Ventolin Inhalers

- Expression of Cyclooxygenase: DISCUSSION(5)


Because a d16 embryo can be successfully transferred to a cycling cow at d16 (the day that luteolysis is initiated), it has been suggested that IFN-т also has a quick, direct effect on endometrial synthesis of PGs. In the present study, the expression of COX-2 is strongly enhanced in the LE during the pregnancy recognition period and after IFN-т treatment. COX-2 might be involved in opposed physiological events, forcing the female reproductive tract either to return to the cycle or to accommodate the embryo, because both luteolysis/OT treatment and pregnancy recognition/ IFN-т treatment are accompanied by an elevated expression of COX-2 in the LE.

Indeed, COX-2 generates PGH-2, the common precursor for PGF2a, PGE2, and PGI2—tonameonlythosePGswelllmowntoparticipate at the materno-fetal interface—which rnerespei:;tivelylu-teolytic, antiluteolytic/luteotropic, and required during decidualization and implantation in mice. It can thus be expected that the fate of the corpus luteum depends in part upon the balance between luteotro-pic PGE2 and luteolytic PGF2a. Even though an elevated COX-2 expression during the periods of luteolysis and pregnancy recognition would result in the simultaneous synthesis of both PGs, PGE2 is not sufficient to prevent luteolysis during a natural cycle and endogenous PGF2a is not sufficient to trigger luteolysis during early pregnancy. Results therefore suggest that the corpus luteum is differentially resistant to both types of PGs.

January 29, 2014 Pregnancy
Tags: growth factors pregnancy uterus