[Influence of hypertonic medium on aquaporin 4 mRNA expression in astrocytes in vitro].

OBJECTIVE

To investigate the expression of aquaporin 4(AQP4) mRNA and the role in cultured rat astrocytes after exposured to hypertonic medium.

METHODS

Rat cerebral cortical astrocytes from 2-day newborn Wistar rats were seperated for the pure culture in vitro and the model of cell dehydration was established by exposed cultured astrocytes to hypertonic medium. The reactivity and rules of AQP4 mRNA expression of astrocytes to hypertonic medium were studied by in situ hybridization, the activity of lactate dehydrogenase (LDH) was detected, and image was analyzed.

RESULTS

After astrocytes cultured for 3, 6, 12, 24 hours with hypertonic medium (320, 333 and 345 mmol/L), the activity of LDH showed a significant increase than that in the control group after astrocytes exposed to hypertonic medium (all P<0.05). In situ hybridization analysis confirmed that the expression of AQP4 mRNA was markedly increased, and especially it was significantly increased in hypertonic medium for 12 hours.

CONCLUSION

The cell viability is significantly decreased and the expression of AQP4 mRNA is remarkably increased in hypertonic medium. The result suggests that AQP4 plays an important role in the early stage of the hypertonic dehydration.