Harrison A P, Flatman J A
Department of Physiology, University of Aarhus, DK-8000 Aarhus C, Denmark.
Am J Physiol. 1999 Dec;277(6):R1646-53. doi: 10.1152/ajpregu.1999.277.6.R1646.
In isolated soleus muscles of 4-wk-old rats, M wave parameters were recorded with surface and deep recording electrodes and examined in relation to both twitch and tetanic force. Addition of ouabain (10(-5) M for 16 min) to isolated muscles caused an approximately 40% decrease in twitch amplitude and area (P < 0.01) that was associated with a 98% decrease in surface M wave amplitude, a 78% decrease in deep M wave amplitude (both P < 0.001), a 98% decrease in surface M wave area (P < 0.01), 48% of which occurred within 60 s of addition of ouabain (P < 0.05), and a 55% decrease in deep M wave area (P < 0.05). The decrease in twitch parameters on addition of ouabain was most closely correlated with deep M wave area (r = 0.92). Direct tetanic stimulation at a frequency of 30 Hz resulted in an initial potentiation of M waves, which was not seen at a frequency of 90 Hz. Instead, 90 Hz stimulation resulted in a prompt decrease in tetanic force that was correlated with a decrease in both deep M wave amplitude (r = 0.94; P < 0.01) and deep M wave area (r = 0.96; P < 0.01). It is concluded that simultaneous surface and deep recordings involving area and amplitude are fundamental to analysis of the effects of pharmacological agents on muscle performance and the use of M waves as predictors of muscle excitability.
在4周龄大鼠的离体比目鱼肌中，使用表面和深部记录电极记录M波参数，并将其与单收缩力和强直收缩力相关联进行检测。向离体肌肉中添加哇巴因（10⁻⁵ M，持续16分钟）导致单收缩幅度和面积降低约40%（P < 0.01），这与表面M波幅度降低98%、深部M波幅度降低78%（均P < 0.001）、表面M波面积降低98%（P < 0.01）相关，其中48%在添加哇巴因后60秒内出现（P < 0.05），深部M波面积降低55%（P < 0.05）。添加哇巴因后单收缩参数的降低与深部M波面积最密切相关（r = 0.92）。以30 Hz频率进行直接强直刺激导致M波最初增强，而在90 Hz频率时未观察到这种情况。相反，90 Hz刺激导致强直收缩力迅速降低，这与深部M波幅度降低（r = 0.94；P < 0.01）和深部M波面积降低（r = 0.96；P < 0.01）相关。结论是，同时进行涉及面积和幅度的表面和深部记录对于分析药物制剂对肌肉性能的影响以及将M波用作肌肉兴奋性预测指标至关重要。
