Sato O, Takeuchi-Maeno H, Maeda T, Takano Y
Department of Oral Anatomy, Niigata University School of Dentistry, Japan.
Arch Histol Cytol. 1992 Dec;55(5):561-8. doi: 10.1679/aohc.55.561.
The ultrastructure of nerves containing immunoreactivity for calcitonin gene-related peptide (CGRP) was investigated in the dental pulp of rat molars. The immunoreactivity was recognized predominantly in unmyelinated nerve fibers, and sparsely in a few myelinated fibers. It was localized throughout the axoplasm, as well as in the large cored vesicles. Small clear vesicles and mitochondria were free of the immunoreaction. The CGRP-immunoreactive nerves were frequently observed to terminate, being devoid of Schwann cell investment, in the vicinity of blood vessels in the coronal pulp, suggesting that CGRP may be involved in the regulation of pulpal blood flow. Moreover, CGRP-immunoreactive axon terminals containing numerous small clear vesicles, a few large cored vesicles and mitochondria were recognized in contact with the cell bodies of odontoblasts and their processes in the dentinal tubules. Although specialized synaptic ultrastructures were not recognizable, a functional association of CGRP nerves and odontoblasts was suggested. Thus, CGRP in the dental pulp appears to have multiple functions, including vascular regulation and sensory transduction.
在大鼠磨牙牙髓中研究了含有降钙素基因相关肽（CGRP）免疫反应性的神经超微结构。免疫反应性主要在无髓神经纤维中被识别，在少数有髓纤维中则较少见。它定位于整个轴浆以及大的有芯小泡中。小而清亮的小泡和线粒体没有免疫反应。经常观察到CGRP免疫反应性神经在冠髓血管附近终止，没有施万细胞包裹，这表明CGRP可能参与牙髓血流的调节。此外，在成牙本质细胞的细胞体及其在牙本质小管中的突起附近，识别出含有大量小而清亮的小泡、少数大的有芯小泡和线粒体的CGRP免疫反应性轴突终末。虽然没有可识别的特殊突触超微结构，但提示CGRP神经与成牙本质细胞之间存在功能联系。因此，牙髓中的CGRP似乎具有多种功能，包括血管调节和感觉传导。
