GR 64349

This compound is a potent and highly selective agonist for the tachykinin NK2 receptor, with an EC50 of 3.7 nM in the rat colon assay. It exhibits over 1000-fold selectivity against NK1 and over 300-fold against NK3 receptors. Its confirmed in vivo activity makes it a valuable tool for studying NK2 receptor function in gastrointestinal, pulmonary, and central nervous system research.