Regulation of fatty acid oxidation in rat brain mitochondria: Inhibition of high rates of palmitate oxidation by ADP

1988 ◽  
Vol 264 (2) ◽  
pp. 546-552 ◽  
Author(s):  
Nariko Kawamura
Keyword(s):  
Fatty Acid ◽  
Rat Brain ◽  
Fatty Acid Oxidation ◽  
Brain Mitochondria ◽  
Acid Oxidation ◽  
Palmitate Oxidation ◽  
Rat Brain Mitochondria

STUDIES OF FATTY ACID OXIDATION: 5. THE EFFECT OF DECANOIC ACID ON OXIDATIVE PHOSPHORYLATION

1956 ◽  
Vol 34 (1) ◽  
pp. 1227-1232 ◽  
Author(s):  
P. G. Scholefield
Keyword(s):  
Fatty Acid ◽  
Oxidative Phosphorylation ◽  
Rat Brain ◽  
Fatty Acid Oxidation ◽  
Rat Kidney ◽  
Atp Synthesis ◽  
Decanoic Acid ◽  
Brain Mitochondria ◽  
Acid Oxidation ◽  
Rat Brain Mitochondria

The effects of potassium decanoate on the phosphorylation associated with the oxidation of pyruvate by rat-kidney and rat-brain mitochondria have been investigated. The suggestion that these two processes may be uncoupled from each other in the presence of decanoate has been confirmed. Further, it has been shown that the decanoate-insensitive oxidation of pyruvate by rat-brain mitochondria, occurring in the absence of such stimulating agents as fumarate, is not associated with ATP synthesis. The fumarate-stimulated oxidation of pyruvate by rat-brain mitochondria, which is inhibited by decanoate, is associated with a phosphorylation process which is uncoupled by decanoate. When pyruvate oxidation by rat-kidney or by rat-brain mitochondria is uncoupled from phosphorylation, the extent of uncoupling is proportional to the amount of decanoate added.

STUDIES OF FATTY ACID OXIDATION: 5. THE EFFECT OF DECANOIC ACID ON OXIDATIVE PHOSPHORYLATION

1956 ◽  
Vol 34 (6) ◽  
pp. 1227-1232 ◽  
Author(s):  
P. G. Scholefield
Keyword(s):  
Fatty Acid ◽  
Oxidative Phosphorylation ◽  
Rat Brain ◽  
Fatty Acid Oxidation ◽  
Rat Kidney ◽  
Atp Synthesis ◽  
Decanoic Acid ◽  
Brain Mitochondria ◽  
Acid Oxidation ◽  
Rat Brain Mitochondria

The effects of potassium decanoate on the phosphorylation associated with the oxidation of pyruvate by rat-kidney and rat-brain mitochondria have been investigated. The suggestion that these two processes may be uncoupled from each other in the presence of decanoate has been confirmed. Further, it has been shown that the decanoate-insensitive oxidation of pyruvate by rat-brain mitochondria, occurring in the absence of such stimulating agents as fumarate, is not associated with ATP synthesis. The fumarate-stimulated oxidation of pyruvate by rat-brain mitochondria, which is inhibited by decanoate, is associated with a phosphorylation process which is uncoupled by decanoate. When pyruvate oxidation by rat-kidney or by rat-brain mitochondria is uncoupled from phosphorylation, the extent of uncoupling is proportional to the amount of decanoate added.

An explanation for decreased ketogenesis in the liver of the obese Zucker rat

1989 ◽  
Vol 257 (4) ◽  
pp. R822-R828 ◽  
Author(s):  
M. J. Azain ◽  
J. A. Ontko
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Rat Liver ◽  
Intact Cell ◽  
Zucker Rats ◽  
Acid Oxidation ◽  
Palmitate Oxidation ◽  
Malonyl Coa ◽  
Obese Zucker Rats ◽  
Rat Livers

These studies were undertaken to further characterize and explain the differences in hepatic fatty acid metabolism between lean and obese Zucker rats. It was shown that the rate of palmitate or octanoate oxidation and the inhibition of palmitate oxidation by malonyl CoA in mitochondria isolated from lean and obese Zucker rats were similar. Cytochrome oxidase activity was similar in lean and obese rat livers. It was found that the addition of cytosol from the obese rat liver inhibited palmitate oxidation by 20-30% in mitochondria isolated from lean or obese rat livers and thus reproduced the conditions observed in the intact cell. Increased concentrations of metabolites such as malonyl CoA and glycerophosphate in the liver of the obese rat are likely contributors to this inhibitory effect. These results are extrapolated to the intact cell and suggest that decreased hepatic fatty acid oxidation in the obese rat can be accounted for by cytosolic influences on the mitochondria. The decreased rate of fatty acid oxidation observed in the intact hepatocyte or perfused liver cannot be explained by a defect in the capacity of mitochondria to oxidize substrate or by a decrease in mitochondrial number in the obese rat liver.

Carnitine effects on palmitate-1-C14 conversion to CO2 and glycerides by various tissues

1964 ◽  
Vol 206 (6) ◽  
pp. 1217-1222 ◽  
Author(s):  
Irving B. Fritz
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Rat Heart ◽  
Liver Microsomes ◽  
Tissue Homogenate ◽  
Acid Oxidation ◽  
Acid Oxidase ◽  
Palmitate Oxidation ◽  
Glyceride Synthesis ◽  
Low Concentrations

Carnitine increased oxidation of palmitate-1-C14 by rat heart and liver preparations, but decreased palmitate incorporation into glycerides. To determine which of the effects was derivative and which was primary, experiments were repeated using tissues whose rates of fatty acid oxidation had been depressed by Amytal poisoning. Under these conditions, carnitine inhibition of fatty acid conversion to glycerides was abolished. Similarly, low concentrations of carnitine were found to enhance palmitate oxidation without influencing palmitate esterification. Isolated liver microsomes which synthesized glycerides without oxidizing fatty acids showed no response to carnitine under all conditions tried. The inability of carnitine to alter glyceride formation in experiments described may signify that acyl-CoA generation from CoA and acylcarnitine is specifically directed toward the fatty acid oxidase system rather than to glyceride synthesis. It was also shown that, under conditions optimal for demonstration of carnitine augmentation of fatty acid oxidation by rat heart preparations, carnitine increased palmitate oxidation by a variety of other tissue homogenate preparations.

scholarly journals The role of protein-mediated transport in regulating mitochondrial long-chain fatty acid oxidation

2008 ◽  
Vol 33 (1) ◽  
pp. 141-142
Author(s):  
Graham Paul Holloway
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
Muscle Contraction ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Mitochondrial Content ◽  
Palmitate Oxidation ◽  
Long Chain

This thesis is an investigation of the role of fatty acid translocase (FAT/CD36), plasma membrane associated fatty acid binding protein (FABPpm), and carnitine palmitoyltransferase I (CPTI) in transporting long-chain fatty acids (LCFAs) across mitochondrial membranes. Maximal CPTI activity, as well as the sensitivity of CPTI for its substrate palmitoyl-CoA (P-CoA) and its inhibitor malonyl-CoA (M-CoA), were measured in mitochondria isolated from human vastus lateralis muscles at rest and following muscle contraction. Exercise did not alter maximal CPTI activity or the sensitivity of CPTI for P-CoA. In contrast, exercise progressively attenuated the ability of M-CoA to inhibit CPTI activity. Mitochondrial FAT/CD36 protein content was also measured at rest, during, and following 2 h of cycling at ~60% maximal oxygen uptake. Exercise progressively increased the content of mitochondrial FAT/CD36 (+59%), which was significantly (p < 0.05) correlated with palmitate oxidation during exercise (r = 0.52), while palmitate oxidation was inhibited ~80% by the administration of a specific FAT/CD36 inhibitor. These data suggest that alterations in CPTI M-CoA sensitivity and increases in mitochondrial FAT/CD36 coordinate exercise-induced increases in fatty acid oxidation. FABPpm, another plasma membrane transport protein, has identical amino acid sequence to mitochondrial aspartate aminotransferase (mAspAT). Since FABPpm contributes to plasma membrane fatty acid transport, the role of FABPpm with respect to mitochondrial LCFA transport was investigated. However, unlike FAT/CD36, muscle contraction did not induce an increase in mitochondrial FABPpm protein in rat or human skeletal muscle. In addition, electrotransfecting FABPpm cDNA into rat skeletal muscle upregulated this protein in mitochondria by 80% without altering mitochondrial palmitate oxidation. In contrast, electrotransfection increased mAspAT activity  by 90%, and this was correlated (r = 0.75; p < 0.01) with FABPpm protein. These data suggest that FABPpm does not contribute to the regulation of mitochondrial LCFA transport. Previously, it has been suggested that mitochondria from obese individuals contain an inherent dysfunction to oxidize LCFAs. In age-matched lean (BMI = 23.3 ± 0.7 kg·m–2) and obese (BMI = 37.6 ± 2.2 kg·m–2) individuals, isolated mitochondrial palmitate oxidation was not altered. In addition, mitochondrial FAT/CD36 content was not different in lean and obese individuals. In contrast, citrate synthase and β-hydroxyacyl-CoA dehydrogenase, common markers of total mitochondrial content, were decreased with obesity. Therefore, the decrease in mitochondrial content appeared to account for the observed reductions in whole-muscle LCFA oxidation.

scholarly journals Increase in fatty acid oxidation in calvaria cells cultured with diphosphonates

1981 ◽  
Vol 196 (1) ◽  
pp. 237-245 ◽  
Author(s):  
R Felix ◽  
H Fleisch
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Lactate Production ◽  
Water Soluble ◽  
Acid Oxidation ◽  
Palmitate Oxidation ◽  
Rate Limiting Step ◽  
Inhibition Of Glycolysis ◽  
Inhibitor Of Protein Synthesis ◽  
Cells Cultured

1. Cultured calvaria cells oxidized palmitate and octanoate to CO2 and water-soluble products. 2. When these cells were treated for 6 days with 0.025 and 0.25 mM-dichloromethanediphosphonate, oxidation of palmitate was increased, whereas that of octanoate was influenced less. 3. When the rate of oxidation was raised by increasing the palmitate concentration in the medium, the effect of the diphosphonate was decreased and finally disappeared. 4. 1-Hydroxyethane-1,1-diphosphonate had only minor effects. 5. The increase in palmitate oxidation appeared 2 days after the addition of dichloromethanediphosphonate, simultaneously with a fall in lactate production. (Inhibition of glycolysis by diphosphonates has already been shown.) 6. Cycloheximide, an inhibitor of protein synthesis, did not influence the effect of dichloromethanediphosphonate on the oxidation of palmitate and the production of lactate. 7. Cells cultured with dichloromethanediphosphonate showed a faster uptake of palmitic acid than did control cells. However, this observation did not explain the increased palmitate oxidation, since uptake was much faster than oxidation, and was therefore not the rate-limiting step. 8. 2-Bromopalmitate, an inhibitor of fatty acid oxidation, did not influence the inhibition of glycolysis by the diphosphonates. This inhibition, therefore, did not result from the increased oxidation of palmitate. It is also unlikely that the increased oxidation of palmitate is connected with the inhibition of glycolysis.

In obese rat muscle transport of palmitate is increased and is channeled to triacylglycerol storage despite an increase in mitochondrial palmitate oxidation

2009 ◽  
Vol 296 (4) ◽  
pp. E738-E747 ◽  
Author(s):  
Graham P. Holloway ◽  
Carley R. Benton ◽  
Kerry L. Mullen ◽  
Yuko Yoshida ◽  
Laelie A. Snook ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Zucker Rats ◽  
Acid Oxidation ◽  
Fatty Acid Transport ◽  
Acid Transport ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Palmitate Oxidation ◽  
Mitochondrial Fatty Acid ◽  
Obese Zucker Rats

Intramuscular triacylglycerol (IMTG) accumulation in obesity has been attributed to increased fatty acid transport and/or to alterations in mitochondrial fatty acid oxidation. Alternatively, an imbalance in these two processes may channel fatty acids into storage. Therefore, in red and white muscles of lean and obese Zucker rats, we examined whether the increase in IMTG accumulation was attributable to an increased rate of fatty acid transport rather than alterations in subsarcolemmal (SS) or intermyofibrillar (IMF) mitochondrial fatty acid oxidation. In obese animals selected parameters were upregulated, including palmitate transport (red: +100%; white: +51%), plasmalemmal FAT/CD36 (red: +116%; white: +115%; not plasmalemmal FABPpm, FATP1, or FATP4), IMTG concentrations (red: ∼2-fold; white: ∼4-fold), and mitochondrial content (red +30%). Selected mitochondrial parameters were also greater in obese animals, namely, palmitate oxidation (SS red: +91%; SS white: +26%; not IMF mitochondria), FAT/CD36 (SS: +65%; IMF: +65%), citrate synthase (SS: +19%), and β-hydroxyacyl-CoA dehydrogenase activities (SS: +20%); carnitine palmitoyltransferase-I activity did not differ. A comparison of lean and obese rat muscles revealed that the rate of change in IMTG concentration was eightfold greater than that of fatty acid oxidation (SS mitochondria), when both parameters were expressed relative to fatty transport. Thus fatty acid transport, esterification, and oxidation (SS mitochondria) are upregulated in muscles of obese Zucker rats, with these effects being most pronounced in red muscle. The additional fatty acid taken up is channeled primarily to esterification, suggesting that upregulation in fatty acid transport as opposed to altered fatty acid oxidation is the major determinant of intramuscular lipid accumulation.

FAT/CD36-null mice reveal that mitochondrial FAT/CD36 is required to upregulate mitochondrial fatty acid oxidation in contracting muscle

2009 ◽  
Vol 297 (4) ◽  
pp. R960-R967 ◽  
Author(s):  
Graham P. Holloway ◽  
Swati S. Jain ◽  
Veronic Bezaire ◽  
Xiao Xia Han ◽  
Jan F. C. Glatz ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Fatty Acid ◽  
Muscle Contraction ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Fatty Acid Transport ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Palmitate Oxidation ◽  
Oxidation Rates ◽  
Mitochondrial Fatty Acid

The plasma membrane fatty acid transport protein FAT/CD36 is also present at the mitochondria, where it may contribute to the regulation of fatty acid oxidation, although this has been challenged. Therefore, we have compared enzyme activities and rates of mitochondrial palmitate oxidation in muscles of wild-type (WT) and FAT/CD36 knockout (KO) mice, at rest and after muscle contraction. In WT and KO mice, carnitine palmitoyltransferase-I, citrate synthase, and β-hydroxyacyl-CoA dehydrogenase activities did not differ in subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria of WT and FAT/CD36 KO mice. Basal palmitate oxidation rates were lower ( P < 0.05) in KO mice (SS −18%; IMF −13%). Muscle contraction increased fatty acid oxidation (+18%) and mitochondrial FAT/CD36 protein (+16%) in WT IMF but not in WT SS, or in either mitochondrial subpopulation in KO mice. This revealed that the difference in IMF mitochondrial fatty acid oxidation between WT and KO mice can be increased ∼2.5-fold from 13% under basal conditions to 35% during muscle contraction. The FAT/CD36 inhibitor sulfo- N-succinimidyl oleate (SSO), inhibited palmitate transport across the plasma membrane in WT, but not in KO mice. In contrast, SSO bound to mitochondrial membranes and reduced palmitate oxidation rates to a similar extent in both WT and KO mitochondria (∼80%; P < 0.05). In addition, SSO reduced state III respiration with succinate as a substrate, without altering mitochondrial coupling (P/O ratios). Thus, while SSO inhibits FAT/CD36-mediated palmitate transport at the plasma membrane, SSO has undefined effects on mitochondria. Nevertheless, the KO animals reveal that FAT/CD36 contributes to the regulation of mitochondrial fatty acid oxidation, which is especially important for meeting the increased metabolic demands during muscle contraction.

Differential effects of high-fat diet on myocardial lipid metabolism in failing and nonfailing hearts with angiotensin II-mediated cardiac remodeling in mice

2012 ◽  
Vol 302 (9) ◽  
pp. H1795-H1805 ◽  
Author(s):  
Corinne Pellieux ◽  
Christophe Montessuit ◽  
Irène Papageorgiou ◽  
Thierry Pedrazzini ◽  
René Lerch
Keyword(s):  
Heart Failure ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
High Fat Diet ◽  
Regulatory Proteins ◽  
Acid Oxidation ◽  
Contractile Dysfunction ◽  
High Fat ◽  
Palmitate Oxidation ◽  
Fat Feeding

Normal myocardium adapts to increase of nutritional fatty acid supply by upregulation of regulatory proteins of the fatty acid oxidation pathway. Because advanced heart failure is associated with reduction of regulatory proteins of fatty acid oxidation, we hypothesized that failing myocardium may not be able to adapt to increased fatty acid intake and therefore undergo lipid accumulation, potentially aggravating myocardial dysfunction. We determined the effect of high-fat diet in transgenic mice with overexpression of angiotensinogen in the myocardium (TG1306/R1). TG1306/R1 mice develop ANG II-mediated left ventricular hypertrophy, and at one year of age approximately half of the mice present heart failure associated with reduced expression of regulatory proteins of fatty acid oxidation and reduced palmitate oxidation during ex vivo working heart perfusion. Hypertrophied hearts from TG1306/R1 mice without heart failure adapted to high-fat feeding, similarly to hearts from wild-type mice, with upregulation of regulatory proteins of fatty acid oxidation and enhancement of palmitate oxidation. There was no myocardial lipid accumulation or contractile dysfunction. In contrast, hearts from TG1306/R1 mice presenting heart failure were unable to respond to high-fat feeding by upregulation of fatty acid oxidation proteins and enhancement of palmitate oxidation. This resulted in accumulation of triglycerides and ceramide in the myocardium, and aggravation of contractile dysfunction. In conclusion, hearts with ANG II-induced contractile failure have lost the ability to enhance fatty acid oxidation in response to increased fatty acid supply. The ensuing accumulation of lipid compounds may play a role in the observed aggravation of contractile dysfunction.

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