scholarly journals IL-15 concentrations in skeletal muscle and subcutaneous adipose tissue in lean and obese humans: local effects of IL-15 on adipose tissue lipolysis

2015 ◽  
Vol 308 (12) ◽  
pp. E1131-E1139 ◽  
Author(s):  
Joseph R. Pierce ◽  
Jill M. Maples ◽  
Robert C. Hickner
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Animal Cell ◽  
Glycerol Concentration ◽  
Tissue Mass ◽  
Obese Subjects ◽  
Adipose Tissue Lipolysis ◽  
Exercise Induced ◽  
Subcutaneous Adipose

Animal/cell investigations indicate that there is a decreased adipose tissue mass resulting from skeletal muscle (SkM) IL-15 secretion (e.g., SkM-blood-adipose tissue axis). IL-15 could regulate fat mass accumulation in obesity via lipolysis, although this has not been investigated in humans. Therefore, the purpose was to examine whether SkM and/or subcutaneous adipose tissue (SCAT) IL-15 concentrations were correlated with SCAT lipolysis in lean and obese humans and determine whether IL-15 perfusion could induce lipolysis in human SCAT. Local SkM and abdominal SCAT IL-15 (microdialysis) and circulating IL-15 (blood) were sampled in lean (BMI: 23.1 ± 1.9 kg/m2; n = 10) and obese (BMI: 34.7 ± 3.5 kg/m2; n = 10) subjects at rest/during 1-h cycling exercise. Lipolysis (SCAT interstitial glycerol concentration) was compared against local/systemic IL-15. An additional probe in SCAT was perfused with IL-15 to assess direct lipolytic responses. SkM IL-15 was not different between lean and obese subjects ( P = 0.45), whereas SCAT IL-15 was higher in obese vs. lean subjects ( P = 0.02) and was correlated with SCAT lipolysis ( r = 0.45, P = 0.05). Exercise increased SCAT lipolysis in lean and obese ( P < 0.01), but exercise-induced SCAT lipolysis changes were not correlated with exercise-induced SCAT IL-15 changes. Microdialysis perfusion resulting in physiological IL-15 concentrations in the adipose tissue interstitium increased lipolysis in lean ( P = 0.04) but suppressed lipolysis in obese ( P < 0.01). Although we found no support for a human IL-15 SkM-blood-adipose tissue axis, IL-15 may be produced in/act on the abdominal SCAT depot. The extent to which this autocrine/paracrine IL-15 action regulates human body composition remains unknown.

Visfatin mRNA expression in human subcutaneous adipose tissue is regulated by exercise

2007 ◽  
Vol 292 (1) ◽  
pp. E24-E31 ◽  
Author(s):  
Lone Frydelund-Larsen ◽  
Thorbjorn Akerstrom ◽  
Søren Nielsen ◽  
Pernille Keller ◽  
Charlotte Keller ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Mrna Expression ◽  
Subcutaneous Adipose Tissue ◽  
Recovery Period ◽  
Control Group ◽  
Time Points ◽  
Metabolic Role ◽  
Exercise Induced ◽  
Subcutaneous Adipose

Visfatin [pre-β-cell colony-enhancing factor (PBEF)] is a novel adipokine that is produced by adipose tissue, skeletal muscle, and liver and has insulin-mimetic actions. Regular exercise enhances insulin sensitivity. In the present study, we therefore examined visfatin mRNA expression in abdominal subcutaneous adipose tissue and skeletal muscle biopsies obtained from healthy young men at time points 0, 3, 4.5, 6, 9, and 24 h in relation to either 3 h of ergometer cycle exercise at 60% of V̇o2 max or rest. Adipose tissue visfatin mRNA expression increased threefold at the time points 3, 4.5, and 6 h in response to exercise ( n = 8) compared with preexercise samples and compared with the resting control group ( n = 7, P = 0.001). Visfatin mRNA expression in skeletal muscle was not influenced by exercise. The exercise-induced increase in adipose tissue visfatin was, however, not accompanied by elevated levels of plasma visfatin. Recombinant human IL-6 infusion to mimic the exercise-induced IL-6 response ( n = 6) had no effect on visfatin mRNA expression in adipose tissue compared with the effect of placebo infusion ( n = 6). The finding that exercise enhances subcutaneous adipose tissue visfatin mRNA expression suggests that visfatin has a local metabolic role in the recovery period following exercise.

Lipid mobilization in subcutaneous adipose tissue during exercise in lean and obese humans. Roles of insulin and natriuretic peptides

2010 ◽  
Vol 299 (2) ◽  
pp. E258-E265 ◽  
Author(s):  
Katrien Koppo ◽  
Dominique Larrouy ◽  
Marie A. Marques ◽  
Michel Berlan ◽  
Magda Bajzova ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Exercise Bout ◽  
Saline Control ◽  
Microdialysis Probe ◽  
Lipid Mobilization ◽  
Obese Subjects ◽  
Exercise Induced ◽  
Subcutaneous Adipose ◽  
The Impact

The aim of this study was to evaluate the relative contributions of various hormones involved in the regulation of lipid mobilization in subcutaneous adipose tissue (SCAT) during exercise and to assess the impact of obesity on this regulation. Eight lean and eight obese men performed a 60-min cycle exercise bout at 50% of their peak oxygen uptake on two occasions: during intravenous infusion of octreotide (a somatostatin analog) or physiological saline (control condition). Lipolysis in SCAT was evaluated using in situ microdialysis. One microdialysis probe was perfused with the adrenergic blockers phentolamine and propranolol while another probe was perfused with the phosphodiesterase and adenosine receptor inhibitor aminophylline. Compared with the control condition, infusion of octreotide reduced plasma insulin levels in lean (from ∼3.5 to 0.5 μU/ml) and in obese (from ∼9 to 2 μU/ml), blunted the exercise-induced rise in plasma GH and epinephrine levels in both groups, and enhanced the exercise-induced natriuretic peptide (NP) levels in lean but not in obese subjects. In both groups, octreotide infusion resulted in higher exercise-induced increases in dialysate glycerol concentrations in the phentolamine-containing probe while no difference in lipolytic response was found in the aminophylline-containing probe. The results suggest that insulin antilipolytic action plays a role in the regulation of lipolysis during exercise in lean as well as in obese subjects. The octreotide-induced enhancement of exercise lipolysis in lean subjects was associated with an increased exercise-induced plasma NP response. Adenosine may contribute to the inhibition of basal lipolysis in both subject groups.

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.

Lipolysis in human adipose tissue during exercise: comparison of microdialysis and a-v measurements

2002 ◽  
Vol 92 (3) ◽  
pp. 1310-1316 ◽  
Author(s):  
Kai Henrik Wiborg Lange ◽  
Jeanne Lorentsen ◽  
Fredrik Isaksson ◽  
Lene Simonsen ◽  
Jens Bülow ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Steady State ◽  
Subcutaneous Adipose Tissue ◽  
Human Adipose Tissue ◽  
Glycerol Concentration ◽  
Early Exercise ◽  
Adipose Tissue Lipolysis ◽  
Subcutaneous Abdominal Adipose Tissue ◽  
Subcutaneous Adipose

Subcutaneous adipose tissue lipolysis was studied in vivo by Fick's arteriovenous (a-v) principle using either calculated (microdialysis) or directly measured (catheterization) adipose tissue venous glycerol concentration. We compared results during steady-state (rest and prolonged continuous exercise), as well as during non-steady-state (onset of exercise and early exercise) experimental settings. Fourteen healthy women [age: 74 ± 1 (SE) yr] were studied at rest and during 60-min continuous bicycling at 60% of peak O2 uptake. Calculated and measured subcutaneous abdominal adipose tissue venous glycerol concentrations increased substantially from rest to exercise but were similar both at rest and during later stages of exercise. In contrast, during the initial ∼40 min of exercise, calculated glycerol concentration was significantly lower (∼40%) than measured adipose tissue venous glycerol concentration. Despite several methodological limitations inherent to both techniques, the results strongly suggest that microdialysis and catheterization provide similar estimates of subcutaneous adipose tissue lipolysis in steady-state experimental settings like rest and continuous prolonged exercise. However, during shorter periods of exercise (<40 min), the results from the two techniques may differ quantitatively in the studied subjects. Caution should, therefore, be taken when lipolysis is evaluated, based on results obtained by the two techniques under non-steady-state conditions.

Interstitial Glycerol Concentration in Human Skeletal Muscle and Adipose Tissue is Close to the Concentration in Blood

1996 ◽  
Vol 90 (6) ◽  
pp. 453-456 ◽  
Author(s):  
Jaswinder S. Samra ◽  
Cate L. Ravell ◽  
Sarah L. Giles ◽  
Peter Arner ◽  
Keith N. Frayn
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Interstitial Fluid ◽  
Normal Subjects ◽  
Glycerol Concentration ◽  
Free Glycerol ◽  
Arterial Concentration ◽  
Subcutaneous Adipose ◽  
Arteriovenous Difference

1. The suggestion that the interstitial glycerol concentration in both adipose tissue and skeletal muscle is around 3 mmol/l (Maggs DG, Jacob R, Rife F, et al. J Clin Invest 1995; 96: 370–7), rather than close to the blood concentration as previously supposed, was tested by independent methods. 2. Free glycerol was infused, as part of a triacylglycerol emulsion, into six normal subjects and the arteriovenous difference for glycerol across the forearm was measured. In addition the relative interstitial glycerol concentration in subcutaneous adipose tissue was assessed simultaneously in four of the subjects by microdialysis. 3. During glycerol infusion the arterialized glycerol concentration rose from 52 ± 5 μmol/l to 250–300 μmol/l (P < 0.001) in a square wave fashion. The net arteriovenous difference for glycerol across the forearm changed from negative (output) to positive (uptake) (P < 0.01). In subcutaneous adipose tissue the interstitial glycerol concentration rose during glycerol infusion (P < 0.001). 4. These observations are most easily explained by the movement of glycerol from plasma to interstitial fluid down a concentration gradient. We conclude that the interstitial glycerol concentration in skeletal muscle and adipose tissue is closer to the arterial concentration than to 3 mmol/l.

Microdialysis assessment of local adipose tissue lipolysis during β-adrenergic stimulation in upper-body-obese subjects with type II diabetes

1999 ◽  
Vol 97 (4) ◽  
pp. 421-428 ◽  
Author(s):  
Ellen E. BLAAK ◽  
Gerrit J. KEMERINK ◽  
Marie Therese W. PAKBIERS ◽  
Bruce H. R. WOLFFENBUTTEL ◽  
Guido A. HEIDENDAL ◽  
...  
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Type Ii Diabetes ◽  
Subcutaneous Adipose Tissue ◽  
Tissue Blood Flow ◽  
Type Ii ◽  
Adipose Tissue Blood Flow ◽  
Obese Subjects ◽  
Adipose Tissue Lipolysis ◽  
Subcutaneous Adipose

The present study was designed to investigate indicators of abdominal adipose tissue lipolysis (microdialysis), and subcutaneous adipose tissue blood flow and whole-body lipolysis, in obesity-associated type II diabetes during overnight-fasted conditions (baseline) and during intravenous infusion of the non-selective β-agonist isoprenaline. Basal subcutaneous adipose tissue blood flow and isoprenaline-induced increases in adipose tissue blood flow were not signifcantly different between subjects with type II diabetes and non-obese, non-diabetic controls. Adipose tissue interstitial glycerol concentrations were significantly higher in subjects with type II diabetes compared with controls (P< 0.01), and during isoprenaline infusion there was a decrease in interstitial glycerol in both groups (P< 0.001). Arterial glycerol concentrations were higher in subjects with type II diabetes compared with controls (P< 0.05), whereas the increases in arterial glycerol concentration in response to isoprenaline infusion were of a similar magnitude in the two groups. Estimated subcutaneous adipose tissue glycerol release was not significantly different between the groups (controls and subjects with type II diabetes: baseline, -129±32 and -97±72 μmol·min-1·100 g-1 adipose tissue respectively; isoprenaline, -231±76 and -286±98 μmol·min-1·100 g-1 respectively). Values for fat oxidation were not significantly different between groups, whereas the isoprenaline-induced increase in fat oxidation tended to be less pronounced in subjects with type II diabetes compared with controls (0.022±0.008 and 0.038±0.003 g/min respectively; P = 0.058). Thus estimated basal subcutaneous adipose tissue glycerol release, expressed per unit of fat mass, is not different in controls and in subjects with type II diabetes. Additionally, the isoprenaline-induced increases in indicators of local abdominal subcutaneous adipose tissue, systemic lipolysis and abdominal adipose tissue blood flow responses were comparable in obese subjects with type II diabetes and in controls. The last two findings contrast with previous data from obese subjects, indicating that the regulation of lipolysis may differ in obesity and obesity-associated type II diabetes.

METABOLISM IN ADIPOSE TISSUE AND MUSCLE OF THE YOUNG PIG

1990 ◽  
Vol 70 (1) ◽  
pp. 199-206 ◽  
Author(s):  
O. ADEOLA ◽  
B. W. McBRIDE ◽  
R. O. BALL ◽  
L. G. YOUNG
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Adipose Tissue ◽  
Key Words ◽  
Adenosine Deaminase ◽  
Subcutaneous Adipose Tissue ◽  
Muscle Metabolism ◽  
Acetate Incorporation ◽  
Glycerol Release ◽  
Subcutaneous Adipose

Subcutaneous adipose tissue and intercostal and sartorius muscles from five barrows and five gilts at 20 kg liveweight were used to study lipogenesis, lipolysis, Na+, K+-ATPase-dependent respiration and protein synthesis. Lipogenesis rate measured by 14C-acetate incorporation into lipid was similar between barrows and gilts; and 100 μg insulin per mL enhanced (P < 0.1) subcutaneous adipose tissue lipogenesis by 74%. Lipolysis rate quantitated by glycerol release was similar between barrows and gilts (3546 and 4160 nmol g−1 2 h−1). Adenosine deaminase and norepinephrine together enhanced adipose tissue lipolytic response by 102%. Fractional and absolute rates of protein synthesis were similar between barrows and gilts (3.24 and 3.69% d−1; 6.01 and 6.06 mg g−1 d−1); and between intercostal and sartorius muscles. Barrows had lower Na+, K+-ATPase-dependent respiration than gilts and the maintenance of Na+ and K+ transmembrane ionic gradient in the muscle preparations accounted for 23–26% of total respiration. Key words: Pigs, adipose tissue, skeletal muscle, metabolism

Thermogenic response to epinephrine in the forearm and abdominal subcutaneous adipose tissue

1992 ◽  
Vol 263 (5) ◽  
pp. E850-E855 ◽  
Author(s):  
L. Simonsen ◽  
J. Bulow ◽  
J. Madsen ◽  
N. J. Christensen
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Energy Expenditure ◽  
Oxygen Uptake ◽  
Glucose Uptake ◽  
Subcutaneous Adipose Tissue ◽  
Whole Body ◽  
Epinephrine Infusion ◽  
Basal Period ◽  
Subcutaneous Adipose

Whole body energy expenditure, thermogenic and metabolic changes in the forearm, and intercellular glucose concentrations in subcutaneous adipose tissue on the abdomen determined by microdialysis were measured during epinephrine infusion in healthy subjects. After a control period, epinephrine was infused at rates of 0.2 and 0.4 nmol.kg-1 x min-1. Whole body resting energy expenditure was 4.36 +/- 0.56 (SD) kJ/min. Energy expenditure increased to 5.14 +/- 0.74 and 5.46 +/- 0.79 kJ/min, respectively (P < 0.001), during the epinephrine infusions. Respiratory exchange ratio was 0.80 +/- 0.04 in the resting state and did not change. Local forearm oxygen uptake was 3.9 +/- 1.3 mumol.100 g-1 x min-1 in the basal period. During epinephrine infusion, it increased to 5.8 +/- 2.1 (P < 0.03) and 7.5 +/- 2.3 mumol.100 g-1 x min-1 (P < 0.001). Local forearm glucose uptake was 0.160 +/- 0.105 mumol.100 g-1 x min-1 and increased to 0.586 +/- 0.445 and 0.760 +/- 0.534 mumol.100 g-1 x min-1 (P < 0.025). The intercellular glucose concentration in the subcutaneous adipose tissue on the abdomen was equal to the arterial concentration in the basal period but did not increase as much during infusion of epinephrine, indicating glucose uptake in adipose tissue in this condition. If it is assumed that forearm skeletal muscle is representative for the average skeletal muscle, it can be calculated that on average 40% of the enhanced whole body oxygen uptake induced by infusion of epinephrine is taking place in skeletal muscle. It is proposed that adipose tissue may contribute to epinephrine-induced thermogenesis.

scholarly journals Continuous Glucose Monitoring in Interstitial Subcutaneous Adipose Tissue and Skeletal Muscle Reflects Excursions in Cerebral Cortex

Diabetes ◽  
2005 ◽  
Vol 54 (6) ◽  
pp. 1635-1639 ◽  
Author(s):  
J. K. Nielsen ◽  
C. B. Djurhuus ◽  
C. H. Gravholt ◽  
A. C. Carus ◽  
J. Granild-Jensen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Cerebral Cortex ◽  
Continuous Glucose Monitoring ◽  
Subcutaneous Adipose Tissue ◽  
Glucose Monitoring ◽  
Subcutaneous Adipose
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