[Influence of electroacupuncture on efficacy of estrogen in regulating hypothalamic reproductive endocrine activity in rats].

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-l) 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-regulated 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.