LH and FSH (basal values and pituitary responses to GnRH) in hyperthyroidism

Gonadotropin behaviour (basal plasma values and pituitary responses to GnRH) in hyperthyroid patients was studied. LH values (both basal and pituitary responses) higher than the controls were documented. Thyroid hormones seem to modulate pituitary response to GnRH for LH only in hyperthyroid patients of both sexes. In order to explain the mechanism of the action of thyroid hormones, rather than the possibility of peripheral effect on binding capacity of the proteins for circulating steroids, a central interaction at medial eminence level is suggested.