Tachykinin-depolarizations mediated by neurokinin-3 receptors in the hamster submandibular ganglion cells.

In the majority of autonomic ganglia, the responses to tachykinins such as substance P, neurokinin A and neurokinin B are primarily mediated by neurokinin-3 (NK-3) receptors. Neurokinin B (NK-B) and senktide are known as an endogenous tachykinin and the related peptide selective for NK-3 receptor. In this study, the generation mechanism of NK-3 receptor agonist-induced response in the hamster submandibular ganglion (SMG) cells was investigated using the current-clamp technique. The SMG cells responded to the NK-3 receptor agonists with two types of depolarizations accompanied by either a decrease or an increase in membrane input resistance. The results showed that K+ channels alone or the combination of K+ and nonselective cation channels coupled with NK-3 receptors on the SMG cells were involved in generation of the NKB- and senktide-depolarizations.