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.

scholarly journals Detraining of exercise-trained rats: effects on energetic efficiency and brown adipose tissue thermogenesis

1987 ◽  
Vol 57 (3) ◽  
pp. 363-370 ◽  
Author(s):  
Jeff Arnold ◽  
Denis Richard
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Body Weight Gain ◽  
The Body ◽  
Metabolizable Energy ◽  
Treadmill Running ◽  
Energetic Efficiency ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis

1. Complete energy balance measurements were made in exercise-trained (treadmill running) rats subjected to 27 d of exercise detraining.2. The 20% difference in body-weight that existed at the end of the training period between sedentary and trained rats was negated by detraining. Detrained rats had twice the body-weight gain of their untrained controls.3. An elevation (12%) in metabolizable energy (ME) intake (relative to body-weight) was observed in detrained rats while their gross energetic efficiency was augmented by 60%.4. Energy expenditure, excluding the estimated costs of fat and protein storage, was similar for detrained and untrained rats. Complementing the latter was the finding that thermogenesis in brown adipose tissue, a known energy buffering process, was also similar.5. Elevated ME intake (relative to body-weight) largely contributed to the increased energetic efficiency of detrained rats.

Energy balance and brown adipose tissue thermogenesis during pregnancy in Syrian hamsters

1986 ◽  
Vol 250 (5) ◽  
pp. R845-R850 ◽  
Author(s):  
G. N. Wade ◽  
G. Jennings ◽  
P. Trayhurn
Keyword(s):  
Adipose Tissue ◽  
Energy Balance ◽  
Food Intake ◽  
Brown Adipose Tissue ◽  
Interscapular Brown Adipose Tissue ◽  
Estrous Cycles ◽  
Syrian Hamsters ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis ◽  
Circulating Levels

Energy balance and brown adipose tissue thermogenesis were examined during pregnancy in Syrian hamsters (Mesocricetus auratus). Neither estrous cycles nor pregnancy had any effect on food intake, but both were accompanied by significant changes in body weight. Despite their substantial weight gains (attributable to growth of fetuses and placentas), pregnant hamsters actually lost a mean of 48 kJ in carcass energy, whereas unmated controls gained 98 kJ over the same 15 days. During pregnancy hamsters exhibited an increase in protein deposition (almost entirely in the fetuses and placentas), but they lost nearly 40% of their body lipid. An apparent increase in energy expenditure occurred despite a highly significant decrease in brown adipose tissue thermogenesis during pregnancy. By day 15 of pregnancy (within 13 h of expected parturition) there were substantial decreases in interscapular brown adipose tissue weight (-59%), protein content (-54%), and cytochrome-c oxidase activity (-69%). These changes in brown adipose tissue were evident by day 4 of pregnancy and persisted through lactation. It is suggested that this suppression of brown adipose tissue function is due to increased circulating levels of prolactin and subsequently to the nutritional stress of conceptus growth in the absence of an increase in food intake.

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.

scholarly journals Glucose transporter expression and glucose utilization in skeletal muscle and brown adipose tissue during starvation and re-feeding

1992 ◽  
Vol 282 (1) ◽  
pp. 231-235 ◽  
Author(s):  
D M Smith ◽  
S R Bloom ◽  
M C Sugden ◽  
M J Holness
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Tibialis Anterior ◽  
Glucose Transporter ◽  
Glucose Utilization ◽  
Interscapular Brown Adipose Tissue ◽  
Glut 4 ◽  
Mrna Concentration ◽  
Brown Adipose ◽  
Transporter Expression

Starvation (48 h) decreased the concentration of mRNA of the insulin-responsive glucose transporter isoform (GLUT 4) in interscapular brown adipose tissue (IBAT) (56%) and tibialis anterior (10%). Despite dramatic [7-fold (tibialis anterior) and 40-fold (IBAT)] increases in glucose utilization after 2 and 4 h of chow re-feeding, no significant changes in GLUT 4 mRNA concentration were observed in these tissues over this re-feeding period. The results exclude changes in GLUT 4 mRNA concentration in mediating the responses of glucose transport in these tissues to acute re-feeding after prolonged starvation.

scholarly journals Changes in β1- and β2-adrenergic receptor mRNA levels in brown adipose tissue and heart of hypothyroid rats

1991 ◽  
Vol 277 (3) ◽  
pp. 625-629 ◽  
Author(s):  
J P Revelli ◽  
R Pescini ◽  
P Muzzin ◽  
J Seydoux ◽  
M G Fitzgerald ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Adrenergic Receptor ◽  
State Level ◽  
Total Density ◽  
Mrna Levels ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Displacement Experiments ◽  
Beta 2

The aim of the present work was to study the effect of hypothyroidism on the expression of the beta-adrenergic receptor (beta-AR) in interscapular brown adipose tissue and heart. The total density of plasma membrane beta-AR per tissue is decreased by 44% in hypothyroid rat interscapular brown adipose tissue and by 55% in hypothyroid rat heart compared with euthyroid controls. The effects of hypothyroidism on the density of both beta 1- and beta 2-AR subtypes were also determined in competition displacement experiments. The densities of beta 1- and beta 2-AR per tissue are decreased by 50% and 48% respectively in interscapular brown adipose tissue and by 52% and 54% in the heart. Northern blot analysis of poly(A)+ RNA from hypothyroid rat interscapular brown adipose tissue demonstrated that the levels of beta 1- and beta 2-AR mRNA per tissue are decreased by 73% and 58% respectively, whereas in hypothyroid heart, only the beta 1-AR mRNA is decreased, by 43%. The effect of hypothyroidism on the beta 1-AR mRNA is significantly more marked in the interscapular brown adipose tissue than in the heart. These results indicate that beta-AR mRNA levels are differentially regulated in rat interscapular brown adipose tissue and heart, and suggest that the decrease in beta-AR number in interscapular brown adipose tissue and heart of hypothyroid animals may in part be explained by a decreased steady-state level of beta-AR mRNA.

Role of thermogenesis in the regulation of energy balance in relation to obesity

1989 ◽  
Vol 67 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Jean Himms-Hagen
Keyword(s):  
Adipose Tissue ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Thermal Balance ◽  
Prominent Feature ◽  
Thermic Effect Of Food ◽  
Brown Adipose ◽  
Effect Of Food ◽  
Thermic Effect

Obligatory thermogenesis is a necessary accompaniment of all metabolic processes involved in maintenance of the body in the living state, and occurs in ail organs. It includes energy expenditure involved in ingesting, digesting, and processing food (thermic effect of food (TEF)). At certain life stages extra energy expenditure for growth, pregnancy, or lactation would also be obligatory. Facultative thermogenesis is superimposed on obligatory thermogenesis and can be rapidly switched on and rapidly suppressed by the nervous system. Facultative thermogenesis is important in both thermal balance, in which control of thermoregulatory thermogenesis (shivering in muscle, nonshivering in brown adipose tissue (BAT)) balances neural control of heat loss mechanisms, and in energy balance, in which control of facultative thermogenesis (exercise-induced in muscle, diet-induced thermogenesis (DIT) in BAT) balances control of energy intake. Thermal balance (i.e., body temperature) is much more stringently controlled than energy balance (i.e., body energy stores). Reduced energy expenditure for thermogenesis is important in two types of obesity in laboratory animals. In the first type, deficient DIT in BAT is a prominent feature of altered energy balance. It may or may not be associated with hyperphagia. In a second type, reduced cold-induced thermogenesis in BAT as well as in other organs is a prominent feature of altered thermal balance. This in turn results in altered energy balance and obesity, exacerbated in some examples by hyperphagia. In some of the hyperphagic obese animals it is likely that the exaggerated obligatory thermic effect of food so alters thermal balance that BAT thermogenesis is suppressed. In all obese animals, deficient hypothalamic control of facultative thermogenesis and (or) food intake is implicated.Key words: thermogenesis, brown adipose tissue, energy balance, obesity, cold, thermoregulation, diet.

scholarly journals Stimulatory, but not anxiogenic, doses of caffeine act centrally to activate interscapular brown adipose tissue thermogenesis in anesthetized male rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. Van Schaik ◽  
C. Kettle ◽  
R. Green ◽  
W. Sievers ◽  
M. W. Hale ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Basolateral Amygdala ◽  
Free Breathing ◽  
Male Rats ◽  
Central Administration ◽  
Hypothalamic Area ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis

AbstractThe role of central orexin in the sympathetic control of interscapular brown adipose tissue (iBAT) thermogenesis has been established in rodents. Stimulatory doses of caffeine activate orexin positive neurons in the lateral hypothalamus, a region of the brain implicated in stimulating BAT thermogenesis. This study tests the hypothesis that central administration of caffeine is sufficient to activate BAT. Low doses of caffeine administered either systemically (intravenous [IV]; 10 mg/kg) and centrally (intracerebroventricular [ICV]; 5–10 μg) increases BAT thermogenesis, in anaesthetised (1.5 g/kg urethane, IV) free breathing male rats. Cardiovascular function was monitored via an indwelling intra-arterial cannula and exhibited no response to the caffeine. Core temperature did not significantly differ after administration of caffeine via either route of administration. Caffeine administered both IV and ICV increased neuronal activity, as measured by c-Fos-immunoreactivity within subregions of the hypothalamic area, previously implicated in regulating BAT thermogenesis. Significantly, there appears to be no neural anxiety response to the low dose of caffeine as indicated by no change in activity in the basolateral amygdala. Having measured the physiological correlate of thermogenesis (heat production) we have not measured indirect molecular correlates of BAT activation. Nevertheless, our results demonstrate that caffeine, at stimulatory doses, acting via the central nervous system can increase thermogenesis, without adverse cardio-dynamic impact.

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