Clinical and endocrinological investigations on superovulation induced in heifers by human menopausal gonadotrophin.
After an i.v. injection of human menopausal gonadotrophin (hMG), three components of the disappearance time in heifers were found for immunoreactive LH (half-life 13.8--1020 min) and immunoreactive FSH (half-life 21.3--1090 min). When heifers were treated daily with hMG from Days 9, 10 or 11 of the cycle for 3 or 5 days, a total dose of 1350 i.u. FSH induced 10.2 +/- 2.5 (mean +/- s.d.) corpora lutea (CL) in 6 animals and 13 persistent follicles in 4 animals, while a total dose of 2100 i.u. FSH induced 14.3 +/- 1.5 CL in 6 heifers and there were no persistent follicles. Nine heifers treated with a single i.m. injection of 1500 i.u. PMSG exhibited 11.4 +/- 8.6 CL with 17 persistent follicles in 7 animals. Progesterone concentrations rose significantly faster and the oestradiol drop was more rapid after oestrus in heifers treated with hMG than in those treated with PMSG. These results demonstrate that stimulation of the ovarian follicles of heifers is more homogeneous when hMG is used.
D000818:Animals; D002417:Cattle; D004624:Embryo Transfer; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006064:Gonadotropins, Equine / Q000494:pharmacology; D006207:Half-Life; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008596:Menotropins / Q000097:blood / Q000494:pharmacology; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction; D011374:Progesterone / Q000097:blood; D013480:Superovulation / Q000187:drug effects*
D006064:Gonadotropins, Equine; D011374:Progesterone; D004958:Estradiol; D008596:Menotropins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone