Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC...Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC),high-fat diet(HFD),HFD with low-dose CGA(20 mg/kg,HFD-LC),and HFD with high-dose CGA(90 mg/kg,HFD-HC).The oral glucose tolerance test was performed,and fast serum insulin(FSI)was detected using an enzyme-linked immunosorbent assay.The m RNA expression levels of glucose transporters(Sglt-1 and Glut-2)and proglucagon(Plg)in different intestinal segments(the duodenum,jejunum,ileum,and colon)were analyzed using quantitative real-time polymerase chain reaction.SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence.Results At both doses,CGA ameliorated the HFD-induced body weight gain,maintained FSI,and increased postprandial 30-min glucagon-like peptide 1 secretion.High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression.Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments.Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis.CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg,thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.展开更多
The hexoses glucose, galactose and fructose serve as important dietary energy sources in animals and glucose plays a central role in energy homeostasis within eucaryotic cells. As relatively little is known about patt...The hexoses glucose, galactose and fructose serve as important dietary energy sources in animals and glucose plays a central role in energy homeostasis within eucaryotic cells. As relatively little is known about patterns of hexose transporters expression in birds gastrointestinal tract, the aim of the study was to examine glucose transporters 2 （GLUT-2） and glucose transporters 5 （GLUT-5） expression in stomach and duodenal epithelium of two different species--broilers （Gallus gallus domesticus） and ostriches （Struthio camelus var. domesticus） chicken. Materials from the two parts of gastrointestinal tract were collected from six 7-day-old female broilers and six 7-day-old female ostriches. Specimens were fixed with 10% formalin, embedded into paraffin, cut into 7 lain thick slices, followed by immunohistochemical staining with polyclonal primary antibodies rabbit anti-GLUT-2 and rabbit anti-GLUT-5; the staining was carried out according to the manufacturers guidelines （IHC kit, Abcam, UK）. The investigation showed that the staining for both antibodies was more intensive in the epithelial cells of stomach and duodenum of the 7-day-old broilers. In duodenal epithelium, goblet cells and brush border membranes were stained in both species, however the signal was stronger for GLUT-5 than GLUT-2. Staining for GLUT-2 and GLUT-5 occurred in different parts of gastrointestinal tract of 7-day-old ostriches, but was weaker compared to 7-day-old broilers, which showed that the gastrointestinal tract of 7-day-old female broilers was more developed for transportation ofhexoses than 7-day-old female ostriches.展开更多
Carbohydrates are an important component of the diet. The carbohydrates that we ingest range from simple monosaccharides （glucose, fructose and galactose） to disaccharides （lactose, sucrose） to complex polysacchar...Carbohydrates are an important component of the diet. The carbohydrates that we ingest range from simple monosaccharides （glucose, fructose and galactose） to disaccharides （lactose, sucrose） to complex polysaccharides. Most carbohydrates are digested by salivary and pancreatic amylases, and are further broken down into monosaccharides by enzymes in the brush border membrane （BBM） of enterocytes. For example, lactase-phloridzin hydrolase and sucraseisomaltase are two disaccharidases involved in the hydrolysis of nutritionally important disaccharides. Once monosaccharides are presented to the BBM, mature enterocytes expressing nutrient transporters transport the sugars into the enterocytes. This paper reviews the early studies that contributed to the development of a working model of intestinal sugar transport, and details the recent advances made in understanding the process by which sugars are absorbed in the intestine.展开更多
基金supported by the National Natural Science foundation of China(No.31071531)the Scientific Research Fund of the Hunan Provincial Education Department(No.14A071)the China National Tobacco Corp Hunan Branch(15-17Aa04)
文摘Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC),high-fat diet(HFD),HFD with low-dose CGA(20 mg/kg,HFD-LC),and HFD with high-dose CGA(90 mg/kg,HFD-HC).The oral glucose tolerance test was performed,and fast serum insulin(FSI)was detected using an enzyme-linked immunosorbent assay.The m RNA expression levels of glucose transporters(Sglt-1 and Glut-2)and proglucagon(Plg)in different intestinal segments(the duodenum,jejunum,ileum,and colon)were analyzed using quantitative real-time polymerase chain reaction.SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence.Results At both doses,CGA ameliorated the HFD-induced body weight gain,maintained FSI,and increased postprandial 30-min glucagon-like peptide 1 secretion.High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression.Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments.Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis.CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg,thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.
文摘The hexoses glucose, galactose and fructose serve as important dietary energy sources in animals and glucose plays a central role in energy homeostasis within eucaryotic cells. As relatively little is known about patterns of hexose transporters expression in birds gastrointestinal tract, the aim of the study was to examine glucose transporters 2 （GLUT-2） and glucose transporters 5 （GLUT-5） expression in stomach and duodenal epithelium of two different species--broilers （Gallus gallus domesticus） and ostriches （Struthio camelus var. domesticus） chicken. Materials from the two parts of gastrointestinal tract were collected from six 7-day-old female broilers and six 7-day-old female ostriches. Specimens were fixed with 10% formalin, embedded into paraffin, cut into 7 lain thick slices, followed by immunohistochemical staining with polyclonal primary antibodies rabbit anti-GLUT-2 and rabbit anti-GLUT-5; the staining was carried out according to the manufacturers guidelines （IHC kit, Abcam, UK）. The investigation showed that the staining for both antibodies was more intensive in the epithelial cells of stomach and duodenum of the 7-day-old broilers. In duodenal epithelium, goblet cells and brush border membranes were stained in both species, however the signal was stronger for GLUT-5 than GLUT-2. Staining for GLUT-2 and GLUT-5 occurred in different parts of gastrointestinal tract of 7-day-old ostriches, but was weaker compared to 7-day-old broilers, which showed that the gastrointestinal tract of 7-day-old female broilers was more developed for transportation ofhexoses than 7-day-old female ostriches.
文摘Carbohydrates are an important component of the diet. The carbohydrates that we ingest range from simple monosaccharides （glucose, fructose and galactose） to disaccharides （lactose, sucrose） to complex polysaccharides. Most carbohydrates are digested by salivary and pancreatic amylases, and are further broken down into monosaccharides by enzymes in the brush border membrane （BBM） of enterocytes. For example, lactase-phloridzin hydrolase and sucraseisomaltase are two disaccharidases involved in the hydrolysis of nutritionally important disaccharides. Once monosaccharides are presented to the BBM, mature enterocytes expressing nutrient transporters transport the sugars into the enterocytes. This paper reviews the early studies that contributed to the development of a working model of intestinal sugar transport, and details the recent advances made in understanding the process by which sugars are absorbed in the intestine.
