The Influence of Muscle Contraction on the Degree of Microvascular Perfusion in Rat Skeletal Muscle Following Transcutaneous Neuromuscular Electrical Stimulation

BACKGROUND: Neuromuscular electrical stimulation (NMES) is a complementary tool for therapeutic exercise for muscle strengthening and may potentially enhance exercise performance. OBJECTIVE: To determine whether high-intensity interval training (HIIT) and continuous aerobic training (CA) coupled with NMES enhance the changes in the eccentric/concentric muscle contraction patterns of hamstring and quadriceps. METHODS: Forty-five healthy sedentary male participants performed cycling training 3 times per week for 8 weeks combined with/without NMES performed at a load equivalent to 65% and 120% of IVO2max (intensity associated with the achievement of maximal oxygen uptake). Anthropometrics, blood lactate measurements, IVO2max, TLimVO2max (time-to-exhaustion) and isokinetic strength parameters were measured at baseline and post-training using a randomized controlled trial. RESULTS: The conventional hamstring-to-quadriceps-ratio (HQR: Hcon/Qcon) at 60∘/s and the Dynamic Control Ratio (DCR: Hecc/Qcon) at 180∘/s significantly increased both in the dominant (D) and non-dominant (ND) limb in the HIIT + NMES group (p< 0.05). There was a positive significant correlation between the individual changes in D HQR at 60∘/s and IVO2max (r= 0.94, p= 0.005) and the DCR at 180∘/s and TLimVO2max (r= 0.90, p= 0.015), respectively. CONCLUSIONS: The increases in the eccentric muscle contraction and DCR following HIIT + NMES seem to improve fatigue tolerance, cause less fatigue and oxidative stress on the lower limb during pedaling at high intensities.

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Effects of central administration of insulin or l-NMMA on rat skeletal muscle microvascular perfusion

Diabetes Obesity and Metabolism ◽

10.1111/j.1463-1326.2010.01253.x ◽

2010 ◽

Vol 12 (10) ◽

pp. 900-908 ◽

Cited By ~ 5

Author(s):

E. A. Bradley ◽

K. J. Willson ◽

D. Choi-Lundberg ◽

M. G. Clark ◽

S. Rattigan

Keyword(s):

Skeletal Muscle ◽

Microvascular Perfusion ◽

Central Administration ◽

Rat Skeletal Muscle

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ATP concentrations and muscle tension increase linearly with muscle contraction

Journal of Applied Physiology ◽

10.1152/japplphysiol.00185.2003 ◽

2003 ◽

Vol 95 (2) ◽

pp. 577-583 ◽

Cited By ~ 92

Author(s):

Jianhua Li ◽

Nicholas C. King ◽

Lawrence I. Sinoway

Keyword(s):

Skeletal Muscle ◽

Electrical Stimulation ◽

Muscle Contraction ◽

Motor Nerve ◽

Muscle Tension ◽

Nerve Fibers ◽

Ventral Root ◽

Ventral Roots ◽

Root Stimulation ◽

Stimulation Of

Previous studies have suggested that activation of ATP-sensitive P2X receptors in skeletal muscle play a role in mediating the exercise pressor reflex (Li J and Sinoway LI. Am J Physiol Heart Circ Physiol 283: H2636–H2643, 2002). To determine the role ATP plays in this reflex, it is necessary to examine whether muscle interstitial ATP (ATPi) concentrations rise with muscle contraction. Accordingly, in this study, muscle contraction was evoked by electrical stimulation of the L7 and S1 ventral roots of the spinal cord in 12 decerebrate cats. Muscle ATPi was collected from microdialysis probes inserted in the muscle. ATP concentrations were determined by the HPLC method. Electrical stimulation of the ventral roots at 3 and 5 Hz increased mean arterial pressure by 13 ± 2 and 16 ± 3 mmHg ( P < 0.05), respectively, and it increased ATP concentration in contracting muscle by 150% ( P < 0.05) and 200% ( P < 0.05), respectively. ATP measured in the opposite control limb did not rise with ventral root stimulation. Section of the L7 and S1 dorsal roots did not affect the ATPi seen with 5-Hz ventral root stimulation. Finally, ventral roots stimulation sufficient to drive motor nerve fibers did not increase ATP in previously paralyzed cats. Thus ATPi is not largely released from sympathetic or motor nerves and does not require an intact afferent reflex pathway. We conclude that ATPi is due to the release of ATP from contracting skeletal muscle cells.

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