[Band 3 protein as a metabolic sensor--CO2 regulates the amount of oxygen delivered to tissues from red blood cells].

Oxygen is essential for most forms of life, but too much oxygen is harmful and can induce tissue damage. Living creatures therefore have a tightly regulated system to deliver the necessary amount of oxygen to specific tissues at the right time. CO2 is not simply waste matter from tissues, but regulates the amount of oxygen delivered to tissues from red blood cells, utilizing the synergistic effects of hemoglobin, carbonic anhydrase and the anion exchange activity of band 3 protein. Red blood cells play an important role in this system and provide an ideal vehicle for delivering oxygen to tissues, depending on their metabolic activity.