Carlton S M, Coggeshall R E
Department of Anatomy and Neuroscience, Marine Biomedical Institute, University of Texas Medical Branch, Galveston 77555-1069, USA.
Brain Res. 1997 Jul 25;763(2):271-5. doi: 10.1016/s0006-8993(97)00489-7.
Serotonin (5-hydroxytryptamine, 5-HT) is a well known inflammatory mediator and algesic substance. It has been hypothesized that 5-HT can have a direct action on peripheral sensory axons, but there has been no anatomical demonstration of 5-HT receptors on peripheral primary afferent processes. The present study shows that 32% of unmyelinated axons at the dermal-epidermal junction are immunohistochemically stained with antibodies directed against the 5-HT2A receptor providing anatomical evidence that 5-HT can have a direct effect on sensory fibers in the skin. Furthermore, encapsulated nerve endings in Pacinian corpuscles also contain reaction product following immunostaining for 5-HT2A receptors, indicating that large myelinated axons can be activated by endogenous serotonin. These data suggest that peripherally acting 5-HT2A antagonists may be effective in reducing pain of peripheral origin.
血清素（5-羟色胺，5-HT）是一种众所周知的炎症介质和致痛物质。据推测，5-HT可直接作用于外周感觉轴突，但尚未有关于外周初级传入神经纤维上5-HT受体的解剖学证据。本研究表明，在真皮-表皮交界处，32%的无髓鞘轴突经抗5-HT2A受体抗体免疫组化染色呈阳性，这为5-HT可直接作用于皮肤感觉纤维提供了解剖学证据。此外，在对5-HT2A受体进行免疫染色后，环层小体中的被囊神经末梢也含有反应产物，表明大的有髓鞘轴突可被内源性血清素激活。这些数据表明，外周作用的5-HT2A拮抗剂可能有效减轻外周源性疼痛。
