Methemoglobin—It's not just blue: A concise review

  title={Methemoglobin—It's not just blue: A concise review},
  author={Jay Nicholas Umbreit},
  journal={American Journal of Hematology},
  • J. Umbreit
  • Published 1 February 2007
  • Biology, Medicine
  • American Journal of Hematology
Hemoglobin has functions besides carrying oxygen to the tissues, and regulates vascular tone and inflammation via a redox couple with methemoglobin. Hemoglobin has iron in the reduced valance Fe(II) and methemoglobin has iron in the oxidized valance Fe (III), with a free energy capable of producing water from oxygen. In generating methemoglobin the couple functions as a nitrite reductase. The degree of oxidation of hemoglobin senses the oxygen level in the blood and uses its ability to produce… 

Alternate and Additional Functions of Erythrocyte Hemoglobin

The review discusses pleiotropic effects of erythrocytic hemoglobin (Hb) and their significance for human health and can be considered as a manifestation of the principle of biochemical economy.

The role of carbon monoxide and heme oxygenase in the prevention of sickle cell disease vaso‐occlusive crises

Preclinical and clinical data with CO provide compelling support for CO as a potential therapeutic in a number of pathological conditions, and considerable scientific data in the non‐SCD literature provide evidence for a beneficial impact of CO on cerebrovascular complications, suggesting that in SCD, CO could potentially limit these highly problematic neurologic outcomes.

Can Gas Replace Protein Function? CO Abrogates the Oxidative Toxicity of Myoglobin

It appear that CO from HO-1 attenuates damage by temporarily binding to deoxy-Mb, until free oxygen exchanges with CO to restore the equilibrium, and the study compared the antioxidant potential of CO in Mb-mediated oxidation with the antioxidants potential of Hp in Hb- mediated oxidation.

Erythrocytes as a preferential target of oxidative stress in blood

An overview of anemic diseases that are closely related to oxidative damage is presented and the results of studies using genetically modified mice suggest that antioxidative enzymes play essential roles in coping with oxidative damage in erythroid cells, and their absence limits erythropoiesis, the life-span of RBC and consequently results in the development of anemia.

Carbon Monoxide Promotes Respiratory Hemoproteins Iron Reduction Using Peroxides as Electron Donors

Results demonstrate that oxidative activity of acellular ferric RH and peroxides may be amended by CO turning on the reducing potential of peroxide and facilitating the formation of redox-inactive carboxyRH.

Heme degradation and vascular injury.

Sickle cell disease, an archetypal example of hemolysis, heme-induced oxidative stress, and cytoprotective adaptation, is reviewed.

Methaemalbumin formation in sickle cell disease: effect on oxidative protein modification and HO‐1 induction

It is suggested that haem transfer from metHb to HSA reduces the oxidative effects of free haemoglobin/haem on endothelium with both beneficial (reduced protein oxidation) and potentially harmful outcomes.

Towards nitrite as a therapy in cardiovascular disease

The experiments presented in this thesis were designed to test the hypothesis that vascular wall myoglobin is one of the responsible proteins, and furthermore that the release of NO in relative hypoxia may be useful therapeutically in conditions such as heart failure and myocardial ischaemia.



Concise review: methemoglobinemia.

In hereditary cytochrome b5 deficiency, treatment is often directed at improving the poor cosmetic effect of persistent cyanosis with the minimum amount of drugs to give satisfactory clinical results.

Proposed Mechanism of Nitrite-Induced Methemoglobinemia

It was found that, contrary to widespread opinion, direct oxidative-reductive interaction between hemoglobin and nitrite is absent or negligible under physiological conditions.

The oxyhemoglobin reaction of nitric oxide.

Hemoglobin serves to regulate the chemistry of NO and maintain it in a bioactive state and motivate a reconsideration of fundamental issues in NO biochemistry and therapy.

Antioxidant protein 2 prevents methemoglobin formation in erythrocyte hemolysates.

Recombinant AOP2 prevented induced as well as noninduced methemoglobin formation in erythrocyte hemolysates, indicating its antioxidant properties, and is part of a sophisticated system developed to protect and support ery Throcytes in their many physiological functions.

Nitric oxide binding to oxygenated hemoglobin under physiological conditions.

Different Faces of the Heme-Heme Oxygenase System in Inflammation

Pre-induction of HO activity has been demonstrated to ameliorate inflammation and mediate potent resistance to oxidative injury and a better understanding of the complex heme-heme.

Haptoglobin phenotypes differ in their ability to inhibit heme transfer from hemoglobin to LDL.

It is concluded that partial heme transfer from the Hb-Hp2-2 complex to LDL is the reason for oxidation of LDL lipids as well as protein, and this findings provide a molecular basis for Hp 2-2 atherogenic properties.

Pro-oxidant and cytotoxic effects of circulating heme.

It is concluded that hemoglobin, when oxidized in plasma, can be indirectly cytotoxic through the generation of oxidized LDL by released heme and that, in response, the intracellular defense-HO-1 and ferritin-is induced.

Mechanism of low-density lipoprotein oxidation by hemoglobin-derived iron.

It is concluded that met-hemoglobin exerts its oxidative activity on LDL via transfer of heme, which serves as a vehicle for iron insertion into the LDL protein, leading to formation of atherogenic LDL aggregates.

Iron release, oxidative stress and erythrocyte ageing.