Evidence for an inverse relationship between cyclooxygenase and lipoxygenase pathways in the pregnant rabbit endometrium.
In the present investigation, experiments were undertaken to determine whether a relationship does exist between cyclooxygenase and 5-lipoxygenase pathways in rabbit endometrial cells on day 6 of pregnancy. Endometrial single-cell suspensions were incubated in RPM1-1640 for 1 h under a gas phase of 95% O2 + 5% CO2 at 37 degrees C for 1 h in the presence and absence of indomethacin, a known inhibitor of cyclooxygenase or nordihydroguaiaretic acid (NDGA), a preferential inhibitor of 5-lipoxygenase. Prostaglandins (PGF2 alpha, PGE2 and 6-keto-PGF1 alpha) and 5 (S)-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE) were measured in the media by radioimmunoassay. Indomethacin or NDGA at all concentrations used suppressed the release of PGs or 5-HETE, respectively. However, NDGA at the lowest dose (15 microM) stimulated, but at higher doses (30-60 microM) suppressed the release of PGs. On the other hand, indomethacin at both the concentrations (55 microM and 110 microM) used stimulated the release of 5-HETE. The results suggest the existence of an inverse relationship between the two pathways in the preimplantation rabbit endometrial cells.
D000818:Animals; D001091:Arachidonate Lipoxygenases; D002396:Catechols / Q000494:pharmacology; D004717:Endometrium / Q000378:metabolism*; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D008084:Lipoxygenase / Q000378:metabolism*; D009637:Masoprocol; D011247:Pregnancy; D011270:Pregnancy, Animal; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D011453:Prostaglandins / Q000096:biosynthesis*; D011817:Rabbits
D002396:Catechols; D011453:Prostaglandins; D009637:Masoprocol; D001091:Arachidonate Lipoxygenases; D008084:Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases; D007213:Indomethacin