NK3 is one of three mammalian G-protein coupled receptors subtypes (NK1, NK2, NK3) that mediate the biological effects of the tachykinin peptide family. Neurokinin B is the tachykinin family peptide with the highest affinity to NK3R, but it still induces a response with NK1 and NK2 with lower potency. NK3, like the other tachykinin receptors, signals through Gq to stimulate intracellular calcium. Mammalian tachykinins are present in the brain and gut. NK3 receptor antagonists reduce intestinal motility and nociception in animal models of gastrointestinal disorders, and may be effective in irritable bowel syndrome.