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Effects of estrogens on the testis of transsexuals: a pathological and immunocytochemical study
1Department of Biomedical Sciences and Human Oncology, University of Turin, Italy.
Abstract:
Testes from five male-to-female transsexuals removed during sex-reversal surgery after administration of estrogens were studied histologically and with immunoperoxidase procedures to locate estrogen receptors (ER) and related antigens. Atrophy of the seminiferous tubules was observed in all cases; its degree, and a marked decrease in Leydig cells, correlated with low plasma gonadotropin levels (rather than with the duration of treatment). In all cases, the rete testis appeared hyperplastic and the other components (efferent ductules, epididymus) well preserved. The efferent ductules proved to be the only structure where ER can be located by the ER-ICA procedure, whereas staining for the p 29 ER-associated antigen is strongly positive both here and in the rete testis. The immunocytochemical data, in parallel with the observed biological effects, indicate that the rete testis and the efferent ductules and, to a minor degree, the epididymus and Leydig cells are the main direct targets of estrogens in the human testis.
Insights
Estrogen therapy in male-to-female transsexuals caused testicular atrophy. Estrogen receptors (ER) were found in the efferent ductules and rete testis, indicating these are key targets of estrogen in the human testis.
Area of Science:
- Endocrinology
- Reproductive Biology
- Histology
Background:
- Estrogen administration is part of feminizing hormone therapy.
- The effects of estrogens on adult human testes are not fully understood.
- Identifying direct targets of estrogen in the testis is crucial for understanding its impact.
Purpose of the Study:
- To investigate the histological changes in testes after estrogen administration in male-to-female transsexuals.
- To locate estrogen receptors (ER) and associated antigens within the human testis using immunoperoxidase staining.
- To identify the primary target sites of estrogen action in the human testis.
Main Methods:
- Histological examination of testicular tissue from five male-to-female transsexuals.
- Immunoperoxidase staining to detect estrogen receptors (ER) and p29 ER-associated antigen.
- Correlation of histological findings with plasma gonadotropin levels.
Main Results:
- All cases showed atrophy of seminiferous tubules and decreased Leydig cells, correlating with low gonadotropin levels.
- The rete testis was hyperplastic, while efferent ductules and epididymis were preserved.
- Estrogen receptors (ER) were localized exclusively in the efferent ductules.
- The p29 ER-associated antigen was strongly positive in the rete testis and efferent ductules.
Conclusions:
- The rete testis and efferent ductules are the primary direct targets of estrogen in the human testis.
- The epididymis and Leydig cells are secondary targets of estrogen action.
- Estrogen therapy significantly impacts testicular structure and receptor localization.
