Specific transport of S ‐nitrosocysteine in human red blood cells: Implications for formation of S ‐nitrosothiols and transport of NO bioactivity within the vasculature

The transport of various S ‐nitrosothiols, NO and NO donors in human red blood cells (RBC) and the formation of erythrocytic S ‐nitrosoglutathione were investigated. Of the NO species tested only S ‐nitrosocysteine was found to form S ‐nitrosoglutathione in the RBC cytosol. l ‐Serine, l ‐cysteine and l ‐lysine inhibited formation of S ‐nitrosoglutathione. Incubation of RBC pre‐incubated with S ‐[ 15 N]nitroso‐ l ‐cysteine with native plasma or platelet‐rich plasma led to formation of S ‐[ 15 N]nitrosoalbumin and inhibited platelet aggregation, respectively. The specific transporter system of S ‐nitroso‐ l ‐cysteine in the RBC membrane may have implications for formation of S ‐nitrosoalbumin and S ‐nitrosohemoglobin and for transport of NO bioactivity within the vasculature.