title: Impaired final follicular maturation in heifers after superovulation with recombinant human FSH.
abstract: The aim of this study was to investigate whether human FSH without contaminating LH can exert a normal superovulation response in cows. One group of heifers (n = 9) was stimulated with recombinant human FSH (rhFSH), an FSH source without any LH activity, and another group (n = 9) was treated with equine chorionic gonadotrophin (eCG), an FSH source with high LH activity. Daily transrectal ultrasonography showed that eCG- and rhFSH-stimulated heifers (n = 9 per group) had the same follicular growth characteristics and equal numbers of follicles > 8 mm in diameter after 3 days of stimulation. The treatment groups differed considerably in steroid production: rhFSH-treated heifers produced much lower oestradiol concentrations than did eCG-stimulated heifers during the first days of stimulation and much lower progesterone concentrations in the period after the LH surge. During the 27-35 h after prostaglandin injection, rhFSH-treated heifers had fewer LH pulses than did eCG-treated heifers (0.3 versus 3.0 per heifer, respectively; n = 3 per group). All rhFSH-treated heifers (n = 6) underwent a preovulatory LH surge, but this occurred significantly later than in the eCG-treated heifers (n = 4; 39.4 +/- 1.9 h versus 47.1 +/- 1.5 h in rhFSH- and eCG-treated heifers, respectively). Multiple ovulations occurred in only three of six rhFSH-treated heifers, but in all four eCG-treated heifers with an LH surge. At 24 h after the LH surge, the percentage of metaphase II stage oocytes with cortical granules distributed close to the oolemma was significantly lower in the rhFSH group (7.3%) than in the eCG group (55.9%). In conclusion, final follicular maturation is impaired in heifers treated with rhFSH, which might be due to the combination of a lack of LH activity in the gonadotrophin preparation and the severe suppression of LH pulsatility.
authors.affiliation: Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL Utrecht, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Takagi
authors.forename: I H
authors.initials: IH
authors.lastname: Kim
authors.forename: F
authors.initials: F
authors.lastname: Izadyar
authors.forename: P
authors.initials: P
authors.lastname: Hyttel
authors.forename: M M
authors.initials: MM
authors.lastname: Bevers
authors.forename: S J
authors.initials: SJ
authors.lastname: Dieleman
authors.forename: P J
authors.initials: PJ
authors.lastname: Hendriksen
authors.forename: P L
authors.initials: PL
authors.lastname: Vos
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D002467:Cell Nucleus / Q000502:physiology; D006063:Chorionic Gonadotropin / Q000008:administration & dosage; D003593:Cytoplasm / Q000502:physiology; D004958:Estradiol / Q000032:analysis / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage*; D015571:Follicular Fluid / Q000737:chemistry; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism; D009865:Oocytes / Q000502:physiology / Q000648:ultrastructure; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D010507:Periodicity; D011374:Progesterone / Q000032:analysis / Q000097:blood; D011994:Recombinant Proteins / Q000008:administration & dosage; D013480:Superovulation; D014463:Ultrasonography
chemical_list: D006063:Chorionic Gonadotropin; D011994:Recombinant Proteins; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone