目的:探讨力竭运动后大鼠心肌线粒体解偶联蛋白2(UCP2)表达的改变及交感神经系统的变化,并探究其在心肌能量代谢中的作用及意义。方法:雄性Wistar大鼠45只,按简单完全随机原则分为3组,每组15只:对照组(A组),耐力训练力竭组(B组),1次力竭组(C组)。4周后,双抗体夹心法测定血浆肾上腺素(E)、去甲肾上腺素(NE)浓度、血浆游离脂肪酸(FFA)浓度及心肌线粒体三磷酸腺苷(ATP)含量,实时荧光定量逆转录聚合酶链反应(RT-PCR)及Western blot法测定心肌线粒体UCP2表达变化。结果:4周后,B组大鼠血浆E、NE浓度明显升高,较A组分别增加103.33%、15.94%,较C组分别增加6 7.85%、8.21%(均P<0.01),C组较A组增加75.38%、55.11%(均P<0.01);心肌组织ATP含量C组最低,其次为B组,与A组相比差异有统计学意义(P<0.01);血浆FFA浓度C组为(0.500±0.020)mmol/L,较B组(0.397±0.021)mmol/L升高25.94%,较A组(0.215±0.050)mmol/L升高132.56%,B组FFA浓度较A组升高84.65%,备组差异均有统计学意义(均P<0.05);RT-PCR反应及Western bolt结果显示:C组UCP2表达水平较A组高75.64%及37.55%,较B组高21.89%及1 7.27%,差异均有统计学意义(均P<0.01);B组UCP2表达水平较A组高44.10%及1 7.29%,差异有统计学意义(P<0.01);相关性分析显示血浆FFA浓度与UCP2表达呈正相关(r=0.832,P<0.01);UCP2表达量与ATP含量呈负相关(r=-0.875,P=0.011)。结论:力竭运动训练可使交感神经系统兴奋性增强,儿茶酚胺类物质分泌增多,心肌线粒体UCP2表达增高,在一定程度上导致心肌ATP含量减少,参与了力竭运动引起衰竭心肌能量代谢障碍。 Objective: To investigate the changes of mitochondrial uncoupling protein 2 (UCP2) and sympathetic nervous system in rats after exhaustive exercise, and to explore the role and significance of UCP2 in myocardial energy metabolism. Methods: Forty-five male Wistar rats were divided into three groups according to a simple and completely random principle: control group (group A), endurance training and exhaustion group (group B), and once exhaustion group (group C) . After 4 weeks, the levels of plasma epinephrine (E), norepinephrine (NE), plasma free fatty acid (FFA) and myocardial mitochondrial ATP content were measured by double antibody sandwich method. Real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot were used to detect the changes of myocardial mitochondrial UCP2 expression. Results: After 4 weeks, the concentration of plasma E and NE in group B increased significantly by 103.33% and 15.94% respectively compared with group A, increased by 6 7.85% and 8.21% respectively compared with group C (all P <0.01) (P <0.01); ATP content in myocardial tissue was the lowest in group C, followed by that in group B, which was significantly different from that in group A (P <0.01); the concentration of plasma FFA in group C (0.500 ± 0.020) mmol / L, which was 25.94% higher than that of group B (0.397 ± 0.021) mmol / L and 132.56% higher than that of group A (0.215 ± 0.050) mmol / L (P <0.05). The results of RT-PCR and Western bolt showed that the expression of UCP2 in group C was 75.64% and 37.55% higher than that in group A, which was 21.89% higher than that in group B (P <0.01). The expression level of UCP2 in group B was 44.10% and 1.29% higher than that in group A, and the difference was statistically significant (P <0.01). The correlation analysis showed that plasma There was a positive correlation between FFA concentration and UCP2 expression (r = 0.832, P <0.01). UCP2 expression was negatively correlated with ATP content (r = -0.875, P = 0.011). CONCLUSION: Exhausted exercise training can increase the excitability of sympathetic nervous system, increase the secretion of catecholamines and increase the expression of UCP2 in myocardial mitochondria, which to a certain extent leads to the decrease of myocardial ATP content, which is involved in the energy metabolism disorder of exhausted myocardium caused by exhaustive exercise.