title: Increased diaphragm expression of GLUT4 in control and streptozotocin-diabetic rats by fish oil-supplemented diets.
abstract: Dietary fat intake influences plasma glucose concentration through modifying glucose uptake and utilization by adipose and skeletal muscle tissues. In this paper, we studied the effects of a low-fat diet on diaphragm GLUT4 expression and fatty acid composition in control and streptozotocin-induced diabetic rats. Control as well as diabetic rats were divided into three different dietary groups each. Either 5% olive oil, 5% sunflower oil, or 5% fish oil was the only fat supplied by the diet. Feeding these low-fat diets for 5 wk induced major changes in fatty acid composition, both in control and in diabetic rats. Arachidonic acid was higher in diabetic olive and sunflower oil-fed rats with respect to fish oil-fed, opposite to docosahexaenoic acid which was higher in diabetic fish oil-fed rats with respect to the other two groups. Animals receiving a fish oil diet had the lowest plasma glucose concentration. GLUT4 expression in diaphragm, as indicated by GLUT4 protein and mRNA, is modulated both by diabetes and by diet fatty acid composition. Diabetes induced a decrease in expression in all dietary groups. Plasma glucose levels correlated well with the increased amount of GLUT4 protein and mRNA found in fish oil-fed groups. Results are discussed in terms of the influence that arachidonic and n-3 polyunsaturated fatty acids may exert on the transcriptional and translational control of the GLUT4 gene.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Granada, Spain. mgiron@goliat.ugr.es
authors.forename: M D
authors.initials: MD
authors.lastname: Girón
authors.forename: R
authors.initials: R
authors.lastname: Salto
authors.forename: P
authors.initials: P
authors.lastname: Hortelano
authors.forename: J L
authors.initials: JL
authors.lastname: Periago
authors.forename: A M
authors.initials: AM
authors.lastname: Vargas
authors.forename: M D
authors.initials: MD
authors.lastname: Suárez
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D003921:Diabetes Mellitus, Experimental / Q000235:genetics*; D003964:Diaphragm / Q000378:metabolism*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage; D019587:Dietary Supplements / Q000032:analysis*; D005227:Fatty Acids / Q000378:metabolism; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology; D005260:Female; D005395:Fish Oils / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D005786:Gene Expression Regulation; D051275:Glucose Transporter Type 4; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D006006:Glycogen Synthase / Q000235:genetics; D008566:Membranes / Q000737:chemistry; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D009124:Muscle Proteins; D000069463:Olive Oil; D010938:Plant Oils / Q000494:pharmacology; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D000074242:Sunflower Oil
chemical_list: D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D005395:Fish Oils; D051275:Glucose Transporter Type 4; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D000069463:Olive Oil; D010938:Plant Oils; D012333:RNA, Messenger; C495694:Slc2a4 protein, rat; D000074242:Sunflower Oil; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D006006:Glycogen Synthase