Effects of moxibustion at different times on prostaglandin and vasopressin levels in uterine tissues of rats with dysmenorrhea due to cold-dampness retention / 针灸推拿医学（英文版）

ABSTRACT

Objective: To observe the effects of moxibustion at different times on prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α) and arginine vasopressin (AVP), in the uterine tissues of rats with dysmenorrhea due to cold-dampness retention, and to explore the differences and possible mechanisms of moxibustion at different times in easing pain in dysmenorrhea due to cold-dampness retention. Methods: Forty-three female Wistar rats were randomly divided into a blank control group (n=7), a model group (n=9), a pre-moxibustion group (n=9), an immediate-moxibustion group (n=9) and a pre-moxibustion plus immediate-moxibustion group (n=9). Rat models of primary dysmenorrhea due to cold-dampness retention were established using (0±1) ℃ ice water immersion method combined with injection of estradiol benzoate for 10 d, followed by injection of oxytocin on the 11th day. Rats in the 3 intervention groups received moxibustion to Shenque (CV 8) and Guanyuan (CV 4), 10 min for each acupoint, once a day. Rats in pre-moxibustion group were given mild moxibustion, beginning on the 8th day during modeling, for 3 continuous days; rats in immediate-moxibustion group were given one time mild moxibustion, immediately after injection of oxytocin on the 11th day during modeling; rats in pre-moxibustion plus immediate-moxibustion group were given mild moxibustion, beginning on the 8th day during modeling till immediately after injection of oxytocin on the 11th day during modeling, for 4 continuous days. The level of PGF2α in the rat uterine tissues was measured by enzyme-linked immunosorbent assay (ELISA), and the levels of PGE2 and AVP in rat uterine tissues were measured by radioimmunoassay. Results: Compared with the blank control group, the levels of PGF2α and AVP, the PGF2α/PGE2 ratio in the model group were significantly increased (P<0.01), and the PGE2 level was significantly decreased (P<0.01) in the rat uterine tissues in the model group. Compared with the model group, the writhing latency was significantly prolonged, the writhing number and the total writhing score were all decreased in the pre-moxibustion group, the immediate-moxibustion group and the pre-moxibustion plus immediate-moxibustion group (all P<0.01); the levels of PGF2α and AVP, and the PGF2α/PGE2 ratio were all significantly decreased (P<0.05, P<0.01), and the PGE2 level was significantly increased (P<0.01) in the rat uterine tissues of the 3 treatment groups. Compared with the pre-moxibustion group, the writhing number and the total writhing score were all decreased in the immediate-moxibustion group and the pre-moxibustion plus immediate-moxibustion group (all P<0.01), the writhing latency was significantly prolonged in the pre-moxibustion plus immediate-moxibustion group(P<0.01); the levels of PGF2α and PGF2α/PGE2 ratio were significantly decreased (P<0.05, P<0.01), and the PGE2 level was significantly increased (P<0.01) in rat uterine tissues in the immediate-moxibustion group and the pre-moxibustion plus immediate-moxibustion group. Compared with the immediate-moxibustion group, the writhing latency was significantly prolonged and the writhing number was decreased (all P<0.05), and the total writhing score was decreased (P<0.01) in the pre-moxibustion plus immediate-moxibustion group; the PGF2α level and the PGF2α/PGE2 ratio were significantly decreased (P<0.01), and the PGE2 level was significantly increased (P<0.01) in rat uterine tissues in the pre-moxibustion plus immediate-moxibustion group. Conclusion: Moxibustion at different times all can produce obvious analgesic effects on dysmenorrhea due to cold-dampness retention in rats, and pre-moxibustion plus immediate-moxibustion ranks the top. The mechanism of this analgesic effect may be via the regulation of abnormal PGF2α, PGE2 and AVP levels, to effectively inhibit the spastic contraction of uterine smooth muscle in dysmenorrhea rat, thereby improving the ischemia and hypoxia in uterus.