Neurotensin receptor 1 (NTS1)

In vitro, Meclinertant (SR 48692) competitively inhibits ¹²⁵ I-labeled neurotensin binding to the high-affinity binding site present in brain tissue from various species with IC ₅₀ values of 0.99 nM (guinea pig), 4.0 nM (rat mesencephalic cells), 7.6 nM (COS-7 cells transfected with the cloned high-affinity rat brain receptor), 13.7 nM (newborn mouse brain), 17.8 nM (newborn human brain), 8.7 nM (adult human brain), and 30.3 nM (HT-29 cells). Meclinertant also displaces ¹²⁵ I-labeled neurotensin from the low-affinity levocabastine-sensitive binding sites but at higher concentrations (34.8 nM for adult mouse brain and 82.0 nM for adult rat brain).
In guinea pig striatal slices, Meclinertant blocks K ⁺ -evoked release of [ ³ H]dopamine stimulated by neurotensin with a potency (IC ₅₀ = 0.46 nM) that correlates with its binding affinity.

Meclinertant (SR 48692) treatment reverses at 80 μg/kg the turning behavior induced by intrastriatal injection of neurotensin in mice and with a long duration of action (6 hours).