title: Reduction of aquaporin-8 on fetal membranes under oligohydramnios in mice lacking prostaglandin F2 alpha receptor.
abstract: OBJECTIVE
  To investigate the association between aquaporin-8 (AQP-8: a water channel protein) expression in fetal membranes and oligohydramnios during near-term and postdate pregnancy, we set up an oligohydramnios model using prostaglandin F2 alpha receptor (FP)-deficient mice.
  
  
  METHODS
  Pregnant FP-deficient mice from 14 to 21 gestational days (GD) were killed to measure the amniotic fluid volume (AFV), and fetal membranes were collected for the analysis of aquaporin-8 expression.
  
  
  RESULTS
  The AFV was highest at 14 GD, and was significantly decreased to 28% and 0% at 20 GD and 21 GD, respectively, compared with the volume at 14 GD. Immunohistochemistry and immunoblot analysis showed that aquaporin-8 was expressed in the basal component of fetal membranes, and that the protein level was significantly decreased to 60% at 20 GD compared with that at 14 GD.
  
  
  CONCLUSIONS
  We demonstrated that AQP-8 expression in the fetal membrane was decreased at post term in FP-deficient mice. Our findings suggest that aquaporin-8 in fetal membranes may be involved in the regulation of AFV, especially when oligohydramnios occurs.
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University, Graduate School of Medicine, Osaka, Japan.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Shioji
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Fukuda
authors.forename: Toru
authors.initials: T
authors.lastname: Kanzaki
authors.forename: Kenshi
authors.initials: K
authors.lastname: Wasada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kanagawa
authors.forename: Koichiro
authors.initials: K
authors.lastname: Shimoya
authors.forename: Junwu
authors.initials: J
authors.lastname: Mu
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Sugimoto
authors.forename: Yuji
authors.initials: Y
authors.lastname: Murata
mesh_terms: D000653:Amniotic Fluid / Q000502:physiology; D000818:Animals; D020346:Aquaporins / Q000096:biosynthesis*; D005321:Extraembryonic Membranes / Q000378:metabolism*; D005260:Female; D051379:Mice; D018345:Mice, Knockout; D016104:Oligohydramnios / Q000378:metabolism*; D011247:Pregnancy; D011982:Receptors, Prostaglandin / Q000378:metabolism*
chemical_list: D020346:Aquaporins; D011982:Receptors, Prostaglandin; C108330:aquaporin 8; C034671:prostaglandin F2alpha receptor