运动预处理对大负荷跑台运动引起的大鼠心肌损伤干预作用及其机制探讨

Protection Effect and Its Mechanism of Exercise Preconditioning on Myocardial Iniury-Induced by Heavy Load Treadmill Training in Rat

目的:明确大负荷运动引起的心肌损伤基本特征,探讨运动预处理(EP)对其保护作用及作用机制。方法:成年雄性SD大鼠64只,随机分为安静对照组(AB组)、运动预处理对照组(AC组)、单纯大负荷运动组(B组)、运动预处理+大负荷运动组(C组);根据大负荷运动后即刻、6h、24h3个时相,又分别随机将B、C组依次分为B1、B2、B3与C1、C2、C3组。AC组与C组进行6周中等负荷跑台运动;C组于末次中等负荷运动后48h与B组进行一次性大负荷跑台运动。测定血清cTnI、CK-MB浓度;测定心肌SOD活性、MDA含量与Ca2+浓度、ATP含量(高效液相色谱仪法测定)及心肌细胞膜Na+-K+-ATPase、Ca2+-ATPase活性。结果:运动预处理可明显减轻大负荷运动引起的大鼠血清cTnI、CK-MB浓度升高程度。运动预处理可明显提高心肌SOD活性;明显减轻大负荷运动后心肌SOD指标下降程度及MDA、Ca2+指标的升高程度;明显减轻大负荷运动后心肌ATP含量及心肌细胞膜Na+-K+-ATPase、Ca2+-ATPase活性的下降程度。结论:EP对大负荷运动引起的心肌损伤具一定保护作用,这可能与EP提高的心肌SOD活性有关。

Objective： To make clear the basic characteristics of myocardial injury-induced by heavy load training, and explore the protective effect and its mechanism of exercise preconditioning （EP） on it. MethodsSixty-four grown male SD rats were randomly divided into control group （group AB）, exercise preconditioning control group （group AC）, heavy load training group, heavy load training after exercise preconditioning group （group C）. According to instantly,6 hour and 24 hour after heavy load training, group B were randomly divided into group B1, group B2, group B3 and group C were randomly divided into group C1, group C2, group C3. Rats in group AC, group C had took part in medium load treadmill training for 6 weeks. Rats in group C took part in a heavy load treadmill training at 48 hour after medium load treadmill training with group B. All groups index of serum cardiac troponin-I （cTnI）, creatine kinase rsoenzyme （CK-MB）, and cardiac superoxide dismutase （SOD）, malondialdehyde （MDA） and Ca2＋ were be test. High performance liquid chromatography （HPLC）text adenosine triphosphate （ATP）. Myocardial cellular membrane Na＋ -K＋ -ATPase, Ca2＋ -ATPase activity were also be test. Results： Heavy load training caused serum cTnI and CK-MB concentration were significant higher, and caused cardiac SOD activity was significant lower, cardiac MDA quantitative, Ca2＋ concentration were significant higher, ATP quantitative was significant higher, myocardial cellular membrane Na＋ -K＋ -ATPase, Ca2＋ -ATPase activity were significant lower. Conelusion：EP has protective effect on myocardial iniury induced by heavy load training. Higher SOD activity induced by EP causes chain reaction after heavy load training, therefore play against myocardial iniury.