Ligustrazine inhibits high voltage-gated Ca^(2+) and TTX-resistant Na^+ channels of primary sensory neuron and thermal nociception in the rat:a study on peripheral mechanism

作     者：Bi-Hua BIE Yong CHEN Zhi-Qi ZHAO 

作者机构：Institute of Shanghai Physiology Chinese Academy of Sciences Shanghai 200031 China Institute of Neurobiology Fu-Dan University Shanghai 200433 China 

出 版 物：《Neuroscience Bulletin》 (神经科学通报（英文版）)

年 卷 期：2006年第22卷第2期

页      面：79-84页

核心收录：

学科分类：0831[工学-生物医学工程（可授工学、理学、医学学位）] 08[工学] 

基　　金：NNSFC(30330230) NBRPC(2006CB500800) 

主　　题：ligustrazine nociception dorsal root ganglion sodium channel calcium channel 

摘      要：Objective Ligustrazine, also named as tetramethylpyrazine, is a compound purified from Ligusticum chuanxiong hort and has ever been testified to be a calcium antagonist. The present investigation was to determine the antinociceptive effect of ligustrazine and, if any, the peripheral ionic mechanism involved. Methods Paw withdrawal Latency （PWL） to noxious heating was measured in vivo and whole-cell patch recording was performed on small dorsal root ganglion （DRG） neurons. Results Intraplantar injection of ligustrazine （0.5 mg in 25 μl） significantly prolonged the withdrawal latency of ipsilateral hindpaw to noxious heating in the rat. Ligustrazine not only reversibly inhibited high-voltage gated calcium current of dorsal root ganglion （DRG） neuron in dose-dependent manner with IC50 of 1.89 mmol/L, but also decreased tetrodotoxin （TTX） -resistant sodium current in relatively selective and dose-dependent manner with IC50 of 2.49 mmol/L. Conclusion The results suggested that ligustrazine could elevate the threshold of thermal nociception through inhibiting the high-voltage gated calcium current and TTX-resistant sodium current of DRG neuron .in the rat.