CENTRAL COMPONENTS OF DIAPHRAGMATIC FATIGUE ASSESSED BY PHRENIC-NERVE STIMULATION
CENTRAL COMPONENTS OF DIAPHRAGMATIC FATIGUE ASSESSED BY PHRENIC-NERVE STIMULATION
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DOI：
10.1152/jappl.1987.62.3.1307
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发表时间：
1987-03-01
影响因子：
3.3
通讯作者：
BIGLANDRITCHIE, B
中科院分区：
文献类型：
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作者：
BELLEMARE, F;BIGLANDRITCHIE, B
神经驱动失效导致的脑疲劳的程度已经使用抽动阻断进行了研究。通过反复产生最大Pdi（Pdimax）的50%或75%的经颅压（Pdi）直到apmax来诱导疲劳。在目标Pdi不能再达到（Tlim）之后10分钟。定期向膈神经递送最大双侧电击引起呼吸之间的Pdi抽搐（Tr）并叠加在自主收缩（Ts）上。比率[1 - Ts/Tr]提供了中枢神经系统肌肉激活程度的指数，随着疲劳的发展而增加。然而，当所有收缩都涉及最大的努力时，在Tlim和超过Tlim时仍然可以检测到叠加的抽搐。在非疲劳肌肉的最大收缩中没有看到它们。最初，膈肌肌电图增加，但随后下降。未见神经肌肉传递受损。我们的结论是，在Tlim及以后，Pdimax的减少约有一半是由于中央运动驱动的减少;其余的是由于外周肌肉收缩失败。在50%Pdimax动态收缩期间没有明显的疲劳。
The extent to which diaphragmatic fatigue results from failure of neural drive has been investigated using twitch occlusion. Fatigue was induced by repeatedly generating transdiaphragmatic pressures (Pdi) of either 50 or 75% maximum Pdi (Pdimax) until .apprx. 10 min after the target Pdi could no longer be reached (Tlim). Maximal bilateral shocks delivered periodically to the phrenic nerves elicited Pdi twitches between breaths (Tr) and superimposed on the voluntary contractions (Ts). The ratio [1 - Ts/Tr], which provides an index of the degree of central nervous system muscle activation, increased as fatigue developed. However, superimposed twitches were still detectable at and beyond Tlim when all contractions involved maximal efforts. They were not seen in maximal contractions of the unfatigued muscle. Initially, the diaphragm electromyogram increased, but then declined. No impairment of neuromuscular transmission was seen. We conclude that at and beyond Tlim about one-half of the reduction in Pdimax resulted from reduced central motor drive; the remainder resulted from peripheral muscle contractile failure. No fatigue was evident during 50% Pdimax dynamic contractions.