Orexin A (hypocretin 1) injected into hypothalamic paraventricular nucleus and spontaneous physical activity in rats

2004 ◽  
Vol 286 (4) ◽  
pp. E551-E559 ◽  
Author(s):  
Kohji Kiwaki ◽  
Catherine M. Kotz ◽  
Chuanfeng Wang ◽  
Lorraine Lanningham-Foster ◽  
James A. Levine
Keyword(s):  
Physical Activity ◽  
Energy Balance ◽  
Paraventricular Nucleus ◽  
Night Vision ◽  
Hypothalamic Paraventricular Nucleus ◽  
Positive Energy ◽  
Orexin A ◽  
Positive Energy Balance ◽  
Activity Sensors ◽  
Spontaneous Physical Activity

In humans, nonexercise activity thermogenesis (NEAT) increases with positive energy balance. The mediator of the interaction between positive energy balance and physical activity is unknown. In this study, we address the hypothesis that orexin A acts in the hypothalamic paraventricular nucleus (PVN) to increase nonfeeding-associated physical activity. PVN-cannulated rats were injected with either orexin A or vehicle during the light and dark cycle. Spontaneous physical activity (SPA) was measured using arrays of infrared activity sensors and night vision videotaped recording (VTR). O2 consumption and CO2 production were measured by indirect calorimetry. Feeding behavior was assessed by VTR. Regardless of the time point of injection, orexin A (1 nmol) was associated with dramatic increases in SPA for 2 h after injection (orexin A: 6.27 ± 1.95 × 103 beam break count, n = 24; vehicle: 1.85 ± 1.13 × 103, n = 38). This increase in SPA was accompanied by compatible increase in O2 consumption. Duration of feeding was increased only when orexin A was injected in the early light phase and accounted for only 3.5 ± 2.5% of the increased physical activity. In a dose-response experiment, increases in SPA were correlated with dose of orexin A linearly up to 2 nmol. PVN injections of orexin receptor antagonist SB-334867 were associated with decreases in SPA and attenuated the effects of PVN-injected orexin A. Thus orexin A can act in PVN to increase nonfeeding-associated physical activity, suggesting that this neuropeptide might be a mediator of NEAT.

Effects of increased energy intake and/or physical activity on energy expenditure in young healthy men

1994 ◽  
Vol 77 (1) ◽  
pp. 366-372 ◽  
Author(s):  
M. I. Goran ◽  
J. Calles-Escandon ◽  
E. T. Poehlman ◽  
M. O'Connell ◽  
E. Danforth
Keyword(s):  
Physical Activity ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Energy Flux ◽  
High Energy ◽  
Negative Energy ◽  
Low Energy ◽  
Positive Energy ◽  
Treatment Groups ◽  
Positive Energy Balance

This study was designed to examine effects of alterations in energy balance on adaptive changes in components of total energy expenditure (TEE). Nineteen young healthy males were studied during a 10-day sedentary energy balance baseline period and then randomly assigned to one of four 10-day treatment groups: 1) no change in energy intake (EI) or physical activity (PA; energy balance at low energy flux), 2) EI increased by 50% with no change in PA (positive energy balance), 3) TEE increased by 50% by increasing PA, matched by a 50% increase in EI (energy balance at high energy flux), and 4) TEE increased by 50% by increasing PA with no change in EI (negative energy balance). TEE was measured with doubly labeled water, resting metabolic rate (RMR) by indirect calorimetry, and thermic response to feeding (TEF) by indirect calorimetry; energy expenditure of physical activity (EEPA) was estimated by subtracting RMR, TEF, and prescribed PA from TEE. TEE was significantly increased by PA (by design) but not EI. There was a significant main effect of intake and a significant intake-by-activity interaction for changes in RMR. In post hoc analysis, RMR was significantly increased during positive energy balance and energy balance at high energy flux relative to change in RMR when energy balance was maintained at low energy flux. A significant increase in RMR was also noted during negative energy balance after adjustment for change in fat-free mass. There was no significant difference in change in RMR among the three treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Metabolic Impacts of Confinement during the COVID-19 Pandemic Due to Modified Diet and Physical Activity Habits

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1549 ◽  
Author(s):  
María Martinez-Ferran ◽  
Fernando de la Guía-Galipienso ◽  
Fabián Sanchis-Gomar ◽  
Helios Pareja-Galeano
Keyword(s):  
Physical Activity ◽  
Energy Balance ◽  
Eating Habits ◽  
Calorie Intake ◽  
Positive Energy ◽  
Short Period ◽  
Daily Step Count ◽  
Potential Risk Factors ◽  
Reduced Physical Activity ◽  
Positive Energy Balance

While the detrimental effects of a chronic positive energy balance due to a sedentary lifestyle have been well established, the impacts of a short period of abruptly reduced physical activity and overeating arising from strict confinement due to the COVID-19 pandemic will soon start to emerge. To reasonably anticipate major consequences according to the available evidence, we hereby review the literature for studies that have explored the health impacts of several weeks of a reduction in physical activity and daily step-count combined with modified eating habits. These studies identify as main metabolic consequences increases in insulin resistance, total body fat, abdominal fat and inflammatory cytokines. All these factors have been strongly associated with the development of metabolic syndrome, which in turn increases the risk of multiple chronic diseases. A plausible mechanism involved in these impacts could be a positive energy balance promoted by maintaining usual dietary intake while reducing energy expenditure. This means that just as calorie intake restriction could help mitigate the deleterious impacts of a bout of physical inactivity, overeating under conditions of home confinement is very likely to exacerbate these consequences. Moreover, hypertension, diabetes, and cardiovascular disease have been identified as potential risk factors for more severely ill patients with COVID-19. Thus, adequate control of metabolic disorders could be important to reduce the risk of severe COVID-19.

Neural site of leptin influence on neuropeptide Y signaling pathways altering feeding and uncoupling protein

1998 ◽  
Vol 275 (2) ◽  
pp. R478-R484 ◽  
Author(s):  
Catherine M. Kotz ◽  
Jacqueline E. Briggs ◽  
James D. Pomonis ◽  
Martha K. Grace ◽  
Allen S. Levine ◽  
...  
Keyword(s):  
Gene Expression ◽  
Energy Balance ◽  
Neuropeptide Y ◽  
Paraventricular Nucleus ◽  
Arcuate Nucleus ◽  
Uncoupling Protein ◽  
Positive Energy ◽  
Potential Mechanism ◽  
Regulatory Pathway ◽  
Positive Energy Balance

Inhibition of a signal that produces positive energy balance involving neuropeptide Y (NPY) projection from arcuate nucleus (Arc; site of NPY synthesis) to paraventricular nucleus (PVN; site of NPY release) is one potential mechanism of leptin action. NPY in the PVN increases feeding and decreases uncoupling protein (UCP) activity in brown fat, whereas leptin decreases NPY biosynthesis in the Arc, which presumably decreases PVN NPY. It is hypothesized that decreased NPY activity is necessary for the satiety and thermogenic effects of leptin. To test this, we first determined the effect of leptin on feeding in two paradigms: satiated rats and food-deprived rats. Leptin was effective in decreasing feeding in the satiated rats but ineffective in the food-deprived rats. Next, we determined that leptin decreases NPY and increases UCP gene expression. Finally, we injected leptin intracerebroventricularly before specific PVN NPY microinjection. We found that repletion of NPY in PVN by specific NPY microinjection reverses the feeding-inhibitory and thermogenic effects of centrally administered leptin, the first functional evidence indicating that leptin acts on the Arc-PVN feeding-regulatory pathway.

scholarly journals Lifestyle Risk Factors and Management of Obesity: A Mini Review

2020 ◽  
pp. 1-6
Author(s):  
Ioannis Patrikios ◽  
Alice Antenucci ◽  
Eleni Anastasilaki ◽  
Giulia Antenucci ◽  
Ioannis Patrikios ◽  
...  
Keyword(s):  
Physical Activity ◽  
Weight Loss ◽  
Energy Balance ◽  
Treatment Strategies ◽  
Food Prices ◽  
Lifestyle Changes ◽  
Calorie Intake ◽  
Positive Energy ◽  
Vigorous Exercise ◽  
Positive Energy Balance

Obesity is one of the most serious public health problems of the 21st century. The most common method used to define obesity is the BMI (weight/height squared in meters). If a person’s BMI is 30 or above is considered to be obese. In this review we focus on the different factors that cause obesity and on the different available treatment strategies. The mechanism behind weight gain is based on the energy intake of an individual. Positive energy balance leads to gain weight. With rapid economic growth, urbanization and westernization traditional diets high in fibres were replaced by diets high in sugar and fats which are high in energy and lead to a positive energy balance and therefore gain weight. Also, energy high food prices have declined leading to increased consumption of the latter. Fast foods which sell low quality/ energy high foods for a convenient price are an example of this phenomenon. Daily choices also influence the prevalence of obesity. For instance, eating out often can expose individuals to larger portions eventually leading to the phenomenon of portion distortion. Physical activity affects the energy balance of an individual along with dietary choices. Increase in physical activity, as shown in different studies, promotes weight loss. Combining low-fat diet with either vigorous exercise or simple lifestyle activity has been proven to be the best modality for weight loss. There are three main management strategies that can be followed in order to lose weight: lifestyle changes, pharmacotherapy and surgery. The primary approach to treat obesity is weight loss through diet and exercise, supported also by behavioural therapy. The aim of the diet should be lowering the calorie intake. People should first of all inform themselves about the different macronutrients normal intake levels and consult an expert. If no adequate weight loss is achieved by lifestyle changes, medications like Orlistat may be taken. If medications and lifestyle changes aren’t successful, surgery may be considered as an option to lose weight.

scholarly journals The effect of breakfast on appetite regulation, energy balance and exercise performance

2015 ◽  
Vol 75 (3) ◽  
pp. 319-327 ◽  
Author(s):  
David J. Clayton ◽  
Lewis J. James
Keyword(s):  
Energy Balance ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Exercise Performance ◽  
Intervention Studies ◽  
Precise Determination ◽  
Positive Energy ◽  
Cross Sectional ◽  
Positive Energy Balance ◽  
The Impact

The belief that breakfast is the most important meal of day has been derived from cross-sectional studies that have associated breakfast consumption with a lower BMI. This suggests that breakfast omission either leads to an increase in energy intake or a reduction in energy expenditure over the remainder of the day, resulting in a state of positive energy balance. However, observational studies do not imply causality. A number of intervention studies have been conducted, enabling more precise determination of breakfast manipulation on indices of energy balance. This review will examine the results from these studies in adults, attempting to identify causal links between breakfast and energy balance, as well as determining whether consumption of breakfast influences exercise performance. Despite the associations in the literature, intervention studies have generally found a reduction in total daily energy intake when breakfast is omitted from the daily meal pattern. Moreover, whilst consumption of breakfast supresses appetite during the morning, this effect appears to be transient as the first meal consumed after breakfast seems to offset appetite to a similar extent, independent of breakfast. Whether breakfast affects energy expenditure is less clear. Whilst breakfast does not seem to affect basal metabolism, breakfast omission may reduce free-living physical activity and endurance exercise performance throughout the day. In conclusion, the available research suggests breakfast omission may influence energy expenditure more strongly than energy intake. Longer term intervention studies are required to confirm this relationship, and determine the impact of these variables on weight management.

Weight Dysregulation, Positive Energy Balance, and Binge Eating in Eating Disorders

Binge Eating ◽  
2020 ◽  
pp. 59-67 ◽  
Author(s):  
Michael R. Lowe ◽  
Leora L. Haller ◽  
Simar Singh ◽  
Joanna Y. Chen
Keyword(s):  
Eating Disorders ◽  
Energy Balance ◽  
Binge Eating ◽  
Positive Energy ◽  
Positive Energy Balance

Effect of protein intake and physical activity on 24-h pattern and rate of macronutrient utilization

1999 ◽  
Vol 276 (5) ◽  
pp. E964-E976 ◽  
Author(s):  
Anders H. Forslund ◽  
Antoine E. El-Khoury ◽  
Roger M. Olsson ◽  
Anders M. Sjödin ◽  
Leif Hambraeus ◽  
...  
Keyword(s):  
Physical Activity ◽  
G Protein ◽  
Protein Intake ◽  
Healthy Adult ◽  
High Protein Diet ◽  
Positive Energy ◽  
Moderate Physical Activity ◽  
Adult Men ◽  
Urea Production ◽  
Positive Energy Balance

Effects of moderate physical activity (90 min at 45–50% of maximal O2 uptake 2 times daily) and “high” (2.5 g protein ⋅ kg−1 ⋅ day−1, n = 6) or “normal” protein intake (1.0 g protein ⋅ kg−1 ⋅ day−1, n = 8) on the pattern and rate of 24-h macronutrient utilization in healthy adult men were compared after a diet-exercise-adjustment period of 6 days. Energy turnover (ET) was determined by indirect and direct (suit) calorimetry, and “protein oxidation” was determined by a 24-h continuous intravenous infusion of [1-13C]leucine. Subjects were in slight positive energy balance during both studies. Protein contributed to a higher (22 vs. 10%) and carbohydrate (CHO) a lower (33 vs. 58%) proportion of total 24-h ET on the high- vs. normal-protein intake. The highest contribution of fat to ET was seen postexercise during fasting (73 and 61% of ET for high and normal, respectively). With the high-protein diet the subjects were in a positive protein ( P < 0.001) and CHO balance ( P < 0.05) and a negative fat balance ( P < 0.05). The increased ET postexercise was not explained by increased rates of urea production and/or protein synthesis.

scholarly journals Murine neuronatin deficiency is associated with a hypervariable food intake and bimodal obesity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Irene Cimino ◽  
Debra Rimmington ◽  
Y. C. Loraine Tung ◽  
Katherine Lawler ◽  
Pierre Larraufie ◽  
...  
Keyword(s):  
Body Weight ◽  
Energy Balance ◽  
Food Intake ◽  
Energy Expenditure ◽  
Positive Energy ◽  
Chow Diet ◽  
Chromatin Regulator ◽  
Positive Energy Balance ◽  
The Impact ◽  
Deficient Mice

AbstractNeuronatin (Nnat) has previously been reported to be part of a network of imprinted genes downstream of the chromatin regulator Trim28. Disruption of Trim28 or of members of this network, including neuronatin, results in an unusual phenotype of a bimodal body weight. To better characterise this variability, we examined the key contributors to energy balance in Nnat+/−p mice that carry a paternal null allele and do not express Nnat. Consistent with our previous studies, Nnat deficient mice on chow diet displayed a bimodal body weight phenotype with more than 30% of Nnat+/−p mice developing obesity. In response to both a 45% high fat diet and exposure to thermoneutrality (30 °C) Nnat deficient mice maintained the hypervariable body weight phenotype. Within a calorimetry system, food intake in Nnat+/−p mice was hypervariable, with some mice consuming more than twice the intake seen in wild type littermates. A hyperphagic response was also seen in Nnat+/−p mice in a second, non-home cage environment. An expected correlation between body weight and energy expenditure was seen, but corrections for the effects of positive energy balance and body weight greatly diminished the effect of neuronatin deficiency on energy expenditure. Male and female Nnat+/−p mice displayed subtle distinctions in the degree of variance body weight phenotype and food intake and further sexual dimorphism was reflected in different patterns of hypothalamic gene expression in Nnat+/−p mice. Loss of the imprinted gene Nnat is associated with a highly variable food intake, with the impact of this phenotype varying between genetically identical individuals.

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