Effects of exercise trainig and long-Term Survival in the BIO 14.6 cardiomyopathic Hamsters with chronic heart failure.

背景资料。尽管运动训练改善了缺血性心力衰竭的预后，但即使在动物模型中，对非缺血性心力衰竭的影响仍不清楚。由于衰竭心脏对交感神经刺激的代谢能力较强，运动训练可能会对非缺血性心力衰竭的预后产生不利影响，尽管运动训练对运动能力有积极影响。为了验证这一假设，我们检验了运动训练加或不加β-受体阻滞剂治疗对心肌病仓鼠运动能力和预后的影响。方法：研究方法。将87只30周龄BIO-14.6仓鼠随机分为3组：安静对照组(C组，n=27)、运动训练组(Ex组，n=30)和运动训练+β-受体阻滞剂组(ExB组，n=29)。在研究的第一天，进行了基线跑步机运动，以确定动物可以赶上的最大跑步速度。在第二天，运动训练和药物治疗开始。跑步机锻炼25分钟…试验组和试验组在160天内以40%的基础最大速度进行试验。试验组在试验期间口服心脏选择性β_1受体阻滞剂美托洛尔1 mg/kg/d。为了评估运动能力，在第30天和第90天进行最大跑步机运动。并对存活率进行评估。结果。C组和ExB组的最大跑台速度逐渐降低，而ExB组在30d时未观察到最初的下降，提示运动训练对运动能力有短期的益处。相反，在整个研究过程中，EX组的存活率低于C组(Kaplan-Meier，p&lt；.01)。ExB组的这种影响部分但显著减弱(p&lt；.005)。160d存活率C组为77%，ExB组为51%，而ExB组仅为33%。结论。尽管运动能力有短期益处，但运动训练加重了心肌病仓鼠的预后。这种作用可被心脏选择性β_1受体阻滞剂减弱。我们的结果提示，长期运动训练通过刺激β_1-肾上腺素能促进心肌病的进展。较少

Background. Although exercise training improves prognosis of ischemic heart failure, the effects on nonischemic heart failure are still unclear even in animal models. Because of metabolic bulnerability to sympathetic stimulation of failing hearts, exercise training may adversely affect the prognosis of nonischemic heart failure despite the beneficial effects on exercise capacity. To test the hypothesis, we examined the effect of exercise training with or without beta-blocker therapy on exercise capacity and prognosis of cardiomyopathic hamsters. Methods. We assigned 87 BIO 14.6 hamsters at 30 weeks of age into 3 groups ; sedentary control group (group C, n=27), exercise training group (group Ex, n=30), and exercise training plus beta-blocker group (group ExB, n=29). On Day 1 of the study, baseline treadmill exercise was performed to determine the maximal running speed at which animals could catch up. On Day 2, exercise training and medication were started. Treadmill exercise for 25 min … More at 40% of the baseline maximal speed was performed on every week days for 160 days in groups Ex and ExB.In group ExB, metoprolol of 1mg/kg/day, a cardioselective beta_1-blocker, was orally administered during the study. To assess exercise capacity, the maximal treadmill exercise was performed on Day 30 and Day 90. The survival rate was assessed . Results. The maximal treadmill speed gradually decreased in groups C and ExB.However, the initial decrease on Day 30 was not observed in group Ex, suggesting a short-term benefits of exercise training on exercise capacity. In contrast, the survival rate was lower throughout the study in group Ex than in group C (Kaplan-Meier, p<.01). This effect was partly but significantly attenuated in group ExB (p<.005). The survival rate on Day 160 was 77% in group C, 51% in group ExB, and only 33% in group Ex. Conclusion. Despite short-term benefits on exercise capacity, exercise training aggravated prognosis of cardiomyopathic hamsters. This effect was attenuated by cardioselective beta_1-blockade. Our results suggest that long-term exercise training promotes the progression of cardiomyopathy via Beta_1-adrenergic stimulation. Less