METHEMOGLOBIN FORMATION BY AMINOPHENOL AND DIPHENOL IN RABBITS

For the elucidation of methemoglobinemia in industrial poisonings caused by aromatic nitro and amino compounds, the study on the mechanism of methemoglobin (metHb) formation by aminophenol and diphenol in vitro has been carried out1). In this paper, the metHb formation in vivo by the above phenols was investigated to ascertain whether the mechanism of the metHb formation in vivo is similar to that in vitro or not.Methemoglobinemia was produced by the administration of o- or p-aminophenol as in vitro study, but no methemoglobinemia was observed by any isomers of diphenol, though pyrocatechin and hydroquinone were found to be the strong metHb formers in vitro as aminophenols. Characteristic of methemoglobinemia by aminophenol was com-pared with those of methemoglobinemia by nitrobenzene, aniline, p-benzoquinone and others. As the results of this study, it was ascertained that methemoglobinemia by aminophenol in vivo was produced by its quinone body formed mainly by the oxidase action of perturbed hemoglobin and not by autoxidation.