Objective:To determine the expression of aquaporin 8 and its localization in human WISH cells and to explore the molecular and cellular mechanisms for water absorption across the amniotic membranes.Methods:Human amnion-derive WISH cells were cultured.Western analysis was used to quantify AQP8 expression level.Reverse transcripton-polymerase chain reaction(RT-PCR)was used to quantify AQP8 mRNA expression levels.Immunofluorescence was used to determine localization of AQP8 in WISH cells.Results:AQP8 mRNA protein was found in human WISH cells.By western-blot

the AQP8 proteim was detected at 34ku in human WISH cells.AQP8 labeling was observed in intracellular vesicular structures throughout the cytosol and plasma membrane.Conclusion:The study demonstrates the expression of aquaporin 8 in human WISH cells.These results suggest that aquaporin 8 may be a channel that mediates amniotic fluid resorption by way of intramembranous pathway.