Hepatomegaly induced by trans-10,cis-12 conjugated linoleic acid in adult hamsters fed an atherogenic diet is not associated with steatosis.
OBJECTIVE
To study the effects of trans-10,cis-12 conjugated linoleic acid (CLA) on liver size and composition, as well as on hepatic lipogenesis and fatty acid oxidation, in adult hamsters.


METHODS
Sixteen male Syrian Golden hamsters (8-month-old; initial body weight 167 +/- 5 g) were divided into two groups and fed on atherogenic diets supplemented either with 0.5% linoleic acid or trans-10,cis-12 CLA, for 6 weeks. Liver lipids, fatty acid profile, protein, water and DNA contents were analysed. The activity and expression of several enzymes involved in liver fatty oxidation and lipogenesis were assessed, as was the expression of transcriptional factors controlling these enzymes.


RESULTS
The addition of CLA to the diet led to significantly greater liver weight due to hyperplasia. No changes were observed in liver composition. CLA did not modify the expression or the activity of analysed oxidative enzymes. With regard to lipogenic enzymes, an increase in the expression and the activity of acetyl-CoA carboxylase was found.


CONCLUSIONS
These results show that the expected body fat-lowering effect of trans-10,cis-12 CLA, observed in young rodents, is not found in adult hamsters. The lack of increase in liver fatty acid oxidation, help to explain why that effect was not found in these animals. Further, the CLA treatment-induced hepatomegaly is a consequence of hyperplasia.
Miranda
Jonatan
J
Dpt Nutrition and Food Science, Facultad de Farmacia, Paseo de la Universidad, Vitoria, Spain.
Fernández-Quintela
Alfredo
A
Churruca
Itziar
I
Rodríguez
Víctor M
VM
Simón
Edurne
E
Portillo
María P
MP
D000103:Acetyl-CoA Carboxylase / Q000378:metabolism; D000367:Age Factors; D000818:Animals; D006224:Cricetinae; D004036:Diet, Atherogenic; D004041:Dietary Fats / Q000494:pharmacology*; D005234:Fatty Liver / Q000139:chemically induced*; D006529:Hepatomegaly / Q000139:chemically induced*; D006965:Hyperplasia; D019787:Linoleic Acid / Q000494:pharmacology; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D008297:Male; D008647:Mesocricetus; D009929:Organ Size / Q000187:drug effects; D010088:Oxidoreductases / Q000378:metabolism
D004041:Dietary Fats; D044243:Linoleic Acids, Conjugated; C496197:trans-10,cis-12-conjugated linoleic acid; D019787:Linoleic Acid; D010088:Oxidoreductases; D000103:Acetyl-CoA Carboxylase