EFFECT OF ELECTRICAL STIMULATION UPON BLOOD FLOW AND TEMPERATURE OF SKELETAL MUSCLE

1953 ◽  
Vol 32 (1) ◽  
pp. 22???26 ◽  
Author(s):  
BARBARA F. RANDALL ◽  
C. J. IMIG ◽  
H. M. HINES
2019 ◽  
Vol 127 (5) ◽  
pp. 1288-1296
Author(s):  
Madoka Yoshikawa ◽  
Takeshi Morifuji ◽  
Tomohiro Matsumoto ◽  
Noriaki Maeshige ◽  
Minoru Tanaka ◽  
...  

This study aimed to clarify the effects of a combined treatment comprising blood flow restriction and low-current electrical stimulation on skeletal muscle hypertrophy in rats. Male Wistar rats were divided into control (Cont), blood flow restriction (Bfr), electrical stimulation (Es), or Bfr with Es (Bfr + Es) groups. Pressure cuffs (80 mmHg) were placed around the thighs of Bfr and Bfr + Es rats. Low-current Es was applied to calf muscles in the Es and Bfr + Es rats. In experiment 1, a 1-day treatment regimen (5-min stimulation, followed by 5-min rest) was delivered four times to study the acute effects. In experiment 2, the same treatment regimen was delivered three times/wk for 8 wk. Body weight, muscle mass, changes in maximal isometric contraction, fiber cross-sectional area of the soleus muscle, expression of phosphorylated and total-ERK1/2, phosphorylated-rpS6 Ser235/236, phosphorylated and total Akt, and phosphorylated-rpS6 Ser240/244 were measured. Bfr and Es treatment alone failed to induce muscle hypertrophy and increase the expression of phosphorylated rpS6 Ser240/244. Combined Bfr + Es upregulated muscle mass, increased the fiber cross-sectional area, and increased phosphorylated rpS6 Ser240/244 expression and phosphorylated rpS6 Ser235/236 expression compared with controls. Combined treatment with Bfr and low-current Es can induce muscle hypertrophy via activation of two protein synthesis signaling pathways. This treatment should be introduced for older patients with sarcopenia and others with muscle weakness. NEW & NOTEWORTHY We investigated the acute and chronic effect of low-current electrical stimulation with blood flow restriction on skeletal muscle hypertrophy and the mechanisms controlling the hypertrophic response. Low-current electrical stimulation could not induce skeletal muscle hypertrophy, but a combination treatment did. Blood lactate and growth hormone levels were increased in the early response. Moreover, activation of ERK1/2 and mTOR pathways were observed in both the acute and chronic response, which contribute to muscle hypertrophy.


1998 ◽  
Vol 85 (3) ◽  
pp. 1142-1149 ◽  
Author(s):  
Josep Roca ◽  
Timothy P. Gavin ◽  
Maria Jordan ◽  
Nikos Siafakas ◽  
Harrieth Wagner ◽  
...  

It has been proposed that, in skeletal muscle, the angiogenic response to exercise may be signaled by the increase in muscle blood flow, via biomechanical changes in the microcirculation (increased shear stress and/or wall tension). To examine this hypothesis, we compared the change in abundance of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and transforming growth factor-β1(TGF-β1) mRNA in skeletal muscles of the canine leg after 1 h of pump-controlled high blood flow alone (passive hyperperfusion; protocol A) and electrical stimulation of the femoral and sciatic nerves producing muscle contraction ( protocol B). The increase in leg blood flow (5.4- and 5.9-fold change from resting values, respectively) was similar in both groups. Passive hyperperfusion alone did not increase message abundance for VEGF (ratio of mRNA to 18S signals after vs. before hyperperfusion, 0.94 ± 0.08) or bFGF (1.08 ± 0.05) but slightly increased that of TGF-β1 (1.14 ± 0.07; P < 0.03). In contrast, as previously found in the rat, electrical stimulation provoked more than a threefold increase in VEGF mRNA abundance (3.40 ± 1.45; P < 0.02). However, electrical stimulation produced no significant changes in either bFGF (1.16 ± 0.13) or TGF-β1 (1.31 ± 0.27). These results suggest that the increased muscle blood flow of exercise does not account for the increased abundance of these angiogenic growth factor mRNA levels in response to acute exercise. We speculate that other factors, such as local hypoxia, metabolite concentration changes, or mechanical effects of contraction per se, may be responsible for the effects of exercise.


1977 ◽  
Vol 233 (6) ◽  
pp. E514 ◽  
Author(s):  
T A Schultz ◽  
S B Lewis ◽  
D K Westbie ◽  
J D Wallin ◽  
J E Gerich

To evaluate glucose delivery and neuromuscular activity as modulators of glucose uptake in skeletal muscle, rat hindlimbs from pentobarbital-anesthetized rats were perfused in the presence of electrically stimulated muscular contractions. Glucose delivery was varied by altering non-cyclic perfusate flow. When flow was increased from 3 to 12 ml/min glucose disappearance increased from 1.1 +/- 0.2 to 4.0 +/- 0.2 mumol/min per 100 g rat (P less than 0.001). When glucose delivery was held constant, glucose disappearance was unaltered during muscular contractions. Insulin enhanced glucose disappearance, and its effect was unaltered during muscular contractions. Muscular contractions increased oxygen disappearance by two- to 3.5-fold and lactate appearance by 4.5- to fivefold (P less than 0.02). It was concluded that glucose delivery and insulin modulate glucose disappearance in isolated perfused rat hindlimbs. Electrical stimulation of muscle enhances lactate appearance and oxygen disappearance but does not alter glucose disappearance when flow is held constant. Because blood flow to muscle increases during exercise in vivo, increased glucose delivery may be a modulator of the augmented muscle glucose consumption observed under these conditions.


Author(s):  
I. Taylor ◽  
P. Ingram ◽  
J.R. Sommer

In studying quick-frozen single intact skeletal muscle fibers for structural and microchemical alterations that occur milliseconds, and fractions thereof, after electrical stimulation, we have developed a method to compare, directly, ice crystal formation in freeze-substituted thin sections adjacent to all, and beneath the last, freeze-dried cryosections. We have observed images in the cryosections that to our knowledge have not been published heretofore (Figs.1-4). The main features are that isolated, sometimes large regions of the sections appear hazy and have much less contrast than adjacent regions. Sometimes within the hazy regions there are smaller areas that appear crinkled and have much more contrast. We have also observed that while the hazy areas remain still, the regions of higher contrast visibly contract in the beam, often causing tears in the sections that are clearly not caused by ice crystals (Fig.3, arrows).


1995 ◽  
Vol 268 (2) ◽  
pp. R492-R497 ◽  
Author(s):  
C. H. Lang ◽  
M. Ajmal ◽  
A. G. Baillie

Intracerebroventricular injection of N-methyl-D-aspartate (NMDA) produces hyperglycemia and increases whole body glucose uptake. The purpose of the present study was to determine in rats which tissues are responsible for the elevated rate of glucose disposal. NMDA was injected intracerebroventricularly, and the glucose metabolic rate (Rg) was determined for individual tissues 20-60 min later using 2-deoxy-D-[U-14C]glucose. NMDA decreased Rg in skin, ileum, lung, and liver (30-35%) compared with time-matched control animals. In contrast, Rg in skeletal muscle and heart was increased 150-160%. This increased Rg was not due to an elevation in plasma insulin concentrations. In subsequent studies, the sciatic nerve in one leg was cut 4 h before injection of NMDA. NMDA increased Rg in the gastrocnemius (149%) and soleus (220%) in the innervated leg. However, Rg was not increased after NMDA in contralateral muscles from the denervated limb. Data from a third series of experiments indicated that the NMDA-induced increase in Rg by innervated muscle and its abolition in the denervated muscle were not due to changes in muscle blood flow. The results of the present study indicate that 1) central administration of NMDA increases whole body glucose uptake by preferentially stimulating glucose uptake by skeletal muscle, and 2) the enhanced glucose uptake by muscle is neurally mediated and independent of changes in either the plasma insulin concentration or regional blood flow.


Author(s):  
Selva Bilge ◽  
Emre Ergene ◽  
Ebru Talak ◽  
Seyda Gokyer ◽  
Yusuf Osman Donar ◽  
...  

AbstractSkeletal muscle is an electrically and mechanically active tissue that contains highly oriented, densely packed myofibrils. The tissue has self-regeneration capacity upon injury, which is limited in the cases of volumetric muscle loss. Several regenerative therapies have been developed in order to enhance this capacity, as well as to structurally and mechanically support the defect site during regeneration. Among them, biomimetic approaches that recapitulate the native microenvironment of the tissue in terms of parallel-aligned structure and biophysical signals were shown to be effective. In this study, we have developed 3D printed aligned and electrically active scaffolds in which the electrical conductivity was provided by carbonaceous material (CM) derived from algae-based biomass. The synthesis of this conductive and functional CM consisted of eco-friendly synthesis procedure such as pre-carbonization and multi-walled carbon nanotube (MWCNT) catalysis. CM obtained from biomass via hydrothermal carbonization (CM-03) and its ash form (CM-03K) were doped within poly(ɛ-caprolactone) (PCL) matrix and 3D printed to form scaffolds with aligned fibers for structural biomimicry. Scaffolds were seeded with C2C12 mouse myoblasts and subjected to electrical stimulation during the in vitro culture. Enhanced myotube formation was observed in electroactive groups compared to their non-conductive counterparts and it was observed that myotube formation and myotube maturity were significantly increased for CM-03 group after electrical stimulation. The results have therefore showed that the CM obtained from macroalgae biomass is a promising novel source for the production of the electrically conductive scaffolds for skeletal muscle tissue engineering.


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