【作者】 周兆丽；

【导师】 王怀良；

【作者基本信息】 中国医科大学 ， 药理学， 2005， 硕士

【摘要】 目的 偏头痛是一种中枢神经系统(central nervous system,CNS)功能紊乱性疾病,患者在发病期间常处于以自发痛(spontaneous pain)、痛觉过敏(hyperalgesia)及触诱发痛(allodynia)为特征的感觉超敏状态。有关偏头痛的病理生理机制,学说较多,主要包括血管扩张、神经源性炎症反应、皮层扩散抑制(cortical spreading depression,CSD)等。相应的,有电刺激三叉神经节(trigeminal ganglion,TG)或上矢状窦(superior sagittal sinus,SSS)、化学刺激硬脑膜、脑皮质表面滴注KCL等构建偏头痛模型方法。本实验采用静脉注射(iv)硝酸甘油(glyceryl trinitrate,GTN)构建偏头痛动物模型。静注GTN可产生与偏头痛发生相似的病理生理过程,如引发硬脑膜的炎症反应,激活三叉血管系统,产生与自发性偏头痛相似的区域性脑血流改变等等。 三叉神经是偏头痛患者头痛及其他症状出现的解剖基础。偏头痛患者三叉系统处于高敏感状态。三叉颈复合体(trigeminocervical complex,TCC)是三叉神经通路的二级神经元,它包括三叉神经尾核(trigeminal nucleus caudalis,SpVc)及C1、C2节段脊髓后角(the dorsal horn of C1 and C2 levels in the upper cervical spinal cord)。该处神经元对疼痛传导的易化,是偏头痛患者高敏感状态产生的原因之一。偏头痛动物模型的研究中已发现,给予硬脑膜化学刺激后,TCC伤害感受性神经元对来自颈部的传人冲动反应增强。 谷氨酸(glutamate,Glu)广泛存在于中枢神经系统,是介导CNS兴奋性冲动传递的最主要的神经递质。它参与CSD、三叉血管系统激活及中枢敏感化等与偏头痛密切相关的病理生理过程。有关其受体N-甲基-D-天门冬氨酸受体(N-methyl-D-aspartate receptor,NMDAR,也作NR)的研究也表明,该受体除了在兴奋性突触传递、突触可塑性及中枢神经系统神经退化等方面起关键作用外,还参与疼痛状态下中枢敏感化的诱导和维持。更多还原

【Abstract】 IntroductionMigraine is an incapacitating neurovascular disorder. Most migraine patients exhibit spontaneous pain, hyperalgesia, and cutaneous allodynia during a fully developed migraine attack. There are multiple mechanisms in the pathogenesis of migraine headache, involving arterial vasodilatation, neurogenic inflammation and cortical spreading depression ( CSD). In laboratory animals the disease models are established by either electrical stimulation of trigeminal ganglion (TG) , chemical stimulation of meninges or by the application of chemicals(e. g. K+ ) to the cortex. In this experiment we established migraine models by glyceryl trinitrate(GTN) infusion in rats. GTN infusion induces development of meningeal inflammation, activation of trigeminovascular system, and regional changes in cerebral bood flow( CBF).Head pain in migraine arises within the trigeminal system. Sensitization of central trigeminal neurons accounts for head pain and other symptoms during migraine attack. The trigeminal nucleus caudalis and its caudal extension to the superficial laminae of the C1/2 dorsal horns make up a functional continuum, the trigeminocervical complex (TCC). Neurons in TCC are the major relay neurons for nociceptive afferent input from the meninges and cervical structures; therefore, they are the neural substrates of head pain. Dural stimulation leads to a sensitization of neurons in TCC.Glutamate, a major source of excitatory transmission within the brain and spinal cord, is implicated in cortical spreading depression (CSD) , trigeminovas-cular activation, and central sensitization. N - methyl - D - aspartate receptors (NMDARs) , play an important role in excitatory synaptic transmission, plasticity , and neurodegenation. Furthermore, they implicate in the induction and maintenance of hypersensitivity. Functional NMDARs requires a combination of NR1, an essential channel - forming subunit, and at least one of the NR2 sub-units. The NR2B subunit containing receptors appear particularly important for noception. However, The involvement of glu - NMDAR - nNOS pathways in the development of central hypersensitivity evoked by Glyceryl Trinitrate infusion in rats is still unclear.Materials and MethodsRat migraine model was established with GTN 2μg. kg-1 . min-1 infusion for 30min. The immunohistochemistry staining was used to observe glutamate expression in trigeminocervical complex, and in trigeminal ganglion of rat following GTN infusion or normal saline infusion, respectively. The levels of NR2B, and phospho - NR2B protein expression in cell membrane of rat trigeminocervical complex were detected following GTN infusion for 0.5, 2.0, 4. 0, 6.0, 10. Oh by Western - blot. Western - blot was also used to facilitate the observation of nNOS protein expression in rat trigeminocervical complex following GTN infusion or normal saline infusion.Results1. The glutamate - like immunoreactivity was detected in rat trigeminocer-vical complex and trigeminal ganglion after GTN infusion. The glutamate increased in rat trigeminocervical complex while decreased in trigeminal ganglion.2. The level of NR2B protein expression remain the same after GTN infusion. The increase of phospho - NR2B protein expression in rat trigeminocervical complex was detected after GTN infusion3. nNOS protein expression increase in rat trigeminocervical complex after GTN infusion.更多还原