Steroid Biosynthetic Potential of Gynaecomastic Tissue in Man

Abstract

In vitro transformation of precursors to androgens and oestrogens was studied in breast tissues from 7 phenotypic males with gynaecomastia and 3 normal females. All the tissues studied showed formation of dihydrotestosterone and oestrogens, thus demonstrating the presence of 5α-reductase and aromatizing enzymes. The results on the values of urinary oestrogens before and after surgical removal of the breast tissue substantiate the biosynthetic potential of gynaecomastic tissue. The aetiological significance of these findings vis-à-vis gynaecomastia is discussed.

Oestradiol Receptors in Non-Neoplastic Gynaecomastic Tissue of Phenotypic Males

“…That the gynaecomastic tissue has the aromatising enzyme systems, as in female breast tumour tissue (14,15) was further confirmed by in vitro studies where considerable conversion of tritiated A4-androstenedione to oestrone and oestradiol was demonstrated (16). These results together with the present finding of oestradiol receptors in the same tissue give credence to an interesting fact that all the prerequisites for the initiation of the molecular events of hormonal action characteristic of oestrogen target tissues are available in the gynaecomastic tissue.…”