Report

Blood Flow Regulation by S-Nitrosohemoglobin in the Physiological Oxygen Gradient

+ See all authors and affiliations

Science  27 Jun 1997:
Vol. 276, Issue 5321, pp. 2034-2037
DOI: 10.1126/science.276.5321.2034

You are currently viewing the abstract.

View Full Text

Via your Institution

Log in through your institution

Log in through your institution


Abstract

The binding of oxygen to heme irons in hemoglobin promotes the binding of nitric oxide (NO) to cysteineβ93, formingS-nitrosohemoglobin. Deoxygenation is accompanied by an allosteric transition in S-nitrosohemoglobin [from the R (oxygenated) to the T (deoxygenated) structure] that releases the NO group. S-nitrosohemoglobin contracts blood vessels and decreases cerebral perfusion in the R structure and relaxes vessels to improve blood flow in the T structure. By thus sensing the physiological oxygen gradient in tissues, hemoglobin exploits conformation-associated changes in the position of cysteineβ93 SNO to bring local blood flow into line with oxygen requirements.

View Full Text

Related Content