Tachykinin-like central activity of neuromedin K in mice

Neuromedin K, a decapeptide isolated from porcine spinal cord and suggested to have tachykinin-like activity in vitro, produced reciprocal hind-limb scratching when injected intrathecally to mice. Neuromedin K was 20-60 times less potent in producing scratching (on a molar basis) than substance P, kassinin, eledoisin or physalaemin. The activity of neuromedin K was blocked by the substance P antagonist [D-Pro2D-Trp7.9]substance P at doses of antagonist which effectively blocked the activity of the other tachykinins. These data provide the first evidence for tachykinin-like activity of neuromedin K in the central nervous system.