title: Presence of positive feedback in males with Klinefelter's syndrome.
abstract: This study examined the effect of 17 beta-estradiol (E2) on basal and luteinizing hormone (LH)-releasing hormone (LHRH)-stimulated gonadotropin secretion in 9 patients with Klinefelter's syndrome. Intramuscular injection of E2 (10 micrograms/kg/day during 5 days) induced a rapid decrease in follicle-stimulating hormone (FSH) and LH levels. The maximum suppression was observed on day 7 (D7) for FSH [median 9.7 mIU/ml (range 4.6-37.8) vs. 21.7 mIU/ml (range 12.2-56.9)] and on D2 for LH [median 13.6 mIU/ml (range 6.8-25.2) vs. 21.2 mIU/ml (range 13-54.7)]. E2 concentrations rose and reached their peak values on D3 [median 723 pmol/l (range 517-1,247.8) vs. 110.1 pmol/l (range 68.6-227.5) on D0]. These changes were followed by a subsequent rise in LH on D4 [36.7 mIU/ml (range 19.4-77.7)]. LH response to LHRH was higher during E2 treatment: median value of absolute peaks: 156.3 mIU/ml (range 56.7-188.6) on D4 vs. 64 mIU/ml (range 38.9-131) on DO. These results demonstrate the presence of a positive feedback in patients with Klinefelter's syndrome.
authors: Service d'Endocrinologie, Hôpital de Bains Romains, Alger, Algérie.
authors: C
authors: C
authors: Boucekkine
authors: M
authors: M
authors: Semrouni
mesh_terms: D000293:Adolescent; D000328:Adult; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology; D005246:Feedback; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects; D007713:Klinefelter Syndrome / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D013739:Testosterone / Q000378:metabolism
chemical_list: D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C010452:estradiol-17 beta-benzoate