Changes in 24-h substrate oxidation in older and younger men in response to exercise

2007 ◽  
Vol 103 (5) ◽  
pp. 1576-1582 ◽  
Author(s):  
Edward L. Melanson ◽  
William T. Donahoo ◽  
Gary K. Grunwald ◽  
Robert Schwartz
Keyword(s):  
Fatty Acids ◽  
Energy Expenditure ◽  
Free Fatty Acids ◽  
Plasma Free Fatty Acid ◽  
Fat Oxidation ◽  
Substrate Oxidation ◽  
Net Energy ◽  
Younger Men ◽  
Response To Exercise ◽  
Time Point

The purpose of this study was to compare 24-h substrate oxidation in older (OM; 60–75 yr, n = 7) and younger (YM; 20–30 yr, n = 7) men studied on sedentary day (Con) and on a day with exercise (Ex; net energy expenditure = 300 kcal). Plasma glucose and free fatty acids were also measured at several time points during the 24-h measurement. Weight was not different in OM and YM (means ± SD; 84.8 ± 16.9 vs. 81.4 ± 10.4 kg, respectively), although percent body fat was slightly higher in OM (25.9 ± 3.5 vs. 21.9 ± 9.7%; P = 0.17).Values of 24-h energy expenditure did not differ in OM and YM on the Con (means ± SE; 2,449 ± 162 vs. 2,484 ± 104 kcal/day, respectively) or Ex (2,902 ± 154 vs. 2,978 ± 122 kcal/day) days. Under both conditions, 24-h respiratory quotient was significantly lower and fat oxidation significantly higher in OM. Glucose concentrations were not different at any time point, but plasma free fatty acid concentrations were higher in OM, particularly following meals. Thus, under these controlled conditions, 24-h fat oxidation was not reduced and was in fact greater in OM. We speculate that differences in the availability of circulating free fatty acids in the postprandial state contributed to the observed differences in 24-h fat oxidation in OM and YM.

Changes in plasma free fatty acid concentrations on passage through the dog kidney

1961 ◽  
Vol 200 (5) ◽  
pp. 1095-1098 ◽  
Author(s):  
Frank J. Hohenleitner ◽  
John J. Spitzer
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Renal Plasma Flow ◽  
Plasma Free Fatty Acid ◽  
Systemic Artery ◽  
Arterial Concentration ◽  
Dog Kidney ◽  
Anesthetized Dogs

To measure the renal removal of free fatty acids from the plasma, simultaneous determinations of this metabolite were performed in a systemic artery and a renal vein in the anesthetized dogs. Renal plasma flow was also determined by the PAH method, and the renal uptake of free fatty acids was calculated. Concentrations of free fatty acids in renal venous plasma were usually lower than the arterial concentrations. The arteriovenous differences were statistically highly significant. The results also suggested that the degree of free fatty acid removal was proportional to the arterial concentration of this metabolite.

scholarly journals Effect of β1- and β2-adrenergic stimulation on energy expenditure, substrate oxidation, and UCP3 expression in humans

2003 ◽  
Vol 285 (4) ◽  
pp. E775-E782 ◽  
Author(s):  
Joris Hoeks ◽  
Marleen A. van Baak ◽  
Matthijs K. C. Hesselink ◽  
Gabby B. Hul ◽  
Hubert Vidal ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Energy Expenditure ◽  
Mrna Expression ◽  
Uncoupling Protein ◽  
Plasma Free Fatty Acid ◽  
Substrate Oxidation ◽  
Mrna Levels ◽  
Adrenergic Stimulation ◽  
Before And After ◽  
Plasma Ffa

In humans, β-adrenergic stimulation increases energy and fat metabolism. In the case of β1-adrenergic stimulation, it is fueled by an increased lipolysis. We examined the effect of β2-adrenergic stimulation, with and without a blocker of lipolysis, on thermogenesis and substrate oxidation. Furthermore, the effect of β1-and β2-adrenergic stimulation on uncoupling protein 3 (UCP3) mRNA expression was studied. Nine lean males received a 3-h infusion of dobutamine (DOB, β1) or salbutamol (SAL, β2). Also, we combined SAL with acipimox to block lipolysis (SAL+ACI). Energy and substrate metabolism were measured continuously, blood was sampled every 30 min, and muscle biopsies were taken before and after infusion. Energy expenditure significantly increased ∼13% in all conditions. Fat oxidation increased 47 ± 7% in the DOB group and 19 ± 7% in the SAL group but remained unchanged in the SAL+ACI condition. Glucose oxidation decreased 40 ± 9% upon DOB, remained unchanged during SAL, and increased 27 ± 11% upon SAL+ACI. Plasma free fatty acid (FFA) levels were increased by SAL (57 ± 11%) and DOB (47 ± 16%), whereas SAL+ACI caused about fourfold lower FFA levels compared with basal levels. No change in UCP3 was found after DOB or SAL, whereas SAL+ACI downregulated skeletal muscle UCP3 mRNA levels 38 ± 13%. In conclusion, β2-adrenergic stimulation directly increased energy expenditure independently of plasma FFA levels. Furthermore, this is the first study to demonstrate a downregulation of skeletal muscle UCP3 mRNA expression after the lowering of plasma FFA concentrations in humans, despite an increase in energy expenditure upon β2-adrenergic stimulation.

scholarly journals Changes in Energy Expenditure and Substrate Oxidation Resulting from Weight Loss in Obese Men and Women: Is There an Important Contribution of Leptin?1

2000 ◽  
Vol 85 (4) ◽  
pp. 1550-1556 ◽  
Author(s):  
Eric Doucet ◽  
Sylvie St. Pierre ◽  
Natalie Alméras ◽  
Pascale Mauriège ◽  
Denis Richard ◽  
...  
Keyword(s):  
Weight Loss ◽  
Energy Expenditure ◽  
Resting Energy Expenditure ◽  
Fat Oxidation ◽  
Substrate Oxidation ◽  
Energy Restriction ◽  
Fat Free Mass ◽  
Hormonal Changes ◽  
Men And Women ◽  
The Impact

The aim of the present study was to determine the impact of weight loss and its related metabolic and hormonal changes on resting energy expenditure (REE) and substrate oxidation. Forty subjects (16 men and 24 women) took part in a 15-week weight loss program that consisted of drug therapy (fenfluramine, 60 mg/day) or placebo coupled to an energy restriction (−700 Cal/day). Subjects were asked to come to the laboratory after an overnight fast for an indirect calorimetry measurement before and after weight loss. Fasting blood samples were also drawn and were analyzed for plasma glucose, insulin, leptin, and free fatty acid determinations. This program reduced body weight by 11% and 9% (P < 0.01) in men and women, respectively. Fat mass (FM) and fat-free mass (FFM) were also significantly reduced in both sexes. A significant decrease in REE (13%; P < 0.01) and fat oxidation (11%; P = 0.08) was observed in men in response to this program, whereas no significant differences were noted for these variables in women. In men, positive correlations were found between changes in FFM and energy-related variables, whereas the best predictor of changes in REE and substrate oxidation was the change in FM in women. The most important finding of this study is that in men, the association between changes in fasting plasma leptin and changes in REE (r = 0.50; P < 0.01) and fat oxidation (r = 0.63; P < 0.01) persist after correction for changes in body composition. These results suggest that a comparable weight loss is accompanied by a greater decrease in REE and substrate oxidation in men than in women, and that these changes are better explained by changes in leptinemia in men and by changes in FM in women.

scholarly journals Effects of dichloroacetate on the metabolism of glucose, pyruvate, acetate, 3-hydroxybutyrate and palmitate in rat diaphragm and heart muscle in vitro and on extraction of glucose, lactate, pyruvate and free fatty acids by dog heart in vivo

1973 ◽  
Vol 134 (4) ◽  
pp. 1067-1081 ◽  
Author(s):  
Anthony McAllister ◽  
S. P. Allison ◽  
Philip J. Randle
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Plasma Free Fatty Acid ◽  
Diabetic Rats ◽  
Inhibitory Effects ◽  
Acetyl Coa ◽  
Citrate Concentration ◽  
Lactate And Pyruvate

1. The extractions of glucose, lactate, pyruvate and free fatty acids by dog heart in vivo were calculated from measurements of their arterial and coronary sinus blood concentration. Elevation of plasma free fatty acid concentrations by infusion of intralipid and heparin resulted in increased extraction of free fatty acids and diminished extractions of glucose, lactate and pyruvate by the heart. It is suggested that metabolism of free fatty acids by the heart in vivo, as in vitro, may impair utilization of these substrates. These effects of elevated plasma free fatty acid concentrations on extractions by the heart in vivo were reversed by injection of dichloroacetate, which also improved extraction of lactate and pyruvate by the heart in vivo in alloxan diabetes. 2. Sodium dichloroacetate increased glucose oxidation and pyruvate oxidation in hearts from fed normal or alloxan-diabetic rats perfused with glucose and insulin. Dichloroacetate inhibited oxidation of acetate and 3-hydroxybutyrate and partially reversed inhibitory effects of these substrates on the oxidation of glucose. In rat diaphragm muscle dichloroacetate inhibited oxidation of acetate, 3-hydroxybutyrate and palmitate and increased glucose oxidation and pyruvate oxidation in diaphragms from alloxan-diabetic rats. Dichloroacetate increased the rate of glycolysis in hearts perfused with glucose, insulin and acetate and evidence is given that this results from a lowering of the citrate concentration within the cell, with a consequent activation of phosphofructokinase. 3. In hearts from normal rats perfused with glucose and insulin, dichloroacetate increased cell concentrations of acetyl-CoA, acetylcarnitine and glutamate and lowered those of aspartate and malate. In perfusions with glucose, insulin and acetate, dichloroacetate lowered the cell citrate concentration without lowering the acetyl-CoA or acetylcarnitine concentrations. Measurements of specific radioactivities of acetyl-CoA, acetylcarnitine and citrate in perfusions with [1-14C]acetate indicated that dichloroacetate lowered the specific radio-activity of these substrates in the perfused heart. Evidence is given that dichloroacetate may not be metabolized by the heart to dichloroacetyl-CoA or dichloroacetylcarnitine or citrate or CO2. 4. We suggest that dichloroacetate may activate pyruvate dehydrogenase, thus increasing the oxidation of pyruvate to acetyl-CoA and acetylcarnitine and the conversion of acetyl-CoA into glutamate, with consumption of aspartate and malate. Possible mechanisms for the changes in cell citrate concentration and for inhibitory effects of dichloroacetate on the oxidation of acetate, 3-hydroxybutyrate and palmitate are discussed.

PLASMA GLUCOSE, LACTATE AND FREE FATTY ACID RESPONSES TO ADRENALINE IN CHRONICALLY WARM- AND COLD-EXPOSED SHEEP

1981 ◽  
Vol 61 (4) ◽  
pp. 919-924 ◽  
Author(s):  
A. D. GRAHAM ◽  
G. D. PHILLIPS
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Cold Exposure ◽  
Plasma Glucose ◽  
Plasma Free Fatty Acid ◽  
Temperature Treatment ◽  
Glucose Response ◽  
Adrenaline Infusion

The effects of chronic cold exposure, fasting, or both on the plasma metabolite responses to jugular infusions of adrenaline were studied in eight five-mo-old wether lambs. Following maintenance at 20–22 °C or −4 to 10 °C for 2–3 wk the sheep received adrenaline infusions (0.15 μg∙kg−1∙min−1) for 75 min prior to and following a 72-h fast. Plasma samples collected at intervals of 10–15 min before and during adrenaline infusion were analyzed for glucose, lactate and total free fatty acids. Chronic cold exposure had no effect on the pre-infusion plasma glucose, lactate or free fatty acid concentrations. Fasting decreased plasma glucose and lactate and increased plasma free fatty acid concentrations. The plasma glucose response to adrenaline was greater (P < 0.01) in cold- than warm-exposed sheep and fasting depressed this response to a greater extent in the cold-exposed sheep. The plasma lactate response to adrenaline was not influenced by temperature treatment or fasting. Both groups of fasted sheep showed a large increase in plasma free fatty acids during adrenaline infusion but when fed the response was minimal.

scholarly journals Albumin Knockout Mice Exhibit Reduced Plasma Free Fatty Acids but No Impairment in Whole Body Fat Oxidation

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 534-534
Author(s):  
Afsoun Abdollahi ◽  
Brianana N Dowden ◽  
Gregory C Henderson
Keyword(s):  
Fatty Acids ◽  
Serum Albumin ◽  
Free Fatty Acids ◽  
Body Fat ◽  
Knockout Mice ◽  
Substrate Oxidation ◽  
Whole Body ◽  
Wild Type ◽  
Plasma Free Fatty Acids ◽  
Plasma Ffa

Abstract Objectives To improve understanding of the control of lipid metabolism, we aimed to determine whether lack of serum albumin decreases plasma free fatty acids (FFA), hepatic triacylglycerol (TAG), and whole body substrate oxidation in albumin knockout mice compared to wild type mice. Methods Male and female homozygous albumin knockout mice and C57BL/6J wild type controls, each on the 5k52 diet which contains a moderate fat content, were studied at 6–8 weeks of age. Body composition was tested by magnetic resonance. Substrate oxidation was measured by indirect calorimetry over 24 hours in metabolic cages. Plasma and tissues were collected after a 5-hour fast. Plasma FFA was measured by liquid chromatography/mass spectrometry (LC/MS). Hepatic TAG was measured by a colorimetric kit. Results In albumin knockout mice compared to the wild type mice, plasma FFA (P &lt; 0.0001) and hepatic TAG content (P &lt; 0.0001) were each reduced, while body fat percentage was increased (P &lt; 0.01). In addition, female versus male showed higher hepatic TAG levels (P &lt; 0.01). These results indicate that the lack of serum albumin decreases plasma FFA and hepatic TAG accumulation. However, the average 24-hour oxygen consumption, metabolic rate, and respiratory quotient (RQ) were not altered in albumin knockout mice, indicating that total fuel oxidation and relative contribution of lipid to whole body metabolism was not significantly unaltered. Conclusions We propose that lack of albumin reduces plasma FFA which diminishes hepatic TAG content through changes in the lipid supply to the liver. The results indicate that tissue lipid accumulation can be altered by targeting albumin without substantially disrupting whole body substrate oxidation, suggesting that metabolic control of FFA trafficking toward sites of ectopic lipid deposition and toward oxidation can be regulated independently of one another. Funding Sources McKinley Educational Initiative and the Purdue University College of Health and Human Sciences

Reduced Prostacyclin Survival After Fasting-Induced Elevation of Plasma Free Fatty Acids

1985 ◽  
Vol 54 (02) ◽  
pp. 418-421 ◽  
Author(s):  
S H Goodnight ◽  
S B Inkeles ◽  
N L Kovach ◽  
W E Connor
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Platelet Reactivity ◽  
Plasma Free Fatty Acid ◽  
Vascular Wall ◽  
Functional Assay ◽  
Ratio Test ◽  
Platelet Aggregate

SummaryThe anti-thrombotic effect of prostacyclin (PGI2) may be determined not only by its synthetic rate but also by its subsequent survival in blood. After its release from the vascular wall, prostacyclin binds to plasma albumin which stabilizes the molecule and prolongs its inhibitory effects on platelets. In vitro studies have shown that free fatty acids compete for the same albumin binding sites and may therefore displace PGI2 and substantially shorten its survival. To see if this competition could also occur in vivo, we produced a three-fold rise of plasma free fatty acid concentrations in ten normal volunteers by four days of fasting, which led to a significant reduction in prostacyclin survival as measured by a functional assay based on inhibition of ADP-induced platelet aggregation. The shortening of prostacyclin survival was associated with evidence of increased platelet reactivity as measured by the circulating platelet aggregate ratio test. Diseases that produce marked elevations of free fatty acids such as acute myocardial infarction may also lead to shortened PGI2 survival with potentiation of platelet mediated thrombosis.

scholarly journals Effects of encapsulated green tea and Guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and fat oxidation in men

2005 ◽  
Vol 94 (3) ◽  
pp. 432-436 ◽  
Author(s):  
Sonia Bérubé-Parent ◽  
Catherine Pelletier ◽  
Jean Doré ◽  
Angelo Tremblay
Keyword(s):  
Blood Pressure ◽  
Energy Expenditure ◽  
Diastolic Blood Pressure ◽  
Green Tea ◽  
Fat Oxidation ◽  
Substrate Oxidation ◽  
Fixed Dose ◽  
Double Blind ◽  
Metabolic Chamber ◽  
Variable Dose

It has been reported that green tea has a thermogenic effect, due to its caffeine content and probably also to the catechin, epigallocatechin-3-gallate (EGCG). The main aim of the present study was to compare the effect of a mixture of green tea and Guarana extracts containing a fixed dose of caffeine and variable doses of EGCG on 24 h energy expenditure and fat oxidation. Fourteen subjects took part to this randomized, placebo-controlled, double-blind, cross-over study. Each subject was tested five times in a metabolic chamber to measure 24 h energy expenditure, substrate oxidation and blood pressure. During each stay, the subjects ingested a capsule of placebo or capsules containing 200 mg caffeine and a variable dose of EGCG (90, 200, 300 or 400 mg) three times daily, 30 min before standardized meals. Twenty-four hour energy expenditure increased significantly by about 750 kJ with all EGCG–caffeine mixtures compared with placebo. No effect of the EGCG–caffeine mixture was observed for lipid oxidation. Systolic and diastolic blood pressure increased by about 7 and 5 mmHg, respectively, with the EGCG–caffeine mixtures compared with placebo. This increase was significant only for 24 h diastolic blood pressure. The main finding of the study was the increase in 24 h energy expenditure with the EGCG–caffeine mixtures. However, this increase was similar with all doses of EGCG in the mixtures.

A Comparison of Fat Utilization during Exercise: Walking and Swimming

1995 ◽  
Vol 4 (2) ◽  
pp. 45-57
Author(s):  
Lauree M. Grubbs
Keyword(s):  
Fatty Acids ◽  
Multivariate Analysis ◽  
Lactic Acid ◽  
Fatty Acid ◽  
Weight Control ◽  
Fat Oxidation ◽  
Energy Sources ◽  
Net Energy ◽  
Fat Utilization ◽  
Significant Difference

Women, considering swimming as a form of exercise to lose weight, have been discouraged from doing so, since researchers suggest that swimming does not burn fat as efficiently as land exercise. The purpose of this study was to compare carbohydrate and fat utilization by women engaging in two different forms of exercise, walking and swimming, at the same intensity and duration. Subjects were 20 moderately trained female subjects, walkers (W) = 10 and swimmers (S) = 10; ages 18-40 years. Measurements of blood free fatty acids (FFA), glycerol, lactate, glucose, free fatty acid turnover (FFAT), respiratory quotient (RQ), and fat oxidation were made during 60 minutes of walking or swimming at the same exercise intensity. Multivariate analysis of variance determined no significant differences between groups in net energy expenditure (NEE), RQ, fat oxidation, blood FFA, glycerol, glucose, and FFAT(p > .05). There was a significant difference between groups in blood lactic acid levels (p < .01). Since it was found that swimming and walking at the same duration and intensity bum similar amounts of fat and carbohydrate as energy sources during exercise, women may find swimming to be a viable form of exercise for weight control.

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