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
It is widely known that intestinal capacities such as the enzymatic hydrolysis of carbohydrates,lipids and proteins,and the subsequent absorption of the hydrolyzed products.are evolutionary matched to dietary loads an...It is widely known that intestinal capacities such as the enzymatic hydrolysis of carbohydrates,lipids and proteins,and the subsequent absorption of the hydrolyzed products.are evolutionary matched to dietary loads and feeding behaviors.In this study,we demonstrate that the protein expression of apically located sodium-dependent glucose cotransporter-1(SGLT-1)throughout rat ontogeny is daily adjusted to afford glucose uptake when the load of this metabolically essential monosaccharide in the intestinal lumen is maximum.The jejunal expression of SGLT-1 protein in 14 one-day-old suckling pups was found to increase at dark and early light phase(P<0.05).when they have a better access to mother milk.In weaning21-d-old and juvenile 28-d-old rats,the cotransporter expression was high throughout the entire day(P<0.05).Finally,adult 90-d-old rats showed a well-developed circadian rhythm for SGLT-1 protein(P<0.05).whose expression increased at late light and dark phase when the highest intestinal glucose load was achieved.To our knowledge,these results are the first reporting the daily profile of SGLT-1 expression during rat early developmental stage and may contribute to understand the biological significance of a well-established molecular capacity to deal with the crucial increase of glucose load in the diet during the weaning process.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.
基金supported by PIP 2016-2018 by CONICET,PROICO 2-0814 and PROICO 2-0516 by CyT-UNSL and PICT-201-0595 by Agencia Nacional de Promocion Cientifica y Tecnologica
文摘It is widely known that intestinal capacities such as the enzymatic hydrolysis of carbohydrates,lipids and proteins,and the subsequent absorption of the hydrolyzed products.are evolutionary matched to dietary loads and feeding behaviors.In this study,we demonstrate that the protein expression of apically located sodium-dependent glucose cotransporter-1(SGLT-1)throughout rat ontogeny is daily adjusted to afford glucose uptake when the load of this metabolically essential monosaccharide in the intestinal lumen is maximum.The jejunal expression of SGLT-1 protein in 14 one-day-old suckling pups was found to increase at dark and early light phase(P<0.05).when they have a better access to mother milk.In weaning21-d-old and juvenile 28-d-old rats,the cotransporter expression was high throughout the entire day(P<0.05).Finally,adult 90-d-old rats showed a well-developed circadian rhythm for SGLT-1 protein(P<0.05).whose expression increased at late light and dark phase when the highest intestinal glucose load was achieved.To our knowledge,these results are the first reporting the daily profile of SGLT-1 expression during rat early developmental stage and may contribute to understand the biological significance of a well-established molecular capacity to deal with the crucial increase of glucose load in the diet during the weaning process.
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.
