Behavior of Electrical Reactance in Gastrocnemius Muscle of Rats During Contractions of Different Intensities

摘要

Electrical Impedance Myography is an experimental myography technique that assesses two passive electrical components of muscle, the resistance and the reactance. Few studies in the literature have addressed and discussed the behavior of the reactance during muscle contractions. Moreover, the rare results are contradictory about these changes, i.e. during the muscular contraction the reactance sometimes increases, decreases or does not change. The present work used an electrical stimulation protocol able to provide different intensities of muscle contraction in the gatrocnernius muscle of Wistar rats (in vivo experiments) in order to assess in real-time the reactance behavior during these contractions. The results have showed a significant positive correlation (r = 0.57) between the reactance magnitude and muscle strength. We conclude that the suitable experimental protocol for electrical stimulation and the electrical impedance measures performed invasively in gastrocnemius muscle had improved the sensitivity in obtaining the reactance findings. However, further studies are required to better understand biochemically, physiologically and morphologically, the reactance behaviors found at the present work.