Influence of noradrenaline on blood flow to brown adipose tissue in rats exhibiting diet-induced thermogenesis

1981 ◽  
Vol 389 (3) ◽  
pp. 237-242 ◽  
Author(s):  
Nancy J. Rothwell ◽  
Michael J. Stock
1989 ◽  
Vol 67 (4) ◽  
pp. 376-381 ◽  
Author(s):  
Stephanie W. Y. Ma ◽  
David O. Foster

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.


1984 ◽  
Vol 62 (7) ◽  
pp. 618-622 ◽  
Author(s):  
David O. Foster

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.


1999 ◽  
Vol 276 (6) ◽  
pp. R1569-R1578 ◽  
Author(s):  
Maryam Bamshad ◽  
C. Kay Song ◽  
Timothy J. Bartness

Brown adipose tissue (BAT) plays a critical role in cold- and diet-induced thermogenesis. Although BAT is densely innervated by the sympathetic nervous system (SNS), little is known about the central nervous system (CNS) origins of this innervation. The purpose of the present experiment was to determine the neuroanatomic chain of functionally connected neurons from the CNS to BAT. A transneuronal viral tract tracer, Bartha’s K strain of the pseudorabies virus (PRV), was injected into the interscapular BAT of Siberian hamsters. The animals were killed 4 and 6 days postinjection, and the infected neurons were visualized by immunocytochemistry. PRV-infected neurons were found in the spinal cord, brain stem, midbrain, and forebrain. The intensity of labeled neurons in the forebrain varied from heavy infections in the medial preoptic area and paraventricular hypothalamic nucleus to few infections in the ventromedial hypothalamic nucleus, with moderate infections in the suprachiasmatic and lateral hypothalamic nuclei. These results define the SNS outflow from the brain to BAT for the first time in any species.


1986 ◽  
Vol 251 (2) ◽  
pp. R240-R242 ◽  
Author(s):  
A. Niijima

The activity of sympathetic nerves innervating interscapular brown adipose tissue of the rat was recorded. Intravenous administrations of glucose (100-300 mg/kg) enhanced the nerve activity. However, mannose, fructose, or galactose (300 mg/kg) showed no effect, suggesting the response is related to diet-induced thermogenesis in the brown adipose tissue.


2020 ◽  
Vol 472 (3) ◽  
pp. 405-417
Author(s):  
Nikola Habek ◽  
Marina Dobrivojević Radmilović ◽  
Milan Kordić ◽  
Katarina Ilić ◽  
Sandra Grgić ◽  
...  

Author(s):  
Rahel Catherina Loeliger ◽  
Claudia Irene Maushart ◽  
Gani Gashi ◽  
Jaël Rut Senn ◽  
Martina Felder ◽  
...  

Objective Human brown adipose tissue (BAT) is a thermogenic tissue activated by the sympathetic nervous system in response to cold. It contributes to energy expenditure (EE) and takes up glucose and lipids from the circulation. Studies in rodents suggest that BAT contributes to the transient rise in EE after food intake, so called diet-induced thermogenesis (DIT). We investigated the relationship between human BAT activity and DIT in response to glucose intake in 17 healthy volunteers. Methods We assessed DIT, cold induced thermogenesis (CIT) and maximum BAT activity at three separate study visits within two weeks. DIT was measured by indirect calorimetry during an oral glucose tolerance-test. CIT was assessed as the difference in EE after cold exposure of two hours duration as compared to warm conditions. Maximal activity of BAT was assessed by 18F-FDG-PET/MRI after cold exposure and concomitant pharmacological stimulation with Mirabegron. Results 17 healthy men (mean age 23.4 years, mean BMI 23.2 kg/m2) participated in the study. EE increased from 1908 (±181) kcal/24 hours to 2128 (±277) kcal/24 hours (p<0.0001, +11.5%) after mild cold exposure. An oral glucose load increased EE from 1911 (±165) kcal/24 hours to 2096 (±167) kcal/24 hours at 60 minutes (p<0.0001, +9.7%). The increase in EE in response to cold was significantly associated with BAT activity (R2=0.43, p=0.004). However, DIT was not associated with BAT activity (R2=0.015, p=0.64). Conclusion DIT after an oral glucose load was not associated with stimulated 18F-FDG uptake into BAT suggesting that DIT is independent from BAT activity in humans.


1984 ◽  
Vol 26 (3) ◽  
pp. 339-347 ◽  
Author(s):  
A. M. Saxton ◽  
E. J. Eisen ◽  
J. M. Leatherwood

A recent hypothesis considers brown adipose tissue (BAT) to be an important source of diet-induced thermogenesis (DIT). In turn, DIT and thermogenesis in general are believed to be key factors in the control of obesity of laboratory rodents. This hypothesis was developed from the study of single gene mutant obese rodents. The present research tested this hypothesis in mice with polygenic control of growth and obesity, which is more characteristic of the type of genetic variation expected in human and other mammalian populations. Control and high fat diets were used to test responses of five genetically selected lines of mice showing different patterns of growth and obesity. All lines deposited more fat on the high fat diet, but the most obese line showed the largest increase in BAT and the lipid-free dry (LFD) component of BAT. Use of LFD per unit body weight gave results which supported the hypothesis being tested, but it was argued that this measure is misleading. When brown and white adipose tissue growth relative to body weight were examined, 2 of the 10 line – diet groups showed alterations in BAT growth patterns. However, it was concluded that BAT, if involved at all, was not a major factor in growth and obesity differences.Key words: obesity, polygenes, adipose tissue, quantitative inheritance, mouse.


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