Notes: GR94800 is a synthetic peptide neurokinin-2 (NK2) receptor antagonist (Ki = 1 nM).{65931} It is selective for NK2 over NK3 (Ki = 1,000 nM). GR94800 (0.1 and 1 µM) decreases balloon distension-induced submaximal and maximal atropine-resistant ascending excitatory reflex (AER) in isolated guinea pig ileum circular muscles.{65932}