Immunolocalization of aromatase and estrogen receptors in ram Leydig cells.

A microsomal enzyme, the cytochrome P450 aromatase, performs aromatization of androgens to estrogens. The site of this action has been detected by immunohistochemistry. Sexually immature and mature rams were the donors of testes. Leydig cells were isolated and cultured during 24 h or whole testes were used for cryosections. Both, cultured cells and sections were analysed immunocyto- or immunohistochemically. In adult ram, Leydig cells were the main site of an active aromatase as well as estrogen receptors. While in immature ram very weak or no activity was observed. Therefore, the localizations of immunoreactive aromatase and estrogen synthesis have been found as age-dependent.