The role of Tachykinins in health and disease

Background & Aim: Tachykinin peptide family is one of the largest peptide families in animals that has been first discovered in the gastrointestinal tract about 70 years ago and isolated for the first time from the small intestine and brain. Up to now, more than 40 tachykinins have been extracted from invertebrates (insects, worms and fungi) and vertebrates (skin, gastro-intestinal duct, central nervous system and peripheral nervous system). Herein we reviewed the structure, function, and role of tachykinins and their receptors in pathophysiology of main systems in human body. Methods: Scopus, Science Direct, and PubMed databases were used in this work. The search was performed using tachykinins, neurokinin receptors, neuropeptide, and tachykinin receptors as key words from 1985 to 2018. Results: Mammalian tachykinins have a similar structural pattern and belong to the G protein superfamily that are derived from two pre-protachykinin genes (PPT-A and PPT-B) and exert their biological effects through binding to specific protein receptors, called neurokinin receptors. The secondary and principal effects of tachykinins depend on the activation of various receptors in the body. In addition to their role in central and peripheral nervous systems as neurotransmitter, tachykinins and their receptors play important roles in interaction among neuromuscular, respiratory, cardiovascular, immune, endocrine, digestive and urogenital systems. Conclusion: Regarding the diversity of physiological functions, the involvement of tachykinins can be expected in the etiology of many diseases and their processes such as pulmonary edema, pain, sleep deprivation, depression, stress, Parkinson's disease, gastrointestinal and respiratory diseases and inflammatory processes of the neuromuscular and neurogenic systems.