Peripheral sensitization of sensory neurons.
Peripheral sensitization of sensory neurons.
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作者：
V. Chaban
引言 定义伤害感受的部位和机制是理解和治疗疼痛的重要一步。在炎症期间，来自发炎器官的伤害性输入增加可以使接收来自未受影响器官的汇聚输入的神经元变得敏感，但内脏交叉敏感的部位尚不清楚。这项研究检查了支配内脏器官的感觉神经元对 ATP 和 P 物质刺激的细胞反应。方法将腰骶背根神经节（L6-S1）切成切片并使用免疫细胞化学处理 P 物质受体表达。背根神经节 (DRG) 神经元的原代培养物用于通过视频显微镜测量 [Ca2+]i。结果 DRG 神经元表达 P 物质受体。短暂添加低剂量三磷酸腺苷（ATP，5 µM）和 P 物质（10 µM）均显着增加随后对同一神经元的 ATP 刺激。讨论 支配不同器官的 DRG 神经元的敏化可能是通过神经节内伤害性递质（例如 ATP 和/或 P 物质）的释放来实现的。总之，这些实验将增加我们对外周敏化在伤害性传播中重要调节作用的理解，并提出治疗干预的潜在外周位点。
INTRODUCTION Defining the sites and mechanisms of nociception is an important step in understanding and treating pain. During inflammation, increased nociceptive input from an inflamed organ can sensitize neurons that receive convergent input from an unaffected organ, but the site of visceral cross-sensitivity is unknown. This study examined the cellular responses to ATP and substance P stimulation in sensory neurons innervating visceral organs. METHODS Lumbosacral dorsal root ganglia (L6-S1) were cut into slices and processed for substance P receptor expression using immunocytochemistry. Primary culture of dorsal root ganglion (DRG) neurons was used for [Ca2+]i measurement by videomicroscopy. RESULTS DRG neurons express substance P receptors. Both brief addition of low dose adenosine triphosphate (ATP, 5 microM) and substance P (10 microM) significantly increased subsequent ATP stimulation at the same neuron. DISCUSSION Sensitization of the DRG neurons innervating the different organs may be through the release of nociceptive transmitters such as ATP and/or substance P within the ganglion. Together, these experiments will increase our understanding of the important modulatory role of peripheral sensitization in nociceptive transmission and suggest potential periphepheral sites for therapeutic intervention.