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Titolo:
REGULATION OF OXYTOCIN, ESTRADIOL AND PROGESTERONE-RECEPTOR CONCENTRATIONS IN DIFFERENT UTERINE REGIONS BY ESTRADIOL, PROGESTERONE AND OXYTOCIN IN OVARIECTOMIZED EWES
Autore:
WATHES DC; MANN GE; PAYNE JH; RILEY PR; STEVENSON KR; LAMMING GE;
Indirizzi:
UNIV LONDON ROYAL VET COLL,DEPT FARM ANIM & EQUINE MED & SURG,BOLTONSPK,HAWKSHEAD RD POTTERS BAR EN6 1NB HERTS ENGLAND BABRAHAM INST CAMBRIDGE CB2 4AT ENGLAND UNIV NOTTINGHAM,DEPT PHYSIOL & ENVIRONM SCI LOUGHBOROUGH LE12 5RD LEICS ENGLAND ZOOL SOC LONDON,INST ZOOL LONDON NW1 4RY ENGLAND
Titolo Testata:
Journal of Endocrinology
fascicolo: 3, volume: 151, anno: 1996,
pagine: 375 - 393
SICI:
0022-0795(1996)151:3<375:ROOEAP>2.0.ZU;2-3
Fonte:
ISI
Lingua:
ENG
Soggetto:
ESTROUS-CYCLE; EARLY-PREGNANCY; OVINE ENDOMETRIUM; EMBRYO SURVIVAL; LUTEAL-PHASE; ESTRADIOL; LOCALIZATION; EXPRESSION; UTERUS; SECRETION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
44
Recensione:
Indirizzi per estratti:
Citazione:
D.C. Wathes et al., "REGULATION OF OXYTOCIN, ESTRADIOL AND PROGESTERONE-RECEPTOR CONCENTRATIONS IN DIFFERENT UTERINE REGIONS BY ESTRADIOL, PROGESTERONE AND OXYTOCIN IN OVARIECTOMIZED EWES", Journal of Endocrinology, 151(3), 1996, pp. 375-393

Abstract

The regulation of oxytocin, oestradiol and progesterone receptors in different uterine cell types was studied in ovariectomized ewes. Animals were pretreated with a progestogen sponge for 10 days followed by 2days of high-dose oestradiol to simulate oestrus. They then received either low-dose oestradiol (Group E), low-dose oestradiol plus progesterone (Group P) or low-dose oestradiol, progesterone and oxytocin (viaosmotic minipump; Group OT). Animals (three to six per time-point) were killed following ovariectomy (Group OVX), at oestrus (Group O) or following 8, 10, 12 or 14 days off, P or OT treatment. In a final group, oxytocin was withdrawn on day 12 and ewes were killed on day 14 (Group OTW). Oxytocin receptor concentrations and localization in the endometrium and myometrium were measured by radioreceptor assay, in situ hybridization and autoradiography with the iodinated oxytocin receptor antagonist d(CH2)(5)[Tyr(Me)(2),Thr(4),Tyr-NH29]-vasotocin. Oestradioland progesterone receptors were localized by immunocytochemistry. Oxytocin receptors were present in the luminal epithelium and superficialglands of ovariectomized ewes. In Group O, endometrial oxytocin receptor concentrations were high (1346+/-379 fmol [H-3]oxytocin bound mg protein(-1)) and receptors were also located in the deep glands and caruncular stroma in a pattern resembling that found at natural oestrus. Continuing low-dose oestradiol was unable to sustain high endometrial oxytocin receptor concentrations with values decreasing significantly to 140 +/- 20 fmol mg protein(-1) (P<0.01), localized to the luminal epithelium and caruncular stroma but not the glands. Progesterone treatment initially abolished all oxytocin receptors with none present on days 8 or 10. They reappeared in the luminal epithelium only between days 12 and 14 to give an overall concentration of 306 +/- 50 mol mg protein(-1). Oxytocin treatment caused a small increase in oxytocin receptor concentration in the luminal epithelium on days 8 and 10 (20 +/- 4in Group P and 107 +/- 35 fmol mg protein(-1) in Group OT, P<0.01) but the rise on day 14 was not affected (267 +/- 82 in Group OT and 411 /- 120 fmol mg protein(-1) in Group OTW). In contrast, oestradiol treatment was able to sustain myo_ metrial oxytocin receptors (635 +/- 277 fmol mg protein(-1) in Group O and 255 +/- 36 in Group E) and there was no increase over time in Groups P, OT and OTW with values of 61 +/- 18, 88 +/- 53 and 114 +/- 76 fmol mg protein(-1) respectively (combined values for da)rs 8-14). Oestradiol receptor concentrations were high in all uterine regions in Group O. This pattern and concentration was maintained in Group E. In all progesterone-treated ewes, oestradiolreceptor concentrations were lower in all regions at all time-points. The only time-related change occurred in the luminal epithelium in which oestradiol receptors were undetectable on day 8 but developed by day 10 of progesterone treatment. Progesterone receptor; were present at moderate concentrations in the deep glands, caruncular stroma, deep stroma and myometrium in Group O. Oestradiol increased progesterone receptors in the luminal epithelium, superficial glands, deep stroma andmyometrium. Progesterone caused the loss of its own receptor from theluminal epithelium and superficial glands and decreased its receptor concentration in the deep stroma and myometrium at all time-points. There was a time-related loss of progesterone receptor; from the deep glands of progesterone-treated ewes between days 8 and 14. These resultsshow differences in the regulation of receptors between uterine regions. In particular, loss of the negative inhibition by progesterone on the oxytocin receptor by day 14 occurred only in the luminal epithelium, but is unlikely to be a direct effect of progesterone as no progesterone receptors were present on luminal epithelial cells between days 8 and 14. The presence of oxytocin receptors in the luminal epitheliumof ovariectomized ewes suggests that oestradiol is not essential for oxytocin receptor synthesis at this site. Oestradiol was able to sustain its own receptor at all sites, but high circulating progesterone was always inhibitory to oestradiol receptors. In general, oestradiol stimulated progesterone receptors in epithelial cells whereas progesterone abolished its own receptor from epithelial cells over a period of time, but had a lesser effect on stromal cells. The concentration of all three receptors is therefore differentially regulated between different uterine cell types, suggesting the importance of paracrine effectswhich remain to be elucidated.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/07/20 alle ore 16:56:21