scholarly journals The effect of repeated bouts of electrical stimulation‐induced muscle contractions on proteolytic signaling in rat skeletal muscle

2021 ◽  
Vol 9 (9) ◽  
Author(s):  
Takaya Kotani ◽  
Junya Takegaki ◽  
Yuki Tamura ◽  
Karina Kouzaki ◽  
Koichi Nakazato ◽  
...  
2003 ◽  
Vol 94 (3) ◽  
pp. 876-882 ◽  
Author(s):  
Thomas J. McLoughlin ◽  
Eleni Mylona ◽  
Troy A. Hornberger ◽  
Karyn A. Esser ◽  
Francis X. Pizza

We determined the effect of muscle contractions resulting from high-frequency electrical stimulation (HFES) on inflammatory cells in rat tibialis anterior (TA), plantaris (Pln), and soleus (Sol) muscles at 6, 24, and 72 h post-HFES. A minimum of four and a maximum of seven rats were analyzed at each time point. HFES, applied to the sciatic nerve, caused the Sol and Pln to contract concentrically and the TA to contract eccentrically. Neutrophils were higher ( P < 0.05) at 6 and 24 h after HFES in the Sol, Pln, and TA muscles relative to control muscles. ED1+ macrophages in the Pln were elevated at 6 and 24 h after HFES and were also elevated in the Sol and TA after HFES relative to controls. ED2+ macrophages in the Sol and TA were elevated at 24 and 72 h after HFES, respectively, and were also elevated in the Pln after HFES relative to controls. In contrast to the TA muscles, the Pln and Sol muscles showed no gross histological abnormalities. Collectively, these data indicate that both eccentric and concentric contractions can increase inflammatory cells in muscle, regardless of whether overt histological signs of injury are apparent.


2001 ◽  
Vol 280 (5) ◽  
pp. E677-E684 ◽  
Author(s):  
Nicolas Musi ◽  
Tatsuya Hayashi ◽  
Nobuharu Fujii ◽  
Michael F. Hirshman ◽  
Lee A. Witters ◽  
...  

The AMP-activated protein kinase (AMPK) has been hypothesized to mediate contraction and 5-aminoimidazole-4-carboxamide 1-β-d-ribonucleoside (AICAR)-induced increases in glucose uptake in skeletal muscle. The purpose of the current study was to determine whether treadmill exercise and isolated muscle contractions in rat skeletal muscle increase the activity of the AMPKα1 and AMPKα2 catalytic subunits in a dose-dependent manner and to evaluate the effects of the putative AMPK inhibitors adenine 9-β-d-arabinofuranoside (ara-A), 8-bromo-AMP, and iodotubercidin on AMPK activity and 3- O-methyl-d-glucose (3-MG) uptake. There were dose-dependent increases in AMPKα2 activity and 3-MG uptake in rat epitrochlearis muscles with treadmill running exercise but no effect of exercise on AMPKα1 activity. Tetanic contractions of isolated epitrochlearis muscles in vitro significantly increased the activity of both AMPK isoforms in a dose-dependent manner and at a similar rate compared with increases in 3-MG uptake. In isolated muscles, the putative AMPK inhibitors ara-A, 8-bromo-AMP, and iodotubercidin fully inhibited AICAR-stimulated AMPKα2 activity and 3-MG uptake but had little effect on AMPKα1 activity. In contrast, these compounds had absent or minimal effects on contraction-stimulated AMPKα1 and -α2 activity and 3-MG uptake. Although the AMPKα1 and -α2 isoforms are activated during tetanic muscle contractions in vitro, in fast-glycolytic fibers, the activation of AMPKα2-containing complexes may be more important in regulating exercise-mediated skeletal muscle metabolism in vivo. Development of new compounds will be required to study contraction regulation of AMPK by pharmacological inhibition.


PLoS ONE ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. e0172761
Author(s):  
Paola Jaramillo Cienfuegos ◽  
Adam Shoemaker ◽  
Robert W. Grange ◽  
Nicole Abaid ◽  
Alexander Leonessa

2015 ◽  
Vol 40 (11) ◽  
pp. 1137-1142 ◽  
Author(s):  
Yu Kitaoka ◽  
Riki Ogasawara ◽  
Yuki Tamura ◽  
Satoshi Fujita ◽  
Hideo Hatta

It is well known that resistance exercise increases muscle protein synthesis and muscle strength. However, little is known about the effect of resistance exercise on mitochondrial dynamics, which is coupled with mitochondrial function. In skeletal muscle, mitochondria exist as dynamic networks that are continuously remodeling through fusion and fission. The purpose of this study was to investigate the effect of acute and chronic resistance exercise, which induces muscle hypertrophy, on the expression of proteins related to mitochondrial dynamics in rat skeletal muscle. Resistance exercise consisted of maximum isometric contraction, which was induced by percutaneous electrical stimulation of the gastrocnemius muscle. Our results revealed no change in levels of proteins that regulate mitochondrial fission (Fis1 and Drp1) or fusion (Opa1, Mfn1, and Mfn2) over the 24-h period following acute resistance exercise. Phosphorylation of Drp1 at Ser616 was increased immediately after exercise (P < 0.01). Four weeks of resistance training (3 times/week) increased Mfn1 (P < 0.01), Mfn2 (P < 0.05), and Opa1 (P < 0.01) protein levels without altering mitochondrial oxidative phosphorylation proteins. These observations suggest that resistance exercise has little effect on mitochondrial biogenesis but alters the expression of proteins involved in mitochondrial fusion and fission, which may contribute to mitochondrial quality control and improved mitochondrial function.


2018 ◽  
Vol 1 (5) ◽  
Author(s):  
Aishan Liu ◽  
Fangming Liu ◽  
Xuelin Zhang ◽  
Yarong Wang ◽  
Mei Kong ◽  
...  

  Objective The purpose of this study was to evaluate the effect of acupuncture intervention on the changes of cytoplasmic and mitochondrial Ca2+ concentration following eccentric contractions (ECC) in rat skeletal muscle. Methods 24 healthy male Wistar rats were randomly divided into 4 groups: control group (C, n=6)、electrical stimulation group (E, n=6)、electrical stimulation group with acupuncture intervention (EA, n=6)、electrical stimulation group with acupuncture +TRP channel inhibitor Gd3+ (EAI, n=6). The animal model of eccentric induced skeletal muscle injury was established by electrical stimulation on spinotrapezius muscle of anaesthetised rats in vivo, that is to say, the intact spinotrapezius muscle of adult Wistar rats was exteriorized, and tetanic eccentric contractions (100 Hz, 10 sets of 50 contractions) were elicited by electrical stimulation during synchronized muscle stretch of 10% resting muscle length. Cytoplasmic Ca2+ accumulation were determined by loading the muscle with fura 4-AM using fluorescent imaging in vivo, and mitochondrial Ca2+ concentration were determined by loading the muscle with fura 2-AM using fluorescent imaging in vitro, and recorded changes of muscle maximum tetanic force. Results (1) In vivo, compared with the C , cytoplasmic Ca2+ accumulation increased more rapidly during ECC in the E (P < 0.001). Acupuncture intervention significantly reduced cytosolic Ca2+ accumulation in the EA compared with the E (P < 0.01), and we discovered that muscle deformation generated by acupuncture intervention induced a robust Ca2+ spark response confined in close spatial proximity to the sarcolemmal membrane in intact muscle fibers. Although no significant differences between the EA and EAI, Gd3+ abolished the majority of cytoplasmic Ca2+ accumulation decrease during ECC in the EAI and a robust Ca2+ spark response disappeared compared with the EA. (2) In vitro, compared with the C, mitochondrial Ca2+ concentration did not elevations in MCC in the E. EA cytoplasmic Ca2+ increased rapidly above the C and E (P < 0.01), respectively, but EAI significantly attenuated the increases in  mitochondrial Ca2+ concentration compared with the EA (P < 0.01). (3). Compared with the C , maximum tetanic force was significantly lower in the E after ECC (P < 0.01). EA maximum tetanic force increased rapidly compared with the E after ECC (P < 0.05), but EAL abolished the majority maximum tetanic force increase after ECC (P < 0.05). Conclusions (1)Eccentric contraction caused cytoplasmic Ca2+ accumulation, but  mitochondrial Ca2+ concentration decrease. (2)Acupuncture can effectively reduce cytosolic Ca2+ overload, following by mitochondrial Ca2+ concentration increase , which in turn abnormally high cytoplasmic Ca2+ levels are buffed by the mitochondria, and improved muscle function, and the effect was associated to the TRP channels.  


2013 ◽  
Vol 27 (S1) ◽  
Author(s):  
Hiroaki Eshima ◽  
Yoshinori Tanaka ◽  
Takashi Sonobe ◽  
Tadakatsu Inagaki ◽  
David C Poole ◽  
...  

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