title: Abolishment of the positive feedback mechanism: a criterion for temporary medical hypophysectomy by LH-RH agonist.
abstract: The hypothalamic pituitary axis was studied in patients with an abnormal pattern of gonadotropin release during chronic treatment with LH-RH agonist. Two patients had PCOD and the third demonstrated the early luteinization phenomenon. Following a well-defined gonadotropin rise with initiation of LH-RH treatment, no further response was noted. Stabilization of the LH:FSH ratio in PCOD patients was noted after 4 weeks of treatment. Administration of both native LH-RH (100 micrograms) and intravenous pulsatile LH-RH did not evoke any rise in LH. In addition to the above LH-RH challenges, the positive feedback was examined by administration of estradiol benzoate (EB). The study demonstrated that, although the pituitary did not respond to any LH-RH challenge, it may still respond by a rise in LH following EB administration. Both functions of the hypothalamic pituitary axis should be examined in order to determine the state of medical hypophysectomy.
authors.affiliation: Department of Obstetrics, Gynecology and Endocrinology, Chaim Sheba Medical Center, Sackler Medical School, Tel-Aviv University, Tel-Hashomer, Israel.
authors.forename: A L
authors.initials: AL
authors.lastname: Shadmi
authors.forename: B
authors.initials: B
authors.lastname: Lunenfeld
authors.forename: C
authors.initials: C
authors.lastname: Bahari
authors.forename: E
authors.initials: E
authors.lastname: Kokia
authors.forename: C
authors.initials: C
authors.lastname: Pariente
authors.forename: J
authors.initials: J
authors.lastname: Blankstein
mesh_terms: D000281:Administration, Intranasal; D002064:Buserelin / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006801:Humans; D007016:Hypophysectomy / Q000379:methods*; D007017:Hypophysectomy, Chemical / Q000379:methods*; D007247:Infertility, Female / Q000097:blood / Q000628:therapy*; D007279:Injections, Subcutaneous; D007986:Luteinizing Hormone / Q000097:blood; D008186:Luteolytic Agents / Q000008:administration & dosage*; D011085:Polycystic Ovary Syndrome / Q000097:blood / Q000628:therapy*; D017329:Triptorelin Pamoate
chemical_list: D008186:Luteolytic Agents; D017329:Triptorelin Pamoate; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D002064:Buserelin