Effect of age and estrogen therapy on the immunoreactive human chorionic gonadotropin content of testes

Levels of human chorionic gonadotropin (HCG) were determined in testicular tissue of young, apparently normal men; older men with carcinoma of the prostate; male transsexuals treated with estrogens; and also in seminal plasma of normal and vasectomized patients. In all samples with one exception (a 76-year-old male with cancer of the prostate), immunoreactive HCG activity could be detected. The immunoassayable HCG content was higher in testicular extracts from young adults as compared with older men with cancer of the prostate. In transsexuals receiving estrogen therapy, testicular HCG levels were also very low. A possible relationship between quantitatively normal spermatogenesis and the testicular HCG level has been discussed. HCG was detected in seminal plasma from both normal and vasectomized men. The origin of this HCG activity may be extratesticular, and the possible role of the prostate and seminal vesicle in the production of HCG-like activity has to be considered.