Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
Pediatr Res. 2010 Apr;67(4):363-8. doi: 10.1203/PDR.0b013e3181d026a5.
Neurogenic-mediated inflammation may be associated with several inflammatory skin diseases including atopic dermatitis. However, age-dependent differences in neurogenic-mediated skin responses are not fully understood. We compared skin plasma leakage in rats aged 2 and 8 wk, which was induced by topical capsaicin, topical formalin, and intracutaneous substance P, whose effects are mediated via tachykinin NK1 receptors. Evans blue dye extravasation served as an index of the increase in skin vascular permeability. Capsaicin, formalin, and substance P caused a skin response in a dose-dependent manner in both age groups. However, the skin response was much greater in adults than in pups. In addition, the localization of sensory C-fibers and tachykinin NK1 receptors in the skin was investigated by immunofluorescent staining with antisubstance P and antitachykinin NK1 receptor antibodies, respectively. Substance P-immunoreactive nerves were detected throughout the dermis and tachykinin NK1 receptors were mainly detected in blood vessel walls in the dermis in both age groups. However, they were more sparsely distributed in pups. In conclusion, the weak neurogenic-mediated skin inflammation in pups is probably because of immature neural mechanisms associated with skin inflammation such as reduced innervation of sensory C-fibers and low expression of tachykinin NK1 receptors.
神经源性炎症可能与几种炎症性皮肤病有关，包括特应性皮炎。然而，神经源性皮肤反应的年龄依赖性差异尚未完全阐明。我们比较了 2 周和 8 周龄大鼠的皮肤血浆渗漏，这些大鼠通过局部辣椒素、局部甲醛和皮内 P 物质诱导，其作用通过速激肽 NK1 受体介导。伊文思蓝染料渗出物作为皮肤血管通透性增加的指标。辣椒素、甲醛和 P 物质在两个年龄组中均以剂量依赖性方式引起皮肤反应。然而，成人的皮肤反应比幼崽强烈得多。此外，通过用抗 P 物质和抗速激肽 NK1 受体抗体进行免疫荧光染色，研究了皮肤中感觉 C 纤维和速激肽 NK1 受体的定位。在两个年龄组中，P 物质免疫反应性神经纤维遍布真皮，速激肽 NK1 受体主要分布在真皮中的血管壁上。然而，它们在幼崽中的分布更为稀疏。总之，幼崽中较弱的神经源性介导的皮肤炎症可能是由于与皮肤炎症相关的不成熟神经机制，例如感觉 C 纤维的神经支配减少和速激肽 NK1 受体的低表达。
