Hamilton Karyn L, Staib Jessica L, Phillips Tracey, Hess Andrea, Lennon Shannon L, Powers Scott K
Department of Exercise and Sport Science, Center for Exercise Science, University of Florida, Gainesville, FL 32611, USA.
Free Radic Biol Med. 2003 Apr 1;34(7):800-9. doi: 10.1016/s0891-5849(02)01431-4.
Endurance exercise is associated with protection against myocardial ischemia/reperfusion (I/R) injury and has been shown to increase heat shock protein 72 (HSP72). Dietary antioxidants have also been reported to decrease I/R-induced injury. Because exercise and antioxidants may provide cardioprotection via different mechanisms, combining these countermeasures could provide additive protection. Alternatively, because exercise-induced oxidant production may promote expression of HSP72, antioxidants could attenuate exercise-induced HSP72 expression and decrease exercise-related cardioprotection. These experiments examined the individual and combined effects of exercise and antioxidants on myocardial I/R injury (in vivo). Rats receiving a mixed antioxidant diet or control diet were assigned to exercise or sedentary groups and randomized to receive: (i) short I/R (myocardial stunning), (ii) long I/R (myocardial infarction), or (iii) sham surgery. Antioxidants significantly increased total antioxidant capacity and attenuated exercise-related HSP72 accumulation. Nonetheless, during short I/R, exercise-trained animals demonstrated improved left ventricular developed pressure (LVDP), independent of diet. Further, antioxidants alone resulted in improved LVDP. Finally, compared to control diet/sedentary animals, both exercise groups (control and antioxidant diets) and the antioxidant diet/sedentary group sustained smaller infarctions. We conclude that exercise and antioxidants can independently provide protection against myocardial contractile dysfunction and infarction, and the combination of these two strategies does not enhance or inhibit the protection observed with each individual countermeasure.
耐力运动与预防心肌缺血/再灌注（I/R）损伤相关，并且已显示可增加热休克蛋白72（HSP72）。据报道，膳食抗氧化剂也可减少I/R诱导的损伤。由于运动和抗氧化剂可能通过不同机制提供心脏保护作用，联合使用这些对策可能会提供额外的保护。或者，由于运动诱导的氧化剂产生可能促进HSP72的表达，抗氧化剂可能会减弱运动诱导的HSP72表达并降低与运动相关的心脏保护作用。这些实验研究了运动和抗氧化剂对心肌I/R损伤（体内）的单独和联合作用。接受混合抗氧化剂饮食或对照饮食的大鼠被分为运动组或久坐组，并随机接受：（i）短时间I/R（心肌顿抑），（ii）长时间I/R（心肌梗死），或（iii）假手术。抗氧化剂显著提高了总抗氧化能力，并减弱了与运动相关的HSP72积累。尽管如此，在短时间I/R期间，运动训练的动物表现出左心室舒张末压（LVDP）改善，与饮食无关。此外，单独使用抗氧化剂也导致LVDP改善。最后，与对照饮食/久坐动物相比，两个运动组（对照饮食和抗氧化剂饮食）以及抗氧化剂饮食/久坐组的梗死面积均较小。我们得出结论，运动和抗氧化剂可独立提供针对心肌收缩功能障碍和梗死的保护作用，并且这两种策略的联合使用不会增强或抑制每种单独对策所观察到的保护作用。
