THE ROLE OF HEME-CONTAINING GLOBINS IN HYPOXIC NO-SIGNALING OF VERTEBRATE CELLS
Nitric oxide is one of the most important signaling molecule of living organisms. It may be produced by two ways: from arginine by means of NO-syntases and from nitrite by means of nitrite reductases. The last way is realized mostly at hypoxic state of organisms and heme-containing globins of vertebrates (hemoglobin, myoglobin, cytoglobin, neuroglobin) mediate the transformation of NO <sub>2</sub> into NO by means of their nitrite reductase activities. Hypoxic NO-signaling depends on oxygen concentration and is important for exercise, vascular hypoxic vasodilation, myocardial preconditioning and angiogenesis. Data of scientific literature of last 15 years show that the nitrite-reductase activity of heme-containing globins was used for oxygen sensing and ROS/RNS defence at early stages of life evolution.