title: Superstimulation of follicular growth in Thai native heifers by a single administration of follicle stimulating hormone dissolved in polyvinylpyrrolidone.
abstract: This study was undertaken to determine whether a single i.m. injection of FSH dissolved in 10 ml of 30% (wt/vol) polyvinylpyrrolidone (PVP; MW=40,000) to form FSHp would induce follicular growth in Thai native heifers and to determine its optimal dose. In Group 1, heifers (n=4) were given multiple i.m. injections of FSHp every 12 h for 3 days at decreasing doses, for a total of 100 mg (control). In Groups 2, 3 and 4, heifers (n=4 in each group) were given single i.m. injections of FSHp at 50, 100 and 150 mg. All heifers received a single injection of 750 μg PGF2α 48 h after the initiation of exogenous FSH treatment. Ovaries of treated heifers were examined by transrectal ultrasonography every day until they showed estrus. Group 3 showed significantly higher numbers of ovulation follicles, significantly higher growth rates of follicles per day and significantly larger diameters of follicles and corpora lutea than groups 1 and 2 but not Group 4 (P<0.05). Group 4 showed significantly higher numbers of large follicles (≥5 mm in diameter), unovulated follicles and ovulations, a significantly higher growth rate of follicles per day, and significantly larger diameters of follicles and corpora lutea (P<0.05) than those of the other groups. This indicates a state of overstimulation of ovaries in this group. Besides, the plasma levels of FSH in Group 4 were significantly higher (P<0.05) than in the other group and were maintained in the range of 2.2-0.7 ng/ml over a period of 6 to 66 h after the FSHp injection. Meanwhile, the plasma levels of P4 and E2 did not differ in any of the groups in the period of 0 to 96 h during the superstimulation program. In conclusion, it was demonstrated that a single i.m. injection of 100 mg FSHp was the most effective dose for superstimulation of follicular growth in Thai native heifers under the experimental conditions in this study.
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Jakkhaphan
authors.initials: J
authors.lastname: Chasombat
authors.forename: Denpong
authors.initials: D
authors.lastname: Sakhong
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
authors.forename: Rangsun
authors.initials: R
authors.lastname: Parnpai
authors.forename: Thevin
authors.initials: T
authors.lastname: Vongpralub
mesh_terms: D000818:Animals; D002417:Cattle; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage* / Q000494:pharmacology; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000254:growth & development; D010053:Ovary / Q000000981:diagnostic imaging / Q000187:drug effects; D011205:Povidone; D011374:Progesterone / Q000097:blood; D013480:Superovulation / Q000187:drug effects*; D014463:Ultrasonography
chemical_list: D011374:Progesterone; D004958:Estradiol; D005640:Follicle Stimulating Hormone; D011205:Povidone