Tachykinin receptors and receptor subtypes
Patacchini, R.; Maggi, C.A.
Archives Internationales de Pharmacodynamie et de Therapie 329(1): 161-184
1995
ISSN/ISBN: 0003-9780 PMID: 7639617 Document Number: 451100
The tachykinins, substance P, neurokinin A and neurokinin B, are a family of neuropeptides widely distributed in the mammalian central and peripheral nervous system. In the peripheral nervous system, tachykinins released from peripheral endings of sensory nerves are responsible for the neurogenic inflammation phenomenon. In the spinal cord/central nervous system, tachykinins play a role in pain transmission/perception and in some autonomic reflexes and behaviors. Their actions are mediated by three distinct receptors, termed NK-1, NK-2 and NK-3. All tachykinin receptors belong to the superfamily of G protein-coupled receptors, with seven putative transmembrane spanning segments. In the past few years, a number of potent and selective antagonists, of both peptide and nonpeptide nature, has been developed for the NK-1, NK-2 and NK-3 receptors. The contemporary isolation and cloning of the three tachykinin receptors enable now to study the molecular determinants for the interaction of natural tachykinins with their receptors, and the mechanism by which the antagonists interfere in this process. Furthermore, the introduction of tachykinin antagonists has revealed a striking species-related heterogeneity among the tachykinin receptors, and has also suggested a possible intra-species heterogeneity for both NK-1 and NK-2 receptors. However, molecular biology studies are needed to prove the existence of true tachykinin receptor subtypes.