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Titolo:
Platelet-activating factor may act as an endogenous pulse generator for sheep of luteolytic PGF(2 alpha) release
Autore:
Chami, O; Megevand, A; Ott, T; Bazer, F; ONeill, C;
Indirizzi:
Univds,dney, Royal N Shore Hosp, Dept Physiol, Human Reprod Unit, St Leonar Univ Sydney St Leonards NSW Australia 2065 , Human Reprod Unit, St Leonar Texas A&M Univ, Inst Biosci & Technol, Ctr Anim Biotechnol, College Stn, TX Texas A&M Univ College Stn TX USA 77843 Anim Biotechnol, College Stn, TX
Titolo Testata:
AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM
fascicolo: 4, volume: 39, anno: 1999,
pagine: E783 - E792
SICI:
0193-1849(199904)39:4<E783:PFMAAA>2.0.ZU;2-E
Fonte:
ISI
Lingua:
ENG
Soggetto:
ACETYL-COA ACETYLTRANSFERASE; LUTEAL PHASE ENDOMETRIUM; FACTOR RECEPTOR; ESTROUS-CYCLE; TROPHOBLAST INTERFERON; RABBIT ENDOMETRIUM; OVINE ENDOMETRIUM; OXYTOCIN RECEPTOR; OVARIAN OXYTOCIN; PHOSPHOLIPASE-D;
Keywords:
prostaglandin F-2 alpha; platelet-activating factor; acetylhydrolase; endometrium; estradiol-17 beta; progesterone; sheep; pulsatility;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
60
Recensione:
Indirizzi per estratti:
Indirizzo: O'Neill, C Univds,dney, Royal N Shore Hosp, Dept Physiol, Human Reprod Unit, St Leonar Univ Sydney St Leonards NSW Australia 2065 rod Unit, St Leonar
Citazione:
O. Chami et al., "Platelet-activating factor may act as an endogenous pulse generator for sheep of luteolytic PGF(2 alpha) release", AM J P-ENDO, 39(4), 1999, pp. E783-E792

Abstract

Pulsatile release of uterine prostaglandin F-2 alpha (PGF(2 alpha)) induces luteolysis in ruminants. However, the mechanism(s) that initiates and maintains luteolysis has not been defined, The present study tested the hypothesis that the endogenous PGF(2 alpha) pulse generator is uterine-derived platelet-activating factor (PAF). Ovariectomized ewes were given exogenous progesterone (P), estradiol (E), or both (P+E, mimicking the normal luteal phase). Only ewes treated with steroids rei leased PAF into the uterine lumenand had increased PAF: acetylhydrolase activity in the uterine lumen. Steroid treatment also influenced the capacity of the uterus to release PGF(2 alpha) in response to exogenous PAF. PAF infusion did not affect plasma PGF(2 alpha) metabolite (PGFM) levels in control (no steroid treatment) ewes but increased plasma PGFM levels in P+E ewes (P < 0.001) and ewes treated with P or E alone (P < 0.05). Infusion of PAF followed by or coincident with oxytocin (OT) acted in a synergistic manner to increase plasma PGFM levels. Repeated infusion of PAF into the uterus at 1-h intervals induced tachyphylaxis of the PGFM response to PAF; however, sensitivity of the uterus to PAFreturned spontaneously by the 6th h. Interferon-tau (IFN-tau) inhibits pulsatile release of PGF(2 alpha) during pregnancy to prevent luteolysis. Exogenous recombinant ovine IFN-tau (50 mu g) inhibited the uterine response toPAF alone or the combined effects of PAF and OT These results indicate that uterine PAF fulfills many of the criteria for an endogenous PGF(2 alpha) pulse-generator: steroid induction of PAF production and uterine responsiveness to PAF-induced release of PGF; synergistic stimulation of PAF-induced PGF release by OT; inhibition of PAF effects by IFN-tau; and PAF's ability to induce pulses of PGF with a periodicity during a period of chronic exposure of the uterus to PAF.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/09/20 alle ore 01:49:47