[Expression of aquaporin 3 and aquaporin 9 in placenta and fetal membrane with idiopathic polyhydramnios.].

OBJECTIVE

To investigate the pathogenesis role of aquaporin 3 and aquaporin 9 in idiopathic polyhydramnios by detecting their expression and distribution in fetal membranes and placenta.

METHODS

Twenty-one of term pregnancy women with idiopathic polyhydramnios were enrolled as patient group matched with 30 women with normal term pregnancy as control group. The expression and localization of aquaporin 3 and aquaporin 9 in fetal membranes and placenta were detected by real-time polymerase chain reaction and streptavidin peroxidase immunohistochemiscal staining.

RESULTS

(1) The mRNA expressions of aquaporin 3 and aquaporin 9 were detected in amnion, chorion and placental tissue in both patient group and control group. Both aquaporin 3 and aquaporin 9 were demonstrated positive staining in the amnion epithelia, chorion cytotrophoblasts and placental trophoblast. (2) The ratio of aquaporin 3 and aquaporin 9 mRNA expressions in amnion in patient group comparing to those in control group were 5.00 and 3.25, while in chorion they were 2.03 and 2.08. When compared with those in amnion and chorion of control group, there was a significant difference (P < 0.01). However, the relative change fold of aquaporin 3 and aquaporin 9 in placental trophoblast in patient group were decreased in comparison of those in control group, which also showed statistical difference (P < 0.01). (3) The expression of aquaporin 3 and aquaporin 9 protein in amnion were 7.5 +/- 2.0 and 11.1 +/- 1.8 in patient group, while they were 5.3 +/- 1.6 and 5.6 +/- 2.3 in control group. In chorion, the expression of aquaporin 3 and aquaporin 9 protein was 7.5 +/- 2.0 and 10.0 +/- 1.6 in patient group, respectively, while in control group, they were 5.4 +/- 2.2 and 5.6 +/- 2.1. When compared with those proteins in control group, it exhibited statistical difference (P < 0.05). However, in placental trophoblast of patient group, the expression of aquaporin 3 and aquaporin 9 protein were 3.5 +/- 1.4 and 4.0 +/- 2.5, respectively, which were significantly decreased than 5.6 +/- 1.3 and 7.1 +/- 2.9 in control group (P < 0.05).

CONCLUSIONS

The alterations of aquaporin 3 and aquaporin 9 expressions in fetal membrane and placenta might be an adaptive response to idiopathic polyhydramnios. Further investigation should be needed to clarify the regulatory mechanism of aquaporin 3 and aquaporin 9 expressions.