EFFECTS OF ETHANOL, XYLOSE, AND GLUCOSE ON CANINE JEJUNAL MOTILITY

Ethanol is an important source of calories that can cause certain gast rointestinal symptoms, notably diarrhea. To examine the effects of eth anol on the small bowel, we intraluminally perfused the jejunum of fou r dogs with ethanol (18, 9, 4.5, and 1.5%, wt/vol), D-xylose (30, 15, 7.5, and 4.5%, wt/vol), or glucose (30 and 5%, wt/vol). In other exper iments, these solutes were infused intravenously. Saline was always gi ven by the alternate route; jejunal manometry was recorded during and after the infusions. Phase III of the interdigestive cycle was delayed by all intraluminal infusions except for 4.5 and 1.5% ethanol, 4.5% x ylose, and 5% glucose. In addition, the onset of irregular contractile activity was delayed more with intraluminal ethanol than with intralu minal xylose or intraluminal glucose (P < 0.01). When administered int raluminally, ethanol and xylose appeared in blood but only ethanol equ ilibrated fully between the lumen and blood. Intravenous infusions of ethanol and xylose, but not glucose, also delayed the return of phase III. When given intravenously, ethanol and xylose were recovered from the lumen, whereas glucose never was. Ethanol and xylose had comparabl e effects on the canine small bowel; they induced prolonged periods of irregular contractile activity and delayed the return of phase III. T hese effects were seen rapidly when solutes were administered intralum inally and more slowly when they were given intravenously. These resul ts suggest that local luminal mechanisms stimulated by solutes influen ce small bowel motility, and they imply that the gut recognizes solute s whether or not these molecules are metabolizable.