Zhang J Q, Nagata K, Iijima T
Department of Oral Anatomy, Faculty of Dentistry, Kyushu University, Fukuoka, Japan.
Anat Rec. 1998 Jun;251(2):214-20. doi: 10.1002/(SICI)1097-0185(199806)251:2<214::AID-AR9>3.0.CO;2-Y.
The innervation of rat incisors, which are continuously erupting teeth, is quite unique. Although many reports have documented the neural control of the pulpal blood flow, only a few studies have examined the structure and distribution of vascular nerves in the rat incisors. This study examined the nerve plexuses and the spatial relationship of nerve terminals to smooth muscle cells of the pulp vessels of rat incisors.
The innervation of the pulp vessels of rat incisors was studied using immunohistochemical evaluations of calcitonin gene-related peptide (CGRP) and neuropeptide-Y (NPY). The three-dimensional ultrastructure of nerve meshworks and terminals on smooth muscle cells of pulp arterioles were examined by scanning electron microscopy (SEM) with a KOH digestion method.
The blood vessels were associated with many nerve fibers immunoreactive for CGRP and NPY. Some NPY and frequent CGRP-immunoreactive nerve fibers were observed in the labial odontoblast layer. Three different morphologies of nerve fibers could be distinguished: fine nerve fibers with numerous terminal varicosities, medium-sized fibers associated with occasional or much scarcer varicosities, and thick fibers that had no varicosity and sometimes ran apart from blood vessels. The SEM observations identified five vascular segment types: terminal arterioles, precapillary arterioles, capillaries, postcapillary venules, and muscular venules. Nerve meshworks were observed around the large terminal arterioles; these meshworks were very comparable to those revealed by immunohistochemistry. The vascular smooth muscle cells were closely attached by one or more terminal varicosities.
It has become evident that the large terminal arterioles in the rat incisors receive a dense nerve supply and provide well-developed wall architecture, suggesting an important role of neuronal regulation on the vessels.
大鼠切牙作为不断萌出的牙齿，其神经支配颇为独特。尽管许多报告记录了牙髓血流的神经控制，但仅有少数研究考察了大鼠切牙中血管神经的结构和分布。本研究检测了大鼠切牙牙髓血管的神经丛以及神经末梢与平滑肌细胞的空间关系。
采用降钙素基因相关肽（CGRP）和神经肽Y（NPY）的免疫组织化学评估方法，研究大鼠切牙牙髓血管的神经支配。运用KOH消化法，通过扫描电子显微镜（SEM）检查牙髓小动脉平滑肌细胞上神经网络和末梢的三维超微结构。
血管与许多对CGRP和NPY呈免疫反应的神经纤维相关联。在唇侧成牙本质细胞层观察到一些NPY和频繁出现的CGRP免疫反应性神经纤维。可区分出三种不同形态学的神经纤维：具有众多终末膨体的细神经纤维、伴有偶尔或更稀少膨体的中等大小纤维以及无膨体且有时与血管分开走行的粗纤维。SEM观察确定了五种血管节段类型：终末小动脉、毛细血管前小动脉、毛细血管、毛细血管后微静脉和肌性微静脉。在大型终末小动脉周围观察到神经网络；这些网络与免疫组织化学显示的网络非常相似。血管平滑肌细胞通过一个或多个终末膨体紧密附着。
已变得明显的是，大鼠切牙中的大型终末小动脉接受密集的神经供应并具有发育良好的管壁结构，提示神经元调节对血管具有重要作用。
