Expression of aquaporin 1 and aquaporin 3 in fetal membranes and placenta in human term pregnancies with oligohydramnios.

OBJECTIVE

To explore the pathophysiology of oligohydramnios, the association between the expression of aquaporin 1 and aquaporin 3 in fetal membranes and placenta and oligohydramnios was investigated.

METHODS

Sixty patients underwent elective cesarean sections at term were studied, 30 patients with isolated oligohydramnios and the other 30 with normal amniotic fluid volume (AFV). Real-time polymerase chain reaction and immunohistochemistry were employed to determine expression and localization of aquaporin 1 and aquaporin 3 in amnion, chorion and placenta, respectively.

RESULTS

The expression of aquaporin 1 and aquaporin 3 was detected in amnion, chorion and placenta using real-time RT-PCR. By immunohistochemistry, aquaporin 1 and aquaporin 3 protein expressions in amnion epithelia and chorion cytotrophoblasts were identified. In placenta, aquaporin 1 was detected in placental vessels, while aquaporin 3 was found in trophoblast cells. In comparison to normal AFV group, there was a significant decrease of aquaporin 1 expression in amnion in oligohydramnios group, but no significant difference in chorion and placenta between the two groups. The expression of the aquaporin 3 in amnion and chorion in oligohydramnios group was significantly decreased, while expression in placenta was significantly increased compared with that in normal AFV group.

CONCLUSIONS

Alteration of aquaporin 1 and aquaporin 3 expression in fetal membranes and placenta may be important in the pathophysiology of isolated oligohydramnios.