The last proposed mechanism of RBC vasodilation from the existence of nitrite will be the reduction of nitrite to NO by Hb. Brooks to start with studied the nitrite Hb interaction in 1937 and this perform was afterwards prolonged by Doyle in 1981 (Brooks, 1937; Doyle et al., 1981). Nitrite reacts with deoxygenated Hb to kind metHb and NO (Brooks, 1