[Influence of electroacupuncture intervention on serum ghrelin content and bone mineral density in ovariectomized rats].

Objective: To observe the influence of electroacupuncture (EA) on serum ghrelin content and bone mineral density in ovariectomized (OVX) rats so as to explore its mechanism underlying improvement of postmenopausal osteoporosis.
Methods: Thirty ovariectomized SD rats with osteoporosis were randomized into model, EA and estrogen groups (n = 10) and other 10 rats received sham operation were assigned to be control group. For OVX rats of the EA group, EA (2 Hz, 1-3 mA) was applied to "Sanyinjiao" (SP 6) + "Guanyuan" (CV 4) or "Shenshu" (BL 23) + "Housanli" (ST 36), alternately for 20 min, once daily for consecutive 3 months. For rats of the estrogen group, subcutaneous injection of estradiol benzoate (0.1 mg/kg) was given once a week for 3 months. The bone mineral density (BMD) of the lumbar vertebrae and femur were detected by using a bone densitometer, and serum ghrelin content was assayed by ELISA.
Results: In comparison with the sham operation group, serum ghrelin level of the model group was significantly increased, and BMD of both lumbar vertebrae and femur were significantly decreased (P < 0.05). Compared with the model group, the serum ghrelin levels were considerably decreased in both EA group and estrogen group, while BMD levels were significantly upregulated in the EA and estrogen groups (P < 0.05). The effects of the EA group were obviously inferior to those of the estrogen group (P < 0.05).
Conclusion: Acupuncture intervention can improve bone density and lower serum ghrelin level in OVX rats, which may contribute to its effect in improving osteoporosis.