Department of Anaesthesiology, Cancer Hospital, Guangzhou Medical University, Guangzhou, 510095, China.
Eur J Pharmacol. 2012 Jan 15;674(2-3):234-8. doi: 10.1016/j.ejphar.2011.10.025. Epub 2011 Oct 26.
This study investigated the antinociceptive effect of intrathecal escin and examined its effect on the formalin-induced activation of c-Fos and phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK) in the rat spinal cord. Rats were chronically implanted with lumbar intrathecal catheters, and the ability of intrathecal escin to alter nociceptive behaviours in the rat formalin test was examined. The expression of c-Fos and p-p38 MAPK in the dorsal horn of the spinal cord was detected in the control and escin (40μg) groups using immunohistochemical techniques. Intrathecal escin produced a dose-dependent reduction in formalin-evoked flinching behaviour in rats during the second phase; however, no effect was observed in the first phase. In addition, immunohistochemical experiments showed that the expression of c-Fos and p-p38 MAPK in the spinal cord dorsal horn increased after an injection of formalin into the paw. Interestingly, the 40μg dose of intrathecal escin, which was the larger of the two doses that blocked formalin-induced hyperalgaesia, attenuated the formalin-induced increases in c-Fos and p-p38 MAPK in the dorsal horn of the spinal cord. The decrease in pain-related behaviours and c-Fos expression indicated that escin produced antinociceptive effects in the rat formalin test. Although the specific mechanisms of these effects were not investigated, the reduction in p-p38 MAPK in the dorsal horn of the spinal cord may be involved.
本研究探讨了鞘内七叶皂苷钠的抗伤害作用，并观察其对大鼠脊髓福尔马林诱导的 c-Fos 和磷酸化 p38 丝裂原活化蛋白激酶（p-p38 MAPK）激活的影响。大鼠被慢性植入腰穿导管，并通过福尔马林试验观察鞘内七叶皂苷钠改变大鼠伤害性行为的能力。使用免疫组织化学技术检测对照组和七叶皂苷钠（40μg）组大鼠脊髓背角中 c-Fos 和 p-p38 MAPK 的表达。鞘内七叶皂苷钠在第二阶段产生了剂量依赖性地减少福尔马林诱发的大鼠退缩行为；然而，在第一阶段没有观察到这种作用。此外，免疫组织化学实验表明，福尔马林注入 paw 后，脊髓背角中 c-Fos 和 p-p38 MAPK 的表达增加。有趣的是，鞘内给予较大剂量的 40μg 七叶皂苷钠可阻断福尔马林诱导的痛觉过敏，减轻福尔马林诱导的脊髓背角 c-Fos 和 p-p38 MAPK 的增加。疼痛相关行为和 c-Fos 表达的减少表明，七叶皂苷钠在大鼠福尔马林试验中产生了镇痛作用。虽然没有研究这些作用的具体机制，但脊髓背角中 p-p38 MAPK 的减少可能与之有关。
