Yamaza Takayoshi, Kido Mizuho A, Wang Bing, Danjo Atsushi, Shimohira Daiji, Murata Naohisa, Yoshinari Masao, Tanaka Teruo
Department of Oral Anatomy and Cell Biology, Graduate School of Dental Science, Kyushu University, Fukuoka 812-8582, Japan.
Cell Tissue Res. 2009 Feb;335(2):407-15. doi: 10.1007/s00441-008-0720-7. Epub 2008 Nov 18.
We examined the distribution of substance P and neurokinin-1 (NK1) receptors and substance-P-containing nerve fibers in the peri-implant mucosa around titanium dental implants in rats. Immunohistochemistry and immunocytochemistry revealed that substance-P-immunoreactive nerve fibers abundantly innervated the peri-implant epithelium (PIE) compared with other epithelia of the peri-implant mucosa. NK1 receptor mRNA and protein expression in the peri-implant mucosa were confirmed by reverse transcription with the polymerase chain reaction and immunoblotting. Immunoelectron microscopy revealed that NK1 receptor immunoreactivity was preferentially localized in peri-implant epithelial cells. NK1-receptor-positive products were found on the plasma membrane and in vesicles and granules in PIE cells. Neutrophils and intraepithelial nerve axons in the PIE were positive for the NK1 receptor. NK1 receptor immunoreactivity was also detected in endothelial cells, fibroblasts, and nerve fibers in the connective tissue beneath the PIE. These findings suggest that peri-implant tissue receives sensory information through regenerated nerves expressing substance P and the NK1 receptor. In the peri-implant mucosa, the substance P/NK1 receptor system may play a role in pain transmission, the endocytosis of neutrophils, the extravasation of crevicular fluid, and the migration of macrophages and neutrophils in response to neurogenic inflammation, as in healthy gingiva.
我们研究了大鼠钛牙种植体周围植入物周围黏膜中P物质和神经激肽-1（NK1）受体以及含P物质神经纤维的分布。免疫组织化学和免疫细胞化学显示，与种植体周围黏膜的其他上皮相比，P物质免疫反应性神经纤维大量支配种植体周围上皮（PIE）。通过聚合酶链反应逆转录和免疫印迹法证实了种植体周围黏膜中NK1受体mRNA和蛋白的表达。免疫电子显微镜显示，NK1受体免疫反应性优先定位于种植体周围上皮细胞。在PIE细胞的质膜以及囊泡和颗粒中发现了NK1受体阳性产物。PIE中的中性粒细胞和上皮内神经轴突NK1受体呈阳性。在PIE下方结缔组织的内皮细胞、成纤维细胞和神经纤维中也检测到NK1受体免疫反应性。这些发现表明，种植体周围组织通过表达P物质和NK1受体的再生神经接收感觉信息。在种植体周围黏膜中，P物质/NK1受体系统可能在疼痛传递、中性粒细胞的内吞作用、龈沟液的外渗以及巨噬细胞和中性粒细胞对神经源性炎症的迁移中发挥作用，就像在健康牙龈中一样。
