Lexell J, Jarvis J, Downham D, Salmons S
Department of Human Anatomy and Cell Biology, University of Liverpool, UK.
Cell Tissue Res. 1993 Aug;273(2):357-62. doi: 10.1007/BF00312838.
The aim of this study was to determine whether muscle fibre degeneration brought about by chronic low-frequency electrical stimulation was related to the pattern and frequency of stimulation. Rabbit fast-twitch muscles, tibialis anterior and extensor digitorum longus, were stimulated for 9 days with pulse trains ranging in frequency from 1.25 Hz to 10 Hz. Histological data from these muscles were analysed with multivariate statistical techniques. At the lower stimulation frequencies there was a significantly lower incidence of degenerating muscle fibres. Fibres that reacted positively with an antineonatal antibody were most numerous in the sections that revealed the most degeneration. The dependence on frequency was generally similar for the two muscles, but the extensor digitorum longus muscles showed more degeneration than the tibialis anterior at every frequency. Muscles subjected to 10 Hz intermittent stimulation showed significantly less degeneration than muscles stimulated with 5 Hz continuously, although the aggregate number of impulses delivered was the same. The incidence of degeneration in the extensor digitorum longus muscles stimulated at 1.25 Hz was indistinguishable from that in control, unstimulated muscles; for the tibialis anterior muscles, this was also true for stimulation at 2.5 Hz. We conclude that damage is not an inevitable consequence of electrical stimulation. The influence of pattern and frequency on damage should be taken into account when devising neuromuscular stimulation regimes for clinical use.
本研究的目的是确定慢性低频电刺激引起的肌纤维退变是否与刺激模式和频率有关。用频率范围为1.25Hz至10Hz的脉冲序列对家兔的快肌（胫骨前肌和趾长伸肌）进行9天的刺激。运用多元统计技术分析这些肌肉的组织学数据。在较低的刺激频率下，退变肌纤维的发生率显著较低。在显示退变最严重的切片中，与抗新生抗体呈阳性反应的纤维数量最多。这两块肌肉对频率的依赖性总体相似，但在每个频率下，趾长伸肌的退变都比胫骨前肌更严重。尽管传递的脉冲总数相同，但接受10Hz间歇刺激的肌肉比持续接受5Hz刺激的肌肉退变明显更少。以1.25Hz刺激的趾长伸肌的退变发生率与未受刺激的对照肌肉无明显差异；对于胫骨前肌，在2.5Hz刺激时也是如此。我们得出结论，损伤并非电刺激的必然结果。在设计用于临床的神经肌肉刺激方案时，应考虑刺激模式和频率对损伤的影响。
