Stretching and electrical stimulation regulate the metalloproteinase-2 in rat denervated skeletal muscle

Abstract

While stretching is the main stimulus leading to the activation of MMP-2, both ES and stretching are able to increase MMP-2 gene expression in rat denervated muscle suggesting ECM remodeling.

Effects of 660 and 780 nm low‐level laser therapy on neuromuscular recovery after crush injury in rat sciatic nerve

“…Muscle and nerve extraction and zymographic analysis were performed according to current methodology 25,26. The molecular mass of gelatinolytic activities was determined by comparison to the reference protein molecular weight marker, PageRuler Prestained Protein Ladder (Fermentas Life Sciences, Burlington, ON, Canada).…”

Effects of electrical stimulation and stretching on the adaptation of denervated skeletal muscle: implications for physical therapy

“…A series of studies from our laboratory and from collaborators have investigated the effects of ES on the adaptation of denervated muscle in animal models 32,[39][40][41][42][43] . The use of animal models allows a greater control over the variables and avoids important ethical issues involved in this type of study in humans.…”

“…However, the reduction of expression of these genes was not sufficient to protect the muscle mass, that is, the ES was not able to stop the loss of muscle mass due to denervation 39,41 . These experiments used a exponential monopolar electric current with pulse duration equal to twice the chronaxie value, being the stimulation performed on alternated days 39,40 or daily 41,42 . An important aspect to be observed by researchers and therapists while assessing the effects of ES on the denervated muscle is to consider, besides the effectiveness of treatment on muscle atrophy, the safety of electrical stimulation on the reinnervation process.…”

“…In the attempt to investigate the effect of a period of stretching (12 minutes) in the treatment of the denervated muscle during the first week after denervation, recent studies from our laboratory identified an increased in the activity and in the gene expression of MMP-2 in the denervated muscle, suggesting therefore a role in remodeling the ECM 42 and a decrease in the accumulation of gene expression related to muscle atrophy, such as atrogin-1, MuRF-1 and miostatin 41 . However, this stimulation was not sufficient to prevent the atrophy of the muscle fiber after denervation.…”

Electrical Stimulation of Denervated Rat Skeletal Muscle Retards Capillary and Muscle Loss in Early Stages of Disuse Atrophy

“…The activity of MMP-2 has been reported to increase following DN and limb immobilization [24, 25] or muscle stretching in the denervated muscle [26]. Similarly, chronic ES and exercise training elevate MMP-2 expression to various levels depending on intensity [27, 28].…”