Peripheral nerve injury and inflammation often leads to some new protein synthesis in dorsal root ganglia and spinal dorsal horn and contributes to the development of chronic pain.Previous studies have shown the expression ofcaveolin-1 plays an active role in the regulation of injury induced synaptic and terminal remodeling in the adult CNS.As an adaptor protein, caveolin-1 also involves in the process of learning and memory in hippocampus by regulating the function of glutamate receptor.However whether caveolin-1 also expressed in dorsal root ganglia and spinal dorsal horn following the development of chronic pain still remained unknown.In the present study, the lumbar 5 spinal nerve ligation (L5 SNL), sciatic nerve transaction and plantar injection of Complete Freunds Adjuvant (CFA) were used in rats to induce chronic pain.The ipsilateral and contralaterial L4-6dorsal root ganglia and spinal dorsal horn (SDH) were collected at different time point after surgery, and then the caveolin-1 protein was detected by using Western Blotting.Our results showed: (1) L5 SNL induced a significant increase expression of caveolin-1 in ipsilateral L4-6 DRGs and L4-6 SDH.Compared with control group, the protein level of caveolin-1 in DRGs rise (51.41±3.67)%, (86.33±4.72)%, (109.12±6.81)% and (79.46±5.31)% at day 7, 10, 14 and 21 after L5 SNL, respectively (P<0.05), and at day 28, the protein returned to basal level.In SDH the significant increase expression of caveolin-1 happened at day 5, 7, 10, 14 and 21 after L5 SNL, and the protein increased (77.54±5.02)%, (116.75±6.07)%, (150.62±7.36)%, (178.91±9.77)% and (169.82±8.56)%, respectively,compared with control group (P<0.05).But, there is no significant change of the expression of caveolin-1 in contralateral DRGs and SDH after L5 SNL.To further confirm the above results, sciatic nerve transactions in another group of rats were also performed.The result showed the expression of caveolin-1 in DRGs and SDH is same as in the model of L5 SNL.(2) Intra plantar injection of CFA caused clear increased expression of caveolin-1 in L4-6 DRGs and L4-6 SDH.Compared with control group, the protein level of caveolin-1 in DRGs rise (81.23±4.35)%, (109.31±3.98)%, (101.79±6.77)% at day 2, 5 and 7, respectively (P<0.05) and returned to basal at day 14 after CFA injection.While, the significant increase expression of caveolin-1 in SDH took place at day 5,7, 10 and 14 after CFA injection, and the protein level rise (65.35±3.31)%, (87.67±3.55)%, (120.91±5.21)% and (111.72±5.06)%, respectively, compared with control (P<0.05).Taken together, the above data indicate peripheral nerve injury and the inflammation caused the increase expression of caveolin-1 in DRGs and SDH following the development of chronic pain.