tcsc0014213 L-NMMA acetate

L-NMMA acetate is a nitric oxide synthase inhibitor of all NOS isoforms including NOS1, NOS2, and NOS3. The K_i values for nNOS (rat), eNOS (human), and iNOS (mouse) are approximately 0.18, 0.4, and 6 µM, respectively.

IC50 & Target: Ki: 0.18 µM (nNOS), 0.4 µM (eNOS), 6 µM (iNOS)^[1]

In Vitro: L-NMMA, starting from 100 μM, produces a concentration-dependent inhibition of the evoked relaxations (2Hz); maximal inhibition at 1 mM averaged about 35%. The inhibitory effect of L-NMMA is unchanged by previous incubation with D-arginine while it is prevented by L-arginine (L-Arg). L-NMMA does not affect isoprenaline-induced relaxation^[2]. Superfusion of L-NMMA reduces arteriolar diameter and causes dose-dependent increases in arteriolar tone. The onset of action of L-NMMA is nearly immediate. L-NMMA inhibits vasodilator responses to the endothelium-dependent vasodilator ACh but not to the endothelium-independent NP. NE induced dose-related vasoconstriction that is significantly potentiated by L-NMMA^[3].