心梗后进行有氧运动干预对大鼠心脏TH、TNF-α和ROS水平的关系探讨
Effect of Aerobic Exercise on TH, TNF-α and ROS of Heart in Rats with Myocardial Infarction

摘要: 目的:探讨心梗后进行4周有氧运动干预对大鼠心脏交感神经标记物TH，促炎因子TNF-α与氧化应激水平的关系。方法: 选取雄性SD大鼠36只，随机分为假手术对照组(SC)，心肌梗死组(MI)，心梗+持续有氧运动组(ME)，每组12只。MI组采用心脏左冠状动脉前降支(LAD)结扎法，建立MI模型。SC组大鼠实施假手术，ME组大鼠在MI手术后一周进行4跑台运动。运动以10 m/min速度开始，运动5 min后，以3 m/min的速度递增至16 m/min。运动总时间均为60 min，5 d/周×4周。训练结束后测定各组大鼠心电图变化。之后开胸摘取心脏，进行组织学制片。免疫组化法观察分析左心室交感神经标记物TH及促炎因子TNF-α表达。Western Blot法检测TH及TNF-α蛋白含量。DHE法检测心肌超氧阴离子水平。结果: 与SC组相比，MI组大鼠左心室中可见大量TH阳性神经纤维(P<0.01)，其蛋白表达显著增加(P<0.01)。同时TNF-α蛋白表达及超氧阴离子水平显著升高(均P<0.01)。与MI组比较，ME组左心室TH，TNF-α蛋白表达及超氧阴离子水平均显著下降(P<0.05, P<0.01, P<0.01)。且发现左心室TH表达与ROS水平呈显著正相关(R=0.53, P<0.05)，而TH与TNF-α相关性不显著 (R=0.41, P=0.11)。结论: 心梗后早期进行四周持续有氧运动干预可抑制心梗大鼠心脏交感神经标志物TH，其可能与抑制心肌氧化应激水平关系密切，与炎性细胞因子TNF-α水平关系不显著。
Abstract: Objectives: The aims of this study were to investigate the effect of aerobic exercise on tyrosine hydroxylase (TH), tumor necrosis factor-alpha (TNF-α) and oxidative stress of heart in rats with myocardial infarction. Methods: Thirty-six male SD rats were randomly divided into three groups (n-12): sham-operated control group (SC), MI group (MI), and MI with aerobic exercise group (ME). MI was induced by ligation of the left anterior descending (LAD) coronary artery. ME rats underwent 4 weeks treadmill training at 1 week post-MI, this exercise program was initiated at 10 m/min, 5 min, then gradually increased to 16 m/min, 60 min/d, 5d/week. After training, the heart was taken for histological section. The expressions of TH and TNF-α in left ventricle (LV) were tested by immunohistochemistry. The protein expressions of TH and TNF-α were measured by Western blot, while superoxide anion (O2-) was detected by DHE staining. Results: Compared with SC group, abundant TH-positive nerves were observed in LV in MI group (P < 0.01), and its expression, TNF-α expression and the production of superoxide anion in LV were significantly increased in MI group (Ps < 0.01). Compared with MI group, TH and TNF-α expressions, and superoxide anion level were significantly decreased (Ps < 0.05). TH expression was positively related to the production of superoxide anion (r = 0.53, P < 0.05), but TH expression was not related to TNF-α expression(r = 0.41, P = 0.11). Conclusions: Four weeks aerobic exercise can inhibit cardiac sympathetic nerve marker- TH, which is potentially related to attenuation of oxidative stress after myocardial infarction, but is not related to TNF-α