Substance P at a glance
| Feature | What it means |
|---|---|
| Peptide type | An 11-amino-acid neuropeptide |
| Family | Tachykinins, a group of fast-acting signalling peptides |
| Primary receptor | Neurokinin-1 receptor, usually abbreviated NK1R |
| Main research areas | Pain transmission, neurogenic inflammation, nausea, immune signalling and gut function |
| Biological distribution | Brain, spinal cord, sensory nerves, gut and several peripheral tissues |
| Research status | Extensive biology, with some therapeutic applications still contested |
| Product status | Check the WL Australia research shop for current availability; a dedicated Substance P product page was not visible in the indexed catalogue used to prepare this article |
The discovery: from an unknown powder to a major neuropeptide
The problem: biology was missing the messenger
In the early twentieth century, scientists knew that nerves influenced organs, but many of the chemical messengers involved had not yet been identified. Researchers could observe an effect without knowing what caused it, much like hearing a doorbell without seeing who pressed it.
In 1931, Ulf von Euler and John Gaddum reported an active substance in extracts from horse brain and intestine. The extract caused intestinal smooth muscle to contract and produced a temporary fall in blood pressure in animal experiments.
The effect was not blocked by atropine, which suggested that the substance was not simply acetylcholine. Researchers were looking at a new biological signal.
The material was eventually called Substance P. The “P” is commonly associated with the original powder preparation. Later work established that the substance was a peptide, and in 1970 researchers purified it and identified its structure as an undecapeptide, meaning a peptide containing 11 amino acids.
Short version: Substance P began as an unexplained laboratory effect and became a foundational neuropeptide discovery.
