Influence of hypoxia-reoxygenation on expression of aquaporin-9 in cultured astrocytes

Objective To investigate the expressions of aquaporin-9(AQP9)and its role in cultured rat astrocytes after exposure to hypoxia-reoxygenation.Methods Rat cerebral cortical astrocytes from 2 days newborn Wistar rats were undergone the pure culture.The hypoxia periods were 12,24,48h.After 24h of hypoxia,the reoxygenated periods were 12,24,48h.We observed the cell viability,the activity of LDH.The reactivity and rules of AQP9 expression of astrocyte to hypoxia-reoxygenation were studied by immunocytochemistry.Results Astrocytes exposed to hypoxia and reoxygenation showed no significant change in cell viability and the activity of LDH than those in the control group.Analysis confirmed that the expression of AQP9 was remarkably increased during hypoxia,up-graduated expression of AQP9 was correlated with hypoxia and time dependent manner(P0.05).The expression of AQP9 was decreased during reoxygenation for 24h.After cells were reoxygenation for 24h,the expression was not restored to the normal level.Conclusion Astrocytes had the better capacity to tolerate hypoxia.There was no change in cell viability.The experiment showed that hypoxia could increase the levels of AQP9 expression and reoxygenation inhibited the increment of this gene expression.