Brown adipose tissue, liver, and diet-induced thermogenesis in cafeteria diet-fed rats

1989 ◽  
Vol 67 (4) ◽  
pp. 376-381 ◽  
Author(s):  
Stephanie W. Y. Ma ◽  
David O. Foster
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Direct Determination ◽  
Metabolizable Energy ◽  
Whole Body ◽  
Tissue Blood Flow ◽  
Direct Measurements ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis

Diet-induced thermogenesis (DIT) in young rats overeating a "cafeteria" (CAF) diet of palatable human foods is characterized by a chronic, propranolol-inhibitable elevation in resting metabolic rate [Formula: see text] and is associated with various changes in brown adipose tissue (BAT) that have been taken as evidence for BAT as the effector of DIT. But direct evidence for participation of BAT in DIT has been lacking. By employing a nonocclusive cannula to sample the venous effluent of interscapular BAT (IBAT) for analysis of its O2 content and measuring tissue blood flow with microspheres, we accomplished direct determination (Fick principle) of the O2 consumption of BAT in conscious CAF rats. In comparison with normophagic controls fed chow, the CAF rats exhibited a 43% increase in metabolizable energy intake, reduced food efficiency, a 22% elevation in resting [Formula: see text] at 28 °C (thermoneutrality) or 24 °C (housing temperature), and characteristic changes in the properties of their BAT (e.g., increased mass, protein content and mitochondrial GDP binding). They also exhibited the greater metabolic response to exogenous noradrenaline characteristic of CAF rats and the near elimination by propranolol of their elevation in [Formula: see text]. By the criterion of their elevated [Formula: see text], the CAF rats were exhibiting DIT at the time of the measurements of BAT blood flow and blood O2 levels. However, BAT O2 consumption was found to be no greater in the CAF rats than in the controls at either 28 or 24 °C. At 28 °C it accounted for less than 1% of whole body [Formula: see text]; at 24 °C it increased to about 10% of overall [Formula: see text] in both diet groups. Direct measurements of BAT O2 consumption during expression of the thermic response to a tube-fed meal were also made in conscious CAF and control rats. Both diet groups exhibited an approximately 15% increase in whole body [Formula: see text] at 90–120 min after the meal. The contribution by BAT to this increase was only 2–3% and did not differ significantly between groups. Thus, the results of these direct measurements of BAT O2 consumption in vivo do not support the theory that DIT in CAF rats is mainly due to increased BAT thermogenesis occurring either chronically or during assimilation of a meal. In further studies of the effector(s) of DIT in CAF rats, partial hepatectomy (two-thirds of the liver removed) was found to acutely reduce the resting [Formula: see text] of CAF rats by 1.85 mL/min, 2.3 times as much as in chow-fed controls. From this difference in response, it was estimated that in the CAF rats liver O2 consumption before hepatectomy exceeded that of the controls by about 1.5 mL/min, an amount that would be sufficient to fully account for the elevation in resting [Formula: see text] of the former. A major role for the liver in the DIT of CAF rats is thus suggested.Key words: cafeteria feeding, diet-induced thermogenesis, thermic effect of food, brown fat, liver.

scholarly journals Brown adipose tissue is involved in diet-induced thermogenesis and whole-body fat utilization in healthy humans

2016 ◽  
Vol 40 (11) ◽  
pp. 1655-1661 ◽  
Author(s):  
M Hibi ◽  
S Oishi ◽  
M Matsushita ◽  
T Yoneshiro ◽  
T Yamaguchi ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Body Fat ◽  
Whole Body ◽  
Fat Utilization ◽  
Healthy Humans ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis

Contribution of BAT and skeletal muscle to thermogenesis induced by ephedrine in man

1985 ◽  
Vol 248 (5) ◽  
pp. E507-E515 ◽  
Author(s):  
A. Astrup ◽  
J. Bulow ◽  
J. Madsen ◽  
N. J. Christensen
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Local Temperature ◽  
Whole Body ◽  
Tissue Blood Flow ◽  
Muscle Oxygen ◽  
Brown Adipose ◽  
Muscle Oxygen Consumption

This investigation was performed to examine the role of brown adipose tissue (BAT) in thermogenesis induced by ephedrine in man. Light microscopy of biopsies from necropsy cases showed BAT to occur most frequently in the perirenal fat. Perirenal BAT thermogenesis was investigated in five lean men before and during stimulation with 1 mg ephedrine orally X kg body wt-1. Perirenal BAT thermogenesis was assessed by continuous measurements of local temperature and blood flow with the 133xenon clearance method. In the same study the effect of ephedrine on skeletal muscle oxygen consumption was estimated by measurements of leg blood flow and arteriovenous oxygen difference. The perirenal adipose tissue blood flow increased approximately twofold, whereas the local temperature increased approximately 0.1 degrees C on an average. Assuming that man possesses 700 g of BAT with a similar thermogenic capacity, this tissue contributed only 10 ml X min-1 to the 40 ml X min-1 increase in oxygen consumption in the subject whose perirenal BAT showed the most pronounced response to ephedrine. The leg oxygen consumption increased on an average 60% after ephedrine. By extrapolation of this value to whole body skeletal muscle, approximately 50% of the increase in oxygen consumption induced by ephedrine may take place in skeletal muscle. It is concluded that skeletal muscle is a tissue of importance with respect to the thermogenic effect of sympathomimetics in man, whereas the results do not support a major role for perirenal BAT.

Differences between the effects of noradrenaline and the β-adrenoceptor agonist BRL 28410 in brown adipose tissue and hind limb of the anaesthetized rat

1986 ◽  
Vol 64 (8) ◽  
pp. 1111-1114 ◽  
Author(s):  
Peter L. Thurlby ◽  
Rodney D. M. Ellis
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Oxygen Uptake ◽  
Brown Adipose Tissue ◽  
Oxygen Delivery ◽  
Hind Limb ◽  
Oxygen Extraction ◽  
Whole Body ◽  
Adrenoceptor Agonist ◽  
Brown Adipose

In mature (450–600 g) 21 °C-acclimated male rats, anaesthetized with urethane, blood flow (measured by the radioactive microsphere technique) to brown adipose tissue (BAT) was determined during the infusion of the β-adrenoceptor agonist BRL 28410 or noradrenaline bitartrate at doses chosen to give similar increases in whole body oxygen uptake. Blood flow to BAT during BRL 28410 infusion was only about one third of that found during noradrenaline infusion although increases in whole body thermogenesis were similar (55 and 77% for BRL 28410 and noradrenaline, respectively). This suggests that BAT may be less involved in the thermogenic response to BRL 28410 than to noradrenaline. In a separate experiment using slightly smaller rats (350–500 g) hind limb oxygen uptake was measured in situ using a venous bypass preparation. BRL 28410, at a dose having a maximum effect on whole body thermogenesis (53% increase), had no effect on oxygen delivery to the hind limb but significantly increased oxygen extraction by 33% (p < 0.001). In contrast, noradrenaline, also at a dose that maximally increased whole body thermogenesis, led to a 35% decrease in oxygen delivery to the hind limb and no change in oxygen extraction. For the thermogenic β-agonist BRL 28410 the hind limb, and presumably muscular tissue in general, may be contributing to thermogenesis.

Disparate effects of fenfluramine on thermogenesis in brown adipose tissue in the rat

1992 ◽  
Vol 70 (2) ◽  
pp. 214-218 ◽  
Author(s):  
Stephanie W. Y. Ma ◽  
Edward Preston
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Ambient Temperature ◽  
Brown Adipose Tissue ◽  
Metabolic Effects ◽  
Whole Body ◽  
Flow Measurements ◽  
Brown Adipose ◽  
Cardiac Ventricle ◽  
Blood Flow Measurements

It has been suggested that fenfluramine, a clinically used appetite suppressant, can also promote weight loss by augmenting energy expenditure, as indicated by increased whole-body O2 consumption [Formula: see text] and mitochondrial GDP binding in brown adipose tissue (BAT) of fenfluramine-treated rats. To further investigate a possible involvement of BAT in the drug's metabolic effects, 113Sn-labelled microspheres were injected into the left cardiac ventricle of conscious rats 70–80 min after intraperitoneal delivery of 20 mg/kg fenfluramine (DL-mixture) or saline vehicle. At 28 °C ambient temperature, fenfluramine augmented resting whole-body [Formula: see text] and increased the microsphere entrapment in BAT, indicating enhanced blood flow and metabolism. At 20 °C ambient temperature, the expected increase in BAT blood flow associated with nonshivering thermogenesis was observed in control rats, but in fenfluramine-treated rats the increase in BAT blood flow was severely attenuated, and [Formula: see text] and body temperature were reduced. The stimulatory effect of fenfluramine on BAT metabolism was not prevented by urethane anesthesia but did not occur if the tissue was denervated. These blood flow measurements corroborate previous reports, based on GDP-binding assays, that fenfluramine treatment can augment thermogenesis in BAT by effects mediated through the innervation of the tissue. However, the data also indicate that this calorigenic effect is dependent on ambient temperature being near thermoneutrality and that in a cool environment the drug inhibits BAT thermogenesis.Key words: fenfluramine, brown adipose tissue, thermogenesis.

scholarly journals Brown Adipose Tissue Blood Flow and Mass in Obesity: A Contrast Ultrasound Study in Mice

2013 ◽  
Vol 26 (12) ◽  
pp. 1465-1473 ◽  
Author(s):  
Maëva Clerte ◽  
David M. Baron ◽  
Peter Brouckaert ◽  
Laura Ernande ◽  
Michael J. Raher ◽  
...  
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Tissue Blood Flow ◽  
Ultrasound Study ◽  
Brown Adipose ◽  
Adipose Tissue Blood Flow ◽  
Contrast Ultrasound

Ephedrine-Induced Thermogenesis in Man: No Role for Interscapular Brown Adipose Tissue

1984 ◽  
Vol 66 (2) ◽  
pp. 179-186 ◽  
Author(s):  
A. Astrup ◽  
J. Bülow ◽  
N. J. Christensen ◽  
J. Madsen
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Skin Temperature ◽  
Control Level ◽  
Tissue Blood Flow ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Adipose Tissue Blood Flow ◽  
Lumbar Area

1. The warmest interscapular skin areas were located by thermography in six healthy subjects during ephedrine-induced thermogenesis. 2. In these interscapular areas, and in lumbar control areas, the skin temperature, subcutaneous temperature and adipose tissue blood flow were measured before and during ephedrine-induced thermogenesis. 3. The skin and subcutaneous temperatures increased in the interscapular area as well as in the lumbar area, by about 0.7-1.2°C. The interscapular skin temperature remained about 1°C higher than the lumbar; the subcutaneous temperatures in the two areas were identical during the experiments. 4. Although the interscapular subcutaneous adipose tissue blood flow increased about sixfold and the lumbar increased twofold, the absolute flows were higher in the lumbar area. 5. The oxygen uptake increased to a maximum of 30% above control level. 6. Plasma glucose and glycerol concentrations remained unchanged, and plasma non-esterified fatty acids, lactate and noradrenaline concentrations increased slightly but significantly. 7. Biopsies taken from the hot interscapular areas did not contain brown adipose tissue. 8. It is concluded that the high interscapular skin temperature may be due to a lower insulating fat thickness and that the increases in skin and subcutaneous temperatures during ephedrine-induced thermogenesis are caused by an increased blood flow. These observations weigh against the hypothesis that the interscapular temperature increase is due to functional, interscapular brown adipose tissue.

Thermogenic effects of dihydrocodeine in the rat

1988 ◽  
Vol 66 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Nancy J. Rothwell ◽  
Michael J. Stock ◽  
Alison E. Tedstone
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Brown Adipose Tissue ◽  
Opiate Receptors ◽  
Zucker Rats ◽  
Tissue Blood Flow ◽  
Dependent Manner ◽  
Brown Adipose ◽  
Adrenergic Antagonist

The object of this study was to assess the effects of dihydrocodeine on thermogenesis and brown adipose tissue activity in the rat from measurements of oxygen consumption and blood flow. Acute injection of dihydrocodeine tartrate (s.c.) stimulated resting oxygen consumption [Formula: see text] in Sprague–Dawley rats in a dose-dependent manner (0.5–50 mg/kg), with a peak response (40–45% increase) occurring at 10–25 mg/kg. This effect was also observed in urethane-anaesthetized rats (although the effect was reduced) and in conscious animals following gastric intubation with the drug. Pretreatment of rats with either a β-adrenergic antagonist (propranolol, 20 mg/kg), ACTH (4 g/kg), or an opiate antagonist (WIN44441-1, 2 mg/kg) significantly reduced the response to dihydrocodeine, whereas corticosterone injection (5 mg/kg) enhanced the effect. Surgical adrenalectomy or hypophysectomy (HYPX) almost completely abolished the thermogenic effect of dihydrocodeine. Dihydrocodeine also stimulated [Formula: see text] in lean (58% increase) and genetically obese Zucker rats (69% increase), and in both Zucker genotypes these responses were only slightly affected by HYPX, but enhanced in HYPX rats treated daily with corticosterone (1 mg/kg). Tissue blood flow, assessed from the distribution of radiolabelled microspheres, was unaffected in white adipose tissue, skeletal muscle, testes, kidney, brain, and liver (arterial supply) after a single injection of dihydrocodeine (25 mg/kg), but flow to interscapular and perirenal brown adipose tissue was increased by 9- to 10-fold. Surgical sympathectomy of brown adipose tissue prevented the increase in blood flow. These potent thermogenic effects of dihydrocodeine in the rat appear to result from sympathetic activation of heat production in brown fat and to involve opiate receptors, but can also be modified by pituitary and (or) adrenal hormones.

Absence of increased oxygen consumption in brown adipose tissue of rats exhibiting "cafeteria" diet-induced thermogenesis

1988 ◽  
Vol 66 (11) ◽  
pp. 1347-1354 ◽  
Author(s):  
Stephanie W. Y. Ma ◽  
David O. Foster ◽  
Brita E. Nadeau ◽  
Joan Triandafillou
Keyword(s):  
Adipose Tissue ◽  
Metabolic Rate ◽  
Brown Adipose Tissue ◽  
Intraventricular Injection ◽  
Tissue Blood Flow ◽  
Sprague Dawley ◽  
Arterial Blood ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis

Young male Sprague–Dawley rats were induced to overeat (~45%) by provision of a "cafeteria" (CAF) diet of palatable human foods. Normophagic rats fed a commercial chow or a semisynthetic diet served as controls. The CAF rats exhibited (a) the reduced food efficiency and the propranolol-inhibitable elevation in resting metabolic rate (resting [Formula: see text]) that are indicative of a facultative diet-induced thermogenesis (DIT) by which excess energy gain is resisted, and (b) certain changes in brown adipose tissue (BAT) that are among those taken as evidence for BAT as the effector of DIT, e. g., increased protein content and increased mitochondrial binding of GDP. To assess directly and quantitatively the contribution by BAT to the elevation in [Formula: see text] (apparent DIT) of the CAF rats, BAT O2 consumption was determined (Fick principle) from measurements of tissue blood flow (microsphere method) and the arteriovenous difference in blood O2 across interscapular BAT (IBAT). To obtain the measurements, the animals were fitted under halothane anesthesia with vascular cannulas for intraventricular injection of microspheres and sampling of arterial blood and the venous effluent of IBAT. After recovery from anesthesia and rewarming to normal body temperature the animals were placed singly in a temperature-controlled metabolic chamber and the measurements, which also included determination of resting [Formula: see text], were made 1.5–2 h later at about 11:30 h. As determined from measurements made at 28 °C (thermoneutrality) mean values of resting [Formula: see text] for the cannulated rats were unchanged from those of intact (unoperated) CAF or control rats. At either 28 or 24 °C (housing temperature) the CAF rats, although exhibiting the elevation in resting [Formula: see text] attributed to DIT, were found to have levels of BAT O2 consumption no greater than those in the control rats. Thus, direct measurement of the metabolic rate of BAT in vivo produced no evidence for BAT as the effector of the DIT of CAF rats.

Quantitative contribution of brown adipose tissue thermogenesis to overall metabolism

1984 ◽  
Vol 62 (7) ◽  
pp. 618-622 ◽  
Author(s):  
David O. Foster
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Wild Mammals ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis ◽  
Diet Induced Thermogenesis ◽  
Quantitative Contribution ◽  
Arteriovenous Difference ◽  
Stimulation Of

Measurement of brown adipose tissue (BAT) blood flow coupled, when feasible, with measurement of the arteriovenous difference in oxygen across the tissue has been used to estimate the contribution of BAT thermogenesis to the metabolism of several species of laboratory, domestic, or wild mammals under various conditions: warm or cold exposure; arousal from hibernation; stimulation of metabolism by exogenous noradrenaline in warm- or cold-acclimated animals, in lean or obese animals, and in animals exhibiting high- or low-diet-induced thermogenesis. These studies have shown that in some species and under certain conditions BAT thermogenesis may account for as much as about one-third of the overall metabolic rate.

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