化学性缺氧致大鼠脑细胞[Ca2+]i和脑红蛋白表达变化及阿司匹林干预研究

目的: 观察化学性缺氧状况下大鼠脑细胞Ca²⁺]_i和脑红蛋白(NGB)表达的变化及阿司匹林(ASA)对其变化的干预,并初步探讨其作用机制。方法: 连二亚硫酸钠致原代培养大鼠脑细胞缺氧,用荧光探针Flou-3负载和NGB荧光免疫组化技术双标,激光共聚焦显微镜动态观察。结果: Ca²⁺]_i和NGB表达与缺氧持续时间有关,随缺氧时间的延长,荧光强度随之增高;经ASA预防性干预,两种荧光强度增高缓慢,其增高程度明显低于单纯缺氧组;治疗性干预,用药早期两种荧光强度增高明显,其增高程度与单纯缺氧组变化相近,后期则增高缓慢,其增高程度明显低于单纯缺氧组。Ca²⁺]_i浓度和NGB表达呈正相关。结论: ASA对原代培养大鼠脑细胞化学性缺氧损伤具有保护作用,其作用可能与ASA抑制细胞内Ca²⁺超载有关;NGB的表达可能是受到Ca²⁺-CaM复合物的调节;ASA预防性用药的早期保护作用明显优于治疗性用药。

Chemical hypoxia induced [Ca2+]i and NGB alteration and aspirin intervention

AIM: To observe changes of intracellular free calcium levels (Ca²⁺]_i) and neuroglobin (NGB) expression when rats′brain cells were exposed to chemical hypoxia, and the influence of aspirin (ASA) on changes as well as to study its mechanism primarily.METHODS: Sodium dihionite was used to deprive the oxygen in culture medium, and confocal laser scanning microscope with double fluorescence labeling methods were used to measure the changes of Ca²⁺]_i and NGB expression in rats′brain cells.Flou-3/AM and Cy-3 were used to indicate calcium concentration and NGB expression respectively.RESULTS: Ca²⁺]_i and NGB expression are related to the time of hypoxia.Compared with the normal control group, average fluorescent intensity of Ca²⁺]_i and NGB expression in the simple hypoxia group increased gradually with the time of the exposure in hypoxia.Moreover, there is the positive correlation between Ca²⁺]_i and NGB expression.Ca²⁺]_i and NGB expression in the ASA pretreated group increased slowly, the increase degree is significantly lower than that in the simple hypoxia group.Ca²⁺]_i and NGB expression in the ASA treated group were increased significantly in early stage, the increase degree is not significant diffexence from the simple hypoxia group.At 120 min, Ca²⁺]_i and NGB expression in the ASA treated group increased slowly, the increase degree is significantly lower than that in the simple hypoxia group.CONCLUSION: ASA has a protective effect on hypoxic injury of rats′ brain cells, which may be attribute to its inhibiting calcium overload, and NGB expression is regulated by Ca²⁺-CaM complex.In addition, the neuroprotective effects of ASA pretreated group were better than ASA treated group in early stage.