The aging of hypothalamo pituitary testicular axis iii. testicular endocrine function in male senescence
Mikuma, N.; Kumamoto, Y.; Maruta, H.
Japanese Journal of Fertility and Sterility 37(1): 152-156
1992
Document Number: 503105
Testicular endocrine function in male senescence was evaluated by analyzing serum levels of basal testosterone, estradiol and gonadotropin and, furthermore, testosterone response to exogenously administered HCG in 216 males with no endocrinological disorders between the ages of 20 and 90 years. Serum levels of basal testosterone, estradiol and their response to HCG tended to decrease after the age of 50 years. The ratio of basal testosterone to its response to HCG was 55.0 .+-. 7.7% in group 1 subjects, who had normal levels of basal LH and testosterone. In group II subjects, who had normal testosterone and elevated LH levels, the ratio was elevated up to 65.6 .+-. 2.5%. In group III subjects, who had low testosterone and elevated LH levels, the ratio was decreased to 43.8 .+-. 4.6%. These results suggest that 1) after the age of 50, testicular endocrine function declines. 2) decreased biological activity gonadotropin might be responsible, at least in part, to the decline of testicular endocrine function in male senescence.