Effect of Acupuncture on Reproductive Endocrine and p-Akt Protein Expression in Polycystic Ovary Syndrome Rats with Insulin Resistance

Abstract

To observe the effect of manual acupuncture intervention on the reproductive endocrine and p-Akt protein expression in polycystic ovary syndrome with insulin resistance (PCOS-IR) rats, so as to reveal its mechanism in relieving PCOS-IR. Female Wistar rats were randomly divided into control, model, medication (Metformin) and acupuncture groups (n＝8 in each). The PCOS-IR model was established by subcutaneous injection of Dehydroepiandrosterone (DHEA, 6 mg/100 g), once daily for 20 days. Rats of the medication group were treated by gavage of Metformin solution (100 mg/kg), once daily for 28 days. For rats of the acupuncture group, manual acupuncture stimulation (lifting-thrusting and rotating of needles) was applied to the bilateral "Shenshu"(BL 23), "Yishu"(EX-B 3), "Zigong" (EX-CA 1), "Sanyinjiao"(SP 6), "Fenglong"(ST 40) and "Guanyuan"(CV 4) for 5 min, once a day for 28 days. H．E. staining was used to observe the histopathologic changes of the ovary tissue. Serum levels of follicle-stimulating hormone (FSH), estradiol (E2), luteinizing hormone (LH), testosterone (T) and fasting insulin (FINS) were measured by ELISA. Fasting plasma glucose (FPG) was measured by blood glucose meter, and homeostasis model assessment-insulin resistance index (HOMA-IR) was calculated. Western blot was used to detect the expression of Akt and p-Akt proteins in ovarian tissues. Following modeling, the ovaries showed polycystic changes and an increase of atresia follicles with a larger diameter and no corpus luteum in the model group. After the intervention, there were various types of follicles and a small amount of corpus luteum at different stages of development in both acupuncture and medication groups. In comparison with the control group, serum FSH and E2 levels as well as ovarian Akt and p-Akt protein expression were considerably decreased (P<0.05, P<0.01), and serum LH, T and FINS contents and HOMA-IR were significantly increased in the model group (P<0.01). Following the intervention, the decreased serum FSH and E2 levels as well as ovarian Akt and p-Akt protein expression, and the increased serum LH, T and FINS contents and HOMA-IR were remarkably reversed in both acupuncture and medication groups (P<0.05，P<0.01), without significant differences between the two groups in the levels of those serum and ovary indexes (P>0.05)．. Acupuncture intervention can regulate the levels of reproductive endocrine hormones and reduce insulin resistance in PCOS-IR rats, which may be related to its effect in up- regulating the expression of p-Akt protein in the ovaries.