This study was designed to investigate the structure and distribution of calcitonin gene-related peptide(CGRP) immunoreactive cells in laryngeal epithelium. The study was undertaken by immunohistochemistry for the cat. CGRP immunoreactive cells were spindle in shape with cytoplasmic processes directed towards the lumen and the basement membrane. Ultrastructurally, the apical surface of CGRP immunoreactive cells extended to the laryngeal lumen, where it formed microvilli. Their cytoplasm often contained abundant and variable numbers of electron-dense core vesicles. CGRP immunoreactive cells were found in the subglottis, arytenoid, supraglottis, glottis in order of decreasing number. These observations suggest that CGRP immunoractive cells play a part in the regulatory function of the cat larynx by release of CGRP, which may act as via an endocrine, paracrine pathway, or neurosecretory pathways, or a combination of these.
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