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Updated: Jul 18, 2026
08:58
En Face Detection of Nitric Oxide and Superoxide in Endothelial Layer of Intact Arteries
Published on: February 25, 2016
Hemolysis-associated endothelial dysfunction mediated by accelerated NO inactivation by decompartmentalized
Peter C Minneci1, Katherine J Deans, Huang Zhi
1Critical Care Medicine Department, NIH, Bethesda, Maryland 20892, USA.
The Journal of Clinical Investigation
|November 19, 2005
Summary
Intravascular hemolysis impairs blood flow by causing cell-free hemoglobin to deplete nitric oxide (NO). Inhaled NO gas protected against these effects, restoring vascular function.
Area of Science:
- Physiology
- Biochemistry
- Pathology
Background:
- Intravascular hemolysis can impair vasomotor tone and organ perfusion.
- Cell-free plasma hemoglobin (Hb) reacts with nitric oxide (NO), reducing its bioavailability.
- Disruption of Hb compartmentalization within erythrocytes is a key factor.
Purpose of the Study:
- To test if cell-free plasma Hb reduces NO bioavailability and causes vasomotor instability.
- To investigate the physiological consequences of acute intravascular hemolysis.
- To explore the role of inhaled NO in mitigating hemolysis-induced toxicity.
Main Methods:
- Acute intravascular hemolysis was induced in a canine model.
- A full-factorial design was used to assess dose-dependent effects.
- Inhaled NO gas was administered to evaluate its protective effects.
Main Results:
- Free water-induced hemolysis caused dose-dependent systemic vasoconstriction and impaired renal function.
- These effects were attributed to NO oxidation by cell-free plasma oxyhemoglobin.
- Inhaled NO (80 ppm) oxidized plasma oxyhemoglobin, attenuated vasoconstriction, and restored NO donor responsiveness.
Conclusions:
- Acute intravascular hemolysis toxicity is secondary to plasma oxyhemoglobin's reaction with NO.
- The erythrocyte plays a crucial role in maintaining NO homeostasis.
- Findings support a syndrome of hemolysis-associated NO dysregulation contributing to vasculopathy.
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