Adipose tissue function in the insulin-resistance syndrome

2005 ◽  
Vol 33 (5) ◽  
pp. 1045-1048 ◽  
Author(s):  
F. Karpe ◽  
G.D. Tan
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Adipose Tissue ◽  
Blood Glucose Concentration ◽  
Insulin Resistance Syndrome ◽  
The Body ◽  
Tissue Blood Flow ◽  
Main Function ◽  
Adipose Tissue Blood Flow

Insulin resistance is often seen as a consequence of obesity and there are several possible links between adipose tissue function and insulin resistance determined in other organs such as skeletal muscle or liver. One such link is the regulation of NEFA (non-esterified fatty acid) delivery to the rest of the body. Simplistically, an expanded adipose tissue mass delivers more NEFA to the systemic circulation and these fatty acids compete for substrate utilization in skeletal muscle, which in turn reduces glucose utilization. This increases blood glucose concentration and provides the stimulus for increased insulin secretion and hyperinsulinaemia is a key feature of the insulin-resistance syndrome. However, there is abundant evidence that adipose tissue is exquisitely insulin sensitive and hyperinsulinaemia may therefore lead to a constant lipolytic inhibition in adipose tissue. Consequently, the main function of adipose tissue, to rapidly switch between fat uptake and fat release, will be hampered. Adipose tissue blood flow is the conveyor of signals and substrates to and from the adipose tissue. In healthy people adipose tissue blood flow is much enhanced by food intake, whereas in insulin-resistant subjects this response is blunted. This is another facet of unresponsiveness of adipose tissue in the insulin-resistance syndrome.

scholarly journals Total Forearm Blood Flow as an Indicator of Skeletal Muscle Blood Flow: Effect of Subcutaneous Adipose Tissue Blood Flow

1994 ◽  
Vol 87 (5) ◽  
pp. 559-566 ◽  
Author(s):  
E. E. Blaak ◽  
M. A. van Baak ◽  
G. J. Kemerink ◽  
M. T. W. Pakbiers ◽  
G. A. K. Heidendal ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Forearm Blood Flow ◽  
Muscle Blood Flow ◽  
Tissue Blood Flow ◽  
Adipose Tissue Blood Flow ◽  
Flow Through ◽  
Subcutaneous Adipose

1. In studying forearm skeletal muscle substrate exchange, an often applied method for estimating skeletal muscle blood flow is strain gauge plethysmography. A disadvantage of this method is that it only measures total blood flow through a segment of forearm and not the flow through the individual parts such as skin, adipose tissue and muscle. 2. In the present study the contribution of forearm subcutaneous adipose tissue blood flow to total forearm blood flow was evaluated in lean (% body fat 17.0 ± 2.2) and obese males (% body fat 30.9 ± 1.6) during rest and during infusion of the non-selective β-agonist isoprenaline. Measurements were obtained of body composition (hydrostatic weighing), forearm composition (magnetic resonance imaging) and of total forearm (venous occlusion plethysmography), skin (skin blood flow, laser Doppler), and subcutaneous adipose tissue blood flow (133Xe washout technique). 3. The absolute forearm area and the relative amount of fat (% of forearm area) were significantly higher in obese as compared to lean subjects, whereas the relative amounts of muscle and skin were similar. 4. During rest, the percentage contribution of adipose tissue blood flow to total forearm blood flow was significantly higher in lean compared with obese subjects (19 vs 12%, P < 0.05), whereas there were no differences in percentage contribution between both groups during isoprenaline infusion (10 vs 13%). Furthermore, the contribution of adipose tissue blood flow to total forearm blood flow was significantly lower during isoprenaline infusion than during rest in lean subjects (P < 0.05), whereas in the obese this value was similar during rest and during isoprenaline infusion. 5. In conclusion, although the overall contribution of adipose tissue blood flow to total forearm blood flow seems to be relatively small, the significance of this contribution may vary with degree of adiposity. Calculations on the contribution of adipose tissue blood flow and SBF to total forearm blood flow indicate that the contribution of non-muscular flow to total forearm blood flow may be of considerable importance and may amount in lean subjects to 35–50% of total forearm blood flow in the resting state.

Effect of training on epinephrine-stimulated lipolysis determined by microdialysis in human adipose tissue

1995 ◽  
Vol 269 (6) ◽  
pp. E1059-E1066 ◽  
Author(s):  
B. Stallknecht ◽  
L. Simonsen ◽  
J. Bulow ◽  
J. Vinten ◽  
H. Galbo
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Subcutaneous Tissue ◽  
Physical Work ◽  
Tissue Blood Flow ◽  
Epinephrine Infusion ◽  
Arterial Blood ◽  
Adipose Tissue Blood Flow ◽  
Subcutaneous Adipose

Trained humans (Tr) have a higher fat oxidation during submaximal physical work than sedentary humans (Sed). To investigate whether this reflects a higher adipose tissue lipolytic sensitivity to catecholamines, we infused epinephrine (0.3 nmol.kg-1.min-1) for 65 min in six athletes and six sedentary young men. Glycerol was measured in arterial blood, and intercellular glycerol concentrations in abdominal subcutaneous adipose tissue were measured by microdialysis. Adipose tissue blood flow was measured by 133Xe-washout technique. From these measurements adipose tissue lipolysis was calculated. During epinephrine infusion intercellular glycerol concentrations were lower, but adipose tissue blood flow was higher in trained compared with sedentary subjects (P < 0.05). Glycerol output from subcutaneous tissue (Tr: 604 +/- 322 nmol.100 g-1.min-1; Sed: 689 +/- 203; mean +/- SD) as well as arterial glycerol concentrations (Tr: 129 +/- 36 microM; Sed: 119 +/- 56) did not differ between groups. It is concluded that in intact subcutaneous adipose tissue epinephrine-stimulated blood flow is enhanced, whereas lipolytic sensitivity to epinephrine is the same in trained compared with untrained subjects.

Regional changes in adipose tissue blood flow and metabolism in rats after a meal

1989 ◽  
Vol 257 (4) ◽  
pp. R711-R716 ◽  
Author(s):  
D. B. West ◽  
W. A. Prinz ◽  
M. R. Greenwood
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Tissue Blood Flow ◽  
Lipoprotein Lipase Activity ◽  
Fat Depots ◽  
Adipose Tissue Blood Flow ◽  
Regional Specificity ◽  
Adipose Tissue Lipoprotein Lipase

Adipose tissue blood flow was measured in five depots, and plasma concentrations of glucose, insulin, and triglyceride were measured at 0, 15, 30, and 45 min after the start of a meal in unanesthetized, freely moving rats. In addition, adipose tissue lipoprotein lipase activity was measured in four depots before and 45 min after the start of a meal. Plasma glucose was significantly elevated only at the 15-min time point, and while plasma triglyceride increased these changes did not reach significance. Plasma insulin was significantly elevated at all time points after a meal. Feeding resulted in a consistent decrease of adipose tissue blood flow expressed per gram wet weight of tissue. This decrease was maximal at 30 min after the start of feeding. The decrease in adipose tissue blood flow averaged 45% at 45 min after the start of feeding for the five depots evaluated. Lipoprotein lipase activity significantly increased in the retroperitoneal and mesenteric fat depots at 45 min after the meal start, but did not change in the epididymal or dorsal subcutaneous fat depots. These results suggest that a decrease in adipose tissue blood flow is a normal result of a meal in the rat. The regional specificity of changes in adipose tissue lipoprotein lipase activity supports the concept of regional specificity of function for adipose tissue and suggests that the mesenteric and retroperitoneal depots are particularly important for the storage of triglycerides immediately after a meal.

scholarly journals Update on adipose tissue blood flow regulation

2012 ◽  
Vol 302 (10) ◽  
pp. E1157-E1170 ◽  
Author(s):  
Richard Sotornik ◽  
Pascal Brassard ◽  
Elizabeth Martin ◽  
Philippe Yale ◽  
André C. Carpentier ◽  
...  
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Proper Function ◽  
Tissue Blood Flow ◽  
Fat Tissue ◽  
Physiological Conditions ◽  
Current State ◽  
Adipose Tissue Blood Flow ◽  
Negative Impacts ◽  
Arteriovenous Difference

According to Fick's principle, any metabolic or hormonal exchange through a given tissue depends on the product of the blood flow to that tissue and the arteriovenous difference. The proper function of adipose tissue relies on adequate adipose tissue blood flow (ATBF), which determines the influx and efflux of metabolites as well as regulatory endocrine signals. Adequate functioning of adipose tissue in intermediary metabolism requires finely tuned perfusion. Because metabolic and vascular processes are so tightly interconnected, any disruption in one will necessarily impact the other. Although altered ATBF is one consequence of expanding fat tissue, it may also aggravate the negative impacts of obesity on the body's metabolic milieu. This review attempts to summarize the current state of knowledge on adipose tissue vascular bed behavior under physiological conditions and the various factors that contribute to its regulation as well as the possible participation of altered ATBF in the pathophysiology of metabolic syndrome.

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