Objective: To investigate the expression of aquaorin-4 (AQP4) in the cultured neonatal rat primary astrocytes during hypoxia and during reoxygenation after hypoxia.
Methods: The astrocytes were randomly assigned to the hypoxia group (the astrocytes were exposed to hypoxia for 3 h, 6 h, 12 h and 24 h respectively), the reoxygenation group (after exposure to 12 h hypoxia, the astrocytes were returned to normoxic cultures for 3 h, 6 h, 12 h and 24 h respectively), and the normoxic group (control group). AQP4 mRNA expression in astrocytes of all groups was detected by Real Time PCR, and AQP4 protein expression was determined by immunofluorescence.
Results: The AQP4 mRNA and protein expressions significantly decreased with the time of hypoxia, and during reoxygenation, the decreased expressions were gradually up-reguated.
Conclusion: It is likely that the decreased expression of AQP4 is associated with brain edema and in such brain edema conditions AQP4 may play a prominent role in the reestablishment of brain osmotic equilibrium.