Dux M, Sann H, Schemann M, Jancsó G
Department of Physiology, Albert Szent-Györgyi Medical University, Dóm tér 10, H-6720 Szeged, Hungary.
Cell Tissue Res. 1999 Jun;296(3):471-7. doi: 10.1007/s004410051307.
Perineural application of capsaicin results in a selective and permanent reduction in the sensitivity to noxious chemical and heat stimuli and elimination of the neurogenic inflammatory response. The present quantitative immunohistochemical study has been undertaken to reveal the populations of cutaneous afferent nerves that are affected by perineural capsaicin treatment. Areas of intact and chemodenervated skin were determined with the aid of the vascular labelling technique. In sections taken from intact skin areas, staining with antibodies against protein gene product 9.5 revealed a rich epidermal innervation. Fibres immunoreactive for growth-associated protein 43 were also abundant; nerve fibres immunoreactive for substance P and calcitonin gene-related peptide were less numerous. Somatostatin- and RT97-immunoreactive fibres were seen only in the subepidermal layer. In sections taken from skin areas supplied by the sciatic nerve treated with capsaicin 3 days previously, the number of epidermal nerve fibres immunoreactive to protein gene product 9.5, growth-associated protein 43, substance P and calcitonin gene-related peptide was reduced by 90%, 95%, 97% and 66%, respectively. These changes persisted for at least 42 days. The findings reveal that the majority of epidermal axons are capsaicin-sensitive and comprise a chemically heterogeneous population. Reductions in cutaneous fibre populations following perineural capsaicin treatment may result from both the degeneration of sensory axons and the depletion of neuron-specific macromolecules. In addition, most cutaneous nociceptive axons may not use the major sensory neuropeptides substance P and calcitonin gene-related peptide as afferent neurotransmitters.
辣椒素经神经周应用可导致对有害化学和热刺激的敏感性选择性且永久性降低，并消除神经源性炎症反应。本定量免疫组织化学研究旨在揭示受神经周辣椒素治疗影响的皮肤传入神经群体。借助血管标记技术确定完整皮肤和化学去神经支配皮肤的区域。在取自完整皮肤区域的切片中，用抗蛋白基因产物9.5的抗体染色显示丰富的表皮神经支配。对生长相关蛋白43免疫反应的纤维也很丰富；对P物质和降钙素基因相关肽免疫反应的神经纤维较少。仅在表皮下层可见生长抑素和RT97免疫反应纤维。在取自3天前用辣椒素处理的坐骨神经所供应皮肤区域的切片中，对蛋白基因产物9.5、生长相关蛋白43、P物质和降钙素基因相关肽免疫反应的表皮神经纤维数量分别减少了90%、95%、97%和66%。这些变化持续至少42天。研究结果表明，大多数表皮轴突对辣椒素敏感，且构成化学性质异质的群体。神经周辣椒素治疗后皮肤纤维群体的减少可能是感觉轴突退化和神经元特异性大分子耗竭共同作用的结果。此外，大多数皮肤伤害性轴突可能不使用主要的感觉神经肽P物质和降钙素基因相关肽作为传入神经递质。
