Alcohol sensitivity related to polymorphism of alcohol-metabolizing enzymes in Japanese.

Normal Japanese subjects were divided into two groups, i.e., one with both low and high Km isozymes of aldehyde dehydrogenase for acetaldehyde, and the other deficient in the low Km isozyme. After intake of 0.4 g/kg alcohol, the deficient subjects showed high level of blood acetaldehyde, facial flushing and the other dysphoric symptoms, including increase of pulse rate, decrease of diastolic blood pressure, changes of pulse wave in the fingertip, and elevation of the arterial pressure and blood flow rate in common carotid arteries as well as increase of plasma catecholamines level. In contrast, subjects with normal ALDH did not show these changes. From the observation of liver specimens obtained at autopsy, the frequency of deficient phenotype of ALDH in Japanese was presumed to be about 36%.