[Renal handling of alcohol and its tubular effects]

The renal handling of ethanol comprises glomerular filtration and tubular reabsorption. Due to its high permeability alcohol concentration in the tubular fluid approaches that of peritubular fluid and under steady state conditions alcohol concentration in the final urine is almost the same as in serum water. Even in high concentrations alcohol does not significantly interfere with kidney cell function. This seems to be due to the fact that renal tissue is almost free from alcohol dehydrogenase. Thus, acetaldehyde, the cytotoxic intermediate of alcohol metabolism, is not accumulated in effective doses. If applied directly in micropuncture experiments alcohol is without distinct effects while acetaldehyde inhibits the main parameters of cellular vitality as measured by electrical membrane potentials and intracellular ion activities.