SR 48692 represents a new, potent, nonpeptide antagonist radioligand of the NT receptor that differentiates between agonist- and antagonist-receptor interactions.
GR 64349 is a potent and highly selective NK2 receptor peptide antagonist, with an EC50 of 3.7 nM in rat colon. GR 64349 exhibits selectivity >1000 and >300-fold with respect to NK1 and NK3 receptors, respectively.
