On the Mechanism of Methemoglobin Formation by Methemoglobin Forming Substances

The Formation of Methemoglobin

The Formation of Methemoglobin by Streptococcus Viridans

Cultures of Streptococcus viridans when brought into contact with red blood corpuscles have the power of transforming oxyhemoglobin into methemoglobin. The reaction occurs only in the presence of living streptococci when they are able to carry on their metabolic activities. The intensity of the reaction runs roughly parallel with the period of growth and multiplication of the bacteria and gradu...

Methemoglobin Formation in Human Blood by Cobalt

Although the erythropoietic effect of cobalt has been amply demonstrated in experimental animals (1-3), in normal human beings (4, 5), and in certain types of anemia (4, 6-8), the mechanism of this increased blood formation has not been elucidated. No evidence has been adduced that administration of cobalt causes a decrease in oxygen capacity (9) or alters the oxygen dissociation curve (10, 11)...

Mechanism of methemoglobin reduction by ascorbic acid under anaerobic conditions.

The time course of methemoglobin reduction by ascorbic acid under anaerobic conditions was analyzed by using isoelectric focusing on Ampholine plate gel in order to compare results obtained by studies of the changes in absorption during the reaction. The intermediate hemoglobin which appeared all through the reaction was single and identified as the alpha3+beta2+ valency hybrid. In the presence...

Methemoglobin formation in human erythrocytes by nitroaromatic explosives.

We have examined the structure-activity relationships in methemoglobin (MetHb) formation by high explosives 2,4,6-trinitrotoluene (TNT), 2,4,6-trinitrophenyl-N-nitramine (tetryl) and 2,4,6-trinitrophenyl-N-nitraminoethylnitrate (pentryl), and a number of model nitrobenzenes. In lysed human erythrocytes the rate constants of oxyhemoglobin (OxyHb) oxidation increased with an increase in single-el...