[Effects of hypoxic preconditioning on hypoxia tolerance of astrocytes in vitro].

To explore the mechanisms of hypoxic preconditioning on protecting cultured astrocytes from hypoxia injury.Cultured astrocytes were divided randomly into several groups: control(C), hypoxia(H) and hypoxic preconditioning (HP). Cells MTT metabolic activity, qualitation of apoptosis and modality to explore the protection effects of hypoxic preconditioning. Immunocytochemistry of Bcl-2 and Bax to explore the mechanisms of hypoxic preconditioning on protecting astrocytes from hypoxia.Compared with H group there was marked increase of MTT metabolic activity in HP48 and HP72 groups. Immunocytochemistry of Bcl-2 and Bax showed that compared with H group, expression of Bcl-2 was increased in HP group, while expression of Bax was decreased in HP group.Hypoxic preconditioning can protect astrocytes from hypoxia. One possible mechanism maybe concerned with inhibition of Bax and maintain of Bcl-2 to depress apoptosis procedure.