Gallbladder responses to modified sham feeding: effects of the composition of a meal.
Changes in gallbladder contraction and plasma cholecystokinin release were studied following modified sham feeding of 3 different isocaloric meals rich in either fat, protein or carbohydrates in healthy volunteers, and results were compared with those following real feeding of comparable meals. In contrast to carbohydrate-rich meals (8 +/- 19 ml/120 min), fat- (-412 +/- 46 ml/120 min) and protein-rich meals (-352 +/- 42 ml/120 min) reduced integrated gallbladder volume (P < 0.05) in response to modified sham feeding. Plasma cholecystokinin levels were not significantly influenced by modified sham feeding of fat, protein or carbohydrates. Real feeding of a carbohydrate-rich meal also failed to significantly reduce gallbladder volume and to stimulate cholecystokinin release (-45 +/- 40 ml/120 min and 51 +/- 11 pmol/120 min, respectively), while real feeding of both fat- and protein-rich meals distinctly reduced gallbladder volume (-679 +/- 76 and -564 +/- 53 ml/120 min, respectively; P < 0.05) and increased cholecystokinin release (651 +/- 72 and 504 +/- 43 pmol/120 min, respectively; P < 0.05). This study demonstrates that gallbladder contraction during the cephalic phase of meal stimulation is dependent on the fat, protein and carbohydrate percentages of a meal, and is activated by different mechanisms than the intestinal phase of a meal.
Witteman
B J
BJ
Department of Gastroenterology and Hepatology, University Hospital of Nijmegen, Leiden, The Netherlands.
Jebbink
M C
MC
Hopman
W P
WP
Masclee
A M
AM
Lamers
C B
CB
Jansen
J B
JB
D000109:Acetylcholine / Q000502:physiology*; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002766:Cholecystokinin / Q000097:blood; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004041:Dietary Fats / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D005260:Female; D005704:Gallbladder / Q000294:innervation / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D014630:Vagus Nerve / Q000502:physiology*
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D002766:Cholecystokinin; D000109:Acetylcholine