title: Role of prostaglandin H2 synthase 2 in murine parturition: study on ovariectomy-induced parturition in prostaglandin F receptor-deficient mice.
abstract: To determine the prostaglandin (PG) H2 synthase (generally referred to as cyclooxygenase [COX]) isozyme responsible for producing uterotonic PGs during parturition, we used PGF2alpha receptor-deficient mice, which exhibit parturition failure due to impaired withdrawal of serum progesterone at term. On ovariectomy-induced parturition in these mice, uterine COX-2 mRNA expression was drastically induced in the myometrium, whereas COX-1 mRNA expression in the endometrial epithelium decreased. The concomitant administration of progesterone with ovariectomy resulted in a delay in parturition and the disappearance of both the increase in COX-2 mRNA and the decrease in COX-1 mRNA. Thus, the expression of myometrial COX-2 and the occurrence of parturition are closely associated in this model. Furthermore, administration of the COX-nonselective inhibitor, indomethacin, or the COX-2-selective inhibitor, Dup-697 or JTE-522, effectively delayed ovariectomy-induced parturition in these mice. These findings suggest that COX-2-derived PGs contribute to the onset of parturition after the decrease in serum progesterone level.
authors.affiliation: Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Tsuboi
authors.forename: Aya
authors.initials: A
authors.lastname: Iwane
authors.forename: Sayako
authors.initials: S
authors.lastname: Nakazawa
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Sugimoto
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ichikawa
mesh_terms: D000818:Animals; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004717:Endometrium / Q000201:enzymology; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009215:Myometrium / Q000201:enzymology; D010052:Ovariectomy; D036801:Parturition / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011982:Receptors, Prostaglandin / Q000172:deficiency* / Q000235:genetics
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D011982:Receptors, Prostaglandin; C034671:prostaglandin F2alpha receptor; D011374:Progesterone; D004958:Estradiol; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496512:Ptgs1 protein, mouse