Effect of weight bearing on recovery from nerve injury in skeletal muscle

We examined the effect of weight bearing (WB) on muscle recovery after nerv e injury. Rats were housed in individual cages for 2 wk under WB or hindlim b suspension (HS) after being subjected to sciatic nerve compression for 1 wk. Sham operated on rats served as controls (sham group). We used P-31- an d F-19-nuclear magnetic resonance spectroscopy combined with histochemical, physiological, and biochemical techniques to assess the outcome in the thr ee groups. Creatine kinase-BB (CK-BB) mRNA levels expression, CK activity, and type I fiber density in the WB group were elevated compared with those in the HS group. In addition, sciatic functional index, tetanic tension, en ergy state, and local circulation dynamics of the WB group were greater tha n those of the HS group. These results suggested that WB plays an important role in muscle regeneration, inhibits the reduction of CK activity, and fa cilitates the activation of neural recovery, energy state, and local circul ation dynamics.