Estrogens and health in males.

Estrogen receptor concentrations are higher in the male reproductive tract than in other organs. Brain structure, neuronal organization and behavioral sex differences result from brain conversion of testosterone into estradiol within the brain. Estrogens modulate hormonal secretion at pituitary level and immune function at thymus level. Estrogens promote vasodilatatory and protective effects on the cardiovascular system by acting on the vascular smooth muscle and endothelium. Adult men with mutations in genes for estrogen receptor or aromatase are affected by osteopenia and tall stature, open epiphysis, which is corrected by estrogen treatment. Over the past few years there has seen a decline in sperm concentration, which has been attributed to exposure of fetal testes to estrogens. Many substances have estrogen-like properties and inhibit the action of estradiol or testosterone action. In conclusion, estrogens play a pivotal role in men also. In particular, taking in account their prevalent origin from testosterone aromatization at tissue and peripheral levels the presence and the distribution of the two receptors (ERalpha and ERbeta) are responsible for different responses in physiological and pathological conditions.