Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Korean J Pain. 2011 Dec;24(4):185-90. doi: 10.3344/kjp.2011.24.4.185. Epub 2011 Nov 30.
Spinal nerve ligation (SNL) injury in rats produces a pain syndrome that includes mechanical and thermal allodynia. Previous studies have indicated that proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) play an important role in peripheral mediation of neuropathic pain, and that altered dorsal root ganglion (DRG) function and degree of DRG neuronal apoptosis are associated with spinal nerve injury. The present study was conducted to evaluate the expression of TNF-α and the extent of apoptosis in the dorsal root ganglion after SNL in rats.
Sprague-Dawley rats were subjected to SNL of the left L5 and L6 spinal nerves distal to the DRG and proximal to the formation of the sciatic nerve. At postoperative day 8, TNF-α protein levels in the L5-6 DRG were compared between SNL and naive groups using ELISA. In addition, we compared the percentage of neurons injured in the DRG using immunostaining for apoptosis and localization of activated caspase-3.
SNL injury produced significant mechanical and cold allodynia throughout the 7-day experimental period. TNF-α protein levels were increased in the DRG in rats that had undergone SNL (12.7 ± 3.2 pg/100 µg, P < 0.001) when compared with naïve rats (4.1 ± 1.4 pg/100 µg). The percentage of neurons or satellite cells co-localized with activated caspase-3 were also significantly higher in rats with SNL than in naïve rats (P < 0.001, P < 0.05, respectively).
SNL injury produces mechanical and cold allodynia, as well as TNF-α elevation and apoptosis in the DRG.
大鼠的脊神经结扎（SNL）损伤会产生一种疼痛综合征，包括机械性和热感觉过敏。先前的研究表明，促炎细胞因子如肿瘤坏死因子-α（TNF-α）在周围介导神经病理性疼痛中起着重要作用，并且背根神经节（DRG）功能的改变和 DRG 神经元凋亡的程度与脊神经损伤有关。本研究旨在评估大鼠 SNL 后 DRG 中 TNF-α的表达和凋亡程度。
将 Sprague-Dawley 大鼠的左侧 L5 和 L6 脊神经在 DRG 远端和坐骨神经形成处进行 SNL。术后第 8 天，通过 ELISA 比较 SNL 组和对照组 L5-6 DRG 中 TNF-α 蛋白水平。此外，我们通过凋亡免疫染色和活化 caspase-3 的定位比较了 DRG 中损伤神经元的百分比。
SNL 损伤导致大鼠在整个 7 天实验期间产生明显的机械性和冷感觉过敏。与对照组相比，SNL 大鼠的 DRG 中 TNF-α 蛋白水平升高（12.7 ± 3.2 pg/100 µg，P < 0.001）。SNL 大鼠与对照组相比，与活化 caspase-3 共定位的神经元或卫星细胞的百分比也显著升高（P < 0.001，P < 0.05）。
SNL 损伤会产生机械性和冷感觉过敏，以及 DRG 中 TNF-α 的升高和凋亡。
