Objective 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. Methods 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(PMCA1 b)

zonula occludens 1(ZO-1)

occludin and claudin in intestinal mucosa were detected by quantitative real-time PCR and Western blot

respectively. Results Following modeling

BMD of both tibia and femur

and expression levels of TRPV5

PMCA1 b

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

PMCA1 b

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

PMCA1 b

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

PMCA1 b

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).Conclusion EA intervention can improve bone mineral density and up-regulate the mRNA and protein expression of TRPV5

PMCA1 b

ZO-1 and occludin

which may be one of the mechanisms of acupuncture in the treatment of osteoporosis.