Nω-Propyl-L-arginine (N-omega-Propyl-L-arginine) hydrochloride is a potent, competitive, and highly selective inhibitor of neuronal nitric oxide synthase (nNOS), with a Ki of 57 nM. Nω-Propyl-L-arginine hydrochloride displays a 149-fold selectivity for nNOS over endothelial NOS (eNOS)[2].In Vivo: Nω-Propyl-L-arginine (N-omega-Propyl-L-arginine) hydrochloride (20 mg/kg; i.p.) blocks both phencyclidine-induced disruption of prepulse inhibition and phencyclidine-induced stimulation of locomotor activity[2].