Ohshima T, Fujii Y, Toyooka H, Udagawa T, Yokoyama K, Amaha K
Department of Anesthesia, Tokyo Metropolitan, Hiroo General Hospital.
Masui. 1990 Oct;39(10):1288-93.
The role of impairment of neuromuscular transmission in fatigued canine diaphragm was investigated by comparing the function of fatigued diaphragm with that of neuromuscular junction (NMJ)-blocked diaphragm. Diaphragmatic fatigue was produced by intermittent supramaximal stimulation of bilateral phrenic nerves. Partial NMJ blockade was obtained by vecuronium bromide administered intravenously. During control study, no fade was observed either in integrated diaphragmatic electric activity (Edi) or transdiaphragmatic pressure (Pdi). In fatigued diaphragm, Edi generated by 100 Hz showed a remarkable fade. The fade was prominent in high frequency fatigue. In NMJ-blocked diaphragm, fade was observed in Pdi as well as in Edi produced by 100 Hz. The fade of Edi by 100 Hz was prominent. In low frequency fatigue, both Pdi and Edi produced by 20 Hz test stimulation were significantly lower than control values. These results show that in addition to impairment of excitation-contraction coupling, neuromuscular blockade is involved, at least in part, in low frequency diaphragmatic fatigue.
通过比较疲劳膈肌与神经肌肉接头（NMJ）阻断膈肌的功能，研究了神经肌肉传递受损在疲劳犬膈肌中的作用。通过间歇性超强刺激双侧膈神经来产生膈肌疲劳。静脉注射溴化维库溴铵可实现部分NMJ阻断。在对照研究期间，整合膈肌电活动（Edi）或跨膈压（Pdi）均未观察到衰减。在疲劳膈肌中，由100Hz产生的Edi出现显著衰减。该衰减在高频疲劳中尤为明显。在NMJ阻断的膈肌中，Pdi以及由100Hz产生的Edi中均观察到衰减。由100Hz产生的Edi衰减尤为明显。在低频疲劳中，由20Hz测试刺激产生的Pdi和Edi均显著低于对照值。这些结果表明，除了兴奋 - 收缩偶联受损外，神经肌肉阻断至少部分参与了低频膈肌疲劳。
