title: Chronic consumption of trans-fat-rich diet increases hepatic cholesterol levels and impairs muscle insulin sensitivity without leading to hepatic steatosis and hypertriglyceridemia in female Fischer rats.
abstract: BACKGROUND
  The impact of industrial trans fatty acids (TFAs) on lipid metabolism and health remains elusive.
  
  
  METHODS
  We compared the effect of long-term (52 weeks) ingestion of 10% partially hydrogenated vegetable oil, providing 4.2% of total energy from TFAs, on hepatic lipid metabolism and muscle insulin sensitivity in weanling female Fischer rats with that of palmolein (monounsaturated fatty acid, MUFA), sunflower (n-6 polyunsaturated fatty acid, PUFA), and a blend of sunflower and fish oil (n-3 PUFA).
  
  
  RESULTS
  The proportion of plasma high-density lipoprotein cholesterol in total cholesterol and reverse cholesterol transport-associated protein expressions were similar in all the groups. Despite higher lipogenic-pathway protein levels, steatosis or hypertriglyceridemia was not observed in TFA-fed rats. Though TFA ingestion had no effect on fasting plasma glucose, insulin levels or oral glucose tolerance, it significantly decreased muscle insulin-stimulated glucose uptake as compared to PUFAs. Further, TFA ingestion increased adipose tissue retinol-binding protein 4 mRNA as compared to PUFAs (n-6 or n-3). The effects of MUFA (oleic acid) on all these parameters were comparable to those observed for TFAs.
  
  
  CONCLUSIONS
  Compared to PUFA-rich diets, chronic consumption of a TFA-rich diet did not lead to steatosis or hypertriglyceridemia; however, it significantly impaired muscle insulin sensitivity, while no changes were found in the oral glucose tolerance test.
authors.affiliation: Department of Biochemistry, National Institute of Nutrition, Indian Council of Medical Research, Hyderabad, India.
authors.forename: Shanmugam M
authors.initials: SM
authors.lastname: Jeyakumar
authors.forename: Ananthathmakula
authors.initials: A
authors.lastname: Prashant
authors.forename: Koppala Swarupa
authors.initials: KS
authors.lastname: Rani
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Laxmi
authors.forename: Acharya
authors.initials: A
authors.lastname: Vani
authors.forename: Putcha Uday
authors.initials: PU
authors.lastname: Kumar
authors.forename: Ayyalasomayajula
authors.initials: A
authors.lastname: Vajreswari
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000097:blood / Q000378:metabolism*; D003964:Diaphragm / Q000378:metabolism; D004032:Diet / Q000009:adverse effects*; D005234:Fatty Liver / Q000209:etiology; D005260:Female; D005511:Food Handling; D005786:Gene Expression Regulation; D018149:Glucose Intolerance / Q000209:etiology; D006865:Hydrogenation; D015228:Hypertriglyceridemia / Q000209:etiology; D007333:Insulin Resistance; D008099:Liver / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D054839:Retinol-Binding Proteins, Plasma / Q000235:genetics / Q000378:metabolism; D044242:Trans Fatty Acids / Q000008:administration & dosage / Q000009:adverse effects*; D014886:Weaning
chemical_list: D012333:RNA, Messenger; C532035:Rbp4 protein, rat; D054839:Retinol-Binding Proteins, Plasma; D044242:Trans Fatty Acids; D002784:Cholesterol