What is "substance p"

n. (context biochemistry English) A tachykinin neuropeptide associated with inflammatory processes and pain.

Substance P (SP) is an undecapeptide (a peptide composed of a chain of 11 amino acid residues) member of the tachykinin neuropeptide family. It is a neuropeptide, acting as a neurotransmitter and as a neuromodulator. Substance P and its closely related neurokinin A (NKA) are produced from a polyprotein precursor after differential splicing of the preprotachykinin A gene. The deduced amino acid sequence of substance P is as follows:

• Arg Pro Lys Pro Gln Gln Phe Phe Gly Leu Met (RPKPQQFFGLM)

with an amidation at the C-terminus. Substance P is released from the terminals of specific sensory nerves. It is found in the brain and spinal cord and is associated with inflammatory processes and pain.