Abstract

The functions of paranasal sinuses have recently undergone a conceptual change in literature, with emerging clinical data highlighting the sinus cavity as an ‘Aerocrine Organ’. Nitric oxide (NO) is an important mediator and
inflammatory marker in human upper airways. High concentration of Nitric oxide produced within the paranasal sinuses by the respiratory epithelium, has proved to be protective against infection or allergy induced airway
inflammation. The term ‘ aerocrine ’ illustrates the airborne transport of nitric oxide as a protective biological messenger in the human respiratory tract from the nasal passages to the respiratory alveoli. NO plays the role of a
messenger between the upper and lower respiratory tracts, reducing pulmonary vascular resistance and facilitating alveolar oxygen transfer into the bloodstream. This has revolutionized the concept of nasal breathing controlling the entire pulmonary function and oxygen uptake in the lungs. This concept has found references in many of the breathing patterns described in ancient Indian yogic practices like the ‘Praanayama and Jal-Neethi'. Nitric oxide level in the paranasal sinuses, has been established today as a bio-marker of well being of the respiratory system and has found numerous clinical applications in the diagnosis and management of upper airway inflammation. Present day research is focused on prophylactic and therapeutic administration of NO in patients with chronic respiratory diseases.

Keywords: Paranasal Sinuses; Aerocrine Organ; Nitric Oxide; Chemiluminiscence