Effect of stress on the progression of periodontitis

有人认为，炎症性疾病（如牙周炎）与应激之间的联系可能在于感觉神经纤维在受到外界刺激时释放神经递质。P物质（SP）被认为是一种可能与炎症有关的神经递质。本研究的目的是探讨SP对牙周炎进展的影响。采用二氨基联苯胺（DAB）反应，光镜和电镜观察SP对大鼠结膜上皮细胞（JE细胞）和结膜上皮中性粒细胞的影响。静脉注射SP （10μg/kg或100μg/kg）或局部应用浓度为10^<-4> M的SP 15分钟可引起乙脑中性粒细胞的迁移。这些迁移的中性粒细胞中的一些将dab阳性的azurophil颗粒释放到乙脑细胞的细胞间隙中。脑炎冠状部分的脑炎细胞似乎吞下这些颗粒并在细胞内消化它们。这些结果表明，脑炎神经末梢释放的SP增强了中性粒细胞的迁移和中性粒细胞和脑炎细胞的内吞能力，形成了一道抵御有害刺激的防线。

It has been suggested that, the link between inflammatory disease (such as periodontitis) and stress may lie in the release of neurotransmitters from sensory nerve fibers upon stimulation by external stimuli. Substance P(SP) has been implicated as one such neurotransmitter which may be associated with inflammation. The purpose of this study was to investigate the effect of SP on the progression of periodontitis. The effect of SP on junctional epithehal cells (JE cells) and neutrophils in the junctional epithelium (JE) was studied by light and electron microscopy using diaminobenzidine (DAB) reaction. Intravenous injection of SP (10μg/kg or 100μg/kg) or local application of SP at concentrations of 10^<-4> M for 15 min caused migration of neutrophils in the JE. Some of these migrating neutrophils released DAB-positive azurophil granules into the intercellular spaces of the JE cells. The JE cells at the coronal portion of the JE seemed to endocytose these granules and digest them in the cells. These findings suggest that SP released from nerve terminals in the JE enhances migration of neutrophils and endocytotic ability of neutrophils and JE cells to form a line of defense against harmful stimuli.