Modulation of biphasic rate of end-plate potential recovery in rat diaphragm.
Modulation of biphasic rate of end-plate potential recovery in rat diaphragm.
复制标题
大鼠膈肌终板电位恢复双相速率的调节。
DOI：
10.1002/mus.20245
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Moyer,Michelle
中科院分区：
文献类型：
--
作者：
vanLunteren,Erik;Moyer,Michelle
之前的隔膜研究发现，在间歇性刺激期间，增加刺激频率会加速肌内端板电位（EPP）振幅下降，而肌间EPP振幅下降与频率无关。我们假设，增加刺激频率加速衰竭恢复，并具有双相时间过程。细胞内记录在体外从大鼠膈神经-半膈制备。在100 ms刺激串和100 ms静止后，200 Hz刺激后的EPP振幅恢复显著大于20-100 Hz刺激后的EPP振幅恢复，尽管先前EPP下降较大。EPP振幅以双相模式恢复：具有快时间常数（0.03-0.06 s）的早期分量和具有慢时间常数（0.5-5 s）的晚期分量。增加先行刺激频率加速了早期成分，但刺激持续时间或脉冲数调制了晚期成分。当在涉及多个池和途径的囊泡再循环和补充模型的背景下解释时，这些数据表明，先行刺激频率主要调节快速途径。这可能对神经肌肉接头疾病（如重症肌无力）的呼吸衰竭的发展具有重要意义，此时放电持续时间和频率与呼吸模式的变化相关。肌肉神经，2005年
Previous diaphragm studies found that during intermittent stimulation, intratrain end‐plate potential (EPP) amplitude rundown is accelerated by increasing stimulation frequency, whereas intertrain EPP rundown is independent of frequency. We hypothesized that increasing stimulation frequency accelerates rundown recovery, and with a biphasic time course. Intracellular recordings were made in vitro from rat phrenic nerve–hemidiaphragm preparations. EPP amplitude recovery after a 100‐ms stimulation train and 100 ms of quiescence was significantly greater following stimulation at 200 HZthan at 20–100 HZ, despite larger antecedent EPP decline. EPP amplitudes recovered with a biphasic pattern: an early component with a fast time‐constant (0.03–0.06 s) and a late component with a slow time‐constant (0.5–5 s). Increased antecedent stimulation frequency accelerated the early component, but stimulation duration or pulse number modulated the late component. When interpreted in the context of vesicle recycling and replenishment models involving multiple pools and pathways, these data suggest that antecedent stimulation frequency regulates predominantly the fast pathways. This may have important implications for the development of respiratory failure in diseases of the neuromuscular junction, such as myasthenia gravis, when the firing duration and frequency are altered in association with changes in breathing pattern. Muscle Nerve, 2005