前列腺酸性磷酸酶在慢性痛大鼠脊髓背角和背根神经节的表达变化

目的:观察前列腺酸性磷酸酶(prostatic acid phosphatase,PAP)在多种慢性痛大鼠脊髓背角(spinaldorsal horn,SDH)和背根神经节(dorsal root ganglion,DRG)内的表达变化。方法:应用免疫组织化学染色法以及免疫荧光多重染色技术在多种慢性痛模型大鼠观察PAP的表达变化。结果:在正常大鼠,PAP阳性反应产物主要位于DRG的中、小型的非肽能神经元,PAP阳性神经元约占DRG神经元总数的64±4.3%;在脊髓背角,PAP阳性纤维和终末主要位于Ⅱ层。在神经病理性痛模型大鼠,术侧脊髓背角Ⅱ层的PAP阳性初级传入终末较对侧减少甚至消失,DRG内PAP阳性神经元较对侧明显减少。在慢性炎性痛模型大鼠,双侧脊髓背角和DRG内PAP的表达未见明显改变。结论:PAP特异地定位于DRG神经元以及脊髓背角Ⅱ层,可能与神经病理性痛信号的传递和加工密切相关。

Changes of the expression of prostatic acid phosphatase in spinal dorsal horn and dorsal root ganglion in different chronic pain models of the rat

Objective: To observe the expression changes of prostatic acid phosphatase(PAP) in the spinal dorsal horn(SDH) and dorsal root ganglion(DRG) in different chronic pain models of the rat.Methods: Immunohistochemistry combined with multiple immunofluorescent histochemical technique was employed to detect the expression changes of PAP in different chronic pain models.Results: In the intact normal rats,PAP was principally located in small-to medium-sized non-peptidergic neurons in the DRG,and the number of PAP-immunoreactive(PAP-ir) neurons was about 64±4.3% to the total number of the DRG neurons.In the SDH,only PAP-ir fibers and terminals but not PAP-ir neurons were exclusively observed in lamina I and II,especially in lamina II.In a model of neuropathic pain rat,PAP immunoreactivities were markedly decreased,or even vanished in the SDH and DRG ipsilateral to the nerve injury side.There were no remarkable changes of the PAP expression on the side contralateral to the nerve injury.In an inflammatory pain model induced by CFA injection into the rat hindpaw,however,there were no obvious expression changes of PAP-ir neurons,fibers and terminals in bilateral SDHs and DRGs.Conclusion: PAP is specifically expressed in the SDH and DRG.It might play important roles in the transduction and process of the signals of the neuropathic pain.