Ethanol tolerance in the rat after inhalation of acetaldehyde for a period of 21 days.

Ethanol tolerance is related to alterations in fatty acid content and physical properties of membranes. Studies have suggested a specific role for acetaldehyde in the pathogenesis of alcoholism. We measured tolerance to EtOH and erythrocyte membrane fatty acid composition after intoxication by continuous inhalation of AcH vapor for a period of 21 days. Pathophysiological and nutritional parameters were compared between treated and pair weight controls. We showed that: intoxication with AcH is technically possible via the pulmonary route, producing plasma AcH levels comparable to those seen after ethanol intoxication. The dose of AcH needs to be increased progressively to maintain constant plasma levels this indicates metabolic tolerance. the AcH-intoxicated animals had a metabolic tolerance to EtOH. AcH intoxication led to alterations in fatty acid composition similar to those seen after EtOH intoxication, especially in the saturated/unsaturated ratio of the phosphatidyl-choline and phosphatidyl-inositol fractions. AcH probably plays a part in the phenomenon of tolerance to EtOH.