Effects of acute ethanol intoxication on aldehyde dehydrogenase in mouse liver

To elucidate the effects of acute ethanol intoxication on hepatic aldehyde dehydrogenase (ALDH), the activities of these isozymes were measured after acute ethanol injection at the doses of 1, 3 or 5 g/Kg body weight in mice. At the same time, blood ethanol and acetaldehyde levels were measured to consider their correlation to the changes in ALDH activities. In the cytosolic fraction, acute ethanol injection caused no effects on high Km ALDH. However, low Km ALDH activity decreased significantly after 0.5 and 12 hr at the dose of 5 g/Kg body weight. In the granule fraction, acute ethanol injection caused more than 50% loss of low Km ALDH activity after 2 to 8 hr at the dose of 1 g/Kg and after 0.5 to 8 hr at the dose of 3 or 5 g/Kg body weight, in comparison with the untreated group. However, high Km ALDH activity decreased only after 4 hr at the dose of 3 or 5 g/Kg body weight. The elimination rate of blood ethanol was 158.0 mumol/min/1 and 125.6 mumol/min/1 after 0.5 to 4 hr of ethanol injection at the dose of 3 or 5 g/Kg body weight, respectively. However, these elimination rates decreased drastically after 4 to 8 hr following ethanol injection. The elimination rate of blood acetaldehyde was 116.6 nmol/min/1 after 1 to 2 hr, and the rate decreased to 6.9 nmol/min/1 after 2 to 8 hr following ethanol injection at the dose of 5 g/Kg body weight. These drastic decreases in acetaldehyde elimination rate appear to be caused by reduction of the granule low Km ALDH activity.