Li Na, Li Chao, Fan Juan, Jiang Xiao-Zhong, Li Jin-Bao, Deng Xiao-Ming, Ma Bei
Department of Anaesthesia, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.
Sheng Li Xue Bao. 2009 Feb 25;61(1):72-8.
The purpose of this study was to establish a model of trigeminal neuralgia (TN) through an approach from lower edge of cheekbone and to observe the functional changes in the voltage-gated potassium currents in the cultured trigeminal ganglion (TG) neurons. Thirty Sprague-Dawley male rats were divided into two groups, the sham-operated (sham) group and the operated group. The TN model was carried out by using a chronic constriction injury of the infraorbital nerve (ION-CCI) from lower edge of cheekbone. Peripheral pain threshold test and whole-cell patch clamp recording were used to determine the difference between sham and ION-CCI rats. The withdrawal threshold of whisker pad in operated side of ION-CCI rat was decreased significantly from 6 d after operation and then maintained until 21 d, with the lowest on the 15th day. The threshold of whisker pad in non-operated side of operated rats was also decreased significantly compared with that in the sham group. Delayed rectifier potassium current (I(K)) in cultured ION-CCI TG neurons was decreased significantly compared with that in the sham group. Transient outward potassium currents (I(A)) in both operated and non-operated sides of TG neurons from ION-CCI rats were also reduced significantly compared with that in the sham group. The present study provided a new method of ION-CCI. In this model, the decrease of I(A) and I(K) might contribute, at least in part, to the decrease in mechanical pain threshold of whisker pad and the subsequent hyperalgia.
本研究的目的是通过从颧骨下缘入路建立三叉神经痛（TN）模型，并观察培养的三叉神经节（TG）神经元中电压门控钾电流的功能变化。将30只Sprague-Dawley雄性大鼠分为两组，即假手术（sham）组和手术组。通过从颧骨下缘对眶下神经（ION-CCI）进行慢性压迫损伤来建立TN模型。采用外周疼痛阈值测试和全细胞膜片钳记录来确定假手术组和ION-CCI大鼠之间的差异。ION-CCI大鼠手术侧触须垫的撤针阈值自术后6天起显著降低，然后持续至21天，在第15天最低。手术大鼠非手术侧触须垫的阈值与假手术组相比也显著降低。与假手术组相比，培养的ION-CCI TG神经元中的延迟整流钾电流（I(K)）显著降低。与假手术组相比，ION-CCI大鼠TG神经元手术侧和非手术侧的瞬时外向钾电流（I(A)）也显著降低。本研究提供了一种新的ION-CCI方法。在该模型中，I(A)和I(K)的降低可能至少部分导致触须垫机械性疼痛阈值的降低及随后的痛觉过敏。
