title: [The response of free alpha-subunit of glycoprotein hormones to LH-RH administration (author's transl)].
abstract: The responses of immunoreactive free alpha-subunit of glycoprotein hormones to LH-RH administration were studied in normal men and women, and in patients with hypergonadotropic hypogonadism, hypogonadotropic hypogonadism, trophoblastic disease and isolated ectopic alpha-subunit producing tumor. In patients with hypergonadotropic hypergonadism, basal levels of serum alpha-subunit were elevated and the responses to LH-RH were also excessive compared to those of normal men and women. Conversely, in hypogonadotropic hypogonadism, basal levels of alpha-subunit were significantly low and its response to LH-RH was barely detectable. The response of alpha-subunit to constant intravenous infusion of LH-RH (1 microgram/kg/h) was studied in 4 normal men. Both LH and alpha-subunit revealed biphasic patterns of elevation. Its releasing pattern suggests the possibility that two pools of gonadotropin are involved in the production and secretion of alpha-subunit. In patients with trophoblastic disease secreting low levels of hCG (18 mIU/ml), the responses of alpha-subunit as well as pituitary gonadotropin to LH-RH were normal. However, in cases of high concentrations of hCG (1000 mIU/ml), the responses of alpha-subunit and gonadotropin were suppressed. After the administration of LH-RH to a patient with an isolated ectopic alpha-subunit producing tumor, the serum concentration of pituitary gonadotropin increased within the normal range, although that of alpha-subunit did not show a significant change. These results suggest that the production of alpha-subunit by tumors may be autonomous in contrast with a regulatory production in the pituitary.
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D015292:Glycoprotein Hormones, alpha Subunit; D006023:Glycoproteins / Q000097:blood*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D006801:Humans; D007006:Hypogonadism / Q000097:blood*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008598:Menstruation; D010446:Peptide Fragments / Q000097:blood*; D011247:Pregnancy; D014328:Trophoblastic Neoplasms / Q000097:blood*; D014594:Uterine Neoplasms / Q000097:blood*
chemical_list: D006063:Chorionic Gonadotropin; D015292:Glycoprotein Hormones, alpha Subunit; D006023:Glycoproteins; D010446:Peptide Fragments; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone