Number of contractions to maintain mass and force of a denervated rat muscle

Abstract

Within 5 weeks, denervated extensor digitorum longus (EDL) muscles of rats lose 66% of mass, 91% of force, and 76% of fiber cross-sectional area (CSA). We previously determined the parameters of electrical stimulation for denervated rat EDL muscles to generate tetanic contractions sufficient to maintain mass and force close to control values. Using these parameters, we tested the hypothesis that a range exists for number of contractions per day, below and above which values for mass, maximum force, and fiber CSA are lower than values for innervated control muscles. For 5 weeks, denervated EDL muscles were stimulated to generate between 25 and 5000 contractions daily with contractions separated by constant intervals of rest, repeated 24 h per day. Force was not maintained with fewer than 200 or more than 800 contractions daily, whereas mass and fiber CSA were not maintained with fewer than 50 contractions daily. Protocols of stimulation that maintain muscle mass and force during prolonged periods of denervation may minimize problems clinically associated with denervation atrophy.

Effect of electrical stimulation of the cranial tibial muscle after end-to-side neurorrhaphy of the peroneal nerve in rats

“…The current intensity was also determined by previous studies where we found the ideal point for muscular contraction. In our literature review, we found studies using intensity ranges from 1 mA to 5 mA , however, these studies used anesthetized rats or implanted electrodes 24,25,27,28,36 .…”

“…In addition to the metabolic effects, ES also helps in minimizing the effects of immobilization, minimizing the reduction of cross-sectional area, interstitial fibrosis and deficiency of blood supply 22 . ES promotes increased effectiveness of contractile muscle fibers, enabling thus the dynamics of uptake via GLUT-4, glucose metabolism and activity of cellular metabolic pathways [23][24][25][26][27][28] .…”

High-voltage electrical stimulation improves nerve regeneration after sciatic crush injury

“…The complete motor function recovery after nerve injury requires the occurrence of morphological and physiological processes that determine the return of motoneurons electrical activity on the involved muscles 9 . The use of muscle electrical stimulation after peripheral nerve injury for the prevention of progressive muscle atrophy, although there is weak evidence that, can be beneficial when applied under favorable conditions 10 . This fact reinforces the importance of controlled trials for the establishment of new treatment strategies to stimulate peripheral nerve regeneration.…”

Effect of locomotor training on muscle performance in the context of nerve–muscle communication dysfunction

“…Of note, LT was not able to reduce the deficit in muscle maximal force and atrophy observed after nerve injury or AChE deficiency, possibly because the program of muscle contractions resulting from LT is not appropriate. 37 We also observed that reduced muscle use aggravated the muscle deficit in maximal force and atrophy after nerve injury. Moreover, we found that LT and muscle disuse did not change muscle functional innervation.…”