title: In vitro secretion of prostaglandins from endometrium of postpartum beef cows expected to have short or normal luteal phases.
abstract: The objective of this study was to characterize endometrial secretion (in vitro) of prostaglandin F (PGF), 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM), prostaglandin E2 (PGE2), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) on Day 5 following the first postpartum estrus of cows anticipated to have a short compared to a normal estrous cycle. Twenty-seven beef cows were randomly assigned into four groups. The Short Cycle (n = 6; control) and Short Cycle/Explant (n = 8; endometrial explants) groups had their calves weaned at 30-32 days postpartum. The Normal Cycle (n = 5, control) and Normal Cycle/Explant (n = 8; endometrial explants) groups received norgestomet (progestin) implants for 9 days beginning 21-23 days postpartum, and calves were weaned at implant insertion. Estrous cycle length (mean +/- SE; p less than 0.01) for the Short Cycle group was 11.5 +/- 1.9 days compared to 18.8 +/- 0.6 days for the Normal Cycle group. On Day 5 following the first postpartum estrus, cows in the Short Cycle/Explant and Normal Cycle/Explant groups were hysterectomized, and endometrial explants were incubated in Earle's Balanced Salt solution/Medium 199 for 90 min with or without arachidonic acid (AA) in the presence of three levels of oxytocin. Mean concentrations of PGF and PGFM were combined to obtain a value for total PGF. Concentrations of total PGF, PGE2 (from explants without AA treatment), and 6-keto-PGF1 alpha in medium of the Short Cycle/Explant group were higher (p less than 0.01) than in medium of the Normal Cycle/Explant group.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Dairy Science, University of Missouri, Columbia 65211.
authors.forename: W G
authors.initials: WG
authors.lastname: Zollers
authors.forename: H A
authors.initials: HA
authors.lastname: Garverick
authors.forename: R S
authors.initials: RS
authors.lastname: Youngquist
authors.forename: J S
authors.initials: JS
authors.lastname: Ottobre
authors.forename: R W
authors.initials: RW
authors.lastname: Silcox
authors.forename: J P
authors.initials: JP
authors.lastname: Copelin
authors.forename: M F
authors.initials: MF
authors.lastname: Smith
mesh_terms: D000818:Animals; D002417:Cattle; D004717:Endometrium / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D008183:Luteal Phase / Q000502:physiology; D049590:Postpartum Period / Q000502:physiology*; D011374:Progesterone / Q000097:blood; D011453:Prostaglandins / Q000378:metabolism*; D011460:Prostaglandins F / Q000378:metabolism; D013997:Time Factors
chemical_list: D011453:Prostaglandins; D011460:Prostaglandins F; D011374:Progesterone