Objective To observe the effect of electroacupuncture(EA) on the efficacy of estrogen-induced regulation of reproductive endocrine in ovariectomized(OVX) rats.Methods Thirty SD rats were randomly divided into control

model(OVX)

EA-Guanyuan(CV 4)

Estrogen(E) and EA+E groups(n=6 in each group).OVX model was duplicated by removing the bilateral ovaries.EA(5 Hz/20 Hz

1-2 mA) was applied to "Guanyuan"(CV 4) for 30 min

once every other day and for 3 sessions.Estrogen at doses of 0.5 mg/kg and 0.25 mg/kg was intraperitonealy given to rats in the E group and EA+E group

respectively.Serum estrogen and cortisol contents were assayed by enzyme linked immunosorbent assay and the expression of hypothalamic gonadotrophin releasing hormone(GnRH)mRNA

G protein-coupled receptor 54(GPR 54)mRNA

kisspeptin-1(Kiss-1) mRNA and corticotropin releasing hormone(CRH) mRNA were detected by using real time polymerase chain reaction(RT-PCR).Results Compared with the control group

the expression levels of GnRH mRNA

GPR 54 mRNA and Kiss-1 mRNA in hypothalamus in the model group were increased significantly(P<0.05)

while the expression of hypothalamic CRH mRNA was down-regu-lated obviously(P<0.05)

and serum cortisol and estrogen levels were reduced significantly(P<0.05).In comparison with the model group

the expression levels of hypothalamic GnRH mRNA in the EA

E and EA+E groups

and those of hypothalamic GPR 54 mRNA and Kiss-1 mRNA in the E and EA+E groups were down-regulated considerably(P<0.05);whereas hypothalamic CRH mRNA expression levels in the E and EA+E groups were up-regulated obviously(P<0.05)

and serum cortisol and estrogen contents in the E and EA+E groups were increased remarkably(P<0.05).Comparison among the EA and EA+E groups showed that the effects of EA+E group were significantly superior to those of EA group in down-regulating hypothalalmic GnRH mRNA and GPR 54 mRNA expression

and in up-regulating hypothalamic CRH mRNA expression and serum cortisol and estrogen contents(P<0.05).No significant differences were found between E and EA+E groups in down-regulating hypothalamic GnRH mRNA

GPR 54 mRNA and Kiss-1 mRNA expression

and in up-regulating hypothalamic CRH mRNA expression and serum cortisol and estrogen levels(P>0.05).Conclusion EA-CV 4 is able to potentiate the effects of low-dose of estrogen in down-regulating hypothalamic GnRH mRNA

GPR 54 mRNA and Kiss-1 mRNA expression

and up-regulating hypothalamic CRH mRNA expression and raising serum cortisol and estrogen contents in OVX rats

showing a favorable modulation effect on reproductive endocrine activity.