鞘内注射促皮质素抑制甲醛痛敏大鼠脊髓NOS阳性神经元增多

目的:研究鞘内注射促皮质素(Cor)对甲醛痛敏大鼠脊髓背角一氧化氮合酶(NOS)阳性神经元增多的影响。方法:采用痛级均数(PIR)测定、NADPH-d组织化学法、Fos免疫组织化学法染色,观察鞘内注射(ith)Cor对甲醛痛敏大鼠脊髓背角NOS阳性神经元、Fos免疫反应神经元、NOS/Fos双标记神经元及痛敏的影响。结果:ith Cor(0.5-1.5U)均能显著抑制甲醛引起的大鼠脊髓背角NOS、Fos、NOS/Fos阳性神经元的增多和痛敏反应,其作用为ith NOS底物左旋精氨酸(Arg,5-15nmol)部分翻转。结论:Cor通过抑制大鼠脊髓背角NOS阳性神经元的增多抑制痛敏。

Intrathecal injection of corticotropin inhibited nitric-oxide synthase-positive neuron increase in rat spinal cord after formalin-induced hyperalgesia

AIM: To study the effects of corticotropin (Cor) on formalin-induced hyperalgesia and the change of nitric-oxide synthase (NOS)-positive neurons in spinal dorsal horn in rats. METHODS: Measurement of pain intensity rating (PIR), NADPH-d histochemistry, and Fos immunohistochemistry were adopted. RESULTS: The increases of NOS-positive neurons, Fos, NOS/Fos double labelling neurons of the spinal dorsal horn and the PIR after formalin injection were markedly inhibited by intrathecal injecting (ith) Cor (0.5 - 1.5 U), which were obviously attenuated by L-arginine (Arg, 5-15 nmol, ith), the substrate of NOS. CONCLUSION: Cor inhibits formalin-induced hyperalgesia by the decrease of NOS-positive neurons in the spinal dorsal horn of rats.