L-745870 (L-745,870) is is a potent, selective, brain-penetrant and orally active dopamine D4 receptor (D4R) antagonist with Ki of 0.43 nM. L-745870 is >100-fold selective for D4R over other dopamine receptors (D1R, D2R, D3R, and D5R) with subnanomolar affinity. L-745870 blocks the inhibition of forskolin-stimulated adenylate cyclase activity in transfected human embryonic kidney (HEK293) and Chinese hamster ovary (CHO) cells. L-745870 blocks dopamine-induced inhibition of Ca2+ currents in transfected GH4C1 pituitary cells. L745870 (10 mg/kg p.o.) induces mild sedation and extrapyramidal motor symptoms, notably bradykinesia.
