Resiniferatoxin-evoked CGRP release and bronchoconstriction in the guinea-pig lung are inhibited by ruthenium red

The recent demonstration of binding sites for resiniferatoxin (RTX), a phorbol-related diterpene with a capsaicin-like structure indicated that capsaicin interacts with a specific receptor present on sensory ganglia. To evaluate this hypothesis we studied whether RTX activates peripheral sensory terminals in the lung via a mechanism similar to that for capsaicin, i.e. ruthenium red-sensitive CGRP release and bronchoconstriction