Effect of hyperglycemia-hyperinsulinemia on whole body and regional fatty acid metabolism

1999 ◽  
Vol 276 (3) ◽  
pp. E427-E434 ◽  
Author(s):  
Labros S. Sidossis ◽  
Bettina Mittendorfer ◽  
David Chinkes ◽  
Eric Walser ◽  
Robert R. Wolfe
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Fatty Acid Uptake ◽  
Whole Body ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
Similar Extent ◽  
Body Level

The effects of combined hyperglycemia-hyperinsulinemia on whole body, splanchnic, and leg fatty acid metabolism were determined in five volunteers. Catheters were placed in a femoral artery and vein and a hepatic vein. U-13C-labeled fatty acids were infused, once in the basal state and, on a different occasion, during infusion of dextrose (clamp; arterial glucose 8.8 ± 0.5 mmol/l). Lipids and heparin were infused together with the dextrose to maintain plasma fatty acid concentrations at basal levels. Fatty acid availability in plasma and fatty acid uptake across the splanchnic region and the leg were similar during the basal and clamp experiments. Dextrose infusion decreased fatty acid oxidation by 51.8% (whole body), 47.4% (splanchnic), and 64.3% (leg). Similarly, the percent fatty acid uptake oxidized decreased at the whole body level (53 to 29%), across the splanchnic region (30 to 13%), and in the leg (48 to 22%) during the clamp. We conclude that, in healthy men, combined hyperglycemia-hyperinsulinemia inhibits fatty acid oxidation to a similar extent at the whole body level, across the leg, and across the splanchnic region, even when fatty acid availability is constant.

Metabolic challenges reveal impaired fatty acid metabolism and translocation of FAT/CD36 but not FABPpm in obese Zucker rat muscle

2007 ◽  
Vol 293 (2) ◽  
pp. E566-E575 ◽  
Author(s):  
Xiao-Xia Han ◽  
Adrian Chabowski ◽  
Narendra N. Tandon ◽  
Jorge Calles-Escandon ◽  
Jan F. C. Glatz ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Acid Metabolism ◽  
Fatty Acid Uptake ◽  
Zucker Rats ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
Rat Muscle ◽  
Fatty Acid Transporter ◽  
Obese Zucker Rats

We examined, in muscle of lean and obese Zucker rats, basal, insulin-induced, and contraction-induced fatty acid transporter translocation and fatty acid uptake, esterification, and oxidation. In lean rats, insulin and contraction induced the translocation of the fatty acid transporter FAT/CD36 (43 and 41%, respectively) and plasma membrane-associated fatty acid binding protein (FABPpm; 19 and 60%) and increased fatty acid uptake (63 and 40%, respectively). Insulin and contraction increased lean muscle palmitate esterification and oxidation 72 and 61%, respectively. In obese rat muscle, basal levels of sarcolemmal FAT/CD36 (+33%) and FABPpm (+14%) and fatty acid uptake (+30%) and esterification (+32%) were increased, whereas fatty acid oxidation was reduced (−28%). Insulin stimulation of obese rat muscle increased plasmalemmal FABPpm (+15%) but not plasmalemmal FAT/CD36, blunted fatty acid uptake and esterification, and failed to reduce fatty acid oxidation. In contracting obese rat muscle, the increases in fatty acid uptake and esterification and FABPpm translocation were normal, but FAT/CD36 translocation was impaired and fatty acid oxidation was blunted. There was no relationship between plasmalemmal fatty acid transporters and palmitate partitioning. In conclusion, fatty acid metabolism is impaired at several levels in muscles of obese Zucker rats; specifically, they are 1) insulin resistant with respect to FAT/CD36 translocation and fatty acid uptake, esterification, and oxidation and 2) contraction resistant with respect to fatty acid oxidation and FAT/CD36 translocation, but, conversely, 3) obese muscles are neither insulin nor contraction resistant at the level of FABPpm. Finally, 4) there is no evidence that plasmalemmal fatty acid transporters contribute to the channeling of fatty acids to specific metabolic destinations within the muscle.

scholarly journals Fatty acid oxidation inhibitor etomoxir suppresses tumor progression and induces cell cycle arrest via PPARγ-mediated pathway in bladder cancer

2019 ◽  
Vol 133 (15) ◽  
pp. 1745-1758 ◽  
Author(s):  
Songtao Cheng ◽  
Gang Wang ◽  
Yejinpeng Wang ◽  
Liwei Cai ◽  
Kaiyu Qian ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bladder Cancer ◽  
Fatty Acid ◽  
Tumor Progression ◽  
Cell Cycle Arrest ◽  
Fatty Acid Oxidation ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Acid Oxidation ◽  
Cycle Arrest

Abstract Tumor cells rely on aerobic glycolysis as their main energy resource (Warburg effect). Recent research has highlighted the importance of lipid metabolism in tumor progression, and certain cancers even turn to fatty acids as the main fuel. Related studies have identified alterations of fatty acid metabolism in human bladder cancer (BCa). Our microarray analysis showed that fatty acid metabolism was activated in BCa compared with normal bladder. The free fatty acid (FFA) level was also increased in BCa compared with paracancerous tissues. Inhibition of fatty acid oxidation (FAO) with etomoxir caused lipid accumulation, decreased adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH) levels, suppressed BCa cell growth in vitro and in vivo, and reduced motility of BCa cells via affecting epithelial–mesenchymal transition (EMT)-related proteins. Furthermore, etomoxir induced BCa cell cycle arrest at G0/G1 phase through peroxisome proliferator-activated receptor (PPAR) γ-mediated pathway with alterations in fatty acid metabolism associated gene expression. The cell cycle arrest could be reversed by PPARγ antagonist GW9662. Taken together, our results suggest that inhibition of FAO with etomoxir may provide a novel avenue to investigate new therapeutic approaches to human BCa.

Theobromine ameliorates nonalcoholic fatty liver disease by regulating hepatic lipid metabolism via mTOR signaling pathway in vivo and in vitro

2020 ◽  
Author(s):  
Dan Wei ◽  
Shaofei Wu ◽  
Jie Liu ◽  
Xiaoqian Zhang ◽  
Xiaoling Guan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Signaling Pathway ◽  
Fatty Acid Oxidation ◽  
Fatty Acid Uptake ◽  
Mtor Signaling ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
Mtor Signaling Pathway

Theobromine, a methylxanthine present in cocoa, has been shown to possess many beneficial pharmacological properties such as anti-oxidative stress, anti-inflammatory property, and anti-microbial activity. In this study, we investigated the effects of theobromine on NAFLD and the possible underlying mechanisms in vivo and in vitro. The results showed that theobromine reduced body weight, fat mass and improved dyslipidemia. Theobromine decreased liver weight, mitigated liver injury, and significantly reduced hepatic TG level in mice with obesity. Histological examinations also showed hepatic steatosis was alleviated after theobromine treatment. Furthermore, theobromine reversed the elevated mRNA and protein expression of SREBP-1c, FASN, CD36, FABP4 and the suppressed expression of PPARα, CPT1a in the liver of mice with obesity, which were responsible for lipogenesis, fatty acid uptake and fatty acid oxidation respectively. In vitro, theobromine also downregulated SREBP-1c, FASN, CD36, FABP4 and upregulated PPARα, CPT1a mRNA and protein levels in hepatocytes in a dose-dependent manner, while these changes were reversed by L-Leucine, an mTOR agonist. The present study demonstrated that theobromine improved NAFLD by inhibiting lipogenesis, fatty acid uptake and promoting fatty acid oxidation in the liver and hepatocytes, which might be associated with its suppression of mTOR signaling pathway.

Increased nonoxidative glycolysis despite continued fatty acid uptake during demand-induced myocardial ischemia

2002 ◽  
Vol 282 (5) ◽  
pp. H1871-H1878 ◽  
Author(s):  
Margaret P. Chandler ◽  
Hazel Huang ◽  
Tracy A. McElfresh ◽  
William C. Stanley
Keyword(s):  
Fatty Acid ◽  
Coronary Artery ◽  
Fatty Acid Oxidation ◽  
Lactate Production ◽  
Fatty Acid Uptake ◽  
Anterior Wall ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
Substrate Uptake ◽  
Exogenous Fatty Acid

During stress, patients with coronary artery disease frequently fail to increase coronary flow and myocardial oxygen consumption (MV˙o 2) in response to a greater demand for oxygen, resulting in “demand-induced” ischemia. We tested the hypothesis that dobutamine infusion with flow restriction stimulates nonoxidative glycolysis without a change in MV˙o 2 or fatty acid uptake. Measurements were made in the anterior wall of anesthetized open-chest swine hearts ( n = 7). The left anterior descending (LAD) coronary artery flow was controlled via an extracorporeal perfusion circuit, and substrate uptake and oxidation were measured with radiotracers. Demand-induced ischemia was produced with intravenous dobutamine (15 μg · kg−1 · min−1) and 20% reduction in LAD flow for 20 min. Despite no change in MV˙o 2, there was a switch from lactate uptake (5.9 ± 3.1) to production (74.5 ± 16.3 μmol/min), glycogen depletion (66%), and increased glucose uptake (105%), but no change in anterior wall power or the index of anterior wall energy efficiency. There was no change in the rate of tracer-measured fatty acid uptake; however, exogenous fatty acid oxidation decreased by 71%. Thus demand-induced ischemia stimulated nonoxidative glycolysis and lactate production, but did not effect fatty acid uptake despite a fall in exogenous fatty acid oxidation.

Hyperglycemia-induced inhibition of splanchnic fatty acid oxidation increases hepatic triacylglycerol secretion

1998 ◽  
Vol 275 (5) ◽  
pp. E798-E805 ◽  
Author(s):  
Labros S. Sidossis ◽  
Bettina Mittendorfer ◽  
Eric Walser ◽  
David Chinkes ◽  
Robert R. Wolfe
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Fatty Acid Uptake ◽  
Secretion Rate ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
Hepatic Triacylglycerol

The effect of hyperglycemia (∼8 mmol/l) on splanchnic fatty acid oxidation and triacylglycerol (TG) secretion rates was investigated in five healthy men. U-13C-labeled fatty acids were infused to estimate fatty acid kinetics and oxidation across the splanchnic region, and in vivo labeled very low density lipoprotein (VLDL)-TG was infused to estimate TG secretion rate. Plasma fatty acid carbon enrichment and concentration were maintained constant by infusion of lipids and heparin in the hyperglycemia experiments. Fatty acid uptake by the splanchnic region was 1.4 ± 0.2 and 2.2 ± 0.9 μmol ⋅ kg−1⋅ min−1in the basal and clamp experiments, respectively, whereas fatty acid oxidation decreased from 0.4 ± 0.04 to 0.2 ± 0.05 μmol ⋅ kg−1⋅ min−1( P < 0.05). Hepatic TG secretion increased from 0.35 ± 0.07 μmol ⋅ kg−1⋅ min−1in the basal state to 0.53 ± 0.11 μmol ⋅ kg−1⋅ min−1after 15 h of hyperglycemia ( P< 0.05). Similarly, plasma VLDL-TG concentration increased from 0.28 ± 0.06 to 0.43 ± 0.05 mmol/l during the clamp ( P < 0.05). In summary, hyperglycemia attenuates fatty acid oxidation in the splanchnic region in human volunteers, even when fatty acid availability is constant. This adaptation results in a significant increase in the VLDL-TG secretion rate and concentration in plasma.

scholarly journals Transfection of L6 myoblasts with adipocyte fatty acid-binding protein cDNA does not affect fatty acid uptake but disturbs lipid metabolism and fusion

1998 ◽  
Vol 329 (2) ◽  
pp. 265-273 ◽  
Author(s):  
F. M. Clemens PRINSEN ◽  
H. Jacques VEERKAMP
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Fatty Acid Binding Protein ◽  
Acid Metabolism ◽  
Binding Protein ◽  
Fatty Acid Uptake ◽  
Acid Uptake ◽  
Fatty Acid Binding ◽  
Transfected Cells ◽  
Acid Binding Protein

We studied the involvement of fatty acid-binding protein (FABP) in growth, differentiation and fatty acid metabolism of muscle cells by lipofection of rat L6 myoblasts with rat heart (H) FABP cDNA or with rat adipocyte (A) FABP cDNA in a eukaryotic expression vector which contained a puromycin acetyltransferase cassette. Stable transfectants showed integration into the genome for all constructs and type-specific overexpression at the mRNA and protein level for the clones with H-FABP and A-FABP cDNA constructs. The rate of proliferation of myoblasts transfected with rat A-FABP cDNA was 2-fold higher compared with all other transfected cells. In addition, these myoblasts showed disturbed fusion and differentiation, as assessed by morphological examination and creatine kinase activity. Uptake rates of palmitate were equal for all clone types, in spite of different FABP content and composition. Palmitate oxidation over a 3 h period was similar in all clones from growth medium. After being cultured in differentiation medium, mock- and H-FABP-cDNA-transfected cells showed a lower fatty acid-oxidation rate, in contrast with A-FABP-cDNA-transfected clones. The ratio of [14C]palmitic acid incorporation into phosphatidylcholine and phosphatidylethanolamine of A-FABP-cDNA-transfected clones changed in the opposite direction in differentiation medium from that of mock- and H-FABP-cDNA-transfected clones. In conclusion, transfection of L6 myoblasts with A-FABP cDNA does not affect H-FABP content and fatty acid uptake, but changes fatty acid metabolism. The latter changes may be related to the observed fusion defect.

scholarly journals Allogeneic T Cells up-Regulate Fatty Acid Metabolism and Can Be Targeted Through Metabolic Inhibition of Fatty Acid Oxidation

2013 ◽  
Vol 19 (2) ◽  
pp. S318-S319
Author(s):  
Craig A. Byersdorfer ◽  
Victor Tkachev ◽  
Stefanie Goodell ◽  
Stacy Sandquist ◽  
Anthony W. Opipari ◽  
...  
Keyword(s):  
T Cells ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Metabolic Inhibition ◽  
Acid Oxidation

scholarly journals Zonation of fatty acid metabolism in rat liver

1989 ◽  
Vol 264 (1) ◽  
pp. 107-113 ◽  
Author(s):  
M Guzmán ◽  
J Castro
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Carnitine Palmitoyltransferase ◽  
Acid Oxidation ◽  
Low Density ◽  
Short Term ◽  
Carnitine Palmitoyltransferase I ◽  
Term Response

Fatty acid metabolism was studied in periportal and perivenous hepatocytes isolated by the method of Chen & Katz [Biochem. J. (1988) 255, 99-104]. The rate of fatty acid synthesis and the activity of acetyl-CoA carboxylase were markedly enhanced in perivenous hepatocytes as compared with periportal cells. However, the response of these two parameters to short-term modulation by cellular effectors such as the hormones insulin and glucagon, the phorbol ester 4 beta-phorbol 12 beta-myristate 13 alpha-acetate and the xenobiotics ethanol and acetaldehyde was similar in the two zones of the liver. In addition, perivenous hepatocytes showed a higher capacity of esterification of exogenous fatty acids into both cellular and very-low-density-lipoprotein lipids. Nevertheless, no difference between the two cell sub-populations seemed to exist in relation to the secretion of very-low-density lipoproteins. On the other hand, the rate of fatty acid oxidation was increased in periportal cells. This could be accounted for by a higher activity of carnitine palmitoyltransferase I and a lower sensitivity of this enzyme to inhibition by malonyl-CoA in the periportal zone. No differences were observed between periportal and perivenous hepatocytes in relation to the short-term response of fatty acid oxidation and carnitine palmitoyltransferase I activity to the cellular modulators mentioned above. In conclusion, our results show that: (i) lipogenesis is achieved at higher rates in the perivenous zone of the liver, whereas the fatty-acid-oxidative process occurs with a certain preference in the periportal area of this organ; (ii) the short-term response of the different fatty-acid-metabolizing pathways to cellular effectors is quantitatively similar in the two zones of the liver.

scholarly journals A Model Construction of Starvation Induces Hepatic Steatosis and Transcriptome Analysis in Zebrafish Larvae

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 92
Author(s):  
Hao Xu ◽  
Yu Jiang ◽  
Xiao-Min Miao ◽  
Yi-Xi Tao ◽  
Lang Xie ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Hepatic Steatosis ◽  
Fatty Acid Metabolism ◽  
Transcriptome Analysis ◽  
Acid Metabolism ◽  
Fatty Acid Uptake ◽  
Acid Uptake ◽  
Alcoholic Fatty Liver ◽  
Zebrafish Larvae ◽  
Hepatic Fatty Acid

Hepatic steatosis caused by starvation, resulting in non-alcoholic fatty liver disease (NAFLD), has been a research topic of human clinical and animal experiments. To understand the molecular mechanisms underlying the triggering of abnormal liver metabolism by starvation, thus inducing hepatic lipid accumulation, we used zebrafish larvae to establish a starvation-induced hepatic steatosis model and conducted comparative transcriptome analysis by RNA-seq. We demonstrated that the incidence of larvae steatosis is positively correlated with starvation time. Under starvation conditions, the fatty acid transporter (slc27a2a and slc27a6-like) and fatty acid translocase (cd36) were up-regulated significantly to promote extrahepatic fatty acid uptake. Meanwhile, starvation inhibits the hepatic fatty acid metabolism pathway but activates the de novo lipogenesis pathway to a certain extent. More importantly, we detected that the expression of numerous apolipoprotein genes was downregulated and the secretion of very low density lipoprotein (VLDL) was inhibited significantly. These data suggest that starvation induces hepatic steatosis by promoting extrahepatic fatty acid uptake and lipogenesis, and inhibits hepatic fatty acid metabolism and lipid transport. Furthermore, we found that starvation-induced hepatic steatosis in zebrafish larvae can be rescued by targeting the knockout cd36 gene. In summary, these findings will help us understand the pathogenesis of starvation-induced NAFLD and provide important theoretical evidence that cd36 could serve as a potential target for the treatment of NAFLD.

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