Sevoflurane preconditioning inhibits brain injury in hypoxic mice / 中国病理生理杂志

ABSTRACT

AIM:To observe the effects of sevoflurane preconditioning on brain injury in hypoxic mice and its possible mechanism. METHODS:Male C57BL/6J mice were randomly divided into control (C) group, hypoxia (H) group,2% sevoflurane preconditioning for 30 min + hypoxia(S1+H) group,2% sevoflurane preconditioning for 60 min+hypoxia (S2+H) group and 4% sevoflurane preconditioning for 30 min + hypoxia(S3+H) group. The hypoxia model was established by continuous inhalation of(6.5±0.1)% O2for 24 h. The sevoflurane preconditioning treatments,S1,S2 and S3,were conducted by inhalation of 2% sevoflurane for 30 min,2% sevoflurane for 60 min and 4% sevoflurane for 30 min,respectively,with the carrier of(21.0±0.5)% O2,followed by washout for 15 min and then hypoxia treatment. The histological changes of the hippocampal CA1 area were observed under light microscope and transmission electron micro-scope(TEM),and serum lactate dehydrogenase (LDH) activity was measured by colorimetric method. Furthermore, the protein levels of erythropoietin (EPO) and vascular endothelial growth factor(VEGF) in brain tissue homogenate were ex-amined by ELISA,and the content of malondialdehyde(MDA) and the activity of superoxide dismutase(SOD) and gluta-thione peroxidase(GPx) were measured by microplate reader. RESULTS:After hypoxia for 24 h,cell edema or pyknosis in the hippocampal CA1 area was observed in H group. Sevoflurane preconditioning reduced hypoxic injury, and the cell ultrastructure under TEM was significantly improved in S2+H group. Compared with C group,the serum LDH activity and the levels of EPO,VEGF and MDA in brain tissues were significantly increased in H group,while the activity of SOD and GPx decreased. After sevoflurane pretreatment,the serum LDH activity and the levels of EPO and VEGF in brain tissues were lower than those in H group,and the most significant difference was observed in S2+H group. Moreover, the MDA content and SOD activity decreased,and the GPx activity increased in the sevoflurane preconditioning groups. CONCLU-SIONSevoflurane preconditioning attenuates brain injury in hypoxic mice by regulating antihypoxic protein synthesis and reducing oxidative stress.