Distribution and Origin of Nitrergic Innervation of the Canine Laryngeal Ventricle / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Recently, nitric oxide (NO) has been considered to be a neurotransmitter or a signaling molecule in a number of distinct subpopulation of neurons in the central and peripheral nervous systems. This study attempted to define the distribution patterns and quantitative participation according to the origin of nitrergic innervation in the canine laryngeal ventricles of eight adult dogs. MATERIALS AND METHODS: The nitrergic innervation in the intralaryngeal, superior cervical and nodose ganglion to the laryngeal ventricle were investigated by using double labelled neuronal NO synthase (nNOS) immunocytochemistry combined with a retrograde tracer, cholera toxin subunit B-conjugated horseradish peroxidase (CTB-HRP). RESULTS: NO is suggested to participate in parasympathetic, sympathetic and sensory innervation. Intralaryngeal ganglion is the main source of nitrergic innervation in the canine laryngeal ventricle. The proportions of the nitrergic innervation in the intralaryngeal ganglion, superior cervical ganglion, and nodose ganglion to the canine laryngeal ventricle were 63.1%, 37.7%, 4.9% respectively. CONCLUSION: NO originating from the intralaryngeal ganglion in a canine laryngeal ventricle may play an important role in controlling the laryngeal gland secretion and in regulating the blood flow by modulating the classical parasympathetic cholinergic neurotransmitter as like a neuronal messenger or comediator. NO also may participate in the same role through the sympathetic innervation of superior cervical ganglion however, NO originating from intralaryngeal ganglion may play more important role than that from superior cervical ganglion. Many neurons of nodose ganglion have demonstrated to have nNOS, but might be less involved in the ventricular sensory innervation.