ABSTRACT
Hemolysates or erythrocytes prepared from Japanese normal and acatalasemic subjects were exposed to nitrogen monoxide or nitrogen dioxide, and methemoglobin formation was determined. Concentrations of methemoglobin in human and mouse acatalasemic hemolysates exposed to nitrogen monoxide or nitrogen dioxide were higher than those in the normal hemolysates. Results similar to Japanese acatalasemic hemolysates or erythrocytes were obtained with mouse hemolysates or erythrocytes. When acatalasemic mice were exposed to nitrogen monoxide, the methemoglobin concentration in the blood was higher than that in the normal mice. Similar results on methemoglobin formation were obtained after exposing mice to nitrogen dioxide, although the rate of methemoglobin formation was lower in the blood of nitrogen dioxide-exposed mice. The methemoglobin concentration in erythrocytes of acatalasemic mice after the addition of sodium nitrite was higher than that in red cells of normal ones. Methemoglobin concentration in the blood of mice receiving sodium nitrites in vivo was determined, and found that the methemoglobin concentration in the blood of acatalasemic mice was higher than that in the blood of normal ones. These results indicated that the formation of methemoglobin from hemoglobin with nitrogen monoxide, nitrogen dioxide and nitrite ion appears to be controlled by the blood catalase.
