title: Effect of nordihydroguaiaretic acid on luteal phase length and oxytocin-induced release of prostaglandin F2 alpha in heifers.
abstract: Two experiments were conducted to determine if intrauterine infusion of nordihydroguaiaretic acid, a lipoxygenase pathway inhibitor, would delay luteolysis (Experiment 1) and inhibit oxytocin-induced release of prostaglandin F2 alpha (as measured by the stable prostaglandin F2 alpha metabolite, 15-keto-13,14-dihydroprostaglandin F2 alpha) in plasma on d 16 (d 0 = estrus) of the estrous cycle (Experiment 2). Nordihydroguaiaretic acid (20 mg) or saline was infused twice daily into the uterus on d 14 to 23 (Experiment 1) or d 14 to 20 (Experiment 2) postestrus, respectively. In Experiment 1 and 2, mean concentration of progesterone was higher and luteolysis was delayed in nordihydroguaiaretic acid-infused heifers compared with saline-infused heifers. In Experiment 2, saline or oxytocin (100 IU, i.v.) was injected into each heifer on d 16 postestrus to stimulate the release of prostaglandin F2 alpha from the uterus. Mean concentration of 15-keto-13,14-dihydroprostaglandin F2 alpha increased within 1.5 h postinjection in heifers infused with saline, whereas concentration of 15-keto-13,14-dihydroprostaglandin F2 alpha in nordihydroguaiaretic acid-infused heifers did not increase within the same time period. Thus, nordihydroguaiaretic acid may inhibit both the lipoxygenase and cyclooxygenase pathways of arachidonic acid metabolism and therefore delay luteolysis.
authors: Department of Dairy Science, University of Missouri, Columbia 65211.
authors: S A
authors: SA
authors: Hamilton
authors: R E
authors: RE
authors: Raw
authors: M F
authors: MF
authors: Smith
authors: H A
authors: HA
authors: Garverick
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle / Q000378:metabolism / Q000502:physiology*; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism*; D005260:Female; D008183:Luteal Phase / Q000187:drug effects*; D009637:Masoprocol / Q000494:pharmacology*; D010121:Oxytocin / Q000494:pharmacology*; D011374:Progesterone / Q000097:blood; D011897:Random Allocation; D014599:Uterus / Q000187:drug effects / Q000378:metabolism
chemical_list: C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D011374:Progesterone; D010121:Oxytocin; D009637:Masoprocol; D015237:Dinoprost