title: Differential effects of high-carbohydrate and high-fat diets on hepatic lipogenesis in rats.
abstract: OBJECTIVE
  Hepatic fatty acid synthesis is influenced by several nutritional and hormonal factors. In this study, we have investigated the effects of distinct experimental diets enriched in carbohydrate or in fat on hepatic lipogenesis.
  
  
  METHODS
  Male Wistar rats were divided into four groups and fed distinct experimental diets enriched in carbohydrates (70% w/w) or in fat (20 and 35% w/w). Activity and expression of the mitochondrial citrate carrier and of the cytosolic enzymes acetyl-CoA carboxylase and fatty acid synthetase were analyzed through the study with assessments at 0, 1, 2, 4, and 6 weeks. Liver lipids and plasma levels of lipids, glucose, and insulin were assayed in parallel.
  
  
  RESULTS
  Whereas the high-carbohydrate diet moderately stimulated hepatic lipogenesis, a strong inhibition of this anabolic pathway was found in animals fed high-fat diets. This inhibition was time-dependent and concentration-dependent. Moreover, whereas the high-carbohydrate diet induced an increase in plasma triglycerides, the high-fat diets determined an accumulation of triglycerides in liver. An increase in the plasmatic levels of glucose and insulin was observed in all cases.
  
  
  CONCLUSIONS
  The excess of sucrose in the diet is converted into fat that is distributed by bloodstream in the organism in the form of circulating triglycerides. On the other hand, a high amount of dietary fat caused a strong inhibition of lipogenesis and a concomitant increase in the level of hepatic lipids, thereby highlighting, in these conditions, the role of liver as a reservoir of exogenous fat.
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Provinciale Lecce-Monteroni, 73100, Lecce, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ferramosca
authors.forename: Annalea
authors.initials: A
authors.lastname: Conte
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Damiano
authors.forename: Luisa
authors.initials: L
authors.lastname: Siculella
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Zara
mesh_terms: D000103:Acetyl-CoA Carboxylase / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002951:Citrates / Q000378:metabolism; D004032:Diet; D059305:Diet, High-Fat; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage; D064429:Fatty Acid Synthases / Q000378:metabolism; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D050155:Lipogenesis / Q000187:drug effects*; D008081:Liposomes / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D002951:Citrates; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D007328:Insulin; D008055:Lipids; D008081:Liposomes; D014280:Triglycerides; D064429:Fatty Acid Synthases; D000103:Acetyl-CoA Carboxylase