There is rapidly growing evidence indicating multiple and important roles of Ca2+-
permeable cation TRP channels in the airways, both under normal and disease conditions. The aim of
this review was to summarize the current knowledge of TRP channels in sensing oxidative, chemical
irritant and temperature stimuli by discussing expression and function of several TRP channels in
relevant cell types within the respiratory tract, ranging from sensory neurons to airway smooth
muscle and epithelial cells. Several of these channels, such as TRPM2, TRPM8, TRPA1 and
TRPV1, are discussed in much detail to show that they perform diverse, and often overlapping or
contributory, roles in airway hyperreactivity, inflammation, asthma, chronic obstructive pulmonary disease and other
respiratory disorders. These include TRPM2 involvement in the disruption of the bronchial epithelial tight junctions
during oxidative stress, important roles of TRPA1 and TRPV1 channels in airway inflammation, hyperresponsiveness,
chronic cough, and hyperplasia of airway smooth muscles, as well as TRPM8 role in COPD and mucus hypersecretion.
Thus, there is increasing evidence that TRP channels not only function as an integral part of the important endogenous
protective mechanisms of the respiratory tract capable of detecting and ensuring proper physiological responses to various
oxidative, chemical irritant and temperature stimuli, but that altered expression, activation and regulation of these
channels may also contribute to the pathogenesis of respiratory diseases.