Dictionary.com
definitions

substance P

noun

a small peptide released upon stimulation in the nervous system and involved in regulation of the pain threshold.

RELATED CONTENT

Were P and R Once the Same Letter?
Do you ever stop and look at the shape of our alphabet? Each letter looks natural to us now, but all those lines and circles have unique histories. It’s easy to make assumptions that our letters make sense, that they developed in some orderly logical way, and one reasonable assumption would be that P and R are related to each other based on their form. …
READ MORE
APAP
Read more in this article about some frequently asked questions and fun facts related to our definitions.
READ MORE

Origin of substance P

earlier standard preparation P (1931); the initial is unexplained by the substance's discoverers
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Medicine definitions for substance p

substance P

n.

A short-chain polypeptide that functions as a neurotransmitter especially in the transmission of pain impulses from peripheral receptors to the central nervous system.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.