title: Infusion of oxytocin induces successful delivery in prostanoid FP-receptor-deficient mice.
abstract: The dramatic increase of oxytocin (OT) receptor (OTR) in the myometrium as well as circulating progesterone withdrawal has been thought to be the most important factor in the induction and accomplishment of parturition since delivery fails in prostaglandin F2alpha receptor (FP) knockout (FP KO) mice. The expression levels of OTR mRNA/protein were not dramatically increased in the near-term uteri of FP KO mice. However, OT-induced myometrial contractions and the concentration-response curves in FP KO in vitro were almost similar to those in wild-type (WT) mice. OT-infusion (0.3 U/day) enabled FP KO mice to experience successful delivery, and furthermore the duration until the onset was hastened by a higher dose of OT (3 U/day). The plasma progesterone levels of FP KO females were maintained at high levels, but decreased during labor by OT-infusion (3 U/day). These results suggest that OT has potentials to induce strong myometrial contractions in uterus with low expression levels of OTR and luteolysis in ovary, which enabled FP KO females to undergo successful delivery.
authors: Department of Molecular Biology, Graduate School of Agriculture, Tohoku University, Sendai, Miyagi 981-8555, Japan. mkawamat@gan2.res.ncc.go.jp
authors: Masaki
authors: M
authors: Kawamata
authors: Masahide
authors: M
authors: Yoshida
authors: Yukihiko
authors: Y
authors: Sugimoto
authors: Tadashi
authors: T
authors: Kimura
authors: Yutaka
authors: Y
authors: Tonomura
authors: Yuki
authors: Y
authors: Takayanagi
authors: Teruyuki
authors: T
authors: Yanagisawa
authors: Katsuhiko
authors: K
authors: Nishimori
mesh_terms: D000818:Animals; D036861:Delivery, Obstetric; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D007260:Infusion Pumps; D007743:Labor, Obstetric / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009215:Myometrium / Q000187:drug effects / Q000378:metabolism; D010121:Oxytocin / Q000008:administration & dosage* / Q000494:pharmacology; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000097:blood; D018045:Receptors, Oxytocin / Q000235:genetics / Q000378:metabolism; D011982:Receptors, Prostaglandin / Q000172:deficiency* / Q000378:metabolism; D014590:Uterine Contraction / Q000187:drug effects
chemical_list: D018045:Receptors, Oxytocin; D011982:Receptors, Prostaglandin; C034671:prostaglandin F2alpha receptor; D011374:Progesterone; D010121:Oxytocin