Changes of P2X_3 receptor of the spinal cord after sciatic nerve injury in rats

Objective To observe the changes of P2X_3 receptor of the spinal cord after chronic constriction injury(CCI)of the sciatic nerve in rats.Methods 20 adult male SD rats were randomly divided into normal group,day 3,day 7 and day 14 after CCI of the sciatic nerve groups.The paw withdrawal pressure threshold(PWPT)of rats was determined by von Frey's method of microfilament.The expression of P2X_3 receptor in the dorsal horn of the spinal cord in rats was detected by immunohistochemical technique.Results After sciatic nerve injury,PWPT of the operated sides decreased at the 7 and 14 days after CCI,and the immune positive reac- tion rate of P2X_3 receptor at the L4-5 levels of dorsal horn of operated sides increased obviously. Conclusion After sciatic nerve injury,the increase of PWPT is consistent with the immune re- action positive rate of P2X_3 receptor in dorsal horn of lumbar spinal cord at L4-5 levels,suggests that P2X_3 receptor may be involved in adjustment of pain information in the spinal cord.