Effects of moxibustion at different times on prostaglandin and vasopressin levels in uterine tissues of rats with dysmenorrhea due to cold-dampness retention

Objective To observe the effects of moxibustion at different times on prostaglandin E 2 (PGE 2 ), prostaglandin F 2α (PGF 2α ) 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 immediatemoxibustion group ( n =9). Rat models of primary dysmenorrhea due to cold-dampness retention were established using (0±1) °C 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 PGF 2α in the rat uterine tissues was measured by enzyme-linked immunosorbent assay (ELISA), and the levels of PGE 2 and AVP in rat uterine tissues were measured by radioimmunoassay. Results Compared with the blank control group, the levels of PGF 2α and AVP, the PGF 2α /PGE 2 ratio in the model group were significantly increased ( P