丹参酮ⅡA对缺氧大鼠前庭内侧核BKCa、NO和MAP-2的影响

Effects of tanshinoneⅡA on the expression of BKCa,NO and MAP-2 in the medial vestibular nucleus of hypoxic rats

目的:探讨丹参酮ⅡA对缺氧大鼠前庭内侧核(MVN)中大电导钙激活钾通道(BKCa)、一氧化氮(NO)以及微管相关蛋白-2(MAP-2)表达的影响。方法:SD大鼠和原代MVN神经元分别缺氧造模,随机分为对照组、模型组、丹参酮ⅡA组。采用免疫荧光法观察原代MVN神经元状态及其MAP-2蛋白表达,Western Blot检测大鼠MVN组织中BKCa-α、BKCa-β表达,硝酸还原法检测MVN组织NO含量。结果:模型组MVN神经元突触结构破坏,MAP-2蛋白表达较对照组显著降低(P<0.01);与模型组比较,丹参酮ⅡA 10μg/mL组突触轨迹复杂度和总长度显著升高(P<0.01),MAP-2蛋白表达显著增加(P<0.05)。与对照组比较,模型组BKCa-α、BKCa-β蛋白表达显著降低(P<0.01),NO含量显著减少(P<0.05);与模型组比较,丹参酮ⅡA 20、40、80 mg/kg组BKCa-α、BKCa-β蛋白表达显著增多(P<0.01),丹参酮ⅡA 80 mg/kg组NO含量显著增加(P<0.05)。结论:丹参酮ⅡA能通过增加BKCa蛋白和NO表达,促进MAP-2生成,对缺氧损伤的MVN神经元发挥神经保护作用。

Objective:To investigate the effects of tanshinoneⅡA on the expression of big-conductance Ca^(2+)-activated potassium channels(BKCa),nitric oxide(NO)and microtubule-associated protein 2(MAP-2)in the medial vestibular nucleus(MVN)of hypoxic rats.Methods:SD rats and MVN primary cells were modeled by hypoxia and randomly divided into control group,model group and tanshinoneⅡA group.Immunofluorescence method was used to observe the state of primary MVN neurons and the expression of MAP-2.Western Blot was used to detect the expression of BKCa-αand BKCa-βin MVN tissues,and nitric acid reduction method was used to detect the content of NO in MVN tissues.Results:The synaptic structure of MVN neurons in the model group was damaged,and the protein expression of MAP-2 was significantly decreased than that of control group(P<0.01).Compared with model group,the synaptic locus complexity and total length of tanshinoneⅡA 10μg/mL group were significantly increased(P<0.01),and the protein expression of MAP-2 was significantly increased(P<0.05).Compared with control group,the protein expression of BKCa-αand BKCa-βin model group were significantly decreased(P<0.01),and the content of NO was decreased(P<0.05).Compared with model group,the protein expression of BKCa-αand BKCa-βin tanshinonoeⅡA 20,40,80 mg/kg group were significantly increased(P<0.01),and NO significantly increased in 80 mg/kg group(P<0.05).Conclusion:TanshinoneⅡA can promote the production of MAP-2 by increasing the expression of BKCa protein and NO,and play a neuroprotective role in MVN neurons injured by hypoxia.