【摘要】 目的 :观察运动应激对吸烟大鼠支气管平滑肌大电导的钙激活的钾通道 (BKCa)和电压依赖性延迟整流钾通道Kv1.5蛋白和mRNA表达的影响。方法 :复制大鼠慢性吸烟模型后 ,进行运动训练 ,测定气道反应性和血浆皮质醇浓度 ,采用HE染色、免疫组织化学染色、原位杂交和免疫印迹等方法检测肺组织病理形态学改变和BKCa、Kv1.5的表达变化。结果 :(1)吸烟对照组的气道反应性明显高于正常对照组 (P <0 0 1) ,而吸烟加运动应激组的气道反应性显著低于吸烟对照组 (P <0 0 5 ) ;(2 )运动后血浆皮质醇浓度明显高于运动前 (P <0 0 1) ,但全部运动结束次日晨测定的血浆皮质醇浓度与运动前无明显差异 (P >0 0 5 ) ;(3)HE染色显示 ,吸烟对照组肺组织出现明显的慢性炎症反应 ,吸烟加运动应激组炎症反应轻于吸烟对照组 ;(4 )慢性吸烟大鼠大气道和小气道BKCamRNA和蛋白表达低于正常对照组 ,吸烟加运动应激组BKCamRNA表达高于吸烟对照组 ,但对小气道的蛋白表达无影响 ;(5 )慢性吸烟大鼠大气道和小气道Kv1.5蛋白和mRNA表达低于正常对照组 ,在小气道吸烟加运动应激组高于吸烟对照组 ,大气道则无变化。结论 :适当运动应激可降低慢性吸烟对大鼠气道平滑肌钾通道BKCa和Kv1.5的表达的抑制作用以及运动引起的皮质醇分泌的增加 ,可能是更多还原

【Abstract】 AIM: To investigate the effect of exercise stress on chronic cigarette smoking-induced downregulation of expression of large-conductance calcium-activated potassium channel (BK_Ca) and voltage-dependent delayed rectifier potassium channel （Kv1.5） in rat bronchial smooth muscle cells. METHODS: Rats were divided into 3 groups: normal control, smoking control and smoking plus exercise training group. The alteration of airway responsiveness and plasma cortisol level were detected, and potassium channel expression and pathological changes in lung tissue were determined with HE staining, immunohistochemistry, in situ hybridization and Western blot techniques. RESULTS: （1） Cigarette smoking induced an increase in airway responsiveness, smoking plus exercise lead to a decrease in airway responsiveness in contrast to smoking control group; （2） Plasma level of cortisol determined immediately after exercise was higher than that determined before exercise; （3） HE staining showed that there was severe chronic pulmonary inflammatory response in smoking control group, which was slight in the smoking plus exercise group; （4） The protein and mRNA expression of BK_Ca in cigarette smoking group were less than that in control group in BSMC, the mRNA expression of BK_Ca in exercise group were higher than that in smoking group; （5） The protein and mRNA expression of Kv1.5 in smoking group were less than that in control group in BSMC, and expression of Kv1.5 in exercise group was higher than that in smoking group in bronchioli. CONCLUSION: Proper exercise training can increase the expression of potassium channel BK_Ca and Kv1.5, and increase the cortisol secretion, which may contribute to the decreasing of airway hyperresponsiveness induced by cigarette smoking. [更多还原