Abstract
The purpose of this study was to investigate the effect of weight-bearing frequency in a week in prevention of disuse muscular atrophy.
Hindlimb suspension (HS) was used to produce muscular atrophy in Wistar rats (n=24). Weight-bearing (WB) was stationary ground support (1 hour/day). Groups were 1) HS only, 2) HS+WB (every other day), 3) HS+WB (everyday), and 4) control. After 2 weeks, right soleus muscle (SOL) and extensor digitorum longus muscle (EDL) were weighed. Muscle ATPase histochemical staining, followed by morphometrical analysis, demonstrated that SOL responded more markedly to non-WB and WB than EDL. The muscle-to-body weight ratio and the percentage distribution of muscle fiber type in SOL were maintained by everyday WB. Muscular atrophy could not be prevented perfectly. But cross-sectional area in SOL indicated that it is possible to delay the progression of disuse muscular atrophy by WB (1 hour/day), and that everyday WB is more effective compared with every other day WB.
