Physiological role of nitric oxide as an enhancer of oxygen transfer from erythrocytes to tissues.
The present study revealed the physiological role of NO as an enhancer of oxygen release from erythrocytes to peripheral tissue by breaking or stretching the heme iron-proximal histidine bond in the alpha subunit of hemoglobin (Hb), while maintaining oxygen binding capacity by restoring the bond in the lungs. Oxygen affinity was significantly decreased in blood containing NO-bound Hb alpha. The results may partly explain nitrosothiols in blood as an NO reservoir for an emergency and why cytokines induce NO synthase in the vascular system during such events as inflammation.
Kosaka
H
H
1st Department of Physiology, Medical School, Osaka University, Japan.
Seiyama
A
A
D000818:Animals; D004578:Electron Spin Resonance Spectroscopy; D004912:Erythrocytes / Q000378:metabolism*; D006454:Hemoglobins / Q000737:chemistry; D006639:Histidine / Q000737:chemistry; D009569:Nitric Oxide / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism*; D051381:Rats
D006454:Hemoglobins; D009569:Nitric Oxide; D006639:Histidine; D010100:Oxygen