Aim: To investigate the stage-specific localization of transforming growth factor (TGF) beta1 and beta3 during spermatogenesis in adult human testis.
Methods: The localization of TGFbeta1 and beta3 was investigated by immunohistochemical staining method employing specific polyclonal antibodies.
Results: Both TGFbeta1 and beta3 and their receptors were preponderant in the Leydig cells. TGFbeta1 could not be detected in the seminiferous tubules. TGFbeta3 and TGFbeta-Receptor (R) I were mainly seen in the elongated spermatids, while TGFbeta-RII in the pachytene spermatocytes and weak in the spermatogonia, spermatids and Sertoli cells. Only TGFbeta-RII was detected in the Sertoli cells. TGFbeta3, TGFbeta-RI and TGFbeta-RII showed a staining pattern dependent upon the stages of the seminiferous epithelium cycle.
Conclusion: TGFbeta isoforms and their receptors are present in the somatic and germ cells of the adult human testis, suggesting their involvement in the regulation of spermatogenesis.