The final proposed system of RBC vasodilation inside the existence of nitrite is the reduction of nitrite to NO by Hb. Brooks initially examined the nitrite Hb interaction in 1937 and this work was later extended by Doyle in 1981 (Brooks, 1937; Doyle et al., 1981). Nitrite reacts with deoxygenated Hb to form metHb and NO (Brooks, 1937; Doyle et al.