title: Seminal Plasma Induces Ovulation in Llamas in the Absence of a Copulatory Stimulus: Role of Nerve Growth Factor as an Ovulation-Inducing Factor.
abstract: Llamas are considered to be reflex ovulators. However, semen from these animals is reported to be rich in ovulation-inducing factor(s), one of which has been identified as nerve growth factor (NGF). These findings suggest that ovulation in llamas may be elicited by chemical signals contained in semen instead of being mediated by neural signals. The present study examines this notion. Llamas displaying a preovulatory follicle were assigned to four groups: group 1 received an intrauterine infusion (IUI) of PBS; group 2 received an IUI of seminal plasma; group 3 was mated to a male whose urethra had been surgically diverted (urethrostomized male); and group 4 was mated to an intact male. Ovulation (detected by ultrasonography) occurred only in llamas mated to an intact male or given an IUI of seminal plasma and was preceded by a surge in plasma LH levels initiated within an hour after coitus or IUI. In both ovulatory groups, circulating β-NGF levels increased within 15 minutes after treatment, reaching values that were greater and more sustained in llamas mated with an intact male. These results demonstrate that llamas can be induced to ovulate by seminal plasma in the absence of copulation and that copulation alone cannot elicit ovulation in the absence of seminal plasma. In addition, our results implicate β-NGF as an important mediator of seminal plasma-induced ovulation in llamas because ovulation does not occur if β-NGF levels do not increase in the bloodstream, a change that occurs promptly after copulation with an intact male or IUI of seminal plasma.
authors.affiliation: Escuela de Medicina Veterinaria (M.A.B., M.E.S.), Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile; Universidad de las Fuerzas Armadas (ESPE) (C.U.-L.), Quito, Ecuador; Instituto de Inmunología (M.B.), Facultad de Medicina, and Department of Animal Science (M.A.B., M.H.R.), Universidad Austral de Chile, Valdivia, Chile; and Division of Neuroscience (H.W., G.A.D., S.R.O.), Oregon National Primate Research Center, Beaverton, Oregon 97006.
authors.forename: Marco A
authors.initials: MA
authors.lastname: Berland
authors.affiliation: Escuela de Medicina Veterinaria (M.A.B., M.E.S.), Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile; Universidad de las Fuerzas Armadas (ESPE) (C.U.-L.), Quito, Ecuador; Instituto de Inmunología (M.B.), Facultad de Medicina, and Department of Animal Science (M.A.B., M.H.R.), Universidad Austral de Chile, Valdivia, Chile; and Division of Neuroscience (H.W., G.A.D., S.R.O.), Oregon National Primate Research Center, Beaverton, Oregon 97006.
authors.forename: Cesar
authors.initials: C
authors.lastname: Ulloa-Leal
authors.affiliation: Escuela de Medicina Veterinaria (M.A.B., M.E.S.), Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile; Universidad de las Fuerzas Armadas (ESPE) (C.U.-L.), Quito, Ecuador; Instituto de Inmunología (M.B.), Facultad de Medicina, and Department of Animal Science (M.A.B., M.H.R.), Universidad Austral de Chile, Valdivia, Chile; and Division of Neuroscience (H.W., G.A.D., S.R.O.), Oregon National Primate Research Center, Beaverton, Oregon 97006.
authors.forename: Miguel
authors.initials: M
authors.lastname: Barría
authors.affiliation: Escuela de Medicina Veterinaria (M.A.B., M.E.S.), Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile; Universidad de las Fuerzas Armadas (ESPE) (C.U.-L.), Quito, Ecuador; Instituto de Inmunología (M.B.), Facultad de Medicina, and Department of Animal Science (M.A.B., M.H.R.), Universidad Austral de Chile, Valdivia, Chile; and Division of Neuroscience (H.W., G.A.D., S.R.O.), Oregon National Primate Research Center, Beaverton, Oregon 97006.
authors.forename: Hollis
authors.initials: H
authors.lastname: Wright
authors.affiliation: Escuela de Medicina Veterinaria (M.A.B., M.E.S.), Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile; Universidad de las Fuerzas Armadas (ESPE) (C.U.-L.), Quito, Ecuador; Instituto de Inmunología (M.B.), Facultad de Medicina, and Department of Animal Science (M.A.B., M.H.R.), Universidad Austral de Chile, Valdivia, Chile; and Division of Neuroscience (H.W., G.A.D., S.R.O.), Oregon National Primate Research Center, Beaverton, Oregon 97006.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Dissen
authors.affiliation: Escuela de Medicina Veterinaria (M.A.B., M.E.S.), Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile; Universidad de las Fuerzas Armadas (ESPE) (C.U.-L.), Quito, Ecuador; Instituto de Inmunología (M.B.), Facultad de Medicina, and Department of Animal Science (M.A.B., M.H.R.), Universidad Austral de Chile, Valdivia, Chile; and Division of Neuroscience (H.W., G.A.D., S.R.O.), Oregon National Primate Research Center, Beaverton, Oregon 97006.
authors.forename: Mauricio E
authors.initials: ME
authors.lastname: Silva
authors.affiliation: Escuela de Medicina Veterinaria (M.A.B., M.E.S.), Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile; Universidad de las Fuerzas Armadas (ESPE) (C.U.-L.), Quito, Ecuador; Instituto de Inmunología (M.B.), Facultad de Medicina, and Department of Animal Science (M.A.B., M.H.R.), Universidad Austral de Chile, Valdivia, Chile; and Division of Neuroscience (H.W., G.A.D., S.R.O.), Oregon National Primate Research Center, Beaverton, Oregon 97006.
authors.forename: Sergio R
authors.initials: SR
authors.lastname: Ojeda
authors.affiliation: Escuela de Medicina Veterinaria (M.A.B., M.E.S.), Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile; Universidad de las Fuerzas Armadas (ESPE) (C.U.-L.), Quito, Ecuador; Instituto de Inmunología (M.B.), Facultad de Medicina, and Department of Animal Science (M.A.B., M.H.R.), Universidad Austral de Chile, Valdivia, Chile; and Division of Neuroscience (H.W., G.A.D., S.R.O.), Oregon National Primate Research Center, Beaverton, Oregon 97006.
authors.forename: Marcelo H
authors.initials: MH
authors.lastname: Ratto
mesh_terms: D000818:Animals; D002161:Camelids, New World / Q000502:physiology*; D003307:Copulation; D003338:Corpus Luteum / Q000000981:diagnostic imaging / Q000502:physiology; D005260:Female; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D020932:Nerve Growth Factor / Q000097:blood / Q000494:pharmacology*; D006080:Ovarian Follicle / Q000166:cytology / Q000000981:diagnostic imaging; D010060:Ovulation / Q000187:drug effects / Q000502:physiology; D010062:Ovulation Induction / Q000662:veterinary*; D011374:Progesterone / Q000097:blood; D012661:Semen / Q000502:physiology*; D014463:Ultrasonography
chemical_list: D011374:Progesterone; D007986:Luteinizing Hormone; D020932:Nerve Growth Factor