糖尿病神经痛大鼠背根神经节细胞动作电位特征变化

Changes of action potential properties in dorsal root ganglion neurons of rats with diabetic neuropathy pain

目的通过观察背根神经节细胞的动作电位特征在糖尿病大鼠周围神经病变中的变化,探讨糖尿病大鼠周围神经病变引起痛觉过敏的发生机制。方法运用全细胞电流钳技术对糖尿病周围神经痛觉过敏大鼠背根神经节细胞进行电生理记录,与正常大鼠比较静息电位水平、动作电位峰值、基强度、动作电位爆发阈值、动作电位时程变化。结果糖尿病神经痛大鼠与正常大鼠静息电位水平和动作电位峰值无显著性差异;糖尿病神经痛大鼠大、中、小直径神经元动作电位爆发阈值下降,动作电位时程变宽,中、小直径神经元基强度降低。结论糖尿病大鼠周围神经病变引起初级感觉神经元背根神经节细胞的兴奋性增强,这可能是引起糖尿病大鼠周围神经痛觉过敏原因之一。

Objective It is to observe the action potential electrophysiological changes of dorsal root ganglion neurons in rats with painful diabetic peripheral neuropathy,and thus to elucidate the mechanism of hyperalgesia during diabetic peripheral neuropathy.Methods Dorsal root ganglion neurons from rats with painful diabetic peripheral neuropathy selected for electrophysiological recording the whole cell current.V rest,V peak,rheobase,Vthreshold,APD level changes were recorded and compared with that of normal rats.Results V rest and V peak showed no significant difference between the rats with painful diabetic peripheral neuropathy and the normal rats.The threshold of action potential outbreak were reduced and the duration of action potential were broadened in large,medium and small dorsal root ganglion neurons in the rats with diabetic peripheral neuropathy;The lower rheobase was observed in both small and medium dorsal root ganglion neurons from diabetic peripheral neuropathy.Conclusion Painful diabetic peripheral neuropathy could induce hyperexcitability of primary sensory neurons,which might be an important mechanism for hyperalgesia during diabetic peripheral neuropathy.