Thiamin depletion after ethanol and acetaldehyde administration to rabbits.

The role of thiamin in the catabolism of ethanol and acetaldehyde has been investigated. When thiamin and subsequently ethanol were administered orally to rabbits, the thiamin concentration in blood increased slightly during the first 3 h and then decreased gradually. After 12 h, it became lower than the value before thiamin administration. Finally, it reached the lowest value after 24 h and then increased slowly to revert to normal in 72 h. It is suggested that thiamin participates in the catabolic pathway of ethanol. An oral administration of pyrazole, an inhibitor of alcohol dehydrogenase, followed by ethanol to rabbits caused a delay in ethanol elimination from blood. When acetaldehyde was injected intravenously to rabbits, thiamin concentration and the transketolase activity in blood decreased gradually and after 12 h the thiamin level reached its lowest value, then increased slowly and normalized in 72 h. Thus, it could be postulated that the decrease in thiamin after an acute ethanol ingestion linked greatly to the acetaldehyde catabolism.