GR 159897 is a highly potent, selective, competitive, brain-penetrated non-peptide neurokinin 2 (NK₂) receptor antagonist. GR 159897 has little or no affinity for NK₁ and NK₃ receptors. GR 159897 inhibits binding of [³H]GR100679 to human NK₂ (hNK₂)-CHO cells and rat colon membranes with pK_is of 9.51 and 10, respectively. Antagonizes bronchoconstriction. Anxiolytic-like and anti-tumor effects^[1][2]. In Vitro: GR 159897 (10-30 μM; 72 hours; 4T1, 4THM, 4TLM and 67NR cells) treatment inhibits proliferation of cells in all cell lines dose- dependently, a response more pronounced in 4T1, 4THM and 4TLM cells compared to 67NR cells^[2].
GR 159897 (10-30 μM; 72 hours; 4TBM, 4TLM, 4THM and 4T1 cells) treatment increases phosphorylation of P38, while inhibiting AKT activation in all metastatic cell lines whereas phosphorylation of ERK decreased in 4TBM, 4TLM and 4THM but not in 4T1 cells^[2]. In Vivo: GR 159897 (0.12 mg/kg; intravenous injection; guinea-pigs) treatment potently antagonizes bronchoconstriction induced by GR64349, with a long duration of action (3 h)^[1].