Expression of cyclooxygenase-1 and -2 in ovine endometrium during the estrous cycle and early pregnancy

• Published in: Endocrinology (Philadelphia) Vol. 138; no. 5; pp. 2163 - 2171
• Main Authors: Charpigny, G, Reinaud, P, Tamby, J P, Créminon, C, Martal, J, Maclouf, J, Guillomot, M
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01-05-1997
• Subjects: Animals; Blotting, Western; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprost - secretion; Endocrinology and metabolism; Endometrium - enzymology; Estradiol - pharmacology; Estrus - physiology; Female; Human health and pathology; Immunohistochemistry; Isoenzymes - analysis; Isoenzymes - metabolism; Life Sciences; Ovariectomy; Pregnancy; Pregnancy, Animal - metabolism; Progesterone - pharmacology; Prostaglandin-Endoperoxide Synthases - analysis; Prostaglandin-Endoperoxide Synthases - metabolism; Sheep
• ISSN: 0013-7227
• DOI: 10.1210/en.138.5.2163

In this study we investigated the expression of the two cyclooxygenases, cox-1 and -2, in sheep uterine tissues during the estrous cycle and early pregnancy. We identified the cox-2 isoform in the ovine uterus by Western blot and demonstrated that the two cyclooxygenases exhibited different patterns of expression. Cox-1 was expressed at steady state levels in the endometrium during the estrous cycle and comparable stages of pregnancy. In contrast, cox-2 was highly and transiently expressed from days 12-15 of the estrous cycle and declined thereafter to undetectable levels. Endometrium from early pregnant ewes showed a similar pattern of cox-2 expression, although there was a slower decrease beyond day 15. Immunohistochemical studies demonstrated that cox-1 was localized in both epithelial and stromal cells, whereas cox-2 was localized solely in the luminal epithelium and to a lesser extent in the superficial glands. Treatment of ovariectomized ewes with steroids indicated that expression of cox-1 remained at constant levels whatever the treatment. In contrast, endometrial cox-2 was highly induced by a 10-day progesterone treatment. Estradiol slightly increased cox-2 expression but only after progesterone priming. Collectively these results suggest that the developing ability of the uterus to synthesize PGs is due to the induction of cox-2.