RESUMEN
<p><b>OBJECTIVE</b>To study the effects of polychlorinated biphenyl (PCB) on the phenotype of the testis tissue and the testis tissue and the expression c-fos, c-Myc and beta-catenin in the rat testis.</p><p><b>METHODS</b>Forty-five Wistar male rats were divided into a control and three perimental groups, the former fed normally, and the latter with PCB at 0.1, 1 and 10 mg/kg respectively for 90 days. Then the effects of PCB on the phenotype of the testis tissue and the expressions of c-fos, c-Myc and p-catenin were determined by histopathology and immunohistochemistry.</p><p><b>RESULTS</b>Histopathological examinations revealed testis edema, damage of the mesenchymal phenotype, morphological changes of the contorted seminiferous tubules, absence of stromal cells, spermiocytes and prespermatids, and decreased number of sperm. The expressions of c-fos and c-Myc were significantly higher in the 1 and 10 mg/kg PCB groups than in the control and 0.1 mg/kg PCB groups (P < 0.01). The expression of beta-catenin was downregulated in the 0.1 mg/kg PCB group, with significant differences from the other groups (P < 0.01), but it was higher in the 1 mg/kg PCB than in the control and 10 mg/kg PCB groups (P < 0.01).</p><p><b>CONCLUSION</b>PCB causes changes in the phenotype of the testis tissue, and the abnormal expressions of c-fos, c-Myc and beta-catenin are closely related to the PCB-induced testis injury.</p>