Hypersensitivity of the human gonadotrophs to the repeated administration of small doses of LH-RH.
The functional capacity of the gonadotrophs was assessed by repeated stimulation with small doses of LH-RH (5 microgram intravenously at 2-hour intervals for 3 injections) in normal women during the early and late follicular phases of the menstrual cycle. The results were compared to those obtained when a single dose (100 microgram) of the neurohormone was administered. During the early follicular phase, the release of LH and FSH remained about equal after the 3 successive injections of the small and after the large dose of LH-RH. During the late follicular phase, the release of LH and fsh increased progressively after the repeated administration of the 5 microgram of the neurohormone while the large dose induced a more pronounced and a more sustained pituitary response. This hypersensitivity of the gonadotrophs is observed when the E2 concentrations are higher than in the early follicular phase of the menstrual cycle.
D000328:Adult; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D005498:Follicular Phase / Q000187:drug effects*; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007247:Infertility, Female / Q000188:drug therapy; D008183:Luteal Phase / Q000187:drug effects; D007986:Luteinizing Hormone / Q000378:metabolism*; D008598:Menstruation / Q000187:drug effects*; D010902:Pituitary Gland / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors
D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone