[Effect of electroacupuncture on intestinal calcium absorption and expression of transmembrane calcium transport-related receptors in ovariectomized rats].

To observe the effect of electroacupuncture (EA) on bone mineral density (BMD) and expression of calcium transport-related receptors in ovariectomized rats, so as to explore its mechanisms underlying improvement of osteoporosis.Thirty-two three-month female SD rats were randomly divided into control, sham operation, model and EA groups (n=8 in each group). The ovariectomy model was established by resection of bilateral ovaries. EA (2 Hz/15 Hz, 2 mA) was applied to "Guanyuan"(CV4)+"Sanyinjiao"(SP6) or "Shenshu"(BL23)+"Housanli"(ST36) alternatively for 20 min, once daily (except the weekends) for 12 weeks. BMD of the tibia and femur were detected by using a bone densitometer. The expression levels of transient receptor potential vanillic receptor 5 (TRPV5), transient receptor potential vanillic receptor 6 (TRPV6), sodium calcium exchanger 1 (NCX1), membrane calcium adenosine triphosphate hydrolase (PMCA1b), zonula occludens 1 (ZO-1), occludin and claudin in intestinal mucosa were detected by quantitative real-time PCR and Western blot, respectively.Following modeling, BMD of both tibia and femur, and expression levels of TRPV5, PMCA1b, ZO-1, occludin and claudin mRNAs were significantly decreased in the model group compared with the control and sham operation groups (P<0.05, P<0.01)，while the mRNAs levels of TRPV6 and NCX1 in the model group were increased (P<0.01). After the treatment, BMD of both tibia and femur, and expression levels of TRPV5, PMCA1b, ZO-1 and occludin mRNAs were significantly increased(P<0.01，P<0.05)，and TRPV6 and NCX1 were significantly decreased(P<0.01，P<0.05) in the EA group than those in the model group. Compared with the control and sham operation groups, protein expression levels of TRPV5, PMCA1b, ZO-1, occludin and claudin in the model group were significantly decreased (P<0.05), while the protein levels of TRPV6 and NCX1 in the model group were increased (P<0.05). After EA intervention, modeling-induced decrease of TRPV5, PMCA1b, ZO-1, occludin and claudin protein levels and increase of TRPV6 and NCX1 protein levels were all completely reversed in the EA group relevant to the model group (P<0.05).EA intervention can improve bone mineral density and up-regulate the mRNA and protein expression of TRPV5, PMCA1b, ZO-1 and occludin, which may be one of the mechanisms of acupuncture in the treatment of osteoporosis.目的：观察针刺对去卵巢大鼠骨密度及钙离子转运相关受体的影响，探讨针灸防治骨质疏松症的机制。方法：3月龄雌性SD大鼠随机分为空白组、假手术组、模型组和电针组，每组8只。模型组和电针组大鼠行双侧卵巢摘除术。电针组交替给予“关元”+“三阴交”(双)和“肾俞”+“后三里”(双)电针干预，每次电针20 min，每日1次，每周连续干预5 d，共12周。12周后用骨密度仪统一测定右侧胫骨、股骨骨密度；采用荧光定量PCR及Western blot法检测肠黏膜内瞬时感受器电位香草酸受体5(TRPV5)、瞬时感受器电位香草酸受体6(TRPV6)、钠钙交换体1(NCX1)和细胞膜钙离子三磷酸腺苷水解酶(PMCA1b)及与钙离子细胞旁转运相关的紧密连接蛋白-1(ZO-1)、封闭蛋白occludin和claudin mRNA和蛋白的表达水平。结果：与空白组、假手术组比较，模型组大鼠骨密度明显降低(P<0.05)；与模型组比较，电针组骨密度明显提高(P<0.05)。与空白组、假手术组比较，模型组肠黏膜内TRPV6、NCX1 mRNA表达上调(P<0.01)，TRPV5、PMCA1b、ZO-1、occludin和claudin的mRNA表达明显下调(P<0.01)；与模型组比较，电针组肠黏膜TRPV6、NCX1 mRNA的表达明显下调(P<0.01，P<0.05)，TRPV5、PMCA1b、ZO-1和occludin的mRNA表达水平均上调(P<0.01，P<0.05)。与空白组、假手术组比较，模型组TRPV6、NCX1蛋白表达量升高(P<0.05)，TRPV5、PMCA1b、ZO-1、occludin和claudin蛋白表达量显著降低(P<0.05)；与模型组比较，电针组TRPV6和NCX1的表达量降低(P<0.05)，TRPV5、PMCA1b、ZO-1、occludin和claudin蛋白表达量显著升高(P<0.05)。结论：电针能提高去卵巢大鼠的骨密度，增强参与钙离子吸收跨细胞途径的TRPV5、PMCA1b的mRNA和蛋白表达以及细胞旁途径ZO-1、occludin的mRNA和蛋白表达，这可能是针灸防治骨质疏松症的机制之一。.