[Study on the underlying mechanism of acupuncture in regulating neuroendocrine activity in dysmenorrhea rats]

To observe the influence of acupuncture on neuroendocrine in rats with primary dysmenorrhea, so as to explore its underlying mechanism in relieving dysmenorrhea.

Forty female Wistar rats were equal randomized into control, model, acupuncture and Extractum Leonuri Inspissatum (ELI) groups, with 10 cases in each. Primary dysmenorrhea model was established by intragastric perfusion of diethylstilbestrol (3 mg/kg), once daily for 12 days. "Guanyuan" (CV 4), bilateral "Sanyinjiao" (SP 6) and "Diji" (SP 8) were punctured once daily for 7 days. ELI (80 g/kg) was given to rats of ELI group via gastrogavage, once daily for 7 days. On the 12th day, the rats of 4 groups were given with oxytocin (14 U/kg, i.p.) for inducing dysmenorrhea. The latency and incidence rate of writhing within 30 min were observed. The serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and progesterone (P) were detected by radioimmunoassay, and the expression of gonadotropin-releasing hormone (GnRH) mRNA in hypothalamus and ovary, GnRH receptor (GnRH-R) mRNA in pituitary, estrodiol receptor (ER) mRNA and progesterone receptor (PR) mRNA in uterus were determined using RT-PCR.

After modeling, the writhing latency shortened considerably and the writhing times, serum FSH, LH and E2 levels increased apparently, and serum P content decreased markedly (P<0.05). Compared with model group, the writhing times, serum FSH, LH, and E2 contents in acupuncture and ELI groups reduced significantly (P<0.05), while the writhing latency and serum P contents in acupuncture and ELI groups increased remarkably (P<0.05). Compared with control group, hypothalamic GnRH mRNA, ovary GnRH mRNA, pituitary GnRH-R mRNA and uterus ER mRNA expressions in model group were up-regulated significantly, while uterus PR mRNA was down-regulated markedly in model group (P<0.05). In comparison with model group, hypothalamic GnRH mRNA, ovary GnRH mRNA, pituitary GnRH-R mRNA and uterus ER mRNA expressions in acupuncture and ELI groups were suppressed significantly (P<0.05), while uterus PR mRNA expressions in the later two groups were up-regulated obviously (P<0.05).

Acupuncture of CV4, SP6 and SP8 can effectively relieve dysmenorrhea in the rat, which may be closely related to its effects in regulating neuroendocrine activities and the related receptor expression of hypothalamus-pituitary-ovary axis.