Capsaicn Effects in Pepper Spray
Natural Oleoresin extract of Capsicum contains Capsaicin which causes the irritation of the trigeminal cells. These cells are pain receptors located in the mouth, nose, stomach and the mucous membrane. They release Substance P (SP), a chemical messenger that communicates any pain or skin inflammation to the brain.
SP is a neurotransmitter. Neurotransmitters are inter-cellular chemical messengers that are secreted by neurons (nerve cells) across specialized structures (synapses) to transmit chemical information to one or more target cells.
Capsaicin as an irritant compound present in CAP-STUN induces neurogenic inflammation upon local application. In recent years this agent has been used extensively in research on primary sensory neurons because of its selective action on a population of C-fibre afferent and possibly also on an A-delta fibre type. Capsaicin stimulation of sensory nerves not only produces central transmission of sensory signals but also releases SP from central and peripheral sensory nerve terminals.
Substance P (SP) belongs to the Tachykinin family, which represents a group of biologically active peptides with a similar sequence of amino acids in the C-terminal region. SP was the first peptide of the tachykinin family to be found in mammals.
Substance P Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH2
The natural release of SP is therefore likely to represent a direct action on postcapillary venules or smooth muscle cells. Both capsaicinoids and SP act as Spasmogens on certain viscera containing smooth muscle causing contractions. Substance P is one of the key causes of total incapacity effects causing contraction of the oesophagus, trachea, respiratory track and iris muscles of the eyes.