Octylphenol induces apoptosis in cultured rat Sertoli cells.

In this study, the effects of 4-tert-octylphenol (OP) were examined on the viability of rat cultured Sertoli cells using the MTT assay and OP-induced apoptosis was detected by transmission electron microscope (TEM), flow cytometric analysis and Hoechst staining. In addition, RT-PCR was used to analyze the levels of Bcl-2 and Bax mRNA. Bcl-2, Bax and caspase-3 protein expressions were determined by Western blot analysis. Sertoli cells were treated with OP from 30 to 60microM for 6-24h. Decreased viability of Sertoli cells and increased apoptosis occurred in a concentration- and a time-dependent manner. The expression of Bcl-2 was down-regulated, while the expression of Bax up-regulated. OP also down-regulated the expression of 32kDa procaspase-3, which was cleaved to generate active subunit (17kDa). These results suggest that OP may induce Sertoli cell apoptosis by regulation of Bcl-2/Bax and caspase-3 activation.