RESUMO
<p><b>OBJECTIVE</b>To study the effects of polychlorinated biphenyl (PCB) on bcl-2 and TGFbeta1 expression in rat testes.</p><p><b>METHODS</b>Forty male Wistar rats were divided into 4 groups at random: Group A (normal control), Group B (fed on 10(-8) mol/L PBC), Group C (feb on 10(-7) mol/L) and Group D (feb on 10(-6) mol/L). After three months, all the rats were killed, the animal model established, and observations made on the expression of bcl2 and TGFbeta1 in the rat testis using the optical microscope and immunohistochemical techniques.</p><p><b>RESULTS</b>The damage to the structure of the testis was related to the dosage of PCB: the higher the dodage, the more serious the damage. PCB induced the expression of bcl-2 and TGFbeta1. The TGFbeta1 expression was significantly higher in the highest dosage group than in others (P < 0.01 ), and the bcl-2 expression was dramatically higher in Group C than in other groups (P < 0.01).</p><p><b>CONCLUSION</b>PCB can cause injury in rat testes.</p>