Similarities between cold- and diet-induced thermogenesis in the rat

1980 ◽  
Vol 58 (7) ◽  
pp. 842-848 ◽  
Author(s):  
Nancy J. Rothwell ◽  
Michael J. Stock
Keyword(s):  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Energy Balance ◽  
Body Temperature ◽  
Percentage Increase ◽  
Stock Diet ◽  
Interscapular Brown Adipose Tissue ◽  
The Core ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis

Rats were maintained at 24 and 4 °C (WA, CA) and fed either a pelleted stock diet (WAS, CAS) or a varied and palatable cafeteria diet (WAC, CAC). Resting oxygen consumption ([Formula: see text], 29 °C) was significantly elevated by 15, 14, and 24% in WAC, CAS, and CAC rats, respectively, compared with WAS controls and these differences were completely abolished by injection of propranolol in all but CAC rats, where [Formula: see text] remained only slightly elevated. Experimental groups showed an increased capacity to respond to the thermogenic effects of norepinephrine (percentage increase in [Formula: see text]: WAS, 43 ± 5; WAC, 88 ± 6; CAS, 75 ± 6; CAC, 128 ± 5) and greather deposits of interscapular brown adipose tissue (IBAT) (WAC, 542 ± 27; CAS, 469 ± 27; CAC, 1111 ± 85 mg) compared with WAS controls (339 ± 22 mg).When exposed to 5 °C, WAS rats shivered continuously whereas in the WAC animals shivering had ceased by 5 h. Rectal temperature was maintained at a higher level in the WAC rats than in the WAS group (WAS, 34.7 ± 0.9 °C; WAC, 36.2 ± 0.5 °C; p < 0.01). Injection of propranolol lowered the core temperature of WAC rats and caused shivering to recommence but had no effect on WAS rats.The similarities between diet- and cold-induced thermogenesis suggest that both have a common metabolic origin residing in BAT and that dietary-induced thermogenesis may be important in the maintenance of body temperature as well as in energy balance regulation.

Energy balance following sympathetic denervation of brown adipose tissue

1984 ◽  
Vol 62 (2) ◽  
pp. 235-240 ◽  
Author(s):  
A. G. Dulloo ◽  
D. S. Miller
Keyword(s):  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Energy Balance ◽  
Brown Adipose Tissue ◽  
Body Fat ◽  
Metabolizable Energy ◽  
Energetic Efficiency ◽  
Interscapular Brown Adipose Tissue ◽  
Body Protein ◽  
Brown Adipose

The effects of sham, bilateral surgical denervation or excision of interscapular brown adipose tissue on body composition and energetic efficiency were studied in young CFLP mice kept at 25 °C and fed a laboratory stock diet. A preliminary experiment showed that 15 weeks following surgery, total body fat was increased by 42% in the denervated group and by 72% in the excised group while body protein was unchanged. In another 7-week energy balance experiment, body fat was also significantly higher by 15 and 18% in the denervated and excised group, respectively, but metabolizable energy intake was slightly lower than that of sham controls. Determination of energy expenditure both by the comparative carcass slaughter technique and by measurement of daily oxygen consumption showed that the metabolic rate was reduced in the denervated and excised groups. The capacity for thermogenesis, as measured by an increase in oxygen consumption following injections of noradrenaline (600 μg/kg body weight) was similar in all groups. These studies show that denervation or excision of interscapular brown adipose tissue causes an elevation in energetic efficiency, and indicates an important role of the sympathetic nervous system in the regulation of animal heat production by brown adipose tissue and in the overall control of thermogenesis.

Suppression of norepinephrine-induced thermogenesis in brown adipose tissue by fasting

1983 ◽  
Vol 245 (6) ◽  
pp. E582-E586 ◽  
Author(s):  
M. Hayashi ◽  
T. Nagasaka
Keyword(s):  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Thyroid Hormones ◽  
Brown Adipose Tissue ◽  
Plasma Levels ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Colonic Temperature ◽  
Induced Changes ◽  
Thermogenic Response

Fasting-induced changes in thermogenic responses to norepinephrine (NE, 4.0 micrograms X kg-1 X min-1 iv) were studied in anesthetized rats previously cold acclimated. The rats were divided into five groups at the end of 30–40 days of cold acclimation (5 degrees C). The five groups were kept for 5 days at 25 degrees C and fed (intact fed), fasted (intact fasted), fasted with daily treatment with thyroxine (T4, 2 micrograms/kg sc), thyroidectomized and fed, or thyroidectomized and fasted. In the intact fasted group, in which the weight of brown adipose tissue decreased, NE-induced increases in oxygen consumption, colonic temperature (T col), and temperature of the interscapular brown adipose tissue (TBAT) were markedly suppressed. The two thyroidectomized groups also showed a reduction in thermogenic response. In these three groups, TBAT was lower than Tcol throughout NE infusion. In the T4-treated fasted group, fasting-induced suppression of thermogenic response to NE was largely prevented. In the intact fed and the T4-treated fasted groups, TBAT attained higher values than Tcol during NE infusion. Plasma levels of thyroid hormones were significantly lower in the intact fasted group than in the intact fed or the T4-treated fasted group. These results suggest that fasting-induced suppression of the thermogenic response to NE is largely due to the reduced thermogenic response of brown adipose tissue to NE. The lowering of the levels of the thyroid hormones induced by fasting may be one of a number of causes of the reduction in the thermogenic response of brown adipose tissue.

Effect of glucose and other hexoses on efferent discharges of brown adipose tissue nerves

1986 ◽  
Vol 251 (2) ◽  
pp. R240-R242 ◽  
Author(s):  
A. Niijima
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Sympathetic Nerves ◽  
Nerve Activity ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis ◽  
Effect Of Glucose

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.

Sympathoadrenal system and regulation of thermogenesis

1984 ◽  
Vol 247 (2) ◽  
pp. E181-E189 ◽  
Author(s):  
L. Landsberg ◽  
M. E. Saville ◽  
J. B. Young
Keyword(s):  
Adipose Tissue ◽  
Dietary Intake ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Critical Role ◽  
Interscapular Brown Adipose Tissue ◽  
Norepinephrine Turnover ◽  
Brown Adipose ◽  
Adult Humans ◽  
Diet Induced Thermogenesis

The sympathetic nervous system (SNS) plays a critical role in the regulation of mammalian thermogenic responses to cold exposure and dietary intake. Catecholamine-stimulated thermogenesis is mediated by the beta-adrenergic receptor. In the rat brown adipose tissue is the major site of metabolic heat production in response to both cold (nonshivering thermogenesis) and diet (diet-induced thermogenesis). Measurements of norepinephrine turnover rate in interscapular brown adipose tissue of the rat demonstrate increased sympathetic activity in response to both cold exposure and overfeeding. In adult humans, a physiologically significant role for brown adipose tissue has not been established but cannot be excluded. It appears likely that dietary changes in SNS activity are related, at least in part, to the changes in metabolic rate that occur in association with changes in dietary intake.

Thermogenesis in the marsupial Sminthopsis crassicaudata: effect of catecholamines and diet

1998 ◽  
Vol 46 (4) ◽  
pp. 381 ◽  
Author(s):  
Fiona Clements ◽  
Perdita Hope ◽  
Chris Daniels ◽  
Ian Chapman ◽  
Gary Wittert
Keyword(s):  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Food Intake ◽  
Nutritional Status ◽  
Macronutrient Composition ◽  
Sminthopsis Crassicaudata ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis ◽  
Carnivorous Marsupial ◽  
Tenebrio Molitor Larvae

The fat-tailed dunnart (Sminthopsis crassicaudata) is a small carnivorous marsupial with detectable brown adipose tissue. In order to determine whether catecholamines and food intake increase thermogenesis in this species, we measured the response of oxygen consumption (Vo2) to (i) intraperitoneal noradrenaline (0.25–4.0 mg kg-1), and (ii) food intake. The effect of nutritional status and macronutrient composition of the diet on the Vo2 response to food intake was determined by feeding both non-deprived and 24-h-food-deprived animals with either laboratory diet (1.01 Kcal g-1 (4.2 KJ g-1), 20% fat) or live mealworms (Tenebrio molitor larvae) (2.99 Kcal g-1 (12.5 KJ g-1), 30% fat). Intraperitoneal injection of noradrenaline at doses of 0.25 and 0.5 mg kg-1 increased Vo2 by 14% and 31% respectively at 30 min (P ≤ 0.05), whereas noradrenaline at 2 and 4 mg kg-1 decreased Vo2 by 10% and 31% respectively (P ≤ 0.05). Following food intake, Vo2 increased in both non-deprived (P < 0.05) and 24-h-food-deprived (P < 0.05) animals. While the magnitude of the increase in Vo2 was similar in animals fed with either laboratory diet or mealworms, both diets increased Vo2 more in non-deprived than in 24-h-food-deprived animals (P < 0.05). These results suggest that in S. crassicaudata (i) catecholamines increase thermogenesis and (ii) the magnitude of diet-induced thermogenesis is dependent on both the nutritional status of the animal and the macronutrient composition of the diet.

Energy balance and facultative diet-induced thermogenesis in mice fed a high-fat diet

1988 ◽  
Vol 66 (10) ◽  
pp. 1297-1302 ◽  
Author(s):  
Denis Richard ◽  
Pierre Boily ◽  
Marie-Claude Dufresne ◽  
Martin Lecompte
Keyword(s):  
Energy Balance ◽  
Energy Intake ◽  
Indirect Calorimetry ◽  
High Fat Diet ◽  
Free Access ◽  
Stock Diet ◽  
High Fat ◽  
Brown Adipose ◽  
Unrestricted Access ◽  
Diet Induced Thermogenesis

The present study was aimed at studying energy balance in mice fed a high-fat diet. Albino mice were divided into three groups. One group had free access to the stock diet, whereas the two other groups consumed a high-fat diet. One of the high-fat fed groups was fed ad libitum, whereas the other was offered a restricted amount of the same diet so that its energy intake was comparable to the group of mice given the stock diet. Energy balance measurements, which included indirect calorimetry and carcass analysis, were performed. Brown adipose tissue (BAT) properties were also investigated. The results show that gains in both body weight and fat were higher in mice that had free access to high-fat diet than in mice fed the stock diet. In animals given a restricted amount of the high-fat diet, fat gain increased, whereas protein gain was reduced in comparison with animals fed the stock diet. Unrestricted access to the high-fat diet led to an increase in both energy intake and energy gain. As revealed by both slaughter and indirect calorimetry techniques energy expenditure was, in high-fat fed mice, 40% higher than in animals fed either stock or a restricted amount of high-fat diet. Nadolol was shown to suppress a large part of the elevated metabolic rate seen in mice fed an unrestricted high-fat diet. In those mice, BAT mitochondrial GDP binding was also increased. In summary, the present results confirm that adaptive diet-induced thermogenesis (DIT) develops in mice made hyperphagic by an energy-dense palatable diet. The present study provides further evidence that adaptive DIT is mediated by the sympathetic nervous system and involves BAT. Finally, it appears that the extent to which adaptive DIT develops is related to the degree of hyperphagia.

Thermoregulatory responses of dystrophic hamsters to changes in ambient temperatures

1985 ◽  
Vol 63 (9) ◽  
pp. 1145-1150 ◽  
Author(s):  
M. Desautels ◽  
R. A. Dulos ◽  
J. A. Thornhill
Keyword(s):  
Carbon Dioxide ◽  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Activity ◽  
Carbon Dioxide Production ◽  
Ambient Temperatures ◽  
Brown Adipose ◽  
Lower Temperature ◽  
Do So

The ability of dystrophic hamsters to maintain their body temperature despite abnormal muscle and brown adipose tissue, two organs involved in thermoregulation, was evaluated. Dystrophic hamsters (CHF 146) between the ages of 30 and 160 days kept at 21 °C had core (rectal) temperatures (TR) that were 0.5–1.5 °C lower than Golden Syrian controls. The reduced core temperatures of dystrophic hamsters were unlikely the result of an incapacity to generate heat since the dystrophic hamsters were able to maintain their TRs during 3 h of acute cold stress (4 °C) and to adapt to prolonged cold exposure. However, TRs of cold-acclimated dystrophic hamsters were still 1 °C below TRs of cold-acclimated control animals. By contrast, increasing the ambient temperature raised TRs of both normal and dystrophic hamsters. When kept at 32 °C overnight, the TRs of dystrophic hamsters remained significantly below those of control animals. When heat-exposed dystrophic hamsters were returned to 21 °C, their TRs returned to values significantly lower than those of control hamsters. Thus, dystrophic hamsters showed a capacity to thermoregulate, like control hamsters, but appeared to do so at a lower temperature. The reduced core temperatures of dystrophic hamsters kept at 21 °C cannot be explained by a reduction in metabolic activity since newborns and 30- and 140-day-old dystrophic hamsters had rates of oxygen consumption [Formula: see text] and carbon dioxide production [Formula: see text] that were similar to those of controls. These results suggest that the thermoregulatory set point may be altered in dystrophic hamsters.

Reduced lipogenesis in cafeteria-fed rats exhibiting diet-induced thermogenesis

1983 ◽  
Vol 3 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Nancy J. Rothwell ◽  
Michael J. Stock ◽  
Paul Trayhurn
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Whole Body ◽  
Stock Diet ◽  
Inhibitory Effects ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis

Fatty-acid synthesis has been measured in vivo with 3H2O in cafeteria-fed rats exhibiting diet-induced thermogenesis. Synthesis was decreased in brown adipose tissue, the liver, white adipose tissue, and the carcass of the cafeteria-fed animals compared to rats fed the normal stock diet. Whole-body synthesis was also decreased in the cafeteria-fed group. Diet-induced thermogenesis, in contrast to cold-induced non-shivering thermogenesis does not lead to increased fatty-acid synthesis and this is presumably due to the inhibitory effects on lipogenesis of the high dietary fat intake characteristic of cafeteria diets. The results also indicate that the energy cost of body fat deposition in cafeteria-fed rats is lower than in animals fed a low-fat/high-carbohydrate stock diet.

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