Lima Silvana Coca, Caierão Quélen Milani, Peviani Sabrina Messa, Russo Thiago Luiz, Somazz Marco César, Salvini Tania Fátima, Teodori Rosana Macher, Minamoto Viviane Balisardo
Department of Physical Therapy, Piracicaba Methodist University, Piracicaba, Brazil.
Am J Phys Med Rehabil. 2009 Feb;88(2):126-35. doi: 10.1097/PHM.0b013e318186bf6c.
Electrical stimulation is a procedure used to treat denervated muscles. The number of electrical stimulation sessions varies across muscle rehabilitation protocols, from daily to certain days throughout the week. The purpose of this study was to evaluate how muscle and nerve respond to different intervals of electrical stimulation applied to denervated muscle.
Denervation of rat gastrocnemius muscle was imposed via nerve crush, and electrical stimulation was applied to the muscle either daily (Monday through Friday) or on alternate days (Monday, Wednesday, and Friday). Four experimental groups were studied: denervated, denervated plus daily electrical stimulation, denervated plus alternate-day electrical stimulation, and control.
On the 12th day after nerve crush, levels of MyoD, myostatin, and atrogin-1 gene expression, as well as muscle fiber and nerve morphometry, were evaluated. Expression levels of all three genes were higher in the denervated group when compared with control. Also, expression levels of MyoD and myostatin were higher in denervated plus alternate-day electrical stimulation and denervated plus daily electrical stimulation groups when compared with denervated. The denervated plus daily electrical stimulation group had lower atrogin-1 expression, lower density of intramuscular connective tissue, and better morphometric nerve characteristics when compared with the denervated and denervated plus alternate-day electrical stimulation.
These results indicate that the responses of both muscle and nerve to electrical stimulation after muscle denervation depend on the intervals of electrical stimulation application.
电刺激是一种用于治疗失神经肌肉的方法。在不同的肌肉康复方案中，电刺激疗程的次数各不相同，从每天进行到一周中的特定几天进行。本研究的目的是评估肌肉和神经对应用于失神经肌肉的不同电刺激间隔的反应。
通过神经挤压造成大鼠腓肠肌失神经支配，并对肌肉进行每日（周一至周五）或隔日（周一、周三和周五）电刺激。研究了四个实验组：失神经组、失神经加每日电刺激组、失神经加隔日电刺激组和对照组。
在神经挤压后的第12天，评估了MyoD、肌生长抑制素和atrogin-1基因表达水平，以及肌肉纤维和神经形态学指标。与对照组相比，失神经组中所有这三个基因的表达水平均较高。此外，与失神经组相比，失神经加隔日电刺激组和失神经加每日电刺激组中MyoD和肌生长抑制素的表达水平更高。与失神经组和失神经加隔日电刺激组相比，失神经加每日电刺激组的atrogin-1表达较低，肌内结缔组织密度较低，神经形态学特征更好。
这些结果表明，肌肉失神经支配后肌肉和神经对电刺激的反应取决于电刺激应用的间隔。
