The function of parvalbumin and calcitonin gene-related peptide in the inflamed pulp

正常大鼠的牙髓中含有小白蛋白免疫反应（ir）神经纤维。根髓内免疫阳性神经纤维粗而光滑。这些神经纤维投射到冠髓，在成牙本质细胞下层形成成牙本质细胞下层神经丛。它们把静脉曲张的末梢送到成牙本质细胞层。免疫电镜研究显示，小白蛋白-IR神经根轴突厚，有髓鞘。在成牙本质细胞层，神经突与成牙本质细胞的胞体和突起紧密接触。牙髓暴露后1-3天，牙髓中无小白蛋白或神经纤维。然而，在5-7天，小清蛋白-ir牙髓神经纤维的数量增加，并在发炎组织下方形成神经丛。这些神经纤维大多数具有细而曲张的外观。在牙髓暴露后14天，在整个牙髓中观察到炎性细胞。在这个阶段，小清蛋白免疫反应神经纤维的数量减少。它们在根髓中观察到，而在冠髓中未观察到。第30-60天根尖形成脓肿。红外线神经纤维丛周围脓肿。双重免疫荧光法显示，小清蛋白和降钙素基因相关肽（CGRP）免疫阳性神经纤维的分布模式在所有阶段是相似的。提示小白蛋白和降钙素基因相关肽在牙髓炎症中起重要作用。

The tooth pulp in the normal rat contained parvalbumin-immunoreactive (ir) nerve fibers. In the root pulp, ir nerve fibers had a thick and smooth appearance. These nerve fibers projected to the coronal pulp, and made subodontoblastic nerve plexuses in the subodontoblastic layer. They sent their varicose terminals to the odontoblastic layer. An immunoelectron microscopic study revealed that parvalbumin-ir radicular axons were thick and myelinated. In the odontoblastic layer, ir neurites made close contact with cell bodies and processes of odontoblasts. At 1-3 days after the pulp exposure, the tooth pulp was devoid of parvalbumin ir nerve fibers. At 5-7 days, however, parvalbumin-ir pulpal nerve fibers increased in number and made nerve plexuses beneath the inflamed tissue. These nerve fibers mostly had a thin and varicose appearance. At 14 days after the pulp exposure, inflammatory cells were observed throughout the tooth pulp. Parvalbumin-ir nerve fibers decreased in number at this stage. They observed in the root pulp but not the coronal pulp. At 30-60 days, the abscess was formed at the root apex. Ir nerve fibers made plexuses around the abscess. A double immunofluorescence method demonstrated that the distribution patterns of parvalbumin- and calcitonin gene-related peptide (CGRP)-ir nerve fibers were similar at all stage. The present study suggests that parvalbumin and CGRP have an important role for the inflammation in the tooth pulp.