scholarly journals Femoral Adipose Tissue May Accumulate the Fat That Has Been Recycled as VLDL and Nonesterified Fatty Acids

Diabetes ◽  
2010 ◽  
Vol 59 (10) ◽  
pp. 2465-2473 ◽  
Author(s):  
Siobhán E. McQuaid ◽  
Sandy M. Humphreys ◽  
Leanne Hodson ◽  
Barbara A. Fielding ◽  
Fredrik Karpe ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Nonesterified Fatty Acids

No effect of acute normobaric hypoxia on plasma triglyceride levels in fasting healthy men

2018 ◽  
Vol 43 (7) ◽  
pp. 727-732 ◽  
Author(s):  
Bimit Mahat ◽  
Étienne Chassé ◽  
Clare Lindon ◽  
Jean-François Mauger ◽  
Pascal Imbeault
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Acute Hypoxia ◽  
Density Lipoprotein ◽  
Ambient Air ◽  
Normobaric Hypoxia ◽  
Fasting State ◽  
Nonesterified Fatty Acids ◽  
Healthy Men ◽  
Adipose Tissue Lipolysis

Circulating fatty acids are a major systemic energy source in the fasting state as well as a determinant of hepatic triglycerides (TG)-rich very-low-density lipoprotein production. Upon acute hypoxia, sympathetic arousal induces adipose tissue lipolysis, resulting in an increase in circulating nonesterified fatty acids (NEFA). Animal studies suggest that TG clearance may also be strongly reduced under hypoxia, though this effect has been shown to be dependent on temperature. Whether the hypoxia-induced rise in blood fatty acid concentrations affects fasting TG levels in humans under thermoneutral conditions remains unknown. TG, NEFA, and glycerol levels were measured in fasted healthy young men (n = 10) exposed for 6 h to either normoxia (ambient air) or acute hypoxia (fraction of inspired oxygen = 0.12) in a randomized, crossover design. Participants were casually clothed and rested in front of a fan in an environmental chamber maintained at 28 °C during each trial. Under hypoxia, a significantly greater increase in NEFA occurred (condition × time interaction, p = 0.049) and glycerol levels tended to be higher (condition × time, p = 0.104), suggesting an increase in adipose tissue lipolysis. However, plasma TG levels did not change over time and did not differ between the normoxia and hypoxia conditions. In conclusion, acute exposure to normobaric hypoxia under thermoneutral condition in healthy men during fasting state increased lipolysis without affecting circulating TG.

scholarly journals Role of adipokines and nonesterified fatty acids in the development of insulin resistance

2009 ◽  
Vol 55 (3) ◽  
pp. 13-16 ◽  
Author(s):  
D. A. Tanyanskiy ◽  
E M. Firova ◽  
L. V. Shatilina ◽  
A. D. Denisenko
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Body Weight ◽  
Adipose Tissue ◽  
Regression Analysis ◽  
Linear Regression Analysis ◽  
Biologically Active ◽  
Homa Index ◽  
Nonesterified Fatty Acids

The purpose of the study was to reveal a possible role of adipokines, biologically active adipose tissue proteins (leptin and adiponectin) and nonesterified fatty acids in generating insulin resistance (IR). One hundred and fifty-seven patients (90 females and 67 males) aged 57.5±9.2 years were enrolled in the study. According to the HOMA index for IR, the patients were divided into 3 equal groups. The examinees with a high HOMA index were found to have elevated levels of fatty acids, leptin and decreased concentrations of adiponectin. At the same time according to the linear regression analysis, all these indices are its independent determinants. However, analysis of the data in the groups of patients with different body weight revealed that the increased concentrations of fatty acids and leptin may play a role in the development of IR in subjects with obesity while the higher level of fatty acids and lower adiponectin may be involved in patients without noticeable obesity. Thus, it may be assumed that leptin, adiponectin and nonesterified fatty acids may affect the development of IR; however, their contribution depends on the degree of adiposity.

scholarly journals Muscle inflammatory response and insulin resistance: synergistic interaction between macrophages and fatty acids leads to impaired insulin action

2009 ◽  
Vol 296 (6) ◽  
pp. E1300-E1310 ◽  
Author(s):  
Vijayalakshmi Varma ◽  
Aiwei Yao-Borengasser ◽  
Neda Rasouli ◽  
Greg T. Nolen ◽  
Bounleut Phanavanh ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Palmitic Acid ◽  
Vastus Lateralis ◽  
Nonesterified Fatty Acids ◽  
Muscle Inflammation ◽  
Human Myotubes ◽  
Phosphorylated Akt

Obesity is characterized by adipose tissue expansion as well as macrophage infiltration of adipose tissue. This results in an increase in circulating inflammatory cytokines and nonesterified fatty acids, factors that cause skeletal muscle insulin resistance. Whether obesity also results in skeletal muscle inflammation is not known. In this study, we quantified macrophages immunohistochemically in vastus lateralis biopsies from eight obese and eight lean subjects. Our study demonstrates that macrophages infiltrate skeletal muscle in obesity, and we developed an in vitro system to study this mechanistically. Myoblasts were isolated from vastus lateralis biopsies and differentiated in culture. Coculture of differentiated human myotubes with macrophages in the presence of palmitic acid, to mimic an obese environment, revealed that macrophages in the presence of palmitic acid synergistically augment cytokine and chemokine expression in myotubes, decrease IκB-α protein expression, increase phosphorylated JNK, decrease phosphorylated Akt, and increase markers of muscle atrophy. These results suggest that macrophages alter the inflammatory state of muscle cells in an obese milieu, inhibiting insulin signaling. Thus in obesity both adipose tissue and skeletal muscle inflammation may contribute to insulin resistance.

Exercise-induced lipid mobilization in subcutaneous adipose tissue is mainly related to natriuretic peptides in overweight men

2008 ◽  
Vol 295 (2) ◽  
pp. E505-E513 ◽  
Author(s):  
Cedric Moro ◽  
Fabien Pillard ◽  
Isabelle de Glisezinski ◽  
Eva Klimcakova ◽  
Francois Crampes ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Natriuretic Peptides ◽  
Subcutaneous Adipose Tissue ◽  
Maximal Oxygen Consumption ◽  
Glycerol Concentration ◽  
Nonesterified Fatty Acids ◽  
Lipid Mobilization ◽  
Exercise Induced ◽  
Subcutaneous Adipose

Involvement of sympathetic nervous system and natriuretic peptides in the control of exercise-induced lipid mobilization was compared in overweight and lean men. Lipid mobilization was determined using local microdialysis during exercise. Subjects performed 35-min exercise bouts at 60% of their maximal oxygen consumption under placebo or after oral tertatolol [a β-adrenergic receptor (AR) antagonist]. Under placebo, exercise increased dialysate glycerol concentration (DGC) in both groups. Phentolamine (α-AR antagonist) potentiated exercise-induced lipolysis in overweight but not in lean subjects; the α2-antilipolytic effect was only functional in overweight men. After tertatolol administration, the DGC increased similarly during exercise no matter which was used probe in both groups. Compared with the control probe under placebo, lipolysis was reduced in lean but not in overweight men treated with the β-AR blocker. Tertatolol reduced plasma nonesterified fatty acids and insulin concentration in both groups at rest. Under placebo or tertatolol, the exercise-induced changes in plasma nonesterified fatty acids, glycerol, and insulin concentrations were similar in both groups. Exercise promoted a higher increase in catecholamine and ANP plasma levels after tertatolol administration. In conclusion, the major finding of our study is that in overweight men, in addition to an increased α2-antilipolytic effect, the lipid mobilization in subcutaneous adipose tissue that persists during exercise under β-blockade is not dependent on catecholamine action. On the basis of correlation findings, it seems to be related to a concomitant exercise-induced rise in plasma ANP when exercise is performed under tertatolol intake and a decrease in plasma insulin.

Catecholamine interference with enzymatic determination of nonesterified fatty acids in two commercially available test kits

1995 ◽  
Vol 41 (3) ◽  
pp. 455-457 ◽  
Author(s):  
R E Carr ◽  
S M Humphreys ◽  
K N Frayn
Keyword(s):  
Hydrogen Peroxide ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Nonesterified Fatty Acids ◽  
Present Evidence ◽  
Adipose Tissue In Vitro ◽  
Enzymatic Determination ◽  
Test Kit

Abstract We present evidence that catecholamines, which are commonly used to stimulate lipolysis in adipose tissue in vitro, interfere with the enzymatic determination of non-esterified fatty acid (NEFA) in two commercially available kits. Measurement of a 100 mumol/L standard with the Wako "NEFA C" test kit was 60% inhibited by 100 mumol/L norepinephrine and was completely inhibited by 100 mumol/L isoproterenol or by 1 mmol/L norepinephrine or epinephrine. Measurement with the Boehringer Mannheim "Free Fatty acids, Half-micro test" was completely inhibited by 100 mumol/L norepinephrine and was also affected by concentrations as low as 0.1 mumol/L. We propose that this effect is due to the catecholamines interfering with a step common to the two kits, the generation of hydrogen peroxide and oxidation of a chromagen; furthermore, this interference appears to be stoichiometric. We also give details of an alternative in-house method, which does not depend on the generation of hydrogen peroxide and is not affected by catecholamines.

In vivo insulin sensitivity of the pyruvate dehydrogenase complex in tissues of the rat

1993 ◽  
Vol 265 (1) ◽  
pp. E102-E107 ◽  
Author(s):  
G. J. Cooney ◽  
G. S. Denyer ◽  
A. B. Jenkins ◽  
L. H. Storlien ◽  
E. W. Kraegen ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Insulin Effect ◽  
Nonesterified Fatty Acids ◽  
Euglycemic Clamp ◽  
Dehydrogenase Complex

Activity of the insulin-activated pyruvate dehydrogenase complex (PDHC) is necessary for the complete oxidation of glucose to carbon dioxide or the conversion of glucose to fatty acids in lipogenic tissues. To determine the in vivo insulin sensitivity of PDHC activity in rat tissues, we measured the amount of PDHC in the active form in heart, diaphragm, red quadriceps, white adipose tissue (WAT), and brown adipose tissue (BAT) of rats exposed to five different circulating insulin concentrations under euglycemic clamp conditions. PDHC was measured in mitochondrial extracts of tissues rapidly dissected from rats in the starved state or after euglycemic clamp (4 mM) at insulin infusion rates of 0, 0.125, 0.25, and 2.0 U.kg-1.h-1. Increasing the insulin concentration increased the PDHC activity in all tissues, but the magnitude of this activation was different in different tissues (heart: 3.5-fold; diaphragm: 2.5-fold; red quadriceps: 1.8-fold; WAT: 3.4-fold; and BAT: 10.5-fold). Calculation of the half-maximal effective dose (ED50) for the activation of PDHC produced values that were similar in all tissues (heart: 112 pM; diaphragm: 108 pM; red quadriceps: 146 pM; WAT: 120 pM; and BAT: 118 pM). The insulin sensitivity of PDHC in these tissues correlated particularly well with the ED50 for the insulin effect of decreasing circulating nonesterified fatty acids (NEFA; 122 pM). The differences in the magnitude of the effect of increasing insulin on PDHC activity implies a tissue difference in the requirement for an increased capacity for glucose oxidation after insulin stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipid composition off tissue and plasma in two mediterranean fishes, the gilt-head sea bream (Chrysophyrys auratus) and the European seabass (Dicentratchus labrx)

1995 ◽  
Vol 52 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Grant McClelland ◽  
Jean-Michel Weber ◽  
Georges Zwingelstein ◽  
Gérard Brichon
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Plasma Concentration ◽  
White Muscle ◽  
Sea Bream ◽  
Nonesterified Fatty Acids ◽  
Fa Composition ◽  
European Seabass ◽  
Lipid Fractions ◽  
Wet Weight

The fatty acid (FA) composition of phospholipid (PL), triacylglycerol (TAG), and total lipid (TL) fractions was determined for liver, adipose tissue, white muscle, and plasma of European seabass (Dicentaratchus labrax) and gilt-head sea bream (Chrysophyrys auratus) fed on the same diet. FA composition of plasma nonesterified fatty acids (NEFA) and TAG as well as tissue TAG and TL correlates with that of the diet. FA composition of PL in tissues and plasma was different from that of the diet and different in the two species. Contribution to tissue wet weight of the different lipid fractions showed that both species store lipid primarily outside of muscle (only 3% in both species) as TAG in adipose tissue (about 80% lipid∙wet weight−1). Seabass store 33% wet weight of lipid in liver, while sea bream store only 5% wet weight. The plasma concentration of NEFA and TAG is 2223 and 12 260 nmol∙mL−1 for seabass and 2790 and 9670 nmol∙mL−1 for sea bream. The data show that these two fishes with similar lifestyle store lipid in the same fashion and that dietary FA composition affects the FA composition of TL and TAG fractions but not PL in tissue and plasma.

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