The lighter side of BDNF

Brain-derived neurotrophic factor (BDNF) mediates energy metabolism and feeding behavior. As a neurotrophin, BDNF promotes neuronal differentiation, survival during early development, adult neurogenesis, and neural plasticity; thus, there is the potential that BDNF could modify circuits important to eating behavior and energy expenditure. The possibility that “faulty” circuits could be remodeled by BDNF is an exciting concept for new therapies for obesity and eating disorders. In the hypothalamus, BDNF and its receptor, tropomyosin-related kinase B (TrkB), are extensively expressed in areas associated with feeding and metabolism. Hypothalamic BDNF and TrkB appear to inhibit food intake and increase energy expenditure, leading to negative energy balance. In the hippocampus, the involvement of BDNF in neural plasticity and neurogenesis is important to learning and memory, but less is known about how BDNF participates in energy homeostasis. We review current research about BDNF in specific brain locations related to energy balance, environmental, and behavioral influences on BDNF expression and the possibility that BDNF may influence energy homeostasis via its role in neurogenesis and neural plasticity.

Download Full-text

Synergistic Control of KNDy Neuronal Influence on Energy Balance by Ghrelin and Estradiol

Journal of the Endocrine Society ◽

10.1210/jendso/bvab048.1130 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. A554-A555

Author(s):

Kristie M Conde ◽

Danielle Kulyk ◽

Troy Adam Roepke

Keyword(s):

Energy Balance ◽

Food Intake ◽

Energy Expenditure ◽

Energy Homeostasis ◽

Body Weight Gain ◽

Negative Energy ◽

Growth Hormone Secretagogue Receptor ◽

Growth Hormone Secretagogue ◽

Meal Pattern ◽

Kndy Neurons

Abstract The gut peptide, ghrelin, mediates negative energy homeostasis and the neuroendocrine control of energy homeostasis by acting through its receptor, growth hormone secretagogue receptor (GHSR). GHSR, expressed in hypothalamic Kisspeptin/Neurokinin B/Dynorphin (KNDy) neurons in the arcuate (ARC), is well known to regulate energy balance. We have previously shown 17-beta-estradiol (E2) robustly increases Ghsr expression in KNDy neurons, enhancing their sensitivity to ghrelin. We hypothesize that E2-induced increase in GHSR expression augments KNDy sensitivity in a fasting state by elevating ghrelin to reduce energy expenditure in females. We developed a Kiss1-specific GHSR knockout to determine the role of GHSR in ARC KNDy neurons and fed them either a low-fat diet (LFD) or a high-fat diet (HFD). Knockout (experimental) females were resistant to HFD in terms of body weight gain, adiposity, and food intake compared to HFD-fed controls. HFD-fed experimental females also exhibited slower glucose clearance compared to HFD-fed controls. Experimental females, regardless of diet, exhibited elevated fasting (5h) glucose. Metabolic rates (V.O2, V.CO2) and energy expenditure (heat) were not different. Respiratory Exchange Ratio (RER) was elevated in LFD-fed females, indicating the utilization of carbohydrates over fat for energy. Further meal pattern analysis revealed a reduction in meal duration in HFD-fed females, but elevated meal frequency, while HFD-fed experimental females exhibited a reduced meal size. In two separate meal pattern experiments, experimental and control females were fasted for 24h and refed or injected with ghrelin (I.P. 1mg/kg) or saline. We observed a striking delay in refeeding behavior in experimental females compared to controls during the refeeding period after fasting. After injection, control females responded to ghrelin with a rapid and sustained increase in food intake which was blunted in experimentals. Collectively, these data suggest that GHSR activation in KNDy neurons modulates metabolism, glucose homeostasis, and feeding behavior, illustrating a novel mechanism for E2 and ghrelin to synergistically control KNDy neuronal output and their subsequent behavioral and physiological outcomes.

Download Full-text

Energy Balance and Energy Availability During a Selection Course for Belgian Paratroopers

Military Medicine ◽

10.1093/milmed/usab140 ◽

2021 ◽

Author(s):

Patrick Mullie ◽

Pieter Maes ◽

Laurens van Veelen ◽

Damien Van Tiggelen ◽

Peter Clarys

Keyword(s):

Physical Activity ◽

Energy Balance ◽

Energy Expenditure ◽

Metabolic Rate ◽

Energy Intake ◽

Rest Metabolic Rate ◽

Negative Energy ◽

Fat Free Mass ◽

Negative Energy Balance ◽

Energy Availability

ABSTRACT Introduction Adequate energy supply is a prerequisite for optimal performances and recovery. The aims of the present study were to estimate energy balance and energy availability during a selection course for Belgian paratroopers. Methods Energy expenditure by physical activity was measured with accelerometer (ActiGraph GT3X+, ActiGraph LLC, Pensacola, FL, USA) and rest metabolic rate in Cal.d−1 with Tinsley et al.’s equation based on fat-free mass = 25.9 × fat-free mass in kg + 284. Participants had only access to the French individual combat rations of 3,600 Cal.d−1, and body fat mass was measured with quadripolar impedance (Omron BF508, Omron, Osaka, Japan). Energy availability was calculated by the formula: ([energy intake in foods and beverages] − [energy expenditure physical activity])/kg FFM−1.d−1, with FFM = fat-free mass. Results Mean (SD) age of the 35 participants was 25.1 (4.18) years, and mean (SD) percentage fat mass was 12.0% (3.82). Mean (SD) total energy expenditure, i.e., the sum of rest metabolic rate, dietary-induced thermogenesis, and physical activity, was 5,262 Cal.d−1 (621.2), with percentile 25 at 4,791 Cal.d−1 and percentile 75 at 5,647 Cal.d−1, a difference of 856 Cal.d−1. Mean daily energy intake was 3,600 Cal.d−1, giving a negative energy balance of 1,662 (621.2) Cal.d−1. Mean energy availability was 9.3 Cal.kg FFM−1.d−1. Eleven of the 35 participants performed with a negative energy balance of 2,000 Cal.d−1, and only five participants out of 35 participants performed at a less than 1,000 Cal.d−1 negative energy balance level. Conclusions Energy intake is not optimal as indicated by the negative energy balance and the low energy availability, which means that the participants to this selection course had to perform in suboptimal conditions.

Download Full-text

Glycogenic induction of thyroid hormone conversion and leptin system activation in the liver of postpartum dairy cows

Acta Veterinaria Hungarica ◽

10.1556/avet.57.2009.1.14 ◽

2009 ◽

Vol 57 (1) ◽

pp. 139-146

Author(s):

Andrea Győrffy ◽

Mónika Keresztes ◽

Vera Faigl ◽

Vilmos Frenyó ◽

Margit Kulcsár ◽

...

Keyword(s):

Thyroid Hormone ◽

Energy Balance ◽

Dairy Cows ◽

Energy Homeostasis ◽

Leptin Receptor ◽

Energy Content ◽

Short Form ◽

Negative Energy ◽

Type I ◽

Leptin System

In the regulation of energy metabolism, the liver plays an important role in the reinforcement of energy production. In periparturient cows the energy homeostasis turns into a negative energy balance that may shift the physiological regulation of energy balance towards pathological processes. Propylene glycol (PG), as a complementary source of energy used in the nutrition of dairy cows, alters systemic thyroid hormone economy; however, the exact mechanism through which highly glycogenic feed supplements impact liver metabolism is little known. Previous studies showed that only leptin receptors are expressed in the liver of cows, and now we report that leptin mRNA is expressed in the liver of cows as well. The present results show that the mRNA of leptin and its receptors are differentially modulated by the increased energy content of the feed consumed. Simultaneous changes in hepatic type I deiodinase activity suggest that hepatic modulation of the leptin system by PG supplementation may be mediated by an increased local thyroxine-triiodothyronine conversion. Since PG supplementation with simultaneous T4–T3 turnover and increased hepatic leptin- and short-form leptin receptor mRNA were not associated with a significant change in hepatic total lipid levels, it is suggested that the leptin system, directly or indirectly modulated by thyroid hormones, may represent a local defence mechanism to prevent fatty liver formation.

Download Full-text

Nutritional demands in acute and chronic illness

Proceedings of The Nutrition Society ◽

10.1079/pns2003302 ◽

2003 ◽

Vol 62 (4) ◽

pp. 777-781 ◽

Cited By ~ 21

Author(s):

Rosemary A. Richardson ◽

H. Isobel M. Davidson

Keyword(s):

Energy Expenditure ◽

Inflammatory Response ◽

Energy Homeostasis ◽

Negative Energy ◽

Disease States ◽

Energy Needs ◽

Sufficient Energy ◽

Effective Treatment Modality ◽

The Individual

Common to both acute and chronic disease are disturbances in energy homeostasis, which are evidenced by quantitative and qualitative changes in dietary intake and increased energy expenditure. Negative energy balance results in loss of fat and lean tissue. The management of patients with metabolically-active disease appears to be simple; it would involve the provision of sufficient energy to promote tissue accretion. However, two fundamental issues serve to prevent nutritional demands in disease being met. The determination of appropriate energy requirements relies on predictive formulae. While equations have been developed for critically-ill populations, accurate energy prescribing in the acute setting is uncommon. Only 25–32% of the patients have energy intakes within 10% of their requirements. Clearly, the variation in energy expenditure has led to difficulties in accurately defining the energy needs of the individual. Second, the acute inflammatory response initiated by the host can have profound effects on ingestive behaviour, but this area is poorly understood by practising clinicians. For example, nutritional targets have been set for specific disease states, i.e. pancreatitis 105–147 KJ (25–35 kcal)/kg; chronic liver disease 147–168 kj (35–40 kcl)/kg, but given the alterations in gut physiology that accompany the acute-phase response, targets are unlikely to be met. In cancer cachexia attenuation of the inflammatory response using eicosapentaenoic acid results in improved nutritional intake and status. This strategy poses an attractive proposition in the quest to define nutritional support as a clinically-effective treatment modality in other disorders.

Download Full-text

Gqα/G11α deficiency in dorsomedial hypothalamus leads to obesity resulting from decreased energy expenditure and impaired sympathetic nerve activity

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00059.2020 ◽

2020 ◽

Author(s):

Eric A. Wilson ◽

Hui Sun ◽

Zhenzhong Cui ◽

Marshal T. Jahnke ◽

Mritunjay Pandey ◽

...

Keyword(s):

Gene Expression ◽

Adipose Tissue ◽

Food Intake ◽

Energy Expenditure ◽

Energy Homeostasis ◽

Dorsomedial Hypothalamus ◽

Ambient Temperatures ◽

Brown Adipose ◽

Inhibit Food Intake ◽

Specific Deletion

The G protein subunits Gqα and G11α (Gq/11α) couple receptors to phospholipase C, leading to increased intracellular calcium. In this study we investigated the consequences of Gq/11α deficiency in the dorsomedial hypothalamus (DMH), a critical site for the control of energy homeostasis. Mice with DMH-specific deletion of Gq/11α (DMHGq/11KO) were generated by stereotaxic injection of AAV-Cre-GFP into the DMH of Gqαflox/flox:G11α-/- mice. Compared to control mice that received DMH injection of AAV-GFP, DMHGq/11KO mice developed obesity associated with reduced energy expenditure without significant changes in food intake or physical activity. DMHGq/11KO mice showed no defects in the ability of the melanocortin agonist melanotan II to acutely stimulate energy expenditure or to inhibit food intake. At room temperature (22oC) DMHGq/11KO mice showed reduced sympathetic nervous system activity in brown adipose tissue (BAT) and heart, accompanied with decreased basal BAT Ucp1 gene expression and lower heart rates. These mice were cold intolerant when acutely exposed to cold (6oC for 5 hours) and had decreased cold-stimulated BAT Ucp1 gene expression. DMHGq/11KO mice also failed to adapt to gradually declining ambient temperatures and to develop adipocyte browning in inguinal white adipose tissue although their BAT Ucp1 was proportionally stimulated. Consistent with impaired cold-induced thermogenesis, the onset of obesity in DMHGq/11KO mice was significantly delayed when housed under thermoneutral conditions (30ºC). Thus, our results show that Gqα and G11α in the DMH are required for the control of energy homeostasis by stimulating energy expenditure and thermoregulation.

Download Full-text

Disturbance of the reproductive axis induced by negative energy balance

Reproduction Fertility and Development ◽

10.1071/r98024 ◽

1998 ◽

Vol 10 (1) ◽

pp. 65 ◽

Cited By ~ 20

Author(s):

Stephen J. Judd

Keyword(s):

Energy Balance ◽

Energy Expenditure ◽

Tertiary Structure ◽

Interleukin 2 ◽

Growth Hormone Secretion ◽

Negative Energy ◽

Negative Energy Balance ◽

Thyrotrophin Releasing Hormone ◽

Releasing Hormone ◽

Crf Neurons

Animal reproduction is impaired when intake of energy is so restricted that activities essential to life are threatened; this is seen as a homeostatic adjustment that restricts wasteful energy expenditure. Fasting or exercising to a degree requiring considerable energy expenditure has major effects on the hypothalamus, including activation of corticotrophin-releasing factor (CRF) neurons, suppression of thyrotrophin-releasing hormone synthesis, and increased growth hormone secretion; these are associated with increased concentrations of hypothalamic neuropeptide Y mRNA and are corrected by administration of leptin, an adipose-tissue protein with a tertiary structure similar to the cytokine interleukin-2. This response to fasting results from a disordered pattern of activity in the gonadotrophin-releasing hormone (GnRH) pacemaker, characterized by reduced luteinizing hormone pulsatility, particularly during daytime. Animal studies have suggested that the response depends on an intact afferent vagal system from the stomach and the presence of oestrogen. Noradrenergic neurons forming the A2 group increase the activity of CRF neurons that, in turn, inhibit GnRH pulsatility. Reproductive impairment due to fasting is reversed by leptin, and abnormalities of leptin are described in individuals who fast or who develop exercise-induced amenorrhoea. This paper discusses these changes induced by negative energy balance and speculates on the involvement of leptin as a contributor to these abnormalities.

Download Full-text

ENERGY BALANCE AND VITAL SIGNS IN PEDIATRIC PATIENTS

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120s00206 ◽

2020 ◽

Vol 8 (4_suppl3) ◽

pp. 2325967120S0020

Author(s):

Julie A. Young ◽

Jessica Napolitano ◽

Mitchell J. Rauh ◽

Jeanne Nichols ◽

Anastasia N. Fischer

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Energy Balance ◽

Energy Expenditure ◽

Vital Signs ◽

Negative Energy ◽

Negative Energy Balance ◽

Energy Deficit ◽

Energy Deficiency ◽

Males And Females

BACKGROUND: Prior studies have shown that vital signs such as heart rate, blood pressure and body temperature are depressed in patients with an eating disorder who have experienced a negative energy balance for a significant amount of time. More recently, a negative energy balance has been the focus of Relative Energy Deficiency in Sport (RED-S), which links energy availability to the health of multiple body systems in adults in as little as 5 days with a negative energy balance. High rates of disordered eating patterns have been reported in high school athletes. As adolescents grow, the consequences of a negative energy balance can be significant and potentially irreversible. Thus, vital signs may help clinicians quickly evaluate a patient’s energy status or highlight them for further evaluation. PURPOSE: The purpose of this study was to examine energy balance and vital signs in a cohort of adolescents who were seen by a sports dietitian to gain weight or optimize sports performance. METHODS: We evaluated 240 subjects, 83% female, average age 15.0±2.3 years. Heart rate and blood pressure were measured with a dynamometer in a seated position. Body temperature was measured orally. Height and weight were recorded. BMI was then calculated and evaluated by percentile. Energy intake was assessed using a 3-day food recall log. Energy expenditure was calculated using Harris Benedict Equation and combined with estimated exercise energy expenditure. Energy balance was estimated as energy intake minus energy expenditure. RESULTS: Average age was 15.03±2.71. 85% were female. 30% were below the 15th percentile for BMI. There were no differences in BMI percentiles between males and females (p=0.99). The average heart rate was 71.62±13.4 bpm and 19% were below the 10th percentile for heart rate. Average systolic blood pressure was 110±11 mm Hg and average diastolic blood pressure was 62±7 mmHg. Average temperature was 98.1±.4 degrees F. 88%were in a negative energy balance with an average energy deficit of 552±511 calories. There were no statistically significant differences in energy balance between males and females (p=0.08). CONCLUSIONS: A disproportional number of children with low BMI and heart rate percentiles was observed, which may indicate a long-standing energy deficiency. We also found a high proportion of adolescents who experienced a standalone negative energy balance itself or vital signs consistent with a negative energy balance. Additional studies are needed to study the relationships between energy deficit magnitude and duration in adolescents and children.

Download Full-text

Energy expenditure and nutrition status of ballet, jazz and contemporary dance students

Progress in Health Sciences ◽

10.5604/01.3001.0010.1771 ◽

2017 ◽

Vol 7 (1) ◽

pp. 31-38 ◽

Cited By ~ 1

Author(s):

D. Rossiou ◽

S. Papadopoulou ◽

I. Pagkalos ◽

A. Kokkinopoulou ◽

D. Petridis ◽

...

Keyword(s):

Physical Activity ◽

Energy Balance ◽

Energy Expenditure ◽

Negative Energy ◽

Nutrition Status ◽

Contemporary Dance ◽

Food Diary ◽

Daily Diaries ◽

Dance Class ◽

Daily Energy

Purpose: To evaluate of the energy expenditure in 3 types of dance classes (ballet, Jazz, and contemporary), as well as of the daily energy balance depending on dance type. Materials and methods: 40 females attending dance classes with a median age of 21.0 (19.0-25.0) and 10 males with a median age of 27.0 (20.0-28.0) participated in this study. The energy cost of each dance class was measured using the BodyMedia SenseWear Sensor and total daily energy expenditure was evaluated using a 3-day recording of physical activity. The dietary intake was evaluated with a 3-day food diary recording. Statistical analysis was performed using the SPSS software. Results: Median energy expenditure varied from 306 (277-328) Kcals/class for contemporary dance to 327 (290-355) Kcals/class for ballet and 369 (333-394) Kcals/class for jazz for females with significant differences between contemporary and jazz classes. For males, energy expenditure was 508 (447-589) Kcals/class and 564 (538-593) Kcals/class for ballet and jazz classes, respectively. Females had lower values for all anthropometric measurements, energy intake, macronutrient intakes, and energy expenditure, compared with males. The anthropometric characteristics did not differ between dance types. Both female and male dance students were in a negative energy balance. Conclusions: The use of sensors such as BodyMedia SenseWear together with keeping daily diaries make measurement of physical activity in dancing reliable and accurate. Exercise expenditure differs across types of dance in females but not in males. Both sexes had inadequate energy and carbohydrate intakes.

Download Full-text

Hipocalcemia e cetose - principais doenças metabólicas da vaca leiteira durante o período de transição - uma revisão de literatura

Revista Agraria Academica ◽

10.32406/v4n5/2021/130-141/agrariacad ◽

2021 ◽

Vol 4 (5) ◽

pp. 130-141

Author(s):

Mylena Garcia Proto ◽

◽

Milena Cristina Bernardo de Barros ◽

Bruna Stanigher Barbosa ◽

◽

...

Keyword(s):

Energy Balance ◽

Energy Expenditure ◽

Dairy Cows ◽

Dry Matter ◽

Transition Period ◽

Negative Energy ◽

Dry Matter Intake ◽

Economic Losses ◽

Balance State ◽

Production Demand

With the increased production demand in the dairy industry comes the need to keep animals healthier, thus avoiding large economic losses due to low productivity. During the transition period, dairy cows are susceptible to the onset of infectious diseases and metabolic imbalances due to the big change in their diet, it could be poor in needed nutrients to maintain the animal's body score, with this, the dry matter intake decreases up to 40% while energy expenditure increases due to milk and colostrum production, getting into a negative energy balance state.

Download Full-text