Substance P: Small Molecules and Peptides

Substance P (SP, Neurokinin-1), is member of the Tachykinin peptide family and binds primarily to the Neurokinin 1 Receptor (NK1R, Substance P receptor, Tachykinin receptor 1) and with low affinity to the NK2 and NK3 receptors. Substance P is processed from preproTachykinin a, b, g and d isoforms that also generate other Tachykinins Neuropeptide K, Neurokinin A, Neurokinin B, and Neuropeptide G. Substance P is produced in the central nervous system, primary sensory neurons (C-type fibers), and endocrine cells of the intestinal mucosa. It triggers pain signals in the spinal cord dorsal horn as well as hypotension, tachycardia, release of inflammatory mediators, and direct antimicrobial action.