IMMUNOHISTOCHEMICAL LOCALIZATION OF GONADOTROPIN AND GONADAL-STEROID RECEPTORS IN HUMAN PINEAL GLANDS

Recently, we demonstrated that melatonin secretion was increased in ma le patients with GnRH deficiency and decreased to normal levels during testosterone treatment. These data suggested that gonadal steroids mo dulate melatonin secretion, probably by activating specific receptors in the pineal gland. We used immunohistochemistry to localize gonadotr opin (LH and FSH) and gonadal steroid (androgens and estrogens) recept ors in human pineal glands. Tissues were obtained at autopsy from 25 m ales, aged 19-87 yr, and five prepubertal children, aged 0.2-10 yr. Po sitive staining for all four types of receptors (LH, FSH, androgen, an d estrogen) in the pineal parenchymal cells, pinealocytes, was evident in all 30 glands examined. Double staining revealed that nuclear rece ptors (androgen or estrogen) coexisted with cytoplasmatic receptors (L H or FSH) in the same cells. The results demonstrate the presence of g onadotropin and gonadal steroid receptors in human pinealocytes from i nfancy to old age.