Neurokinin A

Neurokinin A (formerly known as substance K) is a member of the tachykinin family of neuropeptide neurotransmitters. It is produced from the same preprotachykinin gene as its fellow neuropeptide, substance P. It has various roles roles in the body of humans and other animals. One specific example is mediating contraction of the rat colon. Neuropeptide K (which has also been called neurokinin K )and neuropeptide gamma are N-terminally longer versions of neurokinin A, produced from the same splice forms of the same gene, which appear to be final peptide products in some tissues.