INTERLEUKIN-1-BETA INDUCES INTERLEUKIN-1-ALPHA MESSENGER-RIBONUCLEIC-ACID EXPRESSION IN PRIMARY CULTURES OF LEYDIG-CELLS

Previously, we have reported that interleukin-1 (IL-1) can modulate Leydig cell steroidogenesis. Recently, IL-1-like material has been shown to be present in the testis; however, the cellular source of this material remains unclear. In the present study we found that human recombinant IL-1-beta (1-100 ng/ml) caused dose-dependent increases in IL-1-alpha mRNA expression in Leydig cells. Similar to that reported in other tissues, IL-1-alpha mRNA from Leydig cells is mainly 2.2 kilobases. IL-1-alpha mRNA expression in Leydig cells was detectable as early as 2 h after the addition of IL-1-beta (10 ng/ml) and persisted for up to 24 h. Lipopolysaccharide also stimulated IL-1-alpha mRNA expression in these cells, but phorbol ester had no effect. Our results indicate that Leydig cells are a potential source of IL-1, which has both autocrine and paracrine effects.