Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006, PR China.
Brain Res Bull. 2012 Jan 4;87(1):37-43. doi: 10.1016/j.brainresbull.2011.10.007. Epub 2011 Oct 21.
Tissue injury or inflammation of the nervous system may result in chronic neuropathic pain characterized by sensitivity to painful stimuli. P2X(3) receptors play a crucial role in facilitating pain transmission. Puerarin is an active compound of a traditional Chinese medicine Ge-gen, and Ge-gen soup has anti-inflammatory effects. The present research investigated the role of puerarin in the signalling of chronic neuropathic pain mediated by P2X(3) receptors of rat dorsal root ganglion neurons. Chronic constriction injury (CCI) rat model was adopted. Sprague-Dawley rats were randomly divided into blank control group (Ctrl), sham group (Sham), puerarin-treated control group (Ctrl+PUE), chronic constriction injury (CCI) group and puerarin-treated CCI group (CCI+PUE). Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured by the von-Frey test and the Hargreaves' test respectively. The stain values of P2X(3) protein and mRNA in L4/L5 dorsal root ganglion (DRG) were detected by immunohistochemistry, western blot and in situ hybridization. At day 4-7 after the operation of CCI rats, MWT and TWL in group CCI and CCI+PUE were lower than those in group Ctrl, Sham and Ctrl+PUE, while there was no difference among group Ctrl, Sham and Ctrl+PUE. At day 7-10 after operation, MWT and TWL in group CCI+PUE was higher than those in group CCI, but there was no significant difference between group CCI+PUE and group Ctrl (p>0.05). At day 14 after operation, the stain values of P2X(3) proteins and mRNAs in L4/L5 DRG of group CCI were higher than those in group Ctrl, Sham, Ctrl+PUE and CCI+PUE, while the stain values of P2X(3) proteins and mRNAs in group CCI+PUE were significantly decreased compared with those in group CCI. Therefore, puerarin may alleviate neuropathic pain mediated by P2X(3) receptors in dorsal root ganglion neurons.
组织损伤或神经系统炎症可能导致以对疼痛刺激敏感为特征的慢性神经性疼痛。P2X(3)受体在促进疼痛传递中起着关键作用。葛根素是中药葛根的一种活性化合物，葛根汤具有抗炎作用。本研究探讨了葛根素在 P2X(3)受体介导的大鼠背根神经节神经元慢性神经性疼痛信号中的作用。采用慢性缩窄性损伤（CCI）大鼠模型。将 Sprague-Dawley 大鼠随机分为空白对照组（Ctrl）、假手术组（Sham）、葛根素处理对照组（Ctrl+PUE）、慢性缩窄性损伤组（CCI）和葛根素处理慢性缩窄性损伤组（CCI+PUE）。采用 von-Frey 试验和 Hargreaves 试验分别测量机械性缩足反射阈值（MWT）和热缩足潜伏期（TWL）。采用免疫组织化学、Western blot 和原位杂交法检测 L4/L5 背根神经节（DRG）中 P2X(3)蛋白和 mRNA 的染色值。CCI 大鼠术后 4-7 天，CCI 组和 CCI+PUE 组的 MWT 和 TWL 均低于 Ctrl 组、Sham 组和 Ctrl+PUE 组，而 Ctrl 组、Sham 组和 Ctrl+PUE 组之间无差异。术后 7-10 天，CCI+PUE 组 MWT 和 TWL 高于 CCI 组，但与 Ctrl 组相比无显著性差异（p>0.05）。术后 14 天，CCI 组 L4/L5 DRG 的 P2X(3)蛋白和 mRNAs 的染色值高于 Ctrl 组、Sham 组、Ctrl+PUE 组和 CCI+PUE 组，而 CCI+PUE 组的 P2X(3)蛋白和 mRNAs 的染色值明显低于 CCI 组。因此，葛根素可能通过减轻背根神经节神经元 P2X(3)受体介导的神经性疼痛。
