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

背景虽然运动训练可以改善缺血性心力衰竭的预后，但其对非缺血性心力衰竭的影响在动物模型中仍不清楚。由于衰竭心脏对交感神经刺激的代谢增强，运动训练可能对非缺血性心力衰竭的预后产生不利影响，尽管对运动能力有有益作用。为了验证这一假设，我们研究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.我们将87只30周龄的BIO 14.6仓鼠分为3组：久坐对照组（C组，n=27）、运动训练组（Ex组，n=30）和运动训练加β受体阻滞剂组（ExB组，n=29）。在研究的第1天，进行基线跑步机运动以确定动物可以追赶的最大跑步速度。第2天，开始运动训练和药物治疗。跑步机运动25分钟 ...更多信息 Ex组和ExB组每周1次，以基础最大速度的40%运动，共160天。ExB组在运动过程中口服心脏选择性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。评估存活率。结果C组和ExB组的最大跑台速度逐渐降低。然而，在Ex组中未观察到第30天的初始降低，表明运动训练对运动能力的短期益处。相反，在整个研究中，Ex组的存活率低于C组（Kaplan-Meier，p<0.01）。ExB组的这种效应部分但显著减弱（p<.005）。第160天的存活率在C组中为77%，在ExB组中为51%，而在Ex组中仅为33%。结论尽管运动能力短期受益，运动训练加重心肌病仓鼠的预后。心脏选择性β_1受体阻滞剂可减弱这种作用。我们的研究结果表明，长期运动训练通过β_1-肾上腺素能刺激促进心肌病的进展。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