Endogenous cholecystokinin drives gallbladder emptying in dogs

Area of Science:

• Gastroenterology
• Digestive Physiology
• Endocrinology

Background:

• Gallbladder emptying is crucial for fat digestion.
• The role of duodenal fat and cholecystokinin (CCK) in this process requires further elucidation.

Purpose of the Study:

• To investigate the effect of duodenal fat on gallbladder emptying in dogs.
• To determine the role of circulating cholecystokinin (CCK) in mediating this response.

Main Methods:

• Seven dogs were surgically prepared with gastric, duodenal, and gallbladder cannulas.
• Gallbladder volume was measured, and blood samples were collected after intraduodenal administration of corn oil (Lipomul) in varying doses.
• The effects of CCK receptor antagonist (proglumide) and anti-CCK serum on gallbladder emptying were assessed.

Main Results:

• Intraduodenal fat significantly increased gallbladder emptying in a dose-dependent manner.
• Lipomul administration led to a dose-dependent increase in circulating CCK levels.
• A strong correlation was observed between CCK release and gallbladder emptying.
• Anti-CCK serum abolished gallbladder emptying, while proglumide inhibited it and increased gallbladder volume.

Conclusions:

• Fat in the duodenum stimulates gallbladder emptying in dogs.
• This effect is primarily mediated by the release of endogenous cholecystokinin (CCK).
• Circulating CCK is essential for fat-induced gallbladder contraction.