The in Vivo Effect of Ethanol on Gastrointestinal Motility and Gastrointestinal Handling of Calcium in Rats

Abstract

The acute effects of an intragastric administration of ethanol (2 g/kg body weight) (given as 13.3% w/v solution) on the in vivo gastrointestinal motility and gastrointestinal absorption and secretion of calcium were investigated in 20-h fasted rats. Gastric ethanol concentration remained high for 90 min while the concentration in the duodenum peaked at 30 min before declining to a range slightly higher than that in the mid and distal intestine. Plasma ethanol peaked at 60 min. From the polyethylene glycol (PEG) distribution, ethanol was found to delay gastric emptying, and at 60 min, 40% of PEG was still retained in the stomach of the ethanol-treated group while gastric emptying had been completed in the controls. However, ethanol placed directly into the duodenum was found to enhance intestinal motility.
Under control conditions, exogenous calcium was completely ab-sorbed by the time it reached the mid-small intestine (J₃) and calcium found in more distal segments was of endogenous origin. Ethanol suppressed calcium absorption while markedly stimulating calcium secretion in the stomach and the distal small intestine, resulting in a net 32% increase in the total gastrointestinal calcium content. This effect on the distal small intestine was from ethanol that had reached this area from the circulation, and not from ethanol transit along the gastrointestinal tract.