흰쥐 후두에 분포된 신경에서 Substance P 및 Calcitonin Gene-Related Peptides의 발현양상

The Distribution of Substance P and Calcitonin Gene-Related Peptides Immunoreactive Fibers in the Rat′s Larynx

The larynx has three major functions such as protective reflex, respiration and phonation, and is richly innervated by sensory, sympathetic and parasympathetic nerves. The sensory innervation of the laryngeal mucosa, which is involved in the perception of pain, mechanical and chemical irritation, prtects the airway via various laryngeal reflexes. We studied the distribution of Substance P (SP) and Calcitonin Gene-Related Peptide (CGRP) sensory fibers in the rat's larynx using the immuno-histochemical methods. Many SP and CGRP immunoreactive fibers were found in all regions of the laryngeal mucosa except the vocal cords. SP immunoreactive fibers showed a very similar distribution to the CGRP fibers in the epithelium and submucosa. But SP immunoreactive fibers were sparser than CGRP immunoreactive fibers in distribution density. Both reactive fibers were denser in the supraglottic region than subglottic region. Especially, intraepithelial fibers displayed the densest innervation to the laryngeal surface of the epiglottis. h the subepithelium, SP and CGRP immunoreactive fibers were distributed along the wall of vessels and around the glands. The present results suggest that the regional distribution of SP and CGRP immunoreactivity may be responsible for the protective reflex function of the laryngeal inlet.