Dietary conjugated linoleic acid decreases adipocyte size and favorably modifies adipokine status and insulin sensitivity in obese, insulin-resistant rats.
ABSTRACT Conjugated linoleic acids (CLA) have been shown to alter adiposity in some species with varying effects on insulin resistance. The objective of this 8-week study was to investigate the effects of feeding a CLA mixture (1.5%, wt/wt) on adipocyte size, insulin sensitivity, adipokine status, and adipose lipid composition in fa/fa vs lean Zucker rats. The fa/fa CLA-fed rats had smaller adipocytes and improved insulin sensitivity compared with fa/fa rats fed the control diet. Conjugated linoleic acids did not affect select markers of adipose differentiation, lipid filling, lipid uptake, or oxidation. Dietary CLA, compared with the control diet, reduced circulating leptin and elevated fasting serum adiponectin concentrations in fa/fa rats. Adipose resistin messenger RNA levels were greater in fa/fa CLA-fed rats compared with fa/fa control rats. CLA did not markedly alter adipose phospholipid fatty acid composition, and the changes in the triacylglycerol fatty acid composition reflected a lower delta-9 desaturase index of CLA-fed vs control-fed rats. In conclusion, CLA reduced adipocyte size and favorably modified adipokine status and insulin sensitivity in fa/fa Zucker rats.
SourceAvailable from: Mohamed El-SherbinyBiotechnology of Bioactive Compounds: Sources and Applications, Edited by Vijai Kumar Gupta, Maria G. Tuohy, Anthonia O'Donovan, Mohtashim Lohani, 03/2015: chapter 25: pages 599-630; John Wiley & Sons., ISBN: 978-1-118-73349-3
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ABSTRACT: Background Habitual exercise and dietary restriction are commonly recommended to prevent or ameliorate obesity and lifestyle-related diseases, including fatty liver. This study investigated the effects of habitual exercise and dietary restriction on hepatic triglyceride (TG) levels, serum leptin levels, and histological adipocyte size in periepididymal adipose tissue from Zucker fatty (ZF) rats. Methods Six-week-old male ZF rats were randomly assigned to one of three groups: sedentary (Sed), sedentary and dietary restriction (Sed + DR), and training and dietary restriction (Tr + DR). Male Zucker lean (L) rats were used as control animals. All rats had access to water and the allowed quantity of food ad libitum. The rats in the Sed + DR and Tr + DR groups were fed a 30% restricted diet, while those in the Tr + DR group exercised voluntarily on a wheel ergometer. After 12 weeks, the rats were sacrificed for a histological examination of their liver and periepididymal adipose tissue. Hepatic and serum TG, serum total cholesterol, glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, free fatty acid, and leptin levels were also measured. Results The hepatic TG levels were significantly higher in the Sed + DR group than in the L (P < 0.001) and Sed (P < 0.05) groups. By contrast, the hepatic TG levels in the Tr + DR group were significantly lower than those in the Sed (P < 0.05) and Sed + DR (P < 0.001) groups, but not significantly different from the L group values. The periepididymal adipocytes were significantly larger in the Sed, Sed + DR, and Tr + DR groups than in the L group (P < 0.001) and were significantly smaller in the Tr + DR group compared to the Sed and Sed + DR groups (P < 0.001). Conclusions Our results suggest a relationship between lipid metabolism and the size of adipose cells in ZF rats. Exercising plays an important role in decreasing hepatic TG levels, serum leptin levels, and the size of adipose cells.BMC Research Notes 04/2015; 8. DOI:10.1186/s13104-015-1063-6
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ABSTRACT: Despite the growing interest in deciphering the causes and consequences of obesity-related disorders, the mechanisms linking fat intake to bone behaviour remain unclear. Since bone fractures are widely associated with increased morbidity and mortality, most notably in elderly and obese people, bone health has become a major social and economic issue. Consistently, public health system guidelines have encouraged low-fat diets in order to reduce associated complications. However, from a bone point of view, mechanisms linking fat intake to bone alteration remain quite controversial. Thus, after more than a decade of dedicated studies, this timely review offers a comprehensive overview of the relationships between bone and fatty acids. Using clinical evidences as a starting-point to more complex molecular elucidation, this work highlights the complexity of the system and reveals that bone alteration that cannot be solved simply by taking ω-3 pills. Fatty acid effects on bone metabolism can be both direct and indirect and require integrated investigations. Furthermore, even at the level of a single cell, one fatty acid is able to trigger several different independent pathways (receptors, metabolites…) which may all have a say in the final cellular metabolic response. Copyright © 2015. Published by Elsevier Ltd.Progress in lipid research 03/2015; 58. DOI:10.1016/j.plipres.2015.03.001 · 12.96 Impact Factor