Skip to main content
. 1999 Aug 3;96(16):9027–9032. doi: 10.1073/pnas.96.16.9027

Figure 4.

Figure 4

S-nitrosoHb and iron nitrosylHb formed under various physiological air-oxygenated conditions. (A) SOD increases the yield of NO bound to Hb. The experiments in Fig. 3A were repeated in the absence (solid line; 1.2 μM NO) or presence (dashed line; 1.5 μM NO) of 1,190 units/ml of SOD, which enhances the yield of nitrosyl species to approximately 100% of the NO added. Similar nitrosyl yields were obtained by using stroma-free Hb (25 μM), which is enriched in endogenous SOD (open circle). Data shown are the average of five to nine experiments ±SE. (B) EPR spectrum of a DNIC formed by exposure of oxyHb (≈99% sat; 3.93 mM) to NO (36 μM). (C) S-nitrosoHb and iron nitrosylHb formed by exposure of oxyHb (≈99% sat., 48 μM) to NO (1.2 μM). SNO (hatched bar) and FeNO (solid bar) were measured by photolysis-chemiluminesence (26). Data shown are the average of 12 experiments ±SE. (D) Measurement of intraerythrocytic S-nitrosoHb and iron nitrosylHb formed by exposure of oxygenated RBCs (mean [Hb], 25 μM) to 1 μM NO. Isolation of Hb and measurements were as previously described (26). Data are the mean of 12 experiments ±SE.