Objective: The aim of this study was to observe the effects of extracorporeal shock waves (ECSWs) on neuralgia in diabetic rats.
Materials and methods: Diabetic neuralgia model was established in rats via injection of streptozotocin. The rats were divided into diabetic neuralgia group (Group A, n=6) and ECSW treatment group (Group B, n=6). Another six rats were taken as control group (Group C, n=6). The mechanical withdrawal threshold (MWT) and thermal withdrawal latencies (TWLs) were measured at specific points throughout the experiment, and the sciatic nerve was bluntly severed under anesthesia after the last measurement. The protein expressions of Sphk1 and TNF-α were detected by Western blot, and the mRNA expressions of Sphk1 and TNF-α were detected by reverse transcription PCR. The structure of the sciatic nerve was observed by electron microscopy.
Results: Compared with Group C, MWT and TWLs were decreased significantly in Groups A and B (P< 0.05). The protein expressions of TNF-α and Sphk1 in Groups A and B were both significantly higher than those in Group C (P<0.05), with higher expression in Group A than in Group B (P<0.05). The mRNA expressions of TNF-α and Sphk1 were similar. Electron microscopy showed the intact structure of the myelin sheaths of the sciatic nerve fibers in Group C, whereas the structure of the nerve fibers was damaged, with a large number of vacuoles in the myelin sheath in Group A. In Group B, the vacuoles were occasionally formed on the sciatic nerve myelin sheath, with more compact and tidy layer arrangement compared with Group A.
Conclusion: ECSWs can relieve neuralgia in diabetic rats. Sphk1 and TNF-α may be involved in the occurrence and development of diabetic peripheral neuralgia.
Keywords: ECSWs; Sphk1; TNF-α; diabetic neuralgia; extracorporeal shock waves; rats.