Delpech N, Jonville S, Denjean A
Laboratoire d'Analyse de la Performance Motrice Humaine, UPRES EA 2253, Faculté des Sciences du Sport, Université de Poitiers, 4 allée Jean Monnet, 86000 Poitiers, France.
Respir Physiol Neurobiol. 2003 Mar 28;134(3):231-7. doi: 10.1016/s1569-9048(02)00219-7.
This study aimed at determining whether twitch mouth pressure (TwPmo) induced by cervical magnetic stimulation (CMS) was sensitive to inspiratory muscle fatigue produced by whole body exercise (WBE) in normal subjects. Twenty subjects performed one or two of the following protocols: (i). cycling at 85% V(O(2),max) until exhaustion; (ii). inspiratory resistive load (IRL) breathing at 62% of maximal inspiratory pressure until task failure. In eight subjects, oesophageal (TwPoes), gastric (TwPga) and transdiaphragmatic (TwPdi) pressures were recorded. The TwPmo was significantly reduced (P<0.05) 20 min after both WBE and IRL, from 17.5+/-4.4 to 15.9+/-3.9 cmH(2)O and from 19.4+/-4.9 to 17.7+/-4.5 cmH(2)O, respectively. Subsequently to IRL, the TwPdi decrease was associated with a reduction in TwPoes/TwPga ratio; not after WBE. Independently of the mode of ventilatory loading, inspiratory muscle fatigue was detected. Thus, inspiratory muscle fatigue after WBE can be assessed in normal subjects with a noninvasive technique.
本研究旨在确定在正常受试者中，颈部磁刺激（CMS）诱发的抽搐口压力（TwPmo）是否对全身运动（WBE）产生的吸气肌疲劳敏感。20名受试者进行了以下一种或两种方案：（i）以85%的最大摄氧量（V（O₂）max）进行骑行直至力竭；（ii）以最大吸气压力的62%进行吸气阻力负荷（IRL）呼吸直至任务失败。在8名受试者中，记录了食管（TwPoes）、胃（TwPga）和跨膈（TwPdi）压力。在WBE和IRL后20分钟，TwPmo均显著降低（P<0.05），分别从17.5±4.4降至15.9±3.9 cmH₂O和从19.4±4.9降至17.7±4.5 cmH₂O。在IRL后，TwPdi的降低与TwPoes/TwPga比值的降低相关；而在WBE后则不然。无论通气负荷的模式如何，均检测到了吸气肌疲劳。因此，在正常受试者中，可以用一种非侵入性技术评估WBE后的吸气肌疲劳。
