title: Carbohydrate-enriched diet impairs cardiac performance by decreasing the utilization of fatty acid and glucose.
abstract: OBJECTIVE
  We hypothesized that a high-carbohydrate diet affects the cardiac performance by interfering in the metabolic steps involved in energy transfer in this organ. To verify this, we investigated the myocardial utilization of different substrates and contractile function in rats fed a high-carbohydrate diet, under normal flow and ischemia.
  
  
  METHODS
  and
  
  
  RESULTS
  Male Wistar rats were fed over 9 days with standard (39.5% carbohydrate, 8% fiber) or high-carbohydrate diet (58% carbohydrate) and, afterwards, their cardiac function was examined using isolated heart preparations. The high-carbohydrate diet decreased the activity of the lipoprotein lipase, utilization of fatty acids, expression of the gene of peroxisome proliferator-activated receptor α and its target enzymes. In addition, decreased GLUT4 mass, glucose uptake, glycogen content and glycolytic intermediates were also observed. High-carbohydrate hearts displayed weaker activation of the glycolytic pathway during ischemia, according to minor production of lactate, in relation to control hearts. The functional impairment caused by high-carbohydrate diet shown by the decrease in the ventricular systolic strength, +dT/dt and -dT/dt was, at least in part, due to the low availability of adenosine triphosphate (ATP).
  
  
  CONCLUSIONS
  Our data suggest that a high-carbohydrate diet can damage myocardial contractile function by decreasing the cardiac utilization of glucose and fatty acids and, consequently, the ATP pool.
authors.affiliation: Department of Food Science, Federal University of Lavras, Lavras, MG, Brazil. ljardimporto@gmail.com
authors.forename: Laura C J
authors.initials: LC
authors.lastname: Pôrto
authors.forename: Sílvia S Q
authors.initials: SS
authors.lastname: Savergnini
authors.forename: Carlos H
authors.initials: CH
authors.lastname: de Castro
authors.forename: Erica G
authors.initials: EG
authors.lastname: Mario
authors.forename: Adaliene V M
authors.initials: AV
authors.lastname: Ferreira
authors.forename: Sérgio H S
authors.initials: SH
authors.lastname: Santos
authors.forename: Sílvia P
authors.initials: SP
authors.lastname: Andrade
authors.forename: Robson A S
authors.initials: RA
authors.lastname: Santos
authors.forename: Alvair P
authors.initials: AP
authors.lastname: de Almeida
authors.forename: Leida M
authors.initials: LM
authors.lastname: Botion
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004040:Dietary Carbohydrates / Q000378:metabolism*; D004195:Disease Models, Animal; D004734:Energy Metabolism / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis; D050356:Lipid Metabolism / Q000235:genetics; D008071:Lipoprotein Lipase / Q000378:metabolism; D008297:Male; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D016276:Ventricular Function
chemical_list: D004040:Dietary Carbohydrates; D005227:Fatty Acids; D012333:RNA, Messenger; D000255:Adenosine Triphosphate; D008071:Lipoprotein Lipase; D005947:Glucose