TRANSFORMING GROWTH-FACTOR-ALPHA, EPIDERMAL GROWTH-FACTOR, AND EPIDERMAL GROWTH-FACTOR RECEPTOR IN HUMAN TESTIS OBTAINED FROM BIOPSY AND CASTRATION - IMMUNOHISTOCHEMICAL STUDY

We analyzed expression of transforming growth factor (TGF)-alpha, epid ermal growth factor (EGF) and their receptor, EGF receptor (EGFR), by immunohistochemistry in the human testis to determine the possible rol es of these growth factors in human testicular function. Specimens wer e obtained from 17 patients including 9 patients with infertility, 4 p atients with prostatic carcinoma and 4 patients with contralateral tes ticular tumor. EGF immunoreactivity was positive in the hyperplasic Le ydig cells of one patient but negative in the other cases. On the othe r hand, strong TGF-alpha immunoreactivity was observed in Leydig cells , with weak staining in Sertoli cells and germ cells in cases with nor mal spermatogenesis. EGFR immunoreactivity was observed in the Leydig and peritubular cells, appearing as membrane staining. Marked immunore activity for TGF-alpha was observed in the Sertoli cells in testes wit h decreased spermatogenesis, especially in the Sertoli-cell-only syndr ome. This finding may indicate a compensatory increase of TGF-alpha ex pression in the Sertoli cells accompanying a decrease in spermatogenes is. No significant correlation was found between the degrees of sperma togenesis and immunolocalization of the EGF receptor. These findings s uggestthat TGF-alpha is a locally produced growth factor that is invol ved in spermatogenesis in the human testis via an autocrine and/or par acrine mechanism.