Mild moxibustion at different intervention times on the levels of ET-1 and NO in the uterine tissues of rats with cold-damp coagulation and stagnation type dysmenorrhea

Objective

To observe the differences in analgesic effect of moxibustion at different intervention times on dysmenorrhea rats and explore its effect mechanism.

Methods

Forty-five female Wistar rats were randomly divided into blank control group (group A), model group (group B), pre-moxibustion group (group C), instant moxibustion group (group D) and pre-instant moxibustion group (group E), with 9 rats in each group. Cold-damp coagulation and stagnation type dysmenorrhea models were established. In group C, mild moxibustion on “Shénquè (神阙 CV 8) ” and “Guānyuán (关元 CV 4)” was carried out from the time after modeling on the 8th day for 3 consecutive days. In group D, mild moxibustion was given as the same methods with group C after injection with oxytocin on the 11th day. In group E, mild moxibustion was given as the same methods from the time after modeling on the 8th day to that after injection with oxytocin on the 11th day for 4 consecutive days. The writhing behavior and the changes in levels of ET-1 and NO in uterine tissues of rats with dysmenorrhea in each group were observed.

Results

Comparison of the latent period: compared with (4.38?±?1.06) min in group B, the latent period of rats in group C (9.67?±?1.32) min, group D (11.78?±?1.30) min and group E (15.00?±?1.22) min obviously prolonged (all p < 0.01). Compared with group C, the latent period of group E obviously prolonged (p < 0.01). Compared with group D, the latent period of group E obviously prolonged (p < 0.01).Comparison of the writhing times: compared with (4.38?±?1.06) in group B, the writhing times of rats in group C (9.67?±?1.32), group D (11.78?±?1.30) and group E (15.00?±?1.22) reduced (all p < 0.01). Compared with group C, the writhing times of rats in group D and group E reduced (both p < 0.01). Compared with group D, the writhing times in group E reduced (p < 0.05). Comparison of the total writhing score: compared with (4.38?±?1.06) in group B, the total writhing score of rats in group C (9.67?±?1.32), group D (11.78?±?1.30) and group E (15.00?±?1.22) decreased (all p < 0.01). Compared with group C, the total writhing score of rats in group D and group E decreased (both p < 0.01). Compared with group D, the total writhing score of rats in group E decreased (p < 0.05). Comparison of ET-1 level: compared with (4.80?±?0.47) in group A, the ET-1 level in uterine tissues of rats in group B (7.57?±?0.69) significantly increased (P < 0.01). Compared with group B, the ET-1 level in uterine tissues of rats in group C (6.20?±?0.50), group D (5.67?±?0.29) and group E (5.16?±?0.33) obviously decreased (all p < 0.01). Compared with group C, the ET-1 level in uterine tissues of rats in group D and group E obviously decreased (p < 0.05, p < 0.01). Compared with group D, the ET-1 level in uterine tissues of rats in group Eobviously decreased (p < 0.05). Comparison of NO level: compared with (6.63?±?1.83) in group A, the NO level in uterine tissues of rats in group B (1.62?±?0.58) significantly decreased (p < 0.01). Compared with group B, the NO level in uterine tissues of rats in group C (3.60?±?0.59), group D (4.77?±?0.67) and group E (5.99?±?0.63) obviously increased (all p < 0.01). Compared with group C, the NO level in uterine tissues of rats in group Dand group E obviously increased (p < 0.05, p < 0.01). Compared with group D, the NO level in uterine tissues of rats in group E obviously increased (p < 0.01).

Conclusion

The analgesic effect of mild moxibustion at different intervention times on cold-damp coagulation and stagnation type dysmenorrhea rats was different, which was the most significant in pre-instant moxibustion group. One of the mechanisms of action may be related with the adjustment of abnormal levels of ET-1 and NO.