Objective To investigate the effect of electroacupuncture(EA) on the expression of Kisspeptin protein and activities of the hypothalamic-pituitary-ovarian axis(HPOA) in rats with Letrozole-induced polycystic ovary syndrome(PCOS). Methods Female SD rats were randomly divided into normal control

PCOS model and EA groups(n=6 rats in each group). The PCOS model was established by continuous gavage of letrozole for 21 d. EA(2 Hz/100 Hz

0.6-1.4 mA) was applied to bilateral "Daimai"(GB26) for 20 min

once every day for 15 d. Body mass was measured every 4 days. Serum follicular stimulating hormone(FSH)

luteinizing hormone(LH)

estradiol(E2)

and testosterone(T) were detected by radioimmunoassay. Histopathological changes of the ovarian were observed after H.E. staining

and the expression level of Kisspeptin protein in the hypothalamus was detected by Western blot. Results Following modeling

the body mass

serum T and LH contents

hypothalamic Kisspeptin protein expression and the number of ovarian follicles were significantly increased(P<0.05

P<0.01)

while the number of ovarian corpus luteum was apparently decreased in comparison with the normal group(P<0.01). After EA intervention

the serum T

LH and E2 contents

the expression of Kisspeptin protein and the number of ovarian follicles were notably down-regulated(P<0.05

P<0.01)

and the number of corpus luteum was significantly increased(P<0.01) in comparison with the model group. Conclusion EA can regulate the levels of sex hormones and HPOA of PCOS rats

which may be related to its effect in down-regulating the expression of Kisspeptin protein in the hypothalamus.