Adaptation to high-fat diet reduces inhibition of gastric emptying by CCK and intestinal oleate.
Rats maintained on low-fat (LF) or high-fat (HF) diets were fitted with gastric cannulas and duodenal catheters. Intraperitoneal injection of 0.250-2.0 microg/kg cholecystokinin (CCK) significantly inhibited gastric emptying of a 5-ml NaCl load in LF rats by 26.2-55. 1% compared with emptying after vehicle injection. By contrast, CCK-induced inhibition of gastric emptying was significantly less in HF rats given the same CCK doses (10.0-31.7% inhibition over the same CCK dose range). A 20-min intraduodenal infusion of oleate (0.03 or 0.06 kcal/ml) also resulted in significant inhibition of gastric emptying in LF rats (24 and 89%, respectively). Oleate-induced inhibition of gastric emptying was significantly attenuated in rats maintained on the HF diet (2 and 56%, respectively). Unlike CCK injections or oleate infusion, intraduodenal maltotriose infusion inhibited gastric emptying to a similar degree in LF and HF rats (77 and 78%, respectively). These results indicate that feeding HF diets diminishes the enterogastric inhibition of gastric emptying by intestinal oleate and diminishes the ability of CCK to inhibit gastric emptying.
Covasa
M
M
Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, and Program in Neuroscience, Washington State University, Pullman, Washington 99164, USA. mcovasa@vetmed.wsu.edu
Ritter
R C
RC
D000222:Adaptation, Physiological; D000818:Animals; D002766:Cholecystokinin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004041:Dietary Fats / Q000008:administration & dosage* / Q000494:pharmacology; D005746:Gastric Emptying / Q000187:drug effects*; D007422:Intestines / Q000502:physiology*; D008297:Male; D019301:Oleic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000494:pharmacology
D004041:Dietary Fats; D019301:Oleic Acid; D012965:Sodium Chloride; D002766:Cholecystokinin