[mass noun] A compound thought to be involved in the synaptic transmission of pain and other nerve impulses. It is a polypeptide with eleven amino-acid residues.
- ‘When sensory nerve cells are activated, calcium levels inside these cells rise and the neuropeptides, such as substance P and calcitonin gene related peptide are released.’
- ‘The heady mixture of sleep deprivation, adrenaline, and substance P plus or minus caffeine makes for a euphoric, addictive cocktail.’
- ‘Most types of asthma involve inflammation, with release of chemical mediators like histamine, bradykinin, and substance P, which diffuse to the smooth muscle and make it contract.’
- ‘A variety of possible neurotransmitters were examined, including acetylcholine, dopamine, and substance P, but unequivocal identification of key transmitters eluded investigators.’
- ‘It's thought that this burning depletes nerve cells of a chemical called substance P, which has a role in transmitting pain messages.’