Abstract:

BACKGROUND: Several studies have shown that both passive movement and electrical stimulation can relieve disuse osteoporosis symptoms and improve bone metabolism.
OBJECTIVE: To explore the influence and status of nerve growth factor in the formation of disuse osteoporosis and the underlying mechanisms of prevention.
METHODS: Fifty SD rats according to the principle of equal body weight were randomly divided into sham operation group (n=10) and exercise group (n=40). Rats of the exercise group underwent sciatic nerve and femoral resection (5 mm nerve was cut) and then randomly divided into four subgroups (10 rats in each group): sciatic nerve resection group, sciatic nerve resection+passive movement group (passive movement group), sciatic nerve resection+electrical stimulation group (electrical stimulation group) and sciatic nerve resection+massage+electrical stimulation group (union intervention group). After operation for 24 hours, the rats in the exercises group were given passive movement and electrical stimulation. The rats of the sham operation group had the same procedures as the other four subgroups except for sciatic nerve and femoral resection.
RESULTS AND CONCLUSION: (1)Body mass of sciatic nerve resection group was lower than that of electrical stimulation and union intervention groups (P < 0.01). (2) Real-time PCR test showed that for the expression of nerve growth factor, the sciatic nerve resection group was lower than the sham operation group, and there was a significant difference between the two groups (P < 0.05); the sciatic nerve resection group was lower than electrical stimulation and passive movement groups, and the three groups had significant differences (P < 0.05); union intervention group was higher than sciatic nerve resection group, and there was a significant difference between the two groups (P < 0.01). These results suggest that after electrical stimulation and passive movement, the expression level of endogenous nerve growth factor gene in rat tibia tissues was improved remarkably. The increase of nerve growth factor gene expression in bone tissues is one of the most important mechanisms for osteoporosis prevention, and this process can be promoted by appropriate passive movement and electrical stimulation.