Effect of electroacupuncture preconditioning on the expression of 5-HT7 receptors in the periaqueductal gray of rats with incision pain
Objective:To explore the analgesic effect of repetitive electroacupuncture preconditioning on incisional pain and its effect on the expression of 5-HT7 receptors(5-HT7R)in the periaqueductal gray(PAG)by estab-lishing a rat model of toe incision pain.Methods:Forty male SD rats were randomly divided into control group(group Con),incision pain group(group IP),control + electroacupuncture group(group Con + EA),and incision pain + electroacupuncture group(group IP + EA).Operation was performed on the right toe of rats in group IP and group IP + EA,and electroacupuncture was used to stimulate Zusanli and Huantiao points of the right leg of rats in group Con + EA and group IP + EA for 5 days before operation(with the frequency of 2/10 Hz,the intensity of 1,30 min/day/time).The mechanical withdrawal threshold(MWT)and the thermal withdrawal latency(TWL)of rats were measured at 2 h before the first electroacupuncture pretreatment(T1),2 h before the operation(T2),4 h after the operation(T3),and 24 h after the operation(T4).After the last behavioral test,the brain tissue and cerebrospinal fluid of rats were colleccted.The concentration of 5-HT in cerebrospinal fluid was measured by enzyme linked immunosorbent assay;immunohistochemical and im-munofluorescence methods were used to detect the expression of c-Fos and 5-HT7R proteins in the PAG of rats respectively.Results:Compared with group Con,MWT and TWL of rats in group IP were decreased significantly at T3 and T4,while the concentration of 5-HT in cerebrospinal fluid was increased,and the expression of c-Fos protein and 5-HT7R in PAG were increased significantly(P<0.05);the content of 5-HT in cerebrospinal fluid and the ex-pression of 5-HT7R in PAG were increased in group Con + EA and group IP + EA(P<0.05).Compared with group IP,MWT and TWL of rats in group IP + EA were significantly increased at T3 and T4,the expression of c-Fos pro-tein in PAG was decreased,and the expression of 5-HT7R protein was increased(P<0.05).Conclusion:Electroacu-puncture preconditioning may play an analgesic role by upregulating the expression of 5-HT7R protein in the PAG.
万方数据
维普
