Résumé
Objective To explore the roles of spinal microglial Src-family kinases (SFKs) in diabetic neuropathic pain. Methods Male Sprague-Dawley rats, weighing 200 ~ 220 g, were used in the experiments. The level of p-SFKs in spinal dorsal horn was detected by single immunofluorescence staining on day 7th , 14th and 28th after intraperitoneally injection of Streptozotocin (STZ) and its location was detected by double immunofluorescence staining. The changes of 50% paw-withdrawal thresholds of rat were detected by behavioral tests when PP2 , a specific inhibitor of SFKs , was intrathecally administered before intraperitoneally injection of STZ. Results Compared with vehicle group, the blood glucose level increased on day 1 (P < 0.001) and the hyperglycemia persisted at least for 28 days (P < 0.001) after intraperitoneally administered of STZ (50 mg/kg). Paw-withdrawal threshold (PWT) decreased gradually from day 1 (P < 0.05) and reached the minimum on day 28 (P < 0.001) after STZ administration. Meanwhile, the expression of p-SFKs in spinal dorsal horn markedly increased on day 7 (P < 0.01), day 14 (P < 0.01) and day 28 (P < 0.01). The p-SFKs was mainly co-localized only with microglia , but not with neurons or with astrocytes. Intrathecally administered of PP2 before STZ reversed STZ-induced mechanical hyperalgesia. Conclusion Microglial SFKs in spinal dorsal horn maybe play a pivotal role in diabetic neuropathic pain.
Résumé
AIM:To investigate the effects of P2X4 receptor on peri-sciatic administration of recombinant rat TNF-α(rrTNF)-induced mechanical allodynia.METHODS:Male Sprague-Dawley rats (180~200 g) were used in the experiments.The levels of P2X4 receptor on day 3, day 7 and day 14 after peri-sciatic administration of rrTNF were exam-ined by Western blot, and the location of P2X4 receptor in the spinal dorsal horn was observed by double immunofluores-cence staining.The changes of 50%paw-withdrawal thresholds of the rat were detected by behavioral test, and the level of TNF-αin the spinal dorsal horn was also examined by Western blot when TNP-ATP was intrathecally injected before the ad-ministration of rrTNF.RESULTS:Compared with control group, the expression of P2X4 receptor in the spinal dorsal horn on the ipsilateral side significantly increased on day 3, day 7 and day 14 (P<0.01) after rrTNF (100 ng/L) administra-tion.P2X4 receptor was co-localized only with microglia, but not with neurons or astrocytes.Intrathecal injection of TNP-ATP before rrTNF administration prevented mechanical allodynia induced by rrTNF and inhibited the upregulation of TNF-αin the spinal dorsal horn.CONCLUSION:P2X4 receptors in microglia may be involved in rrTNF-induced mechanical allodynia by the upregulation of TNF-αin the spinal dorsal horn.