The mechanism for lindane-induced inhibition of steroidogenesis in cultured rat Leydig cells

The in vitro effect of the gamma-isomer of hexachlorocyclohexane, lindane, on rat Leydig cell steroidogenesis was studied. Leydig cells from mature ma le rats were incubated with human chorionic gonadotropin (hCG, 1 IU) for 3 h at 34 degreesC in the presence of different doses of lindane (2-200 mug/m l; 2-200 ppm). Results demonstrate that lindane produces a dose-dependent i nhibition of testosterone production in hCG-stimulated Leydig cells. The de creased testosterone synthesis was accompanied with a half-reduced LH/hCG r eceptor number without any modification in the K-d value. In addition, lind ane also decreased cAMP production. These effects were not due to a detrime ntal action of lindane on cell viability. Results of this study demonstrate a direct inhibitory action of lindane on testicular steroidogenesis, at le ast in part, through a reduction in the classical second messenger producti on involved in this pathway. (C) 2001 Elsevier Science Ireland Ltd. All rig hts reserved.