Force-frequency relationships of in vivo human and in vitro rat diaphragm using paired stimuli.
Force-frequency relationships of in vivo human and in vitro rat diaphragm using paired stimuli.
复制标题
使用配对刺激的体内人类和体外大鼠隔膜的力-频率关系。
DOI：
10.1183/09031936.93.06020211
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
F. Bellemare
中科院分区：
文献类型：
--
作者：
S. Yan;A. P. Gauthier;T. Similowski;R. Faltus;P. Macklem;F. Bellemare
在5名正常受试者中，以100 ms（10 Hz）至10 ms（100 Hz）的时间间隔对膈神经进行了成对刺激，同时在呼吸道关闭的情况下记录了呼气末肺容积放松时的经颅压力波动（Pdi，s）。在新鲜的横膈膜中，Pdi，s在10-20 Hz之间增加，并在20-30 Hz之间达到平台。膈肌疲劳降低Pdi，s在所有频率。Pdi，s被假定为两个连续响应（T1+T2）的和，T1在任何频率下都是恒定的并且等于单个抽搐，T2通过减法获得。我们发现，T2振幅，这是显着减少疲劳后，完全恢复正常后15分钟休息在高，而不是在低，刺激频率。因此，10 Hz与100 Hz的T2比值（T2（10/100））从疲劳前的1.33 +/- 0.05降至疲劳后的0.97 +/- 0.12，休息15分钟后降至0.81 +/- 0.06。在体外刺激和疲劳的离体大鼠隔条中也得到了类似的结果，发现T2（10/100）与10 Hz/100 Hz强直力（P10/100）之间呈高度线性关系（r = 0.94，p < 0.001）。我们的结论是，膈神经成对抽搐提供类似的信息时，从膈强直刺激的膈肌收缩性，T2（10/100）比的下降表明膈肌低频疲劳。
Supramaximal stimuli, with time intervals of 100 ms (10 Hz) to 10 ms (100 Hz), were delivered in pairs to the phrenic nerves, bilaterally, in five seated normal subjects, while transdiaphragmatic pressure swings (Pdi,s) were recorded at relaxed end-expiratory lung volume with airways closed. In fresh diaphragms, Pdi,s increased between 10-20 Hz and reached a plateau between 20-30 Hz. Diaphragmatic fatigue decreased Pdi,s at all frequencies. Pdi,s was assumed to be the sum of two successive responses (T1+T2), T1 being constant at any frequency and equal to a single twitch, T2 being obtained by subtraction. We found that T2 amplitude, which was significantly reduced after fatigue, was fully returned to normal after 15 min rest at high, not at low, stimulation frequencies. The ratio of T2 at 10 Hz over 100 Hz (T2(10/100)) thus decreased from 1.33 +/- 0.05 before fatigue to 0.97 +/- 0.12 after fatigue, and to 0.81 +/- 0.06 after 15 min rest. Similar results were obtained in isolated rat diaphragmatic strips stimulated and fatigued in vitro, from which we found a highly linear relationship (r = 0.94, p < 0.001) between the ratio of T2(10/100) and that of tetanic force at 10 Hz over 100 Hz (P10/100). We conclude that phrenic nerve paired twitches provide similar information when obtained from phrenic tetanic stimulation in terms of diaphragmatic contractility, and the decrease in T2(10/100) ratio indicates diaphragm low frequency fatigue.
哺乳动物膈肌的长度-张力关系。
DOI：
10.1152/jappl.1983.54.6.1681
发表时间：
1983
期刊：
Journal of applied physiology: respiratory, environmental and exercise physiology
影响因子：
--
作者：
McCully,KK;Faulkner,JA
通讯作者：
Faulkner,JA
茶碱在体外不会增加最大强直力或膈肌耐力。
DOI：
10.1152/jappl.1989.67.4.1655
发表时间：
1989
期刊：
Journal of applied physiology (Bethesda, Md. : 1985)
影响因子：
--
作者：
Reid,MB;Miller,MJ
通讯作者：
Miller,MJ