Lack of role for the vanilloid receptor in response to several inspired irritant air pollutants in the C57Bl/6J mouse.

Sensory irritants initiate respiratory reflexes by stimulating trigeminal sensory nerves. The vanilloid receptor (TRPV1) is expressed on sensory C fibers. The current experiments were aimed at examining the role of this receptor in mediating responses to several airborne irritants including an acidic (acetic acid), electrophilic (acrolein), and lipophilic solvent (styrene) vapor. Wild-type (C57Bl/6J) and VR1 knockout [B6.129S4-VR1(tm1jul)] mice were exposed to these irritants and breathing pattern responses were assessed by plethysmographic techniques; both wild-type and knockout animals responded similarly to the irritants. The TRPV1 antagonist iodoresiniferatoxin was also without effect on the responses to the irritants. Thus, in the C57Bl/6J mouse the TRPV1 receptor does not appear to play a major role in the stimulation of nasal trigeminal central reflex responses by these irritant air pollutants.