Cyclic muscle twitch contraction inhibits immobilization-induced muscle contracture and fibrosis in rats

Abstract

We investigated the effects of cyclic muscle twitch contraction caused by neuromuscular electrical stimulation (NMES) on immobilization-induced muscle contracture and fibrosis in rats. Twenty-nine rats were divided into control, immobilization, and immobilization with muscle contraction groups. The ankle joints of the immobilization and muscle contraction rats were fixed in full plantar flexion with a plaster cast for 4 weeks. In the muscle contraction group, cyclic muscle twitch contraction of the soleus muscle was induced using a commercial device (1 Hz, 4 ± 2 mA, 60 min/day, 5 times/week) with the ankle joint immobilized. The dorsiflexion range of ankle joint motion in the muscle contraction group was significantly greater than that in the immobilization group. The expressions of fibrosis-related genes (i.e., hypoxia inducible factor-1α, transforming growth factor-β1, α-smooth muscle actin, and types I and III collagen) were significantly decreased in the muscle contraction group compared to the immobilization group. The fluorescence intensities of type I and type III collagen in the perimysium and endomysium in the muscle contraction group were significantly decreased compared to the immobilization group. These results suggest that cyclic muscle twitch contraction induced by NMES might alleviate skeletal muscle fibrosis, reducing immobilization-induced muscle contracture.

Muscle does not drive persistent posttraumatic elbow contracture in a rat model

“…5 Previous studies reported increased ECM production (i.e., Col I and III) in muscle after IM. 25,27 In our rat model of elbow contracture, passive stress was increased at 42 IM in injured limb muscle, but was not supported by a significant increase in ECM area fraction (Fig. 3C).…”

“…Atrophic changes (i.e., decreased muscle length and fiber area) were expected after IM because previous studies reported muscle atrophy in the rodent ankle after 4-6 weeks of ankle IM. 25,27 Thus, decreased muscle length and fiber area likely contributed to the decreased active force generation at 42 IM ( Figs. 1-3), which could reduce joint torque and ultimately contribute to the decreased joint motion at 42 IM.…”

Angiotensin-converting-enzyme inhibitor prevents skeletal muscle fibrosis in myocardial infarction mice

“…Previous studies have mainly reported that skeletal muscle fibrosis is induced by gene mutations [5], mechanical and chemical injury [35], and fixed inactivity [36]. We showed that skeletal muscle fibrosis and the level of hydroxyproline, a key marker of collagen content, were increased in MI model mice (Fig.…”

The mechanisms and treatments of muscular pathological changes in immobilization-induced joint contracture: A literature review

“… 47 Similarly, another experimental study that used of cyclic muscle twitch contraction to inhibit immobilization-induced muscle contracture and fibrosis in rats also found the similar conclusion. 48 The results showed that the expression of type I and type III collagen in the soleus perimysium of the immobilization group was significantly higher than that of the control group, and the expression of type I collagen in the soleus endometrium of the immobilization group was also significantly higher than that of the control group. 48 …”