title: Increased prostaglandin response to oxytocin in ewes fed a diet high in omega-6 polyunsaturated fatty acids.
abstract: Diets high in omega-6 polyunsaturated fatty acids (n-6) are associated with increased prostaglandin F(2α) (PGF(2α)) synthesis in cattle, however, the specific effects on the potential prostaglandin response to an oxytocin challenge in sheep have not been reported. The aim of the current study was to determine whether oxytocin-stimulated PGF(2α) was significantly increased when ewes were fed a diet high in n-6 compared with a control diet low in n-6. Merino x Border Leicester ewes (n = 30) received one of two dietary treatments, either high in n-6 (70 % oat grain) or low in n-6 (control diet, 100 % cereal/legume silage). Ewes consumed the diets for 44 days prior to two consecutive oxytocin challenges. Plasma n-6 and PGF(2α) metabolite (PGFM) concentrations following oxytocin challenge were greater (P < 0.05) when ewes were fed a diet high in n-6 compared with the control diet. A higher availability of n-6 may have lead to an increased in vivo synthesis of PGF(2α), however, further research is required to determine the exact mechanisms involved.
authors.affiliation: School of Animal and Veterinary Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Gulliver
authors.forename: Michael A
authors.initials: MA
authors.lastname: Friend
authors.forename: Belinda J
authors.initials: BJ
authors.lastname: King
authors.forename: Susan M
authors.initials: SM
authors.lastname: Robertson
authors.forename: John F
authors.initials: JF
authors.lastname: Wilkins
authors.forename: Edward H
authors.initials: EH
authors.lastname: Clayton
mesh_terms: D000818:Animals; D004042:Dietary Fats, Unsaturated / Q000097:blood / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000097:blood / Q000378:metabolism; D043371:Fatty Acids, Omega-6 / Q000097:blood / Q000378:metabolism*; D010120:Oxytocics / Q000494:pharmacology*; D010121:Oxytocin / Q000494:pharmacology*; D011453:Prostaglandins / Q000378:metabolism*; D012756:Sheep / Q000097:blood / Q000378:metabolism*
chemical_list: D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D010120:Oxytocics; D011453:Prostaglandins; D010121:Oxytocin