Inspiratory muscle fatigue increases sympathetic vasomotor outflow and blood pressure during submaximal exercise
Inspiratory muscle fatigue increases sympathetic vasomotor outflow and blood pressure during submaximal exercise
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DOI：
10.1152/ajpregu.00006.2012
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发表时间：
2012-05-01
影响因子：
2.8
通讯作者：
Saito, Mitsuru
中科院分区：
文献类型：
--
作者：
Katayama, Keisho;Iwamoto, Erika;Saito, Mitsuru
[10]黄文忠，张文忠，张文忠.吸气肌疲劳增加交感神经血管流出和血压在次极量运动。Am J Physiol Regul Integr Comp Physiol 302：R1167-R1175，2012年。首次发表于2012年3月28日; doi：10.1152/ajpregu.00006.2012.-本研究旨在探讨吸气肌疲劳对次极量运动时肌肉交感神经活动（MSNA）和血压（BP）反应的影响。我们假设，吸气肌疲劳会引起交感血管收缩剂流出和动态腿部运动过程中血压的增加。受试者进行了四次次最大运动试验：两次是最大吸气压（PImax）试验，两次是MSNA试验。在PImax测试中，受试者在40%峰值氧摄取量下使用自行车测力计以半卧位进行两次10分钟的运动[自主呼吸5分钟，伴或不伴吸气阻力呼吸5分钟（呼吸频率：60次呼吸/分钟，吸气和呼气时间均设定为0.5 s）]。在运动前和运动后即刻，估计PImax。在MSNA测试中，受试者进行两次15分钟的运动（自主呼吸5分钟，有或没有吸气阻力呼吸5分钟，自主呼吸5分钟）。通过手肘右侧正中神经的显微神经造影术记录MSNA。运动后，阻力性呼吸的PImax降低，而无阻力时则无变化。在吸气阻力呼吸运动期间出现MSNA爆发频率（BF）的时间依赖性增加，伴随舒张压（DBP）的增加（有阻力：MSNA BF +83.4%; DBP +23.8%;无阻力：MSNA BF +19.2%; DBP-0.4%，来自运动期间的自主呼吸）。这些结果表明，吸气肌疲劳引起肌肉交感神经血管流出和血压增加动态腿部运动在温和的强度。
Katayama K, Iwamoto E, Ishida K, Koike T, Saito M. Inspiratory muscle fatigue increases sympathetic vasomotor outflow and blood pressure during submaximal exercise. Am J Physiol Regul Integr Comp Physiol 302: R1167-R1175, 2012. First published March 28, 2012; doi:10.1152/ajpregu.00006.2012.-The purpose of this study was to elucidate the influence of inspiratory muscle fatigue on muscle sympathetic nerve activity (MSNA) and blood pressure (BP) response during submaximal exercise. We hypothesized that inspiratory muscle fatigue would elicit increases in sympathetic vasoconstrictor outflow and BP during dynamic leg exercise. The subjects carried out four submaximal exercise tests: two were maximal inspiratory pressure (PImax) tests and two were MSNA tests. In the PImax tests, the subjects performed two 10-min exercises at 40% peak oxygen uptake using a cycle ergometer in a semirecumbent position [spontaneous breathing for 5 min and with or without inspiratory resistive breathing for 5 min (breathing frequency: 60 breaths/min, inspiratory and expiratory times were each set at 0.5 s)]. Before and immediately after exercise, PImax was estimated. In MSNA tests, the subjects performed two 15-min exercises (spontaneous breathing for 5 min, with or without inspiratory resistive breathing for 5 min, and spontaneous breathing for 5 min). MSNA was recorded via microneurography of the right median nerve at the elbow. PImax decreased following exercise with resistive breathing, whereas no change was found without resistance. The time-dependent increase in MSNA burst frequency (BF) appeared during exercise with inspiratory resistive breathing, accompanied by an augmentation of diastolic BP (DBP) (with resistance: MSNA, BF +83.4%; DBP, +23.8%; without resistance: MSNA BF, +19.2%; DBP, -0.4%, from spontaneous breathing during exercise). These results suggest that inspiratory muscle fatigue induces increases in muscle sympathetic vasomotor outflow and BP during dynamic leg exercise at mild intensity.