Objective: To observe the effect of electroacupuncture (EA) at different acupoints on hyperandrogenism and ovarian androgen receptor (AR) expression in rats with polycystic ovary syndrome (PCOS), so as to explore its mechanisms underlying improvement of PCOS.
Methods: Sixty female SD rats were randomly divided into control, model, Zusanli (ST 36), Sanyinjiao (SP 6), Guanyuan (CV 4) and comprehensive groups (10 rats/group). The PCOS model was established by giving (gavage) the animals with Letrozole solution (1.0 mg/kg), once daily for 21 consecutive days. EA stimulation was applied to ST 36, SP 6, or CV 4 respectively, once daily for 14 days. The comprehensive group was treated by EA treatment of the abovementioned three acupoints in the meantime. Before and after the treatment, the body mass and the ovary weight were measured. The morphological structure of the ovary was observed under microscope after H．E. staining. The levels of serum hormone and sex hormone binding globulin (SHBG) were assayed by ELISA. Free androgen index (FAI) was calculated and the expression of AR in the ovary was detected by immunohistochemistry.
Results: After modeling, the body mass, ovary weight, serum testosterone (T) and FAI levels and the expression of AR protein in late ovarian follicles were significantly increased (P<0.01, P<0.05), and serum estradiol (E2) and SHBG contents were significantly decreased relevant to the control group (P<0.01). Following EA intervention and compared with the model group, the body weight of each EA group was significantly reduced (P<0.05), the ovarian pathological changes were improved, and serum T and FAI levels were significantly decreased (P<0.01), and serum E2 and SHBG contents significantly increased in the ST 36, CV 4 and comprehensive groups (P<0.01, P<0.05). The ovary weight of only CV 4 group was significantly lower than that of the model group (P<0.01). The expression of AR protein in late follicles of both CV 4 and SP 6 groups was markedly decreased (P<0.05, P<0.01).
Conclusion: EA at ST 36, SP 6, and CV 4 all can improve the hyperandrogenism and ovarian polycystic morphological changes of PCOS rats, while different acupoints have different functional characteristics.
Keywords: Androgen receptorβ; Electroacupuncture; Hyperandrogenism; Polycystic ovarian syndrome.