中IGF-I及其信使核糖核酸（mRNA）的产生很大程度上受促性腺激素刺激；促卵泡激素（FSH）作用于支持细胞，而促黄体生成素（LH）作用于睾丸间质细胞。局部因子的调节作用也得到了证实；生长激素（GH）的作用仍不清楚。在睾丸中，IGF-I有多种作用，但本综述仅聚焦于睾丸间质细胞。这些细胞上已鉴定出特异性受体。它们在促黄体生成素/人绒毛膜促性腺激素（LH/hCG）作用下（在转录水平）上调，而在IGF-I作用下下调。生长激素的作用取决于所使用的实验模型。此外，在本文中我们已表明，在成年大鼠中，禁食会改变睾丸间质液中的IGF-I水平以及睾丸间质细胞上的IGF-I受体。在体内和体外，IGF-I均通过一种尚未完全了解的机制增加LH/hCG受体以及对hCG的类固醇生成反应。
