EFFECT OF INTRAGASTRIC OR INTRADUODENAL ADMINISTRATION OF A POLYMERICDIET ON GALLBLADDER MOTILITY, SMALL-BOWEL TRANSIT-TIME, AND HORMONE-RELEASE

Objective.. During postpyloric tube feeding, GI intolerance is observe d more frequently than during prepyloric feeding, possibly by evoking a stronger GI response. Methods: We investigated the effect of intraga stric and intraduodenal administration of a polymeric diet (125 kcal/h ) on gallbladder motility (by ultrasonography), duodeno-cecal transit time (by lactulose H-2 breath test), and GI hormone release (including cholecystokinin, pancreatic polypeptide, and gastrin). Six healthy su bjects (two male, four female; mean age 22 yr, range 18-27 yr) were st udied on two separate occasions in random order during 6 h of continuo us administration of the diet through either the gastric or duodenal p ort of a two-lumen tube. Results: Intraduodenal feeding resulted in a more rapid contraction of the gallbladder, from 32 +/- 4 to 23 +/- 4 c m(3) at 10 min (p < 0.05), reaching a minimum of 6 +/- 1 cm(3), in con trast to intragastric feeding (31 +/- 4 to 19 +/- 3 cm(3) at 60 min, p < 0.05; minimum 14 +/- 1 cm(3)). The gallbladder remained contracted during the 6-h study period during both intraduodenal and intragastric feeding. Small-bowel transit time was significantly accelerated durin g intraduodenal compared with intragastric feeding (51 +/- 12 vs 81 -/- 9 min; p = 0.003). Plasma cholecystokinin secretion was significant ly (p < 0.05) increased during intraduodenal compared with intragastri c feeding (848 +/- 107 vs 279 +/- 89 pmol . L-1 . 360 min). The same w as true for pancreatic polypeptide secretion. However, gastrin release was significantly (p < 0.05) higher during intragastric feeding. Conc lusions: Intraduodenal feeding elicited a stronger GI response than in tragastric feeding, as demonstrated by accelerated small-bowel transit time, more rapid and stronger gallbladder contractions, and increased cholecystokinin and pancreatic polypeptide release. Gastrin release, on the other hand, was stronger during intragastric feeding. (C) 1998 by Am. Cell. of Gastroenterology.