title: Prostaglandin E2 secretion by oviductal transport-stage equine embryos.
abstract: This study was conducted to identify embryonic products whose secretion was temporally associated with the oviductal transport period of the mare. Chemicals secreted by oviductal-transport-stage equine embryos were identified by incubating Day 6 or Day 7 early uterine embryos with 35S-methionine/cysteine, 3H-progesterone, or 3H-arachidonic acid for 24 h, and subsequently identifying radioactively labeled proteins (SDS-PAGE; n = 3 embryos), steroids (HPLC; n = 3 embryos), or prostaglandins (HPLC; n = 3 embryos) in the culture medium. Early uterine embryos secreted 116.1 +/- 45.5 pg of prostaglandin (PG) E2/embryo, 1.0 +/- 0.2 pg of 17 alpha-hydroxy progesterone/embryo, 4.8 +/- 0.6 pg of androstenedione/embryo, and 11.5 +/- 4.5 pg of PGF2 alpha/embryo. They did not secrete detectable quantities of protein, testosterone, or estradiol-17 beta. A second experiment was conducted to measure temporal changes in embryonic PGE2 secretion during the oviductal and early uterine period. Day 3, Day 4, Day 5, and Day 6 embryos (n = 8 embryos/day) were incubated with 3H-arachidonic acid for 24 h, and the concentration of 3H-PGE2 in the culture medium was subsequently measured by HPLC. Embryos did not secrete detectable amounts of PGE2 prior to the expected time of oviductal transport (Day 3 and Day 4). They secreted 5.7 +/- 1.0 pg of PGE2/embryo immediately before and during the expected time of oviductal transport (Day 5), and they secreted significantly of PGE2/embryo immediately before and during the expected time of oviductal transport (Day 5), and they secreted significantly (p less than 0.01) higher amounts (42.0 +/- 11.5 pg) of PGE2/embryo immediately after uterine entry (Day 6).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Animal and Veterinary Science, University of Idaho, Moscow 83843.
authors.forename: J A
authors.initials: JA
authors.lastname: Weber
authors.forename: D A
authors.initials: DA
authors.lastname: Freeman
authors.forename: D K
authors.initials: DK
authors.lastname: Vanderwall
authors.forename: G L
authors.initials: GL
authors.lastname: Woods
mesh_terms: D000818:Animals; D015232:Dinoprostone / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000378:metabolism*; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D006736:Horses / Q000196:embryology / Q000502:physiology*; D010057:Oviducts / Q000502:physiology; D011247:Pregnancy
chemical_list: D015232:Dinoprostone