Study On The Analgesic Mechanism Of Moxibustion At Zusanli,and The Expression Of P2X3Receptor And SP In The Spinal Cord

Objective:This experiment studies the change of the expression of P2X3receptor and substance P after moxibustion at Zusanli, verify whether through stimulating "Zusanli" with moxibustion, thereby affecting changes of the receptors in nerve receptors innervated points corresponding spinal segment, to study the mechanism of moxibustion analgesia. The experiment could provide put forward scientific experimental basis for clinical application of moxibustion prevention and treatment of rheumatoid arthritis and other inflammatory pain.Methods:30clean male SD rats were used and randomly placed in one of the normal group, the model group and the moxibustion group,10rats in each group. Complete freund’s adjuvant (CFA) was used in the right foot of rats of the model group and the moxibustion group for model. Three groups of rats pain threshold and the right foot volume were respectively measured before the model and building for3days. Then, the rats of moxibustion group were treated by acupuncture the Zusanli of right foot, once per day and15minutes each time. The pain threshold and the right foot volume were measured once again after6days treatment. After that, the spinal cord segment (L4-L6) was fixed by the heart perfusion and the expression of P2X3receptor and substance P in the spinal cord were detected by immunofluorescence histochemical double standard method.Result:1. The result of the right foot volume:(1) The group comparison:both of the model group and the moxibustion group foot volume increased after building(p<0.01); after treatment,the model group foot volume increased compared before building (p<0.01).Compared after treatment, the moxibustion group foot volume increased after building (p<0.05), and decreased before building (p<0.01).(2) The comparison between groups:compared with the normal group, both of the model group and the moxibustion group foot volume increased (p<0.01). After treatment, both of the model group and the moxibustion group increased compared with the normal group (p<0.01),compared with the model group, the moxibustion group foot volume decreased (p<0.05).The results showed that the model was feasible and the moxibustion group had effective treatment. After treatment, the swelling degree of rat right toes of the moxibustion group was smaller with the model group. However, compared with the normal group, rat right toes of the moxibustion group still had obvious swell.2. The result of pain threshold:(1) The group comparison:compared before building, the model group pain threshold decreased after building and treatment (p<0.05); compared after building, the moxibustion group pain threshold increased before building and after treatment (p<0.05).(2) The comparison between groups: compared with the normal group, both of the model group and the moxibustion group pain threshold reduced(p<0.05). After treatment, compared with the normal group,the model group and the moxibustion group pain threshold reduced(p<0.05); and compared with the model group, the moxibustion group pain threshold increased(p<0.01). The results indicated the model was successful and the pain threshold of rats of the moxibustion group significantly improved, which showed that the treatment was effective.3. The results of immunofluorescence histochemical double standard method:The expression of P2X3in the spinal dorsal horn, compared with the normal group, the mean fluorescence intensity of model group and the moxibustion group increased (p<0.05), but the mean fluorescence intensity of moxibustion group was obvious lower than the nodel group (p<0.05), which indicated that the expression of P2X3receptor in the spinal dorsal horn increased significantly after building, and the moxibustion treatment could inhibit its expression. The expression of SP in the spinal dorsal horn. Compared with the normal group, the mean fluorescence intensity of the model group increased (p<0.01), and the mean fluorescence intensity of moxibustion group was slower than the model group (p<0.05), which showed that the expression of SP increased significantly after building, and the moxibustion treatment could inhibit its expression. As Shown in the composite image, the co-expression positive cells of P2X3receptor and SP, which were most in model group and the moxibustion took second place, hardly existed in the normal group. Conclusion:1. The moxibustion has obvious analgesic effect to rheumatoid arthritis and other inflammatory pain.2. P2X3receptor and SP changed in the spinal cord of adjuvant arthritis rats with the development of the pain, we considerd that the moxibustion could play the analgesic action by intervening the expression of P2X3receptor and SP.3. In the mechanism of moxibustion analgesia, the P2X3receptor may be participate in the transmission of information outside of the spinal cord, through decreasing the excitatory synaptic transmission regulated by SP.