Sung Dong-Jun, Jeon Yong-Kyun, Choi Jaeil, Kim Bokyung, Golpasandi Shadi, Park Sang Woong, Oh Seung-Bum, Bae Young Min
Department of Sport and Health Studies, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea.
Sports Convergence Institute, Chungju 27478, Korea.
Korean J Physiol Pharmacol. 2022 Sep 1;26(5):313-323. doi: 10.4196/kjpp.2022.26.5.313.
Atrial fibrillation (AF) is the most common supraventricular arrhythmia, and it corresponds highly with exercise intensity. Here, we induced AF in mice using acetylcholine (ACh)-CaCl for 7 days and aimed to determine the appropriate exercise intensity (no, low, moderate, high) to protect against AF by running the mice at different intensities for 4 weeks before the AF induction by ACh-CaCl. We examined the AF-induced atrial remodeling using electrocardiogram, patch-clamp, and immunohistochemistry. After the AF induction, heart rate, % increase of heart rate, and heart weight/body weight ratio were significantly higher in all the four AF groups than in the normal control; highest in the high-ex AF and lowest in the low-ex (lower than the no-ex AF), which indicates that low-ex treated the AF. Consistent with these changes, G protein-gated inwardly rectifying K currents, which were induced by ACh, increased in an exercise intensity-dependent manner and were lower in the low-ex AF than the no-ex AF. The peak level of Ca current (at 0 mV) increased also in an exercise intensity-dependent manner and the inactivation time constants were shorter in all AF groups except for the low-ex AF group, in which the time constant was similar to that of the control. Finally, action potential duration was shorter in all the four AF groups than in the normal control; shortest in the high-ex AF and longest in the low-ex AF. Taken together, we conclude that low-intensity exercise protects the heart from AF, whereas high-intensity exercise might exacerbate AF.
心房颤动（AF）是最常见的室上性心律失常，且与运动强度高度相关。在此，我们使用乙酰胆碱（ACh）-氯化钙在小鼠中诱导房颤7天，并旨在通过在ACh-氯化钙诱导房颤前让小鼠以不同强度跑步4周，来确定预防房颤的合适运动强度（无、低、中、高）。我们使用心电图、膜片钳和免疫组织化学方法检测了房颤诱导的心房重塑。房颤诱导后，所有四个房颤组的心率、心率增加百分比和心脏重量/体重比均显著高于正常对照组；在高运动强度房颤组中最高，在低运动强度房颤组中最低（低于无运动强度房颤组），这表明低运动强度治疗了房颤。与这些变化一致，由ACh诱导的G蛋白门控内向整流钾电流以运动强度依赖的方式增加，且在低运动强度房颤组中低于无运动强度房颤组。钙电流（在0 mV时）的峰值水平也以运动强度依赖的方式增加，除低运动强度房颤组外，所有房颤组的失活时间常数均较短，低运动强度房颤组的时间常数与对照组相似。最后，所有四个房颤组的动作电位时程均短于正常对照组；在高运动强度房颤组中最短，在低运动强度房颤组中最长。综上所述，我们得出结论，低强度运动可保护心脏免受房颤影响，而高强度运动可能会加重房颤。
