Human chorionic gonadotropin induces interleukin-1 gene expression in rat Leydig cells in vivo

Luteinizing hormone (LH)/human chorionic gonadotropin (hCG) causes inflammatory-type responses in the testis. In the present study, we evaluated the effects of hCG on Leydig cell interleukin-1 (IL-1) gene expression. Using monoclonal antibody (ED2) staining for macrophages, our Leydig cell preparations had no significant contamination with macrophages. When purified Leydig cells from normal rats were cultured for 24 h and then treated with IL-1 beta (1-100 ng/ml) for 6 h, IL-1 beta induced dose-dependent increases in IL-1 beta mRNA levels. IL-1 beta also induced IL-1 alpha mRNA accumulation; however, the level of IL-1 alpha mRNA was much lower than that of IL-1 beta mRNA. When rats were treated with either saline or hCG (5 units i.p.), hCG markedly induced IL-1 beta mRNA accumulation in purified Leydig cells at 6 h which persisted for over 24 h. However, hCG had no direct effect on purified Leydig cell or crude interstitial cell IL-1 mRNA levels. Our results suggest that inflammatory effects of hCG in vivo may be mediated by increased IL-1 gene expression in Leydig cells.