Fig. 6.

Potential mechanism of RBC-mediated nitrite bioactivation and its potentiation by far red light. Nitrite reacts with deoxygenated Hb to make NO which then binds other vacant hemes or forms a nitrosothiol (RSNO). The nitrosyl-heme or nitrosothiol is exported and binds a surface thiol. Another potential NO species that may form is a DNIC (not shown). The NO congener can then be transported in plasma and interact with platelets and other blood components and this action is potentiated by photolysis using far red light.