A pinboard by
Jesse Xu

PhD Candidate, University of Sydney / Woolcock Institute of Medical Research


Understanding that airway epithelium are subject to traumas that may trigger inflammatory cascades

When you eat chili, or inhale capsicum spray; if you suffer from Gastroespohageal reflux disorder, and gastric juices enter your airway - all of these triggers cause you to cough. They do so because a protein in your nerve cells sense a foreign object. But what happens to your airways in the long term?

Cough is a reflex action enacted by the sensory nervous system onto airway smooth muscle. It plays a fundamental role in normal physiological function, by removing unwanted particles and substances in the airways. This reflex is mainly triggered by chemoreceptors and mechanoreceptors of the sensory system located on and underlying the airway epithelium. A major part of the cough reflex is triggered by activation of the Transient Receptor Potential (TRP) group of channels, which are largely expressed in the sensory nervous system in airways. Prolonged or exacerbated cough is a major pathophysiological symptom of airway hypersensitivity, and can be a debilitating symptom associated with respiratory diseases such as asthma, chronic obstructive pulmonary disease, and lung cancer. The symptom of chronic cough places particular burden on patients suffering respiratory diseases, where it impairs breathing, social activities and interferes with sleep. In its own right, chronic cough is defined as prolonged coughing symptoms over a duration of 8 weeks . This respiratory symptom contributes greatly to global mortality and morbidity rates where chronic cough has a prevalence of 9.6% worldwide.

It is suspected that activation of these heat sensor receptors in our airways, may cause permanent changes to our airways that make it more susceptible for future triggers. This research delved into the link between GORD and chronic airway diseases or hypersensitivity. The link between inhalation of capsicum spray which contains capsaicin, was also looked into.