Article

The aim of this study was to investigate the optimal electrical
stimulation (ES) protocol in attenuating disuse muscle atrophy by influencing
satellite cell activity. DESIGN: This study used a pretest-posttest design. Six
ES protocols of different duration (3 hrs day or 2 x 3 hrs day) and frequencies
(2, 10, or 20 Hz) were applied on the soleus muscle in mice (n = 8 in each group)
that were hindlimb-suspended for 14 days. Muscle mass, cross-sectional area and
fiber-type composition, and peak tetanic force of the muscles were measured.
Immunohistochemical staining was used to evaluate satellite cell content,
activation, proliferation, and differentiation. Cell apoptosis was detected by
TdT-mediated dUTP nick end labeling (TUNEL) assay. RESULTS: ES at 2 Hz for 2 x 3
hrs day achieved the best effect in attenuating the loss of muscle fiber
cross-sectional area and force. This stimulation parameter led to a 1.2-fold
increase in satellite cell proliferation and was effective in rescuing cells from
apoptosis. Besides, satellite cells in the atrophic muscles required different
stimulation protocols for different cellular activities such as activation,
proliferation, and myogenic differentiation. CONCLUSIONS: This study showed that
ES at 2 Hz for 2 x 3 hrs day is the optimal protocol for counteracting muscle
disuse atrophy.

Langue : ANGLAIS