Significance of the gastrointestinal tract in the in vivo metabolism of ethanol in the rat.

Abstract

The rate of ethanol metabolism and the extrapolated zero time blood ethanol concentration (C0) were compared in naive and ethanol-fed rats following intracardiac or ingastric administration of a test dose of ethanol (3 g/kg). If the gastrointestinal tract is involved in the disposition of ethanol, intragastric administration should result in a lower C0 and a faster overall rate of metabolism than intracardiac administration, since part of the dose would be metabolized in the gastrointestinal tract without having been absorbed and thereby entering the blood. However, no significant differences were observed in C0. The rate of metabolism was substantially higher in the ethanol-fed rats, but was uninfluenced by route of administration. Thus, the gastrointestinal tract plays no significant role in the metabolism of ethanol.