[Effects of electroacupuncture stimulation at "Guanyuan" (CV 4) on serum insulin-like growth factor-1 content and bone biomechanics in ovariectomy-induced osteoporosis rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on serum insulin-like growth factor-1 (IGF-1) content and bone biomechanics in osteoporosis rats so as to explore its mechanism underlying improvement of postmenopausal osteoporosis (PMOP). METHODS: Forty female SD rats (4.5 months old) were randomly divided into sham-operation (sham), model, medication and EA groups (10 rats/group). The rat's bilateral ovaries were removed to establish the PMOP model. For rats in the sham group, similar procedures were conducted except removing comparable weight of fat tissues around the ovaries. For rats in the EA group, "Guanyuan" (CV 4) was punctured with filiform needles and stimulated electrically (1 mA, 2 Hz) for 20 min, once a day for 30 days. For rats in the medication group, pentanoic acid estradiol (50 microg/500 g) was administrated by gavage. The serum IGF-1 content was examined by ELISA and the bone biomechanics measured by three-point bending tests, respectively. RESULTS: Compared with the sham group, the serum IGF-1 level, femoral maximum load and fracture load were significantly reduced in the model group (P < 0.05, P < 0.01). In comparison with the model group, these indexes were significantly increased in rats of the EA and medication groups (P < 0.05, P < 0.01), but without significant difference between the EA and medication groups (P > 0.05). CONCLUSION: EA produces benefits on postmenopausal osteoporosis through increasing the serum IGF-1 contents and bone strength.