Low-frequency electrical stimulation of bilateral ankles by belt electrodes is effective for preventing denervation-induced atrophies in multiple skeletal muscle groups

Abstract Belt electrode skeletal muscle electrical stimulation (B-SES) is a stimulation method that can simultaneously contract multiple muscle groups. Although the beneficial effects of B-SES in clinical situations have been elucidated, its molecular mechanism remains unknown. Here, we developed a novel rodent B-SES ankle stimulation system to test whether low-frequency stimulation prevents denervation-induced muscle atrophy.Electrical stimulations (7‒8 Hz, 30 min) with ankle belt electrodes were applied to Sprague–Dawley rats, daily for one week. All animals were assigned to control (CONT), denervation-induced atrophy (DEN), and DEN + electrical stimulation (ES) groups. The tibial anterior (TA) and gastrocnemius (GAS) muscles were used to examine the effects of ES treatment.Seven days of continuous stimulation induced significantly higher muscle wet weights and muscle fiber cross-sectional areas(CSA) in both TA and GAS muscles compared to those in the DEN group. B-SES suppressed the decrease in mitochondrial biosynthesis, quantity, and enzyme activity in TA and GAS muscles. mRNAs levels of muscle proteolytic molecules Atrogin-1 and Murf1 were largely increased by denervation, but B-SES repressed their expression.In conclusion, low-frequency electrical stimulation of bilateral ankles by belt electrodes is effective for preventing denervation-induced atrophy in multiple muscles by maintaining mitochondrial quantity, enzyme activity, and suppressing muscle protein degradation.