AbstractAim: 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 F2α 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.
