ABSTRACT
This chapter aims to provide an update on sensory nerves in the mammalian airways and on the biological actions of the tachykinins, which are the major mediators released from these nerves. By contrast, a distinct subpopulation of vagal afferents responds to chemical irritants with the peculiar dual sensory-efferent response. These vagal afferents share the trait of being susceptible to the triple actions of capsaicin; therefore, they are generally termed capsaicin-sensitive vagal afferents. Capsaicin-like molecules appear to be best termed vanilloids, and the receptor at which they interact may be referred to as the vanilloid receptor. The chapter describes a non- neural capsaicin action, that is, the block of potassium conductance in ventricular myocytes, which has been reevaluated by using the ultrapotent capsaicin analog resiniferatoxin. It suggests that these actions are "aspecific" or mediated by receptors that possess structure-activity relations distinct from that of the neural vanilloid receptor.
