Alcohol dehydrogenase of human and rat blood vessels. Role in ethanol metabolism

Alcohol dehydrogenase (ADH) activity has been detected in all arteries and veins examined from humans and rat. In distinct human autopsy vessels, activity values range from 0.9 ± 0.2 to 9.9 ± 7.7 mU/mg. Distribution of the activity in human aorta was: intima (23.5%), media (74%) and adventia (2.5%). In most of the samples the β1β1 isozyme of class I ADH was the only form responsible for the ADH activity. Class IV ADH (σσ-ADH) was present in three of the 28 individuals examined. The rat blood vessels showed class IV, but not class I, ADH localized in endothelium and media. The physiological role of vascular ADH is probably related to retinoid metabolism and elimination of lipid peroxidation aldehydes. A contribution to human ethanol metabolism is supported by the significant amount of low-K(m) activity and the extension of the vascular system.