title: Postprandial glucagon-like peptide-1 secretion is increased during the progression of glucose intolerance and obesity in high-fat/high-sucrose diet-fed rats.
abstract: Glucagon-like peptide-1 (GLP-1) is secreted by distal enteroendocrine cells in response to luminal nutrients, and exerts insulinotropic and anorexigenic effects. Although GLP-1 secretory responses under established obese or diabetic conditions have been studied, it has not been investigated whether or how postprandial GLP-1 responses were affected during the progression of diet-induced obesity. In the present study, a meal tolerance test was performed every week in rats fed a high-fat and high-sucrose (HF/HS) diet to evaluate postprandial glycaemic, insulin and GLP-1 responses. In addition, gastric emptying was assessed by the acetaminophen method. After 8 weeks of HF/HS treatment, portal vein and intestinal mucosa were collected to examine GLP-1 production. Postprandial glucose in response to normal meal ingestion was increased in the HF/HS group within 2 weeks, and its elevation gradually returned close to that of the control group until day 50. Slower postprandial gastric emptying was observed in the HF/HS group on days 6, 13 and 34. Postprandial GLP-1 and insulin responses were increased in the HF/HS group at 7 weeks. Higher portal GLP-1 and insulin levels were observed in the HF/HS group, but mucosal gut hormone mRNA levels were unchanged. These results revealed that the postprandial GLP-1 response to meal ingestion is enhanced during the progression of diet-induced glucose intolerance and obesity in rats. The boosted postprandial GLP-1 secretion by chronic HF/HS diet treatment suggests increased sensitivity to luminal nutrients in the gut, and this may slow the establishment of glucose intolerance and obesity.
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University,Kita-9, Nishi-9, Kita-ku,Sapporo060-8589,Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Nakajima
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University,Kita-9, Nishi-9, Kita-ku,Sapporo060-8589,Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Hira
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University,Kita-9, Nishi-9, Kita-ku,Sapporo060-8589,Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hara
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D050218:Body Fat Distribution; D002766:Cholecystokinin / Q000235:genetics; D004032:Diet; D059305:Diet, High-Fat / Q000009:adverse effects*; D005746:Gastric Emptying / Q000502:physiology; D041981:Gastrointestinal Tract / Q000737:chemistry; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D018149:Glucose Intolerance / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D009765:Obesity / Q000209:etiology / Q000503:physiopathology*; D019518:Postprandial Period / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013395:Sucrose / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D001786:Blood Glucose; D007328:Insulin; D012333:RNA, Messenger; D013395:Sucrose; D052216:Glucagon-Like Peptide 1; D002766:Cholecystokinin
keywords: Glucagon-like peptide-1; High-fat and high-sucrose diet; Meal tolerance test; Obesity