Treatment of human erythrocytes with anesthetic n-alkanols (pentanol, hexanol and hepatanol) results in a decrease in the osmotic water permeability of the red cell membrane. 2. The alcohol-induced changes in osmotic water permeability are proportional to the alcohol concentration and roughly parallel diphenylhexatriene that are induced by the alcohols. 3. Enrichment of the red cell membrane in cholesterol also results in a decrease in the osmotic water permeability. 4. Moderate depletion (9% or 40%) of membrane cholesterol is without effect on the osmotic water permeability, even though this treatment results in a significant increase in the rotational mobility of diphenylhexatriene in the membrane lipids.
