Spinal immunohistochemical NOS positive neurons and hyperalgesia model in rats.

一氧化氮被认为是一种有效的，非典型的神经调质，是由L-精氨酸通过一氧化氮合酶产生的。神经元型一氧化氮合酶不仅存在于脑中，也存在于脊髓中。最近的数据表明，脊髓中的一氧化氮可能在神经损伤后疼痛的病理生理学中起作用。因此，我们确定了疼痛bethavior和神经元型一氧化氮合酶阳性神经元在大鼠模型的神经损伤脊髓中的数量的变化之间的关系。将神经性疼痛模型（左侧L5、L 6脊神经结扎）与脊神经（L5、L 6）撕脱或挤压损伤模型进行比较。假手术对照组包括暴露脊神经但不操作的大鼠。在机构批准后，本研究纳入了76只雄性Sprague-Dawley大鼠。实验分为5组：结扎组（n=18）、撕脱组（n=17）、挤压组（n = 17）、假手术组（n=18）和正常对照组（n=6）。缩爪 ...更多信息 分别于术后4天、1周、3周测定大鼠的阈值和对机械刺激的反应频率，并在T1、L1、L5、L 6节段脊髓切片进行nNOS免疫组织化学染色。背角、中央管和中间外侧细胞柱的神经元型一氧化氮合酶阳性神经元数量与左后爪机械刺激的缩爪反应相关。结扎组大鼠表现出明显的机械性痛觉过敏，而撕脱组和挤压组大鼠的坐骨神经分布是麻醉的。神经元型一氧化氮合酶阳性神经元的定量组织化学分析显示，结扎组术后4天至3周在L1、L5和L 6水平的左侧（同侧）背角神经元型一氧化氮合酶阳性神经元数量增加，术后1周和3周在L1水平的左侧中间外侧细胞柱神经元型一氧化氮合酶阳性神经元数量增加。相比之下，撕脱和挤压组在手术后1周和3周在L1、L5和L 6水平的左侧背角中神经元型一氧化氮合酶阳性神经元的数量减少。缩爪阈值的降低之间存在显著相关性;即，机械性痛觉过敏和L1、L5和L 6水平左侧背角神经元型一氧化氮合酶阳性神经元的数量。这项研究的结果表明，一氧化氮可能参与了神经病理性疼痛的机制，结果从部分神经损伤。少

Nitric oxide is regarded as a potent, atypical neuromodulator that is produced from L-arginine by nitric oxide synthase. Neuronal nitric oxide synthase is localized not only in the brain but also in the spinal cord. Recent data indicate that nitric oxide in the spinal cord may play a role in the pathphysiology of pain following nerve injury. We therefore determined the relationship between pain bethavior and alterations in the number of neuronal nitric oxide synthase-positive neurons in the spinal cord in rat models of nerve injury. A model of neuropathic pain (left L5, L6 spinal nerve ligations) was compared to models of spinal nerve (L5, L6) avulsion or crush injuries. Sham controls inculuded rats where the spinal nerves were exposed but not manipulated. After institutional approval 76 male Sprague-Dawley rats were included in this study. They were divided into 5 groups ; Ligation (n=18), Avulsion (n=17), Crush (n=17), Sham Control (n=18), and Normal Control (n=6) groups. Paw withdra … More wal thresholds and frequency of responses to mechanical stimuli were determined and nNOS immunohistochemical staining of the spinal cord sections at the T1, L1, L5 and L6 levels were performed at 4 days, 1 week, and 3weeks after surgery. The number of neuronal nitric oxide synthase-positive neurons at dorsal horus, central canal, and intermediolateral cell columns were correlated with the paw withdrawal responses to mechanical stimulation of left hind paw. The Ligation group rats showed overt mechanical hyperalgesia while the Avulsion and Crush groups of rats were anesthetic in the sciatic distribution. The quantitative histochemical analysis of neuronal nitric oxide synthase-positive neurons revealsd that the Ligation group developed increased number of neuronal nitric oxide synthase-positive neurons in the left (ipsilateral) dorsal horn 4 days through 3 weeks after surgery at the L1, L5 and L6 levels and those in left intermediolateral cell column 1 and 3 weeks after surgery at the L1 level. In contrast, Avulsion and Crush groups demonstrated a decreased number of neuronal nitric oxide synthase-positive neurons in the left dorsal horn 1 and 3 weeks after surgery at the L1, L5 and L6 levels. There were significant correlations between the decrease in paw withdraw threshold ; i.e., mechanical hyperalgesia, and the number of neuronal nitric oxide synthase-positive neurons in the left dorsal horn at L1, L5 and L6 levels in the Ligation group. The results of this study indicate that nitric oxide may be involved in the mechanism of neuropathic pain that results from partial nerve injuries. Less