The pulmonary ethanol metabolizing system (PET).

Rat lung slices incubated in a Krebs ringer bicarbonate buffer respired at a rate of 0.62 mumoles/g lung X min. Respiration was inhibited by cyanide and stimulated by dinitrophenol. PET was insensitive to the action of pyrazole, cyanide or azide. Lung microsomes metabolized ethanol at rates which were less than 1% of PET. They showed an apparent Km for ethanol of the order of 10 mM and a Vmax of about 7 nmoles acetaldehyde/mg prot X min. Oxidation of ethanol by lung slices to acetaldehyde and CO2 was less than 0.3% and 1.15% than PET, respectively. Chromatographic determination of the products of ethanol metabolism by lung slices showed that a metabolite similar to glucuronic acid was formed. It is concluded that PET is a nonoxidative process which from the evidence presented in this work, would seem to involve the formation of ethyl glucuronide.