Localization of mesenteric hyperemia during digestion in dogs.

For localization of the site of post-prandial mesenteric hyperemia, low-fat, low-protein food was placed in either the stomach, duodenum, or jejunum while blood flow was measured in the celiac artery, superior mesenteric artery (SMA), or jejunal vein of anesthetized dogs. Distribution of flow in the jejunal wall was also measured. After intragastric placement of food, celiac arterial flow increased within 5 min and remained elevated for 30-60 min; SMA flow increased within 30 min and stayed up for at least 3 h. Intra-duodenal infusion of digested food increased SMA flow but did not alter celiac flow or flow to an isolated jejunal segment. Placement of digested food into one jejunal segment increased flow to that segment did not affect flow was localized to the mucosal layer. These studies indicate that during digestion, blood flow increases in the mucosa of the intestine when exposed to chyme and is not changed in other areas of the gastrointestinal tract. Postprandial mesenteric hyperemia induced by low-fat, low-protein food is a local phenomenon.