trans-10, cis-12 Conjugated linoleic acid inhibits lipoprotein lipase but increases the activity of lipogenic enzymes in adipose tissue from hamsters fed an atherogenic diet

• Published in: British journal of nutrition Vol. 95; no. 6; pp. 1112 - 1119
• Main Authors: Zabala, Amaia, Churruca, Itziar, Fernández-Quintela, Alfredo, Rodríguez, Víctor M., Macarulla, M. Teresa, Martínez, J. Alfredo, Portillo, María P.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.06.2006
• Subjects: Acetyl-CoA Carboxylase - genetics; Adipose tissue; Adipose Tissue - anatomy & histology; Adipose Tissue - drug effects; Adipose Tissue - enzymology; animal models; Animals; atherogenic diet; Atherosclerosis - enzymology; Atherosclerosis - metabolism; Biological and medical sciences; blood chemistry; Body fat; Body weight; Body Weight - drug effects; Conjugated linoleic acid; Cricetinae; Dehydrogenases; Diet; Eating; Enzymatic activity; enzyme activity; enzyme inhibition; enzyme inhibitors; Enzymes; Fatty Acid Synthases - genetics; Fatty acids; fatty-acid synthase; Feeding. Feeding behavior; Food; food intake; Fundamental and applied biological sciences. Psychology; gene expression; gene expression regulation; Glucose; glucose-6-phosphate 1-dehydrogenase; Glucosephosphate Dehydrogenase - genetics; hamsters; Insulin; Insulin - blood; Laboratory animals; Linoleic Acids, Conjugated - pharmacology; Lipogenesis; Lipogenesis - drug effects; Lipoprotein lipase; Lipoprotein Lipase - analysis; Lipoprotein Lipase - antagonists & inhibitors; Lipoprotein Lipase - genetics; Lipoproteins; Malate Dehydrogenase - genetics; Male; malic enzyme; Mesocricetus; Metabolism; Nutrition; Organ Size - drug effects; PPAR gamma - genetics; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; Sterol Regulatory Element Binding Protein 1 - genetics; Sterols; transcription factors; Vertebrates: anatomy and physiology, studies on body, several organs or systems; United States > US; Spain; Conjugated linoleic acid; Lipoprotein lipase; Adipose tissue; Lipogenesis; Enzyme; Rodentia; Esterases; Carboxylic ester hydrolases; Feeding; Vertebrata; Mammalia; Conjugated linoleic acid: Lipogenesis: Lipoprotein lipase: Adipose tissue; Enzymatic activity; Diet; Animal; Hydrolases; Hamster
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1079/BJN20061774

The aim of the present work was to investigate the effects of trans-10,cis-12conjugated linoleic acid (CLA) on the activity and expression of lipogenic enzymes and lipoprotein lipase (LPL), as well as on the expression of transcriptional factors controlling these enzymes, in adipose tissue from hamsters, and to evaluate the involvement of these changes in the body fat-reducing effect of this CLA isomer. Thirty male hamsters were divided into three groups and fed atherogenic diets supplemented with 0 (linoleic group), 5 or 10g trans-10,cis-12CLA/kg diet, for 6 weeks. Body and adipose tissue weights, food intake and serum insulin were measured. Total and heparin-releasable LPL and lipogenic enzyme activities (acetyl-CoA carboxylase (ACC); fatty acid synthase (FAS); glucose-6-phosphate dehydrogenase (G6PDH); and malic enzyme (ME)) were assessed. ACC, FAS, LPL, sterolregulatory element-binding proteins (SREBP-1a), SREBP-1c and PPARγ mRNA levels were alsodetermined by real-time PCR. CLA did not modify food intake, body weight and serum insulin level. CLA feeding reduced adipose tissue weight, LPL activity and expression, and increased lipogenic enzyme activities, despite a significant reduction in ACC and FAS mRNA levels. The expression of the three transcriptional factors analysed (SREBP-1a, SREBP-1c and PPARγ) wasalso reduced. These results appear to provide a framework for partially understanding the reduction in body fat induced by CLA. Inhibition of LPL activity seems to be an important mechanism underlying body fat reduction in hamsters. Further research is needed to better characterizethe effects of CLA on lipogenesis and the role of these effects in CLA action.