Tachykinin peptides are one of the largest families of neuropeptides, found from amphibians to mammals. They were so named due to their ability to rapidly induce contraction of gut tissue.[2] The tachykinin family is characterized by a common C-terminal sequence, Phe-X-Gly-Leu-Met-NH2, where X is either an Aromatic or an Aliphaticamino acid. The genes that produce tachykinins encode precursor proteins called preprotachykinins, which are chopped apart into smaller peptides by posttranslationalproteolytic processing. The genes also code for multiple splice forms that are made up of different sets of peptides.
Tachykinins[3][4][5] excite neurons, evoke behavioral responses, are potent vasodilators, and contract (directly or indirectly) many smooth muscles. Tachykinins are from ten to twelve residues long.
The two human tachykinin genes are called TAC1 and TAC3 for historical reasons, and are equivalent to Tac1 and Tac2 of the mouse, respectively. TAC1 encodes neurokinin A (formerly known as substance K), neuropeptide K (which has also been called neurokinin K[6]), neuropeptide gamma, and Substance P.[7] Alpha, beta, and gamma splice forms are produced; the alpha form lacks exon 6 and the gamma form lacks exon 4. All three splice forms of TAC1 produce substance P, but only the beta and gamma forms produce the other three peptides. Neuropeptide K and neuropeptide gamma are N-terminally longer versions of neurokinin A that appear to be final peptide products in some tissues.[2]
Tachykinin peptides are also involved in inflammation, and tachykinin receptor antagonists have been researched for use in treating inflammatory conditions such as asthma and irritable bowel syndrome.[15][16][17] The main use for which these antagonist drugs have been applied so far, however, is as antiemetics, in both human and veterinary medicine.[18][19]
^Avanov AIa (1992). "Tachykinins and conformational aspects of their interactions with receptors". Mol. Biol. (Mosk). 26 (1): 5–24. PMID1324401.
^Dornan WA, Vink KL, Malen P, Short K, Struthers W, Barrett C (August 1993). "Site-specific effects of intracerebral injections of three neurokinins (neurokinin A, neurokinin K, and neurokinin gamma) on the expression of male rat sexual behavior". Physiol. Behav. 54 (2): 249–58. doi:10.1016/0031-9384(93)90107-Q. PMID7690487. S2CID33412235.
^Alvaro G, Di Fabio R (September 2007). "Neurokinin 1 receptor antagonists--current prospects". Curr Opin Drug Discov Dev. 10 (5): 613–21. PMID17786860.
^Duffy RA (May 2004). "Potential therapeutic targets for neurokinin-1 receptor antagonists". Expert Opin Emerg Drugs. 9 (1): 9–21. doi:10.1517/eoed.9.1.9.32956. PMID15155133.
^Salomé N, Stemmelin J, Cohen C, Griebel G (April 2006). "Selective blockade of NK2 or NK3 receptors produces anxiolytic- and antidepressant-like effects in gerbils". Pharmacol. Biochem. Behav. 83 (4): 533–9. doi:10.1016/j.pbb.2006.03.013. PMID16624395. S2CID15134994.
^Louis C, Stemmelin J, Boulay D, Bergis O, Cohen C, Griebel G (March 2008). "Additional evidence for anxiolytic- and antidepressant-like activities of saredutant (SR48968), an antagonist at the neurokinin-2 receptor in various rodent-models". Pharmacol. Biochem. Behav. 89 (1): 36–45. doi:10.1016/j.pbb.2007.10.020. PMID18045668. S2CID21490514.
^Spooren W, Riemer C, Meltzer H (December 2005). "Opinion: NK3 receptor antagonists: the next generation of antipsychotics?". Nat Rev Drug Discov. 4 (12): 967–75. doi:10.1038/nrd1905. PMID16341062. S2CID13270787.
^Boot JD, de Haas S, Tarasevych S, et al. (March 2007). "Effect of an NK1/NK2 receptor antagonist on airway responses and inflammation to allergen in asthma". Am. J. Respir. Crit. Care Med. 175 (5): 450–7. doi:10.1164/rccm.200608-1186OC. PMID17170385. S2CID22707433.
^Navari RM (December 2007). "Fosaprepitant (MK-0517): a neurokinin-1 receptor antagonist for the prevention of chemotherapy-induced nausea and vomiting". Expert Opin Investig Drugs. 16 (12): 1977–85. doi:10.1517/13543784.16.12.1977. PMID18042005. S2CID21437603.
^Hickman MA, Cox SR, Mahabir S, et al. (June 2008). "Safety, pharmacokinetics and use of the novel NK-1 receptor antagonist maropitant (Cerenia) for the prevention of emesis and motion sickness in cats". J. Vet. Pharmacol. Ther. 31 (3): 220–9. doi:10.1111/j.1365-2885.2008.00952.x. PMID18471143.