Chemical sympathectomy alters regulation of body weight during prolonged ICV leptin infusion

2003 ◽  
Vol 284 (4) ◽  
pp. E778-E787 ◽  
Author(s):  
Robert L. Dobbins ◽  
Lidia S. Szczepaniak ◽  
Weiguo Zhang ◽  
J. Denis McGarry
Keyword(s):  
Physical Activity ◽  
Nervous System ◽  
Body Weight ◽  
Food Intake ◽  
Energy Expenditure ◽  
Sympathetic Nervous System ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Chemical Sympathectomy ◽  
Sympathetic Nervous

To assess the importance of the sympathetic nervous system in regulating body weight during prolonged leptin infusion, we evaluated food intake, body weight, and physical activity in conscious, unrestrained rats. Initial studies illustrated that prolonged intracerebroventricular (ICV) infusion of leptin enhanced substrate oxidation so that adipose tissue lipid stores were completely ablated, and muscle triglyceride and liver glycogen stores were depleted. After neonatal chemical sympathectomy, changes in weight and food intake were compared in groups of sympathectomized (SYM) and control (CON) adult animals during ICV infusion of leptin. CON animals lost 60 ± 9 g over 10 days vs. 25 ± 3 g in the SYM animals when food intake was matched between the two groups. Greater weight loss despite similar energy intake points to an important role of the sympathetic nervous system in stimulating energy expenditure during ICV leptin infusion by increasing the resting metabolic rate, since no differences in physical activity were observed between CON and SYM groups. In conclusion, activation of the SNS by leptin increases energy expenditure by augmenting the resting metabolic rate.

scholarly journals Urinary Norepinephrine Is a Metabolic Determinant of 24-Hour Energy Expenditure and Sleeping Metabolic Rate in Adult Humans

2020 ◽  
Vol 105 (4) ◽  
pp. 1145-1156 ◽  
Author(s):  
Tim Hollstein ◽  
Alessio Basolo ◽  
Takafumi Ando ◽  
Susanne B Votruba ◽  
Jonathan Krakoff ◽  
...  
Keyword(s):  
Physical Activity ◽  
Nervous System ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Sympathetic Nervous System ◽  
Metabolic Rate ◽  
Sympathetic Nervous System Activity ◽  
System Activity ◽  
Nervous System Activity ◽  
Sympathetic Nervous

Abstract Background Interindividual variability in 24-hour energy expenditure (24EE) during energy-balance conditions is mainly determined by differences in body composition and demographic factors. Previous studies suggested that 24EE might also be influenced by sympathetic nervous system activity via catecholamine (norepinephrine, epinephrine) secretion. Therefore, we analyzed the association between catecholamines and energy expenditure in 202 individuals from a heterogeneous population of mixed ethnicities. Methods Participants (n = 202, 33% female, 14% black, 32% white, 41% Native American, 11% Hispanic, age: 36.9 ± 10.3 y [mean ± SD], percentage body fat: 30.3 ± 9.4) resided in a whole-room calorimeter over 24 hours during carefully controlled energy-balance conditions to measure 24EE and its components: sleeping metabolic rate (SMR), awake-fed thermogenesis (AFT), and spontaneous physical activity (SPA). Urine samples were collected, and 24-h urinary epinephrine and norepinephrine excretion rates were assessed by high-performance liquid chromatography. Results Both catecholamines were associated with 24EE and SMR (norepinephrine: +27 and +19 kcal/d per 10 μg/24h; epinephrine: +18 and +10 kcal/d per 1 μg/24h) in separate analyses after adjustment for age, sex, ethnicity, fat mass, fat-free mass, calorimeter room, temperature, and physical activity. In a multivariate model including both norepinephrine and epinephrine, only norepinephrine was independently associated with both 24EE and SMR (both P < .008), whereas epinephrine became insignificant. Neither epinephrine nor norepinephrine were associated with adjusted AFT (both P = .37) but epinephrine was associated with adjusted SPA (+0.5% per 1 μg/24h). Conclusions Our data provide compelling evidence that sympathetic nervous system activity, mediated via norepinephrine, is a determinant of human energy expenditure during nonstressed, eucaloric conditions.

Ethnic differences in sympathetic nervous system-mediated energy expenditure

1991 ◽  
Vol 261 (6) ◽  
pp. E789-E794 ◽  
Author(s):  
M. F. Saad ◽  
S. A. Alger ◽  
F. Zurlo ◽  
J. B. Young ◽  
C. Bogardus ◽  
...  
Keyword(s):  
Nervous System ◽  
Energy Expenditure ◽  
Sympathetic Nervous System ◽  
Fat Mass ◽  
Weight Maintenance ◽  
Resting Metabolic Rate ◽  
Fat Free Mass ◽  
Beta Adrenoceptor ◽  
Sympathetic Nervous ◽  
The Impact

The impact of sympathetic nervous system (SNS) activity on energy expenditure (EE) was evaluated in nondiabetic Caucasian and Pima Indian men while on a weight-maintenance diet using two approaches as follows. 1) The relationship between 24-h EE, measured in a respiratory chamber, and 24-h urinary norepinephrine was studied in 36 Caucasians [32 +/- 8 (SD) yr, 95 +/- 41 kg, 22 +/- 13% fat] and 33 Pimas (29 +/- 6 yr, 103 +/- 28 kg, 30 +/- 9% fat). There was no difference between the two groups in 24-h EE (2,422 vs. 2,523 kcal/24 h) and in urinary norepinephrine (28 vs. 31 micrograms/24 h), even after adjusting for body size and composition. Twenty-four-hour EE correlated significantly with 24-h urinary norepinephrine in Caucasians (r = 0.78, P less than 0.001) but not in Pimas (r = 0.03), independent of fat-free mass (FFM), fat mass, and age. 2) The effect of beta-adrenoceptor blockade with propranolol (120 micrograms/kg FFM bolus and 1.2 micrograms.kg FFM-1.min-1 for 45 min) on the resting metabolic rate (RMR) was evaluated in 36 Caucasians (30 +/- 6 yr, 103 +/- 36 kg, 25 +/- 11% fat) and 32 Pimas (28 +/- 6 yr, 100 +/- 34 kg, 27 +/- 10% fat). The RMR was similar in the two groups (2,052 vs. 1,973 kcal/24 h) even after adjustment for FFM, fat mass, and age and dropped significantly after propranolol infusion in Caucasians (-3.9%, P less than 0.001) but not in Pimas (-0.8%, P = 0.07).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Tonic Sympathetic Support of Metabolic Rate Is Attenuated with Age, Sedentary Lifestyle, and Female Sex in Healthy Adults

2001 ◽  
Vol 86 (9) ◽  
pp. 4440-4444 ◽  
Author(s):  
Christopher Bell ◽  
Douglas R. Seals ◽  
Mary Beth Monroe ◽  
Danielle S. Day ◽  
Linda F. Shapiro ◽  
...  
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Metabolic Rate ◽  
Endurance Exercise ◽  
Adrenergic Receptor ◽  
Resting Metabolic Rate ◽  
Saline Control ◽  
Receptor Antagonism ◽  
Adult Humans ◽  
Sympathetic Nervous

We recently demonstrated in young adult humans that the sympathetic nervous system contributes to the control of resting metabolic rate via tonic β-adrenergic receptor stimulation. In the present follow-up study we determined the respective effects of age, habitual exercise status, and sex on this regulatory mechanism. Resting metabolic rate (ventilated hood, indirect calorimetry) was determined in 55 healthy sedentary or endurance exercise-trained adults, aged 18–35 or 60–75 yr (29 men and 26 women), before (baseline) and during the infusion of either a nonselective β-adrenergic receptor antagonist (propranolol) or saline (control). Relative to baseline values, during β-adrenergic receptor antagonism resting metabolic rate adjusted for fat-free mass was reduced to a lesser extent in older (mean ± se,− 130 ± 46 kJ/d) compared with young (−297 ± 46) adults, sedentary (−151 ± 50) compared with endurance exercise-trained (−268 ± 46) adults, and women (−105 ± 33) compared with men (−318 ± 50; all P < 0.01). Reductions in resting metabolic rate during β-adrenergic receptor antagonism were positively related to higher baseline resting metabolic rate and plasma catecholamine concentrations and negatively related to adiposity (all P < 0.05). Resting metabolic rate was unchanged in response to saline control in all groups. These results provide experimental support for the hypothesis that aging, sedentary living, and female sex are associated with attenuated sympathetic nervous system support of resting metabolic rate in healthy adult humans.

scholarly journals Estimating energy requirements: regression based prediction equations or multiples of resting metabolic rate

2005 ◽  
Vol 8 (7a) ◽  
pp. 1184-1186 ◽  
Author(s):  
Michael I Goran
Keyword(s):  
Physical Activity ◽  
Body Weight ◽  
Energy Expenditure ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Total Energy Expenditure ◽  
Energy Requirements ◽  
Activity Levels ◽  
Doubly Labelled Water ◽  
Alternative Approaches

AbstractEnergy requirements have traditionally been determined based on multiples of resting metabolic rate (RMR), known as Physical Activity Levels (PAL). With more data from doubly labelled water studies alternative approaches for estimating energy requirements have been suggested. Statistical analysis reveals that body weight explains more of the variance in total energy expenditure (TEE) than does RMR. The explanation for this phenomenon is that body weight contributes to the variance of both RMR and the other major determinant of TEE, i.e. physical activity related energy expenditure. Thus, in effect, the regression-based approach provides a more physiological appropriate model for TEE. Its major departure from tradition, difference from current adult proposals, and time taken for acceptance are the disadvantages of the regression-based approach.

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