| Objective To study the effect of electroacupuncture combined with alendronate sodium on the improvement of osteoporosis in ovariectomized rats and the regulation of integrin-α2/FAK/Runx2 pathway. Methods Thirty rats were randomly divided into sham operation group (6 rats) and modeling group (24 rats). The postmenopausal osteoporosis rat model was established by surgical ovariectomy of the rats in the modeling group. The rats after modeling were randomly divided into osteoporosis model group, electroacupuncture group, alendronate sodium group, and combined treatment group, with 6 rats per group. Electroacupuncture stimulated Shenshu and Zusanli acupoints of rats. The intervention continued for 8 weeks. Rats in alendronate group received alendronate sodium by intragastric administration of 0.5 mg/kg once a day for 8 weeks. In the combined treatment group, rats received alendronate sodium and electroacupuncture therapy for 8 weeks. Serum levels of alkaline phosphatase (ALP), osteocalcin (BGP), tartrate-resistant acid phosphatase (TRACP)-5b, carboxyl terminal peptide of type I collagen (ICIP), and amino terminal prolongating peptide of type I collagen (PINP) were determined with enzyme-linked immunosorbent assay (ELISA) kit. Bone mineral content and bone mineral density of rat femurs were determined with dual-energy X-ray bone densitometer and bone mechanical property tester. Histopathological changes of rat femurs were examined with hematoxylin-eosin (HE) staining. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the mRNA levels of integrin-α2, FAK, and Runx2 in the femur. Immunoblot was used to determine the protein levels of integrin-α2, FAK, and Runx2 in the femur. Results Compared to those in the normal control group, serum levels of ALP, BGP, TRACP-5b, ICIP, and PINP in osteoporosis model group increased significantly (P<0.05), and bone mineral content, maximum load, maximum stress, and stiffness decreased significantly (P<0.05). The mRNA and protein levels of integrinα2, FAK, and Runx2 in femur tissue decreased significantly (P<0.05). Compared to those in the osteoporosis model group, serum levels of ALP, BGP, TRACP-5b, ICIP, and PINP in electroacupuncture group, alendronate sodium group, and combined treatment group decreased significantly (P<0.05), and bone mineral density, bone mineral content, maximum load, maximum stress, and stiffness increased significantly (P<0.05). The mRNA and protein levels of integrinα2, FAK, and Runx2 in the femur increased significantly (P<0.05). Compared to those in the electroacupuncture treatment group and alendronate sodium group, serum ALP, BGP, TRACP-5b, ICIP, and PINP levels in combined treatment group decreased significantly (P<0.05), and bone mineral density, bone mineral content, maximum load, maximum stress, and stiffness increased significantly (P<0.05). The mRNA and protein levels of integrinα2, FAK, and Runx2 in the femur increased significantly (P<0.05). Conclusion Electroacupuncture combined with alendronate sodium significantly increases bone mineral density in postmenopausal rats with osteoporosis, inhibits the pathological progression of osteoporosis, improve bone metabolism and bone biomechanical changes in rats. The mechanism may be related to the regulation of integrin-α2 /FAK/Runx2 pathway. |