scholarly journals Non-Mammalian Vertebrates: Distinct Models to Assess the Role of Ion Gradients in Energy Expenditure

2017 ◽  
Vol 8 ◽  
Author(s):  
Caroline E. Geisler ◽  
Kyle P. Kentch ◽  
Benjamin J. Renquist
Keyword(s):  
Energy Expenditure ◽  
Ion Gradients

scholarly journals Effects of Growth Hormone on Leptin Metabolism and Energy Expenditure in Hemodialysis Patients with Protein-Calorie Malnutrition

2000 ◽  
Vol 11 (11) ◽  
pp. 2106-2113
Author(s):  
GIACOMO GARIBOTTO ◽  
ANTONINA BARRECA ◽  
ANTONELLA SOFIA ◽  
RODOLFO RUSSO ◽  
FULVIO FIORINI ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Energy Expenditure ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Resting Energy Expenditure ◽  
Hemodialysis Patients ◽  
Gh Treatment ◽  
Peripheral Tissues

Abstract. The relationships among growth hormone (GH), leptin, and resting energy expenditure (REE) are not understood. It has been reported that in malnourished hemodialysis patients, GH increases muscle protein synthesis, a process that requires energy. The present study evaluated the arterial levels and the forearm exchange of leptin, as well as the REE of the same patients during their participation in the same study, in four sequential 6-wk periods: I, baseline; II, GH treatment; III, washout; and IV, GH + intradialytic parenteral nutrition. During periods II and IV, patients received GH (5 mg three times per week). REE rose by 5% in period II, declined during period III, and rose by 7% during period IV. Basal leptin levels were low (2.0 ± 0.19 ng/L). Insulin and leptin levels, as well as leptin release from the forearm, were unchanged during periods I through III but rose (+ 36%; P < 0.05) during period IV. Changes in arterial leptin were directly related to changes in forearm leptin release (P < 0.002), indicating a role of leptin production by peripheral tissues on leptinemia. Changes in leptin release were directly related to insulin (P < 0.001) and, less consistently, to insulin-like growth factor-binding protein-1 levels (P < 0.02). Similarly, variations in leptin levels were directly related to insulin (P < 0.01). Variations in REE were not related to variations in leptin or insulin levels but to changes in muscle protein synthesis (P < 0.025). The data show that in malnourished hemodialysis patients, treatment with GH is not invariably associated with an increase in leptin production. An increase in leptin release by peripheral tissues and leptin levels occurs only in the setting of hyperinsulinemia. The increase in REE that is induced by treatment with GH is not dependent on changes in leptin but is largely accounted for by the energy cost of the stimulation of muscle protein synthesis.

scholarly journals Brown Fat Dnmt3b Deficiency Ameliorates Obesity in Female Mice

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1325
Author(s):  
Fenfen Li ◽  
Xin Cui ◽  
Jia Jing ◽  
Shirong Wang ◽  
Huidong Shi ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Energy Expenditure ◽  
Knockout Mice ◽  
Dna Methyltransferase ◽  
De Novo ◽  
Brown Fat ◽  
Chow Diet ◽  
Female Mice ◽  
Diet Induced Obesity

Obesity results from a chronic energy imbalance due to energy intake exceeding energy expenditure. Activation of brown fat thermogenesis has been shown to combat obesity. Epigenetic regulation, including DNA methylation, has emerged as a key regulator of brown fat thermogenic function. Here we aimed to study the role of Dnmt3b, a DNA methyltransferase involved in de novo DNA methylation, in the regulation of brown fat thermogenesis and obesity. We found that the specific deletion of Dnmt3b in brown fat promotes the thermogenic and mitochondrial program in brown fat, enhances energy expenditure, and decreases adiposity in female mice fed a regular chow diet. With a lean phenotype, the female knockout mice also exhibit increased insulin sensitivity. In addition, Dnmt3b deficiency in brown fat also prevents diet-induced obesity and insulin resistance in female mice. Interestingly, our RNA-seq analysis revealed an upregulation of the PI3K-Akt pathway in the brown fat of female Dnmt3b knockout mice. However, male Dnmt3b knockout mice have no change in their body weight, suggesting the existence of sexual dimorphism in the brown fat Dnmt3b knockout model. Our data demonstrate that Dnmt3b plays an important role in the regulation of brown fat function, energy metabolism and obesity in female mice.

scholarly journals Habitual meal frequency in relation to resting and activity-induced energy expenditure in human subjects: the role of fat-free mass

2003 ◽  
Vol 90 (3) ◽  
pp. 643-649 ◽  
Author(s):  
Margriet S. Westerterp-Plantenga ◽  
Annelies H. C. Goris ◽  
Erwin P. Meijer ◽  
Klaas R. Westerterp
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Human Subjects ◽  
Older Men ◽  
Activity Level ◽  
Fat Free Mass ◽  
Meal Frequency ◽  
Younger Women ◽  
Younger Men

Habitual meal frequency was assessed as a possible function of components of energy expenditure (EE) in human subjects. Fifty-six subjects participated (four categories differing in body composition): ten older women (fat-free mass (FFM) 42·0 (sd 6·3) kg, aged 59 (sd 2) years, BMI 27·5 (sd 6·9) kg/m2), fifteen younger women (FFM 45·5 (sd 5·2) kg, aged 34 (sd 10) years, BMI 21·9 (sd 2·3) kg/m2), twelve older men (FFM 56·8 (sd 5·9) kg, aged 62 (sd 4) years, BMI 25·7 (sd 3·3) kg/m2) and nineteen younger men (FFM 63·9 (sd 7·5) kg, aged 23·1 (sd 3·9) years, BMI 22·9 (sd 1·8) kg/m2). Measurements consisted of habitual meal frequency by validated food-intake diaries, physical activity by tri-axial accelerometers and resting EE by a ventilated hood system. Habitual meal frequency was expressed as a function of resting EE (including resting EE as a function of FFM), and of activity-induced EE, using regression analysis. FFM differed according to gender and age categories (P < 0·01). Physical activity level was higher in the younger men than in the other categories (P < 0·05). No relationship of meal frequency with the variables assessed was observed in subjects with a low FFM (the women). In the subjects with a medium FFM (the older men), meal frequency was positively related to resting EE (r2 0·4, P < 0·05), but not to the residuals of resting EE as a function of FFM, and inversely related to activity-induced EE (r2 0·3, P < 0·05). Resting EE explained 40% of the variation in meal frequency; adding activity-induced EE increased this to 60%. In the subjects with a high FFM (the younger men), meal frequency was inversely related to resting EE (r2 0·8, P < 0·0001) and to the residuals of resting EE as a function of FFM (P = 0·03), and positively related to activity-induced EE (r2 0·6, P < 0·0001). Resting EE explained 85% of the variation in meal frequency; adding activity-induced EE increased this to 89%. Habitual meal frequency was a function of components of EE, namely resting EE and activity-induced EE, only in subjects with a medium to high FFM (men). FFM-related differences in these relationships suggest a role of physical activity.

scholarly journals Knockout of inositol-requiring enzyme 1α in pro-opiomelanocortin neurons decreases fat mass via increasing energy expenditure

Open Biology ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 160131 ◽  
Author(s):  
Yuzhong Xiao ◽  
Tingting Xia ◽  
Junjie Yu ◽  
Yalan Deng ◽  
Hao Liu ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Metabolic Diseases ◽  
Critical Role ◽  
Liver Steatosis ◽  
Leptin Resistance ◽  
Hormone Production ◽  
Melanocyte Stimulating Hormone ◽  
Diet Induced Obesity ◽  
Brown Adipose

Although numerous functions of inositol-requiring enzyme 1α (IRE1α) have been identified, a role of IRE1α in pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus is largely unknown. Here, we showed that mice lacking IRE1α specifically in POMC neurons (PIKO) are lean and resistant to high-fat diet-induced obesity and obesity-related insulin resistance, liver steatosis and leptin resistance. Furthermore, PIKO mice had higher energy expenditure, probably due to increased thermogenesis in brown adipose tissue. Additionally, α-melanocyte-stimulating hormone production was increased in the hypothalamus of PIKO mice. These results demonstrate that IRE1α in POMC neurons plays a critical role in the regulation of obesity and obesity-related metabolic disorders. Our results also suggest that IRE1α is not only an endoplasmic reticulum stress sensor, but also a new potential therapeutic target for obesity and obesity-related metabolic diseases.

scholarly journals Congruent Validity of Resting Energy Expenditure Predictive Equations in Young Adults

Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 223 ◽  
Author(s):  
Francisco Amaro-Gahete ◽  
Guillermo Sanchez-Delgado ◽  
Juan Alcantara ◽  
Borja Martinez-Tellez ◽  
Victoria Muñoz-Hernandez ◽  
...  
Keyword(s):  
Young Adults ◽  
Energy Expenditure ◽  
United Nations ◽  
Weight Status ◽  
Resting Energy Expenditure ◽  
Normal Weight ◽  
Healthy Adults ◽  
Predictive Equations ◽  
Resting Energy

Having valid and reliable resting energy expenditure (REE) estimations is crucial to establish reachable goals for dietary and exercise interventions. However, most of the REE predictive equations were developed some time ago and, as the body composition of the current population has changed, it is highly relevant to assess the validity of REE predictive equations in contemporary young adults. In addition, little is known about the role of sex and weight status on the validity of these predictive equations. Therefore, this study aimed to investigate the role of sex and weight status in congruent validity of REE predictive equations in young adults. A total of 132 young healthy adults (67.4% women, 18–26 years old) participated in the study. We measured REE by indirect calorimetry strictly following the standard procedures, and we compared it to 45 predictive equations. The most accurate equations were the following: (i) the Schofield and the “Food and Agriculture Organization of the United Nations/World Health Organization/United Nations” (FAO/WHO/UNU) equations in normal weight men; (ii) the Mifflin and FAO/WHO/UNU equations in normal weight women; (iii) the Livingston and Korth equations in overweight men; (iv) the Johnstone and Frankenfield equations in overweight women; (v) the Owen and Bernstein equations in obese men; and (vi) the Owen equation in obese women. In conclusion, the results of this study show that the best equation to estimate REE depends on sex and weight status in young healthy adults.

Sign in / Sign up

Export Citation Format

Share Document