INTEGRATION OF CANINE PROXIMAL GASTRIC, ANTRAL, PYLORIC, AND PROXIMALDUODENAL MOTILITY DURING FASTING AND AFTER A LIQUID MEAL

The aim was to investigate the integration of proximal gastric, antral , pyloric, and duodenal motility during fasting and after feeding. Usi ng a proximal gastric barostat and a manometric assembly with an array of side holes astride the gastroduodenal junction, the gastrointestin al interdigestive migrating motor complex was detected in five of seve n conscious fasting dogs. During phase III of the complex, which laste d a mean +/- SEM of 13 +/- 0.5 min, 9.6 +/- 0.9 volume waves were pres ent in the proximal stomach. The volume waves were coordinated with cl usters of antral waves 64 +/- 11% of the time and with inhibition of d uodenal waves 91 +/- 3% of the time. A 300-ml calorie-dense liquid mea l abolished the complex and promptly increased proximal gastric volume in five of six dogs. Volume waves were nearly completely suppressed, while antral waves decreased from 24 +/- 3.0 waves/10 min to 10 +/- 2. 8 waves/10 min (P < 0.05) and isolated pyloric pressure waves increase d from 7.2 +/- 2.8 waves/10 min to 22 +/- 3.3 waves/10 min (P < 0.005) . In summary, proximal gastric motility was integrated with antral, py loric, and duodenal motility under both fasting and fed conditions. Th e integrated patterns likely account for the efficient clearance of in digestible solids during fasting and the controlled emptying of nutrie nts with feeding.