Acetaldehyde concentration in rat blood and brain during the calcium carbimide--ethanol interaction.

Ethanol was administered to rats by oral intubation 3 h after intraperitoneal administration of calcium carbimide. Increased blood acetaldehyde concentration and the presence of acetaldehyde in brain were found for the calcium carbimide--ethanol interaction. There was no detectable brain acetaldehyde for ethanol administration following saline treatment. The magnitude of the acetaldehyde concentration in blood and brain during the calcium carbimide--ethanol interaction was directly dependent on the doses of calcium carbimide (0.7, 3.5, 7.0 mg/kg) and ethanol (0.5, 1.0, 1.5 g/kg). There was an exponential relationship between brain acetaldehyde concentration and blood acetaldehyde concentration. The threshold blood acetaldehyde concentration, above which acetaldehyde was found in brain, was approximately 6 micrograms/mL.