Objective To observe the effect of electroacupuncture(EA)intervention on hyperplastic mammary glands

serum estradiol(E2)and progesterone(P)contents

estrogen receptor alpha(ERα)and progesterone receptor(PR)expression of breast tissues in mammary gland hyperplasia(MGH)rats

so as to reveal its mechanisms underlying improvement of MGH.Methods Sixty female SD rats were randomly divided into control

model

EA

EA+ovariectomy(OVX)and EA+sham-OVX groups(n=12 in each).The MGH model was established by injection of Estradiol Benzoate injection(0.5 mg/kg

once daily for25 d)and P injection(0.5 mg/kg

once daily for 5 dafter estradiol injection)into the medial hind-leg muscle.After model establishment

bilateral OVX was performed for rats of the EA+OVX group

and sham OVX(only exposure of ovaries)was performed for rats of the EA+sham OVX group.EA(2 Hz

2 mA)was applied to bilateral"Tianzong"(SI 11)

"Ganshu"(BL 18)

"Zusanli"(ST 36)for point group A

and"Wuyi"(ST 15)

"Hegu"(LI 4)

"Danzhong"(CV 17)for point group B for 20 min

once daily

5 days a week for 4 weeks.The two acupoint groups were used alternately.The height of the rats' nipples(the 2 nd pairs)were measured.Serum E2 and P levels were assayed by ELISA.The expression of ERαand PR in mammary tissues was detected by immunofluorescence staining and Western blot

separately.Results The height of nipples

serum E2 content

and mammary ERαprotein expression level were significantly higher in the model group than in the control group(P<0.01)

while serum P content and PR expression were remarkably lower in the model group than in the control group(P<0.01).Following EA intervention

the height of nipples

serum E2 content and mammary ERαprotein expression level in both EA and EA+sham OVX groups

and ERαexpression in the EA+OVX group were considerably lower in comparison with those of the model group(P<0.01)

and serum P content and PR expression in the 3 EA groups were significantly higher than those in the model group(P<0.01

P<0.05).But there were no significant changes in the nipple height and serum E2 levels in the EA+OVX group relevant to the model group(P>0.05)

suggesting an important role of the ovary in producing EA's effect.Conclusion EA intervention can improve hyperplastic mammary glands by down-regulating serum E2 content and mammary ERαprotein expression

and up-regulating serum P content and PR expression in MGH rats

which has a close relation with the intact ovaries.