[Effects of preventive-electroacupuncture of "Guanyuan" (CV 4) and "Sanyinjiao" (SP 6) on hypothalamus-pituitary-ovary axis in ovariectomized rats].

Objective: To observe the effect of preventive-electroacupuncture (PEA) at "Guanyuan" (CV 4) and "Sanyinjiao" (SP 6)on hypothalamus-pituitary-ovary (HPO)activities in ovariectomized (OVX) rats, and to compare the specificity of efficacy of acupoints.

Methods: Sixty-two female SD rats were randomly divided into normal group (n = 6), sham-operation (sham) group (n = 6), model group (n = 6), PEA-Guanyuan (CV 4, PEA-CV 4) group (n = 11), PEA-Sanyinjiao (SP 6, PEA-SP 6) group (n = 11), complementary (C)-PEA-CV 4 (n = 11) and C-PEA-SP 6 group (n = 11). Climacterium model was duplicated by removing the bilateral ovaries. Before OVX, electroacupuncture (EA, 2 Hz/100 Hz, ) was applied to bilateral SP 6, CV 4 for 20 min, once every other day for 15 times. For rats of the C-PEA-CV 4 and C-PEA-SP 6 groups and 12 days after the OVX, PEA was applied to CV 4 and SP 6 again, once every other day for 5 times. For rats of the sham group, a little of fat nearby the ovary was removed. Enzyme-linked immunosorbent assay was used to measure the contents of gonadotropin releasing hormone (GnRH) in the hypothalamus, follicule-stimulating hormone (FSH) and luteinizing hormone (LH) in the hypophysis, and estrogen (E2) in the uterus.

Results: In comparison with the normal group, uterus E2 content was decreased significantly (P < 0. 05), and pituitary FSH and LH contents and hypothalamic GnRH content were increased obviously (P < 0.01) in the model group. Compared with the model group, uterus E2 levels in the PEA-CV 4 and C-PEA-CV 4 groups were increased apparently (P < 0.05), while both pituitary FSH and hypothalamic GnRH levels in the PEA-CV 4, C-PEA-CV 4, PEA-SP 6 and C-PEA-SP 6 groups, and pituitary LH levels in the C-PEA-CV 4 and PEA-SP 6 groups were down-regulated markedly (P < 0.05, P < 0.01), suggesting an improvement of the HPO axis activity following PEA and C-PEA. No significant differences were found between the normal and sham groups in uterus E2, pituitary FSH and LH, and hypothalamic GnRH contents, and between the model and PEA-SP 6 groups, and between the model and C-PEA-SP 6 groups in uterus E2 levels, and between the model and PEA-CV 4 groups, and between the model and C-PEA-SP 6 groups in pituitary LH levels (P > 0.05).

Conclusion: Preventive EA of "Guanyuan" (CV 4) and "Sanyinjiao" (SP 6) can function in up-regulating uterus E2 level, and down-regulating pituitary FSH and LH contents and hypothalamic GnRH level in OVX rats, which may contribute to its efficacy in relieving climacteric syndrome in clinic.