力竭运动性猝死模型大鼠运动皮质Bax、Bcl-2及脑源性神经营养 因子的表达变化

    文章快速阅读： 文题释义： 运动性猝死：是运动员或体育锻炼者在运动中或运动后24 h内,有症状或无症状情况下的意外死亡,运动负荷是诱发运动性猝死的主要因素之一,并且猝死的危险性随负荷强度增高而增大,大强度运动下运动性猝死的发生机制尚不清楚,分析大强度运动下出现的运动性猝死案例有助于探索其发生机制。 脑源性神经营养因子：是主要在中枢神经系统内表达的具有神经营养作用的蛋白质,它是一种脑组织细胞保护因子,在海马体和脑皮质内含量最高。力竭运动时大脑的相对缺血缺氧诱导发生了两个相反的级联过程,一个是由基因表达调控的神经元细胞主动性的死亡过程;另一个则是受到损伤刺激的神经元通过上调脑源性神经营养因子的表达水平而产生的一种主动性的细胞保护过程,从而使细胞能够抵御运动性脑缺血缺氧引起的病理生理损伤而得以存活。摘要 背景：运动性猝死是运动实践中的常见现象,因偶发故其机制不明。 目的：观察运动性猝死大鼠的运动皮质细胞形态学改变、凋亡调控因子Bax、Bcl-2及脑源性神经营养因子的表达变化,探讨连续力竭性负重游泳训练中运动性猝死的发生及调控机制。 方法：130只雄性SD大鼠随机选7只为空白对照组,其余大鼠在疲劳造模后按36 h的训练周期、对大鼠进行连续力竭性负重游泳训练,并分别在6×36 h、9×36 h与12×36 h训练后随机处死7只大鼠分别记为连续力竭性负重游泳训练1,2,3组(力竭运动1,2,3组);将多次相同模型实验中、6×36 h后偶然出现在每次训练中或训练后24 h内的死亡大鼠(排除因呛水死亡)记为运动性猝死组(n=5)。采用苏木精-伊红染色观察大脑运动皮质细胞的形态结构变化,免疫组织化学染色检测Bax、Bcl-2蛋白及脑源性神经营养因子的阳性表达变化。 结果与结论：①与空白对照组相比,力竭运动1,2,3组和运动性猝死组的运动皮质细胞形态结构发生明显改变,Bax、Bcl-2蛋白及脑源性神经营养因子的阳性表达率明显增高(P < 0.05);②在力竭运动1,2,3组和运动性猝死组中Bax及Bcl-2蛋白呈递增趋势,Bcl-2蛋白表达增强程度高于Bax蛋白;而脑源性神经营养因子的表达呈先增加后降低的趋势;③结果表明,力竭运动组及运动性猝死组中运动皮质细胞内Bax、Bcl-2蛋白及脑源性神经营养因子的阳性表达的增强可能与运动皮质细胞的保护抑制机制有关;过度疲劳时运动皮质内脑源性神经营养因子表达的下降可能是诱发运动性猝死的原因之一。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程 ORCID: 0000-0001-5187-9404(阳仁均)     

不同强度有氧运动周期训练疲劳模型大鼠心肌形态变化及超量恢复规律

BACKGROUND: “Over-recovery theory” is the basic theory of sports training, but study about the visceral over-recovery is few, let alone about heart after aerobic exercise. OBJECTIVE:To observe the morphological changes of myocardial tissue in rats after different cycles of aerobic exercise, and the recovery pattern of heart function within 72 hours. METHODS:132 Sprague-Dawley rats were randomly divided into groups of control (n=6), single-cycle (low-intensity exercise, n=42), double-cycle (moderate-intensity exercise, n=42), and triple-circle (high-intensity exercise, n=42). Rats in the latter three groups underwent 1-week adaptive swimming in accordance with the way of increasing load (from 3% to 6%), followed by aerobic exercise of swimming according to their corresponding training cycle. Subsequently, samples were collected to detect the levels of creatine kinase, superoxide dismutase, succinic dehydrogenase and glutamic-oxaloacetic transaminase in myocardial tissue; left cardiac apex tissues after embedded section were observed by hematoxylin-eosin staining. RESULTS AND CONCLUSION: (1) Compared with the control group, the morphological changes of myocardial tissue immediately after exercise became more obvious with the increasing intensity. (2) Compared with the control group, significantly increased levels of superoxide dismutase, succinic dehydrogenase and glutamic-oxaloacetic transaminase conld be found in the single-cycle group (P < 0.05), and showed over-recovery at 12-36 hours after exercise; all indicators were significantly increased in the double-cycle group showing over-recovery at 24-48 hours (P < 0.05); while in the triple-circle group, succinic dehydrogenase exhibited over-recovery only (P < 0.05), and each indicator level was low probably indicating over fatigue. (3) These findings suggest that compared with the triple-cycle high- intensity training, single-cycle and double-cycle training will be better, and it is advisable to undergo double-cycle aerobic exercise in practice. 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程