CANINE SMALL-BOWEL MOTOR PATTERNS AND CONTRACTIONS ARE NOT NEURALLY REGULATED DURING ENTERIC NUTRIENT INFUSION

The aims of this study were to determine the effects of duodenal and j ejunoileal nutrient infusions on small intestinal motor patterns and i ntestinal contractions in neurally intact and neurally isolated small bowel. Fifteen dogs were prepared with duodenal and jejunal infusion a nd manometry catheters and a diverting jejunal cannula. Tell of the do gs underwent in situ neural isolation of the jejunoileum. A mixed nutr ient meal (0.5 kcal/ml) was infused into the duodenum or jejunum at 3 ml/min for 5 h. Control experiments involved infusion of a balanced sa lt solution. Manometric data collected on-line to a microcomputer were analyzed for direction, distance, and velocity of spread of single pr essure waves (SPW) and clustered contractions. Isolated duodenal and j ejunoileal nutrient infusions inhibited the fasting motor pattern in n eurally intact and neurally isolated small bowel. Motor activity (moti lity index) increased slightly during nutrient infusion within groups, but there were few differences between groups. Neither neural isolati on nor nutrient infusion had a consistent effect on spread of SPW or m igration of clustered contractions. Isolated duodenal and jejunoileal nutrient infusions in the dog inhibit fasting motor patterns and incre ase motor activity slightly but have little effect on characteristics of individual and clustered contractions. Extrinsic innervation to the jejunoileum or intrinsic neural continuity of the jejunum with the du odenum had little effect on single or grouped contractions. Although t he changes in motor activity demonstrated in this study appear small, alterations in intestinal transit and absorption may still occur and m ay be of importance physiologically.