title: Exogenous interferon delays luteal regression in red deer hinds (Cervus elaphus) by suppressing steroid-induced endometrial oxytocin sensitivity.
abstract: Three groups of intact hinds (n = 10-18) and one group of ovariectomized hinds were treated with progesterone by mean, of Controlled Internal Drug Releasing (CIDR) devices for 13 days (device removal = Day 0). Group 1 served as controls; group 2 received injections of 4 mg recombinant bovine interferon-alpha,1 twice daily from Days 13 to 21; group 3 was run with a stag from Days 0 to 3, and all hinds were subsequently diagnosed pregnant; group 4 (ovariectomized) was treated with CIDR devices and estradiol to mimic steroid secretion during the estrous cycle. Progesterone profiles were determined from thrice-weekly plasma samples from Days -13 to 28. Rectal temperature was measured in a subset of groups 1 and 2 from Days 9 to 21. Oxytocin-induced prostaglandin F2 alpha release was measured in a subset of groups 1, 2, and 4 on Days 2, 4, 10, 16, and 18. Data are presented as means +/- SEM. Exogenous interferon delayed luteolysis (> or = 28 vs. 21.2 +/- 0.55 days, P < 0.0005) and induced transient pyrexia after the first injection (39.89 +/- 0.11 vs. 38.88 +/- 0.19 degrees C, p < 0.0005). Incidence of oxytocin-induced PGF2 alpha release in control hinds was greater on Days 2 and 18 than on Days 4 and 10 (8/8 and 7/8 vs. 3/8 and 0/8, respectively; p < 0.05) and was greater in control than in interferon-treated hinds on Days 16 and 18 (5/8 and 7/8 vs. 1/8 and 1/8, respectively; p < 0.05). Profiles of plasma progesterone concentration and oxytocin sensitivity in steroid-treated ovariectomized hinds did not differ from those in control hinds. These results suggest that steroid-controlled uterine oxytocin sensitivity is important in luteolysis and is suppressed by the administration of interferon, the putative embryonic pregnancy recognition signal in red deer.
authors.affiliation: Zoological Society of London, United Kingdom.
authors.forename: D R
authors.initials: DR
authors.lastname: Bainbridge
authors.forename: M H
authors.initials: MH
authors.lastname: Davies
authors.forename: R J
authors.initials: RJ
authors.lastname: Scaramuzzi
authors.forename: H N
authors.initials: HN
authors.lastname: Jabbour
mesh_terms: D000282:Administration, Intravaginal; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D002417:Cattle; D015331:Cohort Studies; D003670:Deer / Q000378:metabolism*; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D007370:Interferon Type I / Q000494:pharmacology*; D003341:Luteolysis / Q000187:drug effects* / Q000378:metabolism; D010052:Ovariectomy / Q000662:veterinary; D010120:Oxytocics / Q000008:administration & dosage / Q000494:pharmacology*; D010121:Oxytocin / Q000008:administration & dosage / Q000494:pharmacology*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood / Q000378:metabolism; D011994:Recombinant Proteins; D013997:Time Factors
chemical_list: D007370:Interferon Type I; D010120:Oxytocics; D011994:Recombinant Proteins; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D011374:Progesterone; D010121:Oxytocin; D015237:Dinoprost