Dietary nitrate augments RBC-induced hypoxic cardioprotection.
Inorganic nitrate can be reduced to nitrite and deoxygenated hemoglobin can further reduce nitrite to NO (To identify the mechanism by which nitrate induces protection via RBCs, we again focused on the sGC-cGMP pathway. In these experiments, control RBCs collected from mice given normal drinking water (vehicle) or nitrate for 4 weeks were compared both with RBCs incubated with the sGC inhibitor ODQ before being administered to the isolated hearts and with RBCs from sGC-KO mice treated with nitrate. The control experiments and those with incubation with ODQ were matched in time, whereas the experiments using RBCs from sGC-KO mice were run at a separate occasion due to limitation in availability of the KO mice. Preincubation of the RBCs with ODQ blocked the protective effect induced by RBCs from nitrate-treated mice (