Haldane, hot dogs, halitosis, and hypoxic vasodilation: the emerging biology of the nitrite anion

Abstract

While it has long been known that the reduction of nitrite to nitric oxide (NO) forms iron-nitrosyl-myoglobin and is the basis of meat curing, a greater biological activity of the nitrite anion has only recently been appreciated. In the stomach, NO is formed from acidic reduction of nitrite and increases mucous barrier thickness and gastric blood flow (see the related study beginning on page 106). Nitrite levels in blood reflect NO production from endothelial NO synthase enzymes, and recent data suggest that nitrite contributes to blood flow regulation by reaction with deoxygenated hemoglobin and tissue heme proteins to form NO.

Figure 1

The broad biological activity of the nitrite anion. Nitrite levels in blood reflect NO production from endothelial NO synthase enzymes. Furthermore, nitrite contributes to blood flow regulation by reaction with deoxygenated hemoglobin and tissue heme proteins to form NO. In the stomach, NO is formed from acidic reduction of nitrite and increases mucous barrier thickness and gastric blood flow. Finally, the reaction of nitrite to form NO and iron-nitrosyl-myoglobin forms the basis of meat curing. sGC, soluble guanylyl cyclase.