In 1983, NKA (previously known as substance K or neuromedin L) was isolated from porcine spinal cord and was also found to stimulate intestinal contraction.
En 1983, illouse a neuroquinina A (previamente coñecida como substancia K ou neuromedina L) da medula espiñal do porco e viuse que tamén estimulaba a contracción intestinal.