title: Ovulation-inducing factor (OIF/NGF) from seminal plasma origin enhances Corpus Luteum function in llamas regardless the preovulatory follicle diameter.
abstract: Ovulation-inducing factor (OIF) is a protein present in llama seminal plasma that has recently been identified as β-Nerve Growth Factor (NGF) and it induces not only a high rate of ovulation but also appears to have luteotrophic properties in this species. A 2-by-2 experimental design was used to determine the effect of treatments (OIF/NGF vs GnRH) and categories of preovulatory follicle diameter (7-10 vs >10mm) on ovulation rate, CL diameter and function in llamas. Llamas (n=32 llamas per group) were randomly assigned to receive an intramuscular dose of: (a) 1mg purified OIF/NGF in the presence of a follicle of 7-10mm in diameter; (b) 50 μg of GnRH in the presence of a follicle of 7-10mm in diameter; (c) 1mg purified OIF/NGF in the presence of a follicle >10mm in diameter; (d) 50 μg of GnRH in the presence of a follicle >10mm in diameter. Llamas were examined by ultrasonography every 12h from treatment to Day 2 (Day 0=treatment) to detect ovulation, and again on Day 8 to determine CL diameter. Ovulation rates did not differ among groups. There was an effect of preovulatory follicle size on Corpus Luteum diameter at Day 8 (P<0.001), however plasma progesterone concentration (n=15/per group) was higher (P<0.05) in the OIF/NGF - than that of the GnRH - treated group by the same day. We conclude that OIF/NGF treatment enhances CL function regardless preovulatory follicle size at the time of treatment.
authors.affiliation: Escuela de Medicina Veterinaria, Universidad Católica de Temuco, Temuco, Chile; Núcleo de investigación en Producción Alimentaria, Universidad Católica de Temuco, Temuco, Chile.
authors.forename: M
authors.initials: M
authors.lastname: Silva
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile; Programa de Doctorado en Ciencias Veterinarias, Escuela de Postgrado, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Ulloa-Leal
authors.affiliation: Escuela de Medicina Veterinaria, Universidad Católica de Temuco, Temuco, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Norambuena
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: A
authors.initials: A
authors.lastname: Fernández
authors.affiliation: Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: G P
authors.initials: GP
authors.lastname: Adams
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile; Ross University School of Veterinary Medicine, Basseterre, St. Kitts, West Indies. Electronic address: marceloratto@uach.cl.
authors.forename: M H
authors.initials: MH
authors.lastname: Ratto
mesh_terms: D000818:Animals; D002161:Camelids, New World / Q000502:physiology*; D048429:Cell Size; D003338:Corpus Luteum / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000502:physiology; D005260:Female; D005498:Follicular Phase; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D008297:Male; D020932:Nerve Growth Factor / Q000302:isolation & purification* / Q000494:pharmacology*; D006080:Ovarian Follicle / Q000166:cytology* / Q000000981:diagnostic imaging; D010060:Ovulation / Q000187:drug effects; D010062:Ovulation Induction / Q000379:methods / Q000662:veterinary; D012661:Semen / Q000737:chemistry*; D014463:Ultrasonography; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D007987:Gonadotropin-Releasing Hormone; D020932:Nerve Growth Factor
keywords: Corpus Luteum; Follicles; Llama; Nerve Growth Factor; Ovulation-inducing factor