Effect of intraperitoneal injection of SRT1720 on nociceptor sensitization and expression and activity of Sirt1 in spinal cord of rats with chronic sciatic nerve constriction injury

Objective To observe the effect of intraperitoneal injection of SRT1720 on the nociceptor sensitization and expression and activity of Sirt1 in spinal cord of rats with chronic sciatic nerve constriction injury. Methods Total 96 case of SD rats were randomly divided into 6 groups:blank control group,sham operation group,chronic constriction injury(CCI) group of the sciatic nerve,CCI+saline injection group,CCI+low dose SRT1720 group,and CCI+high dose group.After the CCI model was established,NS 2.5 ml/kg,SRT1720 20 mg/kg and SRT1720 50 mg/kg were injected into the abdominal cavity through the micro syringe,for 7 consecutive days.The mechanical shrinkage foot reflex threshold(MWT) by von Frey filaments and thermal withdrawal latency(TWL) by heat radiation method were determined before the operation and at 1,3,5,7,10 and 14 d after the operation.The spinal cord was extracted surgically to test Sirt1 protein expression and deacetylase activity. Results SRT1720 could inhibit the mechanical paw withdrawal reflex threshold and thermal paw latency,and the inhibition was more significant with the increased concentration of SRT1720 (P<0.05);SRT1720 increased the expression of Sirt1 protein in the spinal dorsal horn,and the effect increased with the concentration of SRT1720(P<0.05);SRT1720 increased Sirt1 deacetylase activity in spinal dorsal horn,and increased with the concentration(P<0.05). Conclusion Intraperitoneal injection of SRT1720 can inhibit the mechanical and thermal pain sensitivity of CCI rats,which may be related to the increase of Sirt1 expression and activity in spinal cord.