Octylphenol affects morphology and steroidogenesis in mouse tumor Leydig cells

Abstract

Exposure to xenoestrogens has been shown to cause adverse effects on reproductive function of various animal species. However, direct effects of xenoestrogens on Leydig cell function remain scarcely known. The aim of our study was to demonstrate the effects of 4-tert-Octylphenol (OP) on the expression of 3β-hydroxysteroid dehydrogenase (3β-HSD) and androgen receptor (AR) in MA-10 Leydig cells. Cells were treated for 3 and 12h with OP (10(-4)-10(-8)M). In cell cultures treated with high OP concentrations for 3 and 12h morphological alterations were observed. Oil Red O staining revealed differences in lipid droplet size and distribution when compared to controls. Immunoreactive 3β-HSD was found in the cytoplasm, whereas immunoreactive AR was detected in the nuclei of both control and OP-exposed Leydig cells. A dose-related decrease in the expression of both proteins in OP-exposed cells was found. Qualitative results by immunocytochemistry and Western blot were confirmed by further quantitative analyses. Radioimmunological analysis revealed time-dependent secretion of progesterone (P(4)) by control and OP-exposed Leydig cells. In 3 and 12h OP-treated Leydig cells a significant decrease in P(4) level was found. Our study demonstrated a dose- and time-dependent action of OP on both morphology and steroidogenic function of MA-10 cells. It seems likely that OP besides acting via ER may mediate its action through AR modulating Leydig cell function.