Fig. 1.

Reaction of nitrite with deoxy fetal sheep hemoglobin (deoxy-sHbF) and adult sheep hemoglobin (deoxy-sHbA). A: disappearance of sheep adult deoxyhemoglobin (deoxy-Hb) and the formation of iron nitrosyl-hemoglobin over time in the reaction of 50 μM deoxy-Hb with 10 mM nitrite at pH 7.4 and 25°C. Inset: spectra collected during the reaction selected at regular intervals of 60 s. B: same as in A for sHbF. C: initial rate of fetal and adult deoxy-Hb consumption for the reaction of 50 μM with increasing concentrations of nitrite (1–10 mM) at pH 7.4 and 25°C. All Hb concentrations are reported on a heme basis. NO, nitric oxide.