title: Comparison of mammalian luteinizing hormone releasing hormone (LH-RH), and of an analog (ICI 118630), on luteinizing hormone and ovarian steroid (progesterone, oestradiol) secretions in laying hens. (Gallus domesticus).
abstract: This experiment was conducted to compare the luteinizing hormone (LH), progesterone (P4) and oestradiol (E2) release in response to injections of various doses of synthetic mammalian luteinizing hormone-releasing hormone (LH-RH) and of an LH-RH agonist, ICI 118630, administered to laying hens 4 to 9 hours after a mid-sequence ovulation. Plasma LH increased significantly within 10 minutes of injection of either compound whereas any increases in plasma steroid concentrations were discerned later, at approximately minutes post-injection. No dose-response relationship was found for either compound with respect to LH release, but ICI 118630 appeared more potent than LH-RH. This analog also produced a greater mean incremental rise in plasma progesterone, but not oestradiol, than LH-RH, and this was found in animals injected at a time when the largest ovarian follicle was not mature. These result suggest that ICI 118630 is a more potent releasing hormone in the hen at the level of the pituitary, and that it may have a stimulating effect on ovarian progesterone secretion.
mesh_terms: D000818:Animals; D002064:Buserelin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002645:Chickens / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000097:blood / Q000378:metabolism*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology*; D017273:Goserelin; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D008297:Male; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D010058:Oviposition; D011374:Progesterone / Q000097:blood / Q000378:metabolism*
chemical_list: D017273:Goserelin; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D002064:Buserelin