To observe the effect of drug-paste separated moxibustion of "Mingmen" (GV 4) on the levels of serum estrogen (E2) and progesterone (P) and their endometrial receptor mRNA expression in rats with primary dysmenorrhea in order to investigate its mechanism underlying improvement of primary dysmenorrhea.
A total of 100 female SD rats were randomized into control, model, medication, acupuncture and moxibustion groups, with 20 rats in each group. Primary dysmenorrhea model was established by subcutaneous injection of Benzestrofol for 10 days and intraperitoneal injection of Oxytocin for 1 d. Rats of the medication group were fed with extractum leonuri inspissatum (8 g/100 g) and those of the moxibustion group treated with drug-paste separated moxibustion at "Mingmen" (GV 4). For rats of the acupuncture group, a filiform needle was inserted into GV 4, manipulated for a while and retained for 30 min. The treatment of the latter 3 groups was conducted once daily for 7 days. The rat's body-writhing latency and times during 30 min were recorded. The contents of serum E2 and P were detected by ELISA, and the expression of estrogen receptor (ER) mRNA and progesterone receptor (PR) mRNA in the endometrium was determined by quantitative real-time (RT)-PCR.
(1) The body-writhing latency was shorter and the writhing times were more in the model group than in the control group (P < 0.01). Compared with the model group, the body-writhing latency was significantly increased and the writhing times were obviously decreased in the medication, acupuncture and moxibustion groups (P < 0.01). There were no significant differences among the medication, acupuncture and moxibustion groups in the body-writhing latency (P > 0.05), but the body-writhing numbers of the acupuncture and moxibustion groups were markedly lower than that of the medication group (P < 0.01). (2) Compared with the control group, serum E2 content and endometrial ER mRNA expression level were significantly increased, and serum P content and endometrial PR mRNA level evidently decreased in the model group (P < 0.01, P < 0.05). In comparison with the model group, serum E2 contents and endometrial ER mRNA expression levels were considerably down-regulated, and serum P contents and endometrial PR mRNA expression levels markedly up-regulated in the medication, acupuncture and moxibustion groups (P < 0.01, P < 0.05). The effects of the moxibustion group were significantly superior to those of the acupuncture and medication groups, and those of the acupuncture group were also significantly superior to those of the medication group in lowering E2 and endometrial ER mRNA levels, and raising serum P and endometrial PR mRNA expression levels (P < 0.01, P < 0.05).
Drug-paste separated moxibustion of GV 4 is effective in relieving pain in primary dysmenorrheal rats, which is probably associated with its effects in down-regulating serum E2 content and endometrial ER mRNA expression, and up-regulating serum P and endometrial PR mRNA expression levels.