蕨麻对低压缺氧大鼠脑组织脑红蛋白表达的影响

Expression of neuroglobin in brain of rats exposed to hypobaric hypoxia and effects of Potentilla anserina L.

关键词:  低压缺氧  蕨麻  脑红蛋白

Key words:  hypobaric hypoxia  potentilla anserine L.  neuroglobin

摘要:

[目的] 建立大鼠高原低压缺氧模型,研究大鼠脑组织中脑红蛋白(Ngb)表达及蕨麻乙醇提取物干预的影响。[方法] 将50只健康成年雄性SD大鼠随机分为5组：正常对照组、低压缺氧模型组、蕨麻乙醇提取物0.9、1.8和3.6 g/kg组,每组10只。分别按0.9、1.8和3.6 g/kg剂量将蕨麻乙醇提取物溶于1 mL 0.3%羧甲基纤维素钠溶液。每天于固定时间(8:00)灌胃给药1次,正常对照组、低压缺氧模型组同时给予等体积0.3%羧甲基纤维素钠。连续灌胃14 d.各组大鼠在最后1次灌胃后1 h置于低压缺氧舱在海拔7 000 m低压缺氧12 h.缺氧结束后,用免疫组织化学方法检测Ngb在脑组织中的表达定位,用逆转录-聚合酶链反应法(RT-PCR法)检测皮质Ngb mRNA水平,用Western blot方法检测皮质Ngb表达量。[结果] 低压缺氧模型组大鼠皮质Ngb蛋白免疫反应阳性细胞数增加,胞浆、胞核均可见棕黄色颗粒状免疫反应阳性产物,海马各区未见Ngb表达;脑皮质表达Ngb mRNA及蛋白水平较对照组明显升高(P<0.01);与模型组相比,蕨麻乙醇提取物3.6 g/kg组大鼠脑皮质中Ngb mRNA及蛋白水平明显升高 (P<0.01).[结论] 低压缺氧可刺激脑组织表达Ngb,蕨麻乙醇提取物在低压缺氧时可通过促进Ngb的表达,发挥脑保护作用。

Abstract:

[Objective] To establish the model of rat exposed to hypobaric hypoxia, and detect the expressions of neuroglobin (Ngb) in brain and study the effect of Potentilla anserina L. on it. [Methods] Fifty adult healthy male Sprague-Dawley rats were randomly divided into five groups with ten rats per group: control group, hypobaric hypoxia model group, hypobaric hypoxia+ Potentilla anserina L. alcohol extract(3.6, 1.8, 0.9 g/kg). The Potentilla anserina L. alcohol extract were dissolved in 1 mL 0.3% sodium caboxylmethylcellulose solution according to the dosage of Potentilla anserina L. alcohol extract (3.6, 1.8, 0.9 g/kg), and then was given orally to the rats at the fixed time(8:00) once every day, for 14 successive days. At the same time, 1 mL 0.3% sodium carboxymethylcellulose solution was given orally to the rats in control group and hypobaric hypoxia model group. All of the rats without the control group were underwent hypobaric hypoxia under 0.06 kPa (7 000 m) in decompression chamber for 12 hours. After the hypobaric hypoxia was finished, the position of neuroglobin in brain of rats was observed by immunohistochemistry staining. The levels of neuroglobin mRNA and its protein were detected respectively by methods of RT-PCR and Western blot. [Results] The number of positive cells in immune response to Ngb protein increased in the cortex in hypobaric hypoxia model group compared with control group. The positive substances of immune response appeared as brown yellow particles were observed in the cytoplasm and nuclei of the neurons of cortex in rats in hypobaric hypoxia model group while the expression of Ngb protein was not observed in the hippocampus. The levels of mRNA and protein of Ngb in the cortex of rats in hypobaric hypoxia model group increased compared with control group. The levels of mRNA and protein of Ngb significantly increased in the cortex of rats in 3.6 g/kg Potentilla anserina L. alcohol extract group compared with hypobaric hypoxia model group. [Conclusion] Hypobaric hypoxia can stimulate brain to express neuroglobin. The Potentilla anserina L. alcohol extract can promote the expression of neuroglobin and then protect the brain from hypobaric hypoxia injury.