Antioxidant Effects of Stereoisomers of N-Acetylcysteine (NAC), L-NAC and D-NAC, on Angiotensin II-Stimulated MAP Kinase Activation and Vascular Smooth Muscle Cell Proliferation

Abstract

We examined the effects of the stereoisomers of N-acetylcysteine (NAC), L-NAC and D-NAC, on cellular glutathione (GSH) concentration and whether NAC-regulated cellular GSH levels are directly associated with angiotensin II (Ang II)-induced intracellular signaling events in vascular smooth muscle cells (VSMC). Both L-NAC and D-NAC similarly increased intracellular GSH concentration. We found that L-NAC and D-NAC both inhibited Ang II-induced c-Jun N-terminal kinase and p38 mitogen-activated protein kinase activation and [3H]-thymidine incorporation in VSMC. Our present study indicates the comparable effects of NAC stereoisomers in regulating intracellular GSH and the redox-dependent intracellular signaling mechanisms in VSMC. Keywords:: N-acetylcysteine, glutathione, vascular smooth muscle cell