leptin and octanoic-acid

Inflammatory bowel disease (IBD) is associated with delay in gastric emptying, increase in ghrelin, and decrease in leptin. The aim was to investigate the correlation between gastroduodenal (GD) symptoms, gastric emptying, and serum levels of active ghrelin and leptin in IBD. Twenty-seven IBD patients and 26 healthy volunteers were asked to complete the Porto Alegre Dyspeptic Symptoms Questionnaire. A gastric emptying test for solids was performed using a C13 octanoic acid breath test. During this test, serum samples were collected for measuring active ghrelin and leptin concentrations by radioimmunoassay.. Patients with IBD demonstrated delayed gastric emptying compared with healthy volunteers. In patients with GD symptoms, the delay in gastric emptying was more pronounced, and there were significant correlations of satiety and vomiting with gastric emptying. Basal leptin, but not active ghrelin, increased in patients with GD symptoms compared with patients without these symptoms. There were negative correlations between basal active ghrelin with total Porto Alegre score and epigastric pain in IBD patients with GD symptoms. Key Messages: In IBD, satiety and vomiting were associated with delay in gastric emptying. Conversely, epigastric pain had a negative correlation with active ghrelin. Our results suggest that different pathophysiological mechanisms contribute to GD symptoms in IBD.

Topics: Adult; Aged; Breath Tests; Caprylates; Carbon Isotopes; Case-Control Studies; Duodenum; Female; Gastric Emptying; Ghrelin; Humans; Inflammatory Bowel Diseases; Leptin; Male; Middle Aged; Stomach

Mammary epithelial cells, which express and secrete leptin into milk, accumulate triacylglycerol (TAG). We examined effects on the accumulation of cytosolic TAG of addition of short- (acetate and butyrate) or medium- (octanoate) chain fatty acids to the medium bathing bovine mammary epithelial cells (bMEC). Octanoate stimulated the accumulation of TAG in a concentration-dependent manner from 1 to 10 mM and increased lipid droplet formation and mRNA expression of CD36 (a fatty acid translocase). Additionally, expression of a peroxisome proliferator activated receptor (PPAR) gamma 2 protein that is a lipid-activated transcription factor, was increased by the addition of acetate or octanoate. However, leptin mRNA expression was significantly reduced by addition of acetate or butyrate. Both short- and medium-chain fatty acids inhibited acetyl coenzyme A carboxylase (ACC) activities, which is pivotal in lipid synthesis, but elevated expression of uncoupling protein 2 (UCP2) mRNA, which is important in energy expenditure. These results suggest that octanoate induces cytosolic TAG accumulation and the formation of lipid droplets, and that acetate and butyrate inhibit leptin expression and lipid synthesis in bMEC.

Topics: Acetyl-CoA Carboxylase; Animals; Caprylates; Cattle; CD36 Antigens; Cells, Cultured; Cytosol; Enzyme Inhibitors; Epithelial Cells; Female; Gene Expression; Ion Channels; Leptin; Mammary Glands, Animal; Membrane Transport Proteins; Mitochondrial Proteins; PPAR gamma; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Triglycerides; Uncoupling Protein 2

To test the hypothesis that adipose tissue could be one of the primary targets through which medium-chain fatty acids (MCFAs) exert their metabolic influence.. Sprague-Dawley rats were fed a control high-fat diet compared with an isocaloric diet rich in medium-chain triglycerides (MCTs). We determined the effects of MCTs on body fat mass, plasma leptin and lipid levels, acyl chain composition of adipose triglycerides and phospholipids, adipose tissue lipoprotein lipase activity, and the expression of key adipogenic genes. Tissue triglyceride content was measured in heart and gastrocnemius muscle, and whole body insulin sensitivity and glucose tolerance were also measured. The effects of MCFAs on lipoprotein lipase activity and adipogenic gene expression were also assessed in vitro using cultured adipose tissue explants or 3T3-L1 adipocytes.. MCT-fed animals had smaller fat pads, and they contained a considerable amount of MCFAs in both triglycerides and phospholipids. A number of key adipogenic genes were down-regulated, including peroxisome proliferator activated receptor gamma and CCAAT/enhancer binding protein alpha and their downstream metabolic target genes. We also found reduced adipose tissue lipoprotein lipase activity and improved insulin sensitivity and glucose tolerance in MCT-fed animals. Analogous effects of MCFAs on adipogenic genes were found in cultured rat adipose tissue explants and 3T3-L1 adipocytes.. These results suggest that direct inhibitory effects of MCFAs on adiposity may play an important role in the regulation of body fat development.

Topics: 3T3 Cells; Adipocytes; Adipose Tissue; Animals; Body Composition; Caprylates; Cell Differentiation; Cell Line; Dietary Fats; Dietary Fats, Unsaturated; Fatty Acids; Gene Expression Regulation; Glucose Tolerance Test; Insulin; Leptin; Lipids; Lipoprotein Lipase; Male; Mice; Muscle, Skeletal; Myocardium; Oleic Acid; Phospholipids; Rats; Rats, Sprague-Dawley; Triglycerides