Hot channels in airways: pharmacology of the vanilloid receptor

Airway hyperresponsiveness of the tracheobronchial path is recognized as the critical feature of bronchial asthma. Sensory nerves in the airway are implicated strongly in this hyperresponsiveness. The vanilloid VR1 receptor, a cloned capsaicin receptor and a nociceptor-specific cation channel, is known to detect and transduce various harmful stimuli to electrical signals. Recent findings suggest that bradykinin can activate VR1 through generation of lipoxygenase products and that protein kinase C and phospholipase C mediate the sensitization of VR1 by many key inflammatory mediators. Such findings will lead to a better understanding of the enigmatic etiology of asthma.