Experimental lung research
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American guidelines, unlike European guidelines, support the use of antihistamines as a first line of treatment for some causes of chronic cough. Transient receptor potential vanilloid-1 (TRPV1) is an ion channel activated by the tussive agents capsaicin, resiniferatoxin, and protons. It is predominantly expressed by C-fiber and some Adelta -fiber sensory neurons and is thought to be a cough receptor. ⋯ Dexbrompheniramine also inhibited activation of rat TRPV1 expressed in HEK and Pro5 cells, without interfering with TRPA1 and proteinase-activated receptor-2 (PAR(2)) activation. Finally, in rat dorsal root ganglia neuron preparations, dexbrompheniramine dose-dependently inhibited capsaicin-evoked calcium responses. Thus, the inhibition of TRPV1 activation by dexbrompheniramine may provide one potential mechanism whereby this antihistamine exerts its therapeutic effect in chronic cough.