Differential release of LH and FSH in cyclic mares in response to synthetic Gn-RH.
Mares at different stages of the oestrous cycle were given a single intravenous injection of 0.5 mg synthetic Gn-RH. The mean area of the induced LH peak was significantly less at mid-cycle (Day 10-11) than at any other time. The mean height of the LH peak above preinjection concentration was greater at late oestrus and early cycle (Day 5-6) than at mid-cycle and early oestrus. There were no significant different in mean FSH responses. The LH:FSH ratio for both height and area of induced peaks was significantly less at mid-cycle than at other times of injection. These results suggest that one releasing hormone could cause the release of both FSH and LH in the normal cyclic mare.
D000818:Animals; D004971:Estrus; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D006728:Hormones / Q000494:pharmacology; D006736:Horses / Q000502:physiology*; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D010906:Pituitary Hormone-Releasing Hormones / Q000494:pharmacology*; D011247:Pregnancy
D006728:Hormones; D010906:Pituitary Hormone-Releasing Hormones; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone