목적: Bradykinin and related Kinins have been proved to have many important physiological and pathophysiological functions e.g. inflammation, nociception, vascular regulation. Also bradykinin has role in sensitizing the sensory nerves of the airways and enhancing the cough reflex which may have a protective role on the tracheobronchial tree. Angiotensin-converting enzyme inhibitors potentiate bradykinin accumulation by blocking its hydrolysis and inhibiting the desensitization of its receptor. They have been suggested as an alternative strategy for lowering the risk and mortality of pneumonia in the elderly and debilitated patients. Our aim of this study was to clarify the localization and distribution of bradykinin receptors (BRs) subtypes in larynx and trachea of rat which not fully understood till now. 방법:Immunohistochemistry (IHC) study of the nucleus tractus solitarius (NTS), nodose ganglion, larynx and trachea of normal adult male Wistar rat was done. B1R and B2R primary antibodies Alexa fluor 488 goat anti-rabbit secondary antibody and Propidium iodide nuclear counterstaining were used. Also right superior laryngeal nerve and vagal nerve deinnervation was tried for 1-3 weeks then the same IHC studies were done. 결과:B1R and B2R were significant expressed in NTS, nodose ganglion, respiratory epithelium, serous gland, blood vessels and subepitheial nerve fibers. But they were poorly expressed in the surface layer of stratified squamous epithelium compared to transitional columnar epithelium. While both were not expressed in the mucinous glands and the intrinsic laryngeal ganglions. There were no changes in expression after deinnervation. 결론:Both B1R and B2R were constitutionally expressed in the rat larynx, trachea and their sensory nervous systems. These findings indicate the importance of bradykinin receptors in the laryngeal sensory systems and the mucosal inflammation.