Zhang Zhao, Wang Yang, Xu Peng, Cui Yingkai, Li Wang, Cao Xuebin
Hebei Institute of Northern, Zhangjiakou 071500, Hebei, China (Zhang Z, Li W); Department of Clinical Pharmacy, the 252nd Hospital of PLA, Baoding 071000, Hebei, China (Wang Y); Department of Cardiology, the 252nd Hospital of PLA, Baoding 071000, Hebei, China (Xu P, Cui YK, Cao XB). Corresponding author: Cao Xuebin, Email:
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2018 Apr;30(4):369-373. doi: 10.3760/cma.j.issn.2095-4352.2018.04.017.
To observe the heart protective effect of exercise preconditioning (EP) in the acute exhaustion exercise (EE) rats, and explore its action mechanism further.
Eighty healthy male Sprague-Dawley (SD) rats were divided into control group (C group), EP group, EE group, and EP+EE group randomly, with 20 rats in each group. The rats in EP and EP+EE groups were trained for 3 weeks according to the daily swimming for 60 minutes (swimming 15 minutes, resting 5 minutes, repeating 3 times) with 6 days each week. The rats in EE and EP+EE groups on the last 1 day after 3 weeks, 3% weight heavy weight was carried once for swimming EE. Two hours after the last EE, abdominal aortic blood and heart was harvested, the levels of serum MB isoenzyme of creatine kinase (CK-MB) and calcitonin gene related peptide (CGRP) were determined by enzyme linked immunosorbent assay (ELISA); the ultrastructure of myocardium was observed by optical microscopy; the levels of myocardial malondialdehyde (MDA) and superoxide dismutase (SOD) were determined by ELISA, the mRNA expression of myocardial CGRP was assayed by reverse transcription-polymerase chain reaction (RT-PCR), and the protein expression of myocardial CGRP was assayed by Western Blot.
Compared with C group, the levels of serum CK-MB and myocardial MDA were significantly increased, serum CGRP content, myocardial SOD activity, and mRNA and protein expressions of myocardial CGRP were significantly decreased in EE group and EP+EE group. Compared with EE group, the levels of serum CK-MB and myocardial MDA in EP+EE group were decreased [CK-MB (U/L): 13.11±0.77 vs. 15.55±0.90, MDA (μmol/L): 389.57±49.60 vs. 709.08±160.49], the level of serum CGRP, and mRNA and protein expressions of myocardium CGRP were increased [serum CGRP (ng/L): 120.41±9.07 vs. 97.97±9.05, CGRP mRNA (2 ): 0.45±0.09 vs. 0.14±0.02, CGRP protein (gray value): 0.78±0.08 vs. 0.41±0.04, all P < 0.05], the degree of myocardial injury was obviously alleviated. There was no significant difference in the indexes between the EP group and C group.
EP has the heart protective effect for the acute EE rats, and the mechanism is closely related to the endogenous protective substance CGRP.
观察运动预适应（EP）对急性力竭运动（EE）大鼠的心脏保护作用，并进一步探讨其作用机制。
将80只健康雄性Sprague-Dawley（SD）大鼠随机分为对照组（C组）、EP组、EE组和EP+EE组，每组20只。EP组和EP+EE组大鼠按每周6天、每天游泳60分钟（游泳15分钟，休息5分钟，重复3次）的方式训练3周。3周后最后1天，EE组和EP+EE组大鼠负重3%体重进行1次游泳力竭运动。末次力竭运动后2小时，采集腹主动脉血和心脏，采用酶联免疫吸附测定（ELISA）法测定血清肌酸激酶MB同工酶（CK-MB）和降钙素基因相关肽（CGRP）水平；用光镜观察心肌超微结构；采用ELISA法测定心肌丙二醛（MDA）和超氧化物歧化酶（SOD）水平，采用逆转录-聚合酶链反应（RT-PCR）法检测心肌CGRP的mRNA表达，采用蛋白质免疫印迹法检测心肌CGRP的蛋白表达。
与C组比较，EE组和EP+EE组血清CK-MB水平和心肌MDA含量显著升高，血清CGRP含量、心肌SOD活性及心肌CGRP的mRNA和蛋白表达显著降低。与EE组比较，EP+EE组血清CK-MB水平和心肌MDA含量降低[CK-MB（U/L）：13.11±0.77比15.55±0.90，MDA（μmol/L）：389.57±49.60比709.08±160.49]，血清CGRP水平及心肌CGRP的mRNA和蛋白表达升高[血清CGRP（ng/L）：120.41±9.07比97.97±9.05，CGRP mRNA（2-ΔΔCt）：0.45±0.09比0.14±0.02，CGRP蛋白（灰度值）：0.78±0.08比0.41±0.04，均P<0.05]，心肌损伤程度明显减轻。EP组与C组各项指标比较差异无统计学意义。
EP对急性力竭运动大鼠具有心脏保护作用，其机制与内源性保护物质CGRP密切相关。
