Possible effects of various neuropeptides on cells related to bone resorption during tooth movement

在这项研究中，我们研究了实验性牙齿移动过程中神经肽（如CGRP）与PDL细胞（包括破骨细胞）结合的改变。热休克蛋白（HSP）在大鼠PDL中的免疫反应性及其变化也被免疫组织化学检测，因为正畸力被认为可能诱导应激蛋白如HSP的表达改变。采用50日龄Wistar品系大鼠。实验采用Waldo法进行牙齿移动。每只动物在每个指定的时间被实施安乐死。脱钙后，连续水平冷冻切片，切片厚度40 μ。自由漂浮切片采用ABC法处理，对每种物质（如CGRP、substance P或HSP）使用抗血清。得到了以下结果：1。生理状态下观察到含有CGRP和/或P物质的神经纤维在治疗开始后立即减少或消失，几天后又开始逐渐增加。在张力部位新形成的类骨表面的肺泡成骨细胞中可见cgrp免疫反应性。受压部位Hawship腔隙内部分破骨细胞均观察到CGRP-和p物质免疫反应性。另一方面，体外培养的破骨细胞中添加CGRP可抑制破骨细胞活性。牙齿移动过程中，PDL中HSP的免疫组化染色强度发生显著变化，提示正畸牙齿移动过程中，HSP可能与对物理或化学刺激的防御反应有关。

In this study, we investigated altered binding of neouropeptides such as CGRP to PDL cells including osteoclasts during experimental tooth movement. Heat Shock Protein (HSP)-immunoreactivity in the rat PDL and its change were also examined immunohistochemically since the orthodontic force had been thought to possibly induce alterations in the expression of stress protein like HSP. 50-day-old Wistar strain rats were used. Experimental tooth movement was performed according to Waldo's method.Each animal was euthanized at each appointed time. After decalcification, serial horizontal frozen sections, 40 μ in thickness were cut. Free-floating sections were processed for the ABC method by the use of an antiserum to each substance such as CGRP, Substance P or HSP.The following results were obtained :1. The nerve fibers containing CGRP and/or Substance P observed under physiological condition decreased or disappeared immediately after the onset of treatment, and then began to increase gradually a few days later again.2. CGRP-immunoreactivity was seen in the alveolar osteoblasts on the surface of newly formed osteoid in the tension site. Both CGRP- and Substance P-immunoreactivity were observed in some osteoclasts existing in the Hawship lacunae in the compression site. On the other hand, In vitro, addition of CGRP to cultured osteoclasts caused inhibition of osteoclastic activity.3. Immunohistochemical staining intensity for HSP in the PDL showed significant change during tooth movement, suggesting that HSP may be associated with defensive responses against physical or chemical stimuli with orthodontic tooth movement.