ABSTRACT
<p><b>OBJECTIVE</b>To study the expression of alpha-catenin in the rat testis after intra-testicular testosterone withdrawal induced by injection of testosterone undecanoate (TU).</p><p><b>METHODS</b>Ten adult male SD rats received vehicle (n = 5 ) or TU (19 mg/kg every 15 days, n = 5) for 130 days. Paraffin-embedded testicular sections were used for immunohistochemistry against a polyclonal anti-alpha-catenin antibody.</p><p><b>RESULTS</b>In the control, alpha-catenin was expressed in the acrosome of spermatids and the cytoplasm of Leydig cells and peritubular myoid cells. In the TU-treated rat testis, Leydig cells were atrophied and the expression of alpha-catenin was markedly decreased or absent, but there was no evident change in the immunostaining of spermatids or myoid cells.</p><p><b>CONCLUSION</b>Intra-testicular testosterone withdrawal-induced looser arrangement or sloughing of spermatogenic cells is not related to the adhesion molecule alpha-catenin. Alpha-catenin may be used as a cell identification marker for Leydig cells.</p>