Wafi Ahmed M, Gao Lie, Zucker Irving H
Basic Medical Science Department, Faculty of Medicine, Jazan University, Jazan, Saudi Arabia.
Department of Anesthesiology, University of Nebraska Medical Center, Omaha, Nebraska, USA.
Physiol Rep. 2025 Aug;13(15):e70485. doi: 10.14814/phy2.70485.
Treadmill exercise tests assess aerobic capacity in chronic heart failure (CHF) mice, but subjective exhaustion criteria limit reproducibility. Elevated blood lactate (La) at exhaustion may provide an objective fatigue marker. This study evaluated La at exhaustion and the effects of exercise training (ExT) on resting La in CHF mice. Sham and coronary artery ligation-induced CHF mice were assigned to sedentary (Sed) or ExT groups. Blood La was measured from 0.7 μL tail vein samples at rest and at exhaustion during exercise tests after 8 weeks of ExT. Blood La at rest was slightly higher in CHF-Sed mice (3.33 ± 1.23 mmol/L) than in Sham-Sed mice (2.96 ± 0.42 mmol/L; p = 0.86). ExT slightly reduced La in CHF mice (2.55 ± 0.63 mmol/L; p = 0.34 vs. CHF-Sed), but differences were not significant. At exhaustion, blood La increased significantly across groups. Baseline La in CHF-Sed mice negatively correlated with running distance (r = -0.84, p = 0.03). Blood La levels at exhaustion offer a cost-effective method to confirm exhaustion criteria and enhance the reliability of exercise tests. La at rest may not reflect CHF severity or exercise adaptation but correlates better with exercise capacity in CHF.
跑步机运动试验可评估慢性心力衰竭（CHF）小鼠的有氧能力，但主观疲劳标准限制了其可重复性。运动至疲劳时血乳酸（La）升高可能提供一个客观的疲劳标志物。本研究评估了运动至疲劳时的La以及运动训练（ExT）对CHF小鼠静息La的影响。将假手术组和冠状动脉结扎诱导的CHF小鼠分为久坐组（Sed）或ExT组。在进行8周ExT后，于运动试验休息时和运动至疲劳时，从0.7μL尾静脉样本中测量血La。CHF-Sed小鼠静息时的血La（3.33±1.23 mmol/L）略高于假手术-Sed小鼠（2.96±0.42 mmol/L；p = 0.86）。ExT使CHF小鼠的La略有降低（2.55±0.63 mmol/L；与CHF-Sed组相比，p = 0.34），但差异不显著。运动至疲劳时，各组血La均显著升高。CHF-Sed小鼠的基线La与跑步距离呈负相关（r = -0.84，p = 0.03）。运动至疲劳时的血La水平提供了一种经济有效的方法来确定疲劳标准并提高运动试验的可靠性。静息La可能无法反映CHF的严重程度或运动适应性，但与CHF患者的运动能力相关性更好。
