Objective       To determine the protective effect of hyperbaric oxygen preconditioning (HBOP) on rat brain astrocytes against hypoxia and on the expression of R2X

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receptor and AQP4.       Methods       Cultured primary astrocytes were isolated from neonatal SD rats

primarily cultured and identified by GFAP staining at passage 2. The astrocytes at passage

3 were divided into control group

HBOP group

oxygen glucose deprivation (OGD) group and HBOP+OGD group. The apoptotic rate was detected by flow cytometry at 24 and 48 h after OGD. The ATP concentration in the culture medium were measured by chemiluminescence detection. The protein expression of R2X

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receptor and AQP4 was detected by Western blotting

and their mRNA levels were determined by RT-qPCR.       Results        The expression of AQP4 and R2X

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receptor was enhanced in HBOP group than control group (

P

0.05). The apoptotic rate was significantly lower in the HBOP+OGD group than the OGD group at 24 and 48 h (

P

0.05). The protein level of AQP4 and R2X

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receptor was obviously higher in the HBOP group than control group (

P

0.05). The AQP4 and R2X

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receptor mRNA transcription levels were inhibited in HBOP+OGD group when compared with those in OGD group at 6 h (

P

0.05).       Conclusion       HBOP improves the mitochondrial ATP production by rat brain astrocytes exposure to hypoxia

promotes the cell tolerance to hypoxia and aglycemia

reduces cell apoptosis

and exerts absolutely cytoprotective effect. The underlying mechanism may be due to the down-regulation of AQP4 and R2X

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receptor at mRNA levels after OGD.