The movement of blood formaldehyde in methanol intoxication. II. The movement of blood formaldehyde and its metabolism in the rabbit.

The movement of blood formaldehyde in rabbits that were intoxicated with methanol has been investigated by simple headspace gas chromatography-mass spectrometry for the microdetermination of formaldehyde in the blood. When methanol alone was administered to rabbits orally, formaldehyde could not be detected in the blood. Further, in an experiment on the metabolism of methanol in vitro, formaldehyde was not detected in specimen samples but formate was. In contrast, when methanol was orally administered to rabbits that had been pretreated with diethyldithiocarbamate (DDC), an aldehyde dehydrogenase (ALDH) inhibitor, 17 to 33 microM of formaldehyde were detected in the blood 4 hours later. However, formaldehyde was not detected in the blood when methanol was orally administered to rabbits that had been pretreated with pyrazole, an alcohol dehydrogenase (ADH) inhibitor. After rabbits were given an intravenous administration of formaldehyde, and on the addition of formaldehyde to a rabbit liver homogenate and blood, the formaldehyde in both instances was metabolized rapidly. Formaldehyde that was not metabolized within 10 to 15 minutes, however, bound to the tissue proteins. Therefore, according to the results of this study, formaldehyde was seen to be rapidly metabolized to formate without accumulating in the blood or binding to the tissue proteins. Formaldehyde thus appears to have little influence on the symptoms of methanol poisoning.