Home About us Contact
|
Home About us Contact | ||
|
|
||
Resting Metabolic Rate (resting + metabolic_rate)
Selected AbstractsUncoupling proteins 2 and 3 interact with members of the 14.3.3 familyFEBS JOURNAL, Issue 9 2000Benoit Pierrat Uncoupling proteins (UCPs) are members of the superfamily of the mitochondrial anion carrier proteins (MATP). Localized in the inner membrane of the organelle, they are postulated to be regulators of mitochondrial uncoupling. UCP2 and 3 may play an important role in the regulation of thermogenesis and, thus, on the resting metabolic rate in humans. To identify interacting proteins that may be involved in the regulation of the activity of UCPs, the yeast two-hybrid system was applied. Segments of hUCP2 containing the hydrophilic loops facing the intermembrane space, or combinations of these, were used to screen an adipocyte activation domain (AD) fusion library. The 14.3.3 protein isoforms ,, ,, , were identified as possible interacting partners of hUCP2. Screening of a human skeletal muscle AD fusion library, on the other hand, yielded several clones all of them encoding the , isoform of the 14.3.3 family. Mapping experiments further revealed that all these 14.3.3 proteins interact specifically with the C-terminal intermembrane space domain of both hUCP2 and hUCP3 whereas no interactions could be detected with the C-terminal part of hUCP1. Direct interaction between UCP3 and 14.3.3 , could be demonstrated after in vitro translation by coimmunoprecipitation. When coexpressed in a heterologous yeast system, 14.3.3 proteins potentiated the inhibitory effect of UCP3 overexpression on cell growth. These findings suggest that 14.3.3 proteins could be involved in the targeting of UCPs to the mitochondria. [source] Elevated metabolic costs while resting on water in a surface feeder: the Black-legged Kittiwake Rissa tridactylaIBIS, Issue 1 2007ELIZABETH M. HUMPHREYS Measurements of the energy costs of individual behaviours provide insights into how animals trade-off resource allocation and energy acquisition decisions. The energetic costs while resting on water are poorly known for seabirds but could comprise a substantial proportion of their daily energy expenditure. We measured the cost of resting on water in Black-legged Kittiwakes Rissa tridactyla, a species which does not fly during the night and for which estimating energy expenditure while resting on the water is therefore important. Their resting metabolic rate on water at 12.5 °C was at least 40% higher compared with resting at the same temperature in air. This indicates that, at comparable temperatures, metabolic costs are elevated for birds resting at sea compared with on land. We argue that Kittiwakes meet much of this extra thermoregulatory demand by dedicated metabolic activity. During the winter months, their costs are likely to be even higher owing to lower sea temperatures. Accordingly, we suggest that migration to milder latitudes, following breeding, will provide enhanced benefits, particularly to seabirds such as Kittiwakes which rest on the sea surface during darkness. [source] Energetic cost of calling: general constraints and species-specific differencesJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 7 2010A. G. OPHIR Abstract The energetic cost of acoustic signalling varies tremendously among species. Understanding factors responsible for this heterogeneity is important for understanding the costs and benefits of signalling. Here, we present a general model, based on well-established principles of bioenergetics, which predicts the energetic cost of call production across species. We test model predictions using an extensive database of resting and calling metabolic rates of insects, amphibians and birds. Results are largely supportive of model predictions. Calling metabolic rates scale predictably with body mass and temperature such that calling and resting metabolic rates are directly proportional to each other. The cost of acoustic signalling is ,8 times higher than resting metabolic rate in ectotherms, and ,2 times higher in birds. Differences in the increase in metabolic rate during calling are explained by the relative size of species' sound-producing muscles. Combined with published work, we quantify call efficiency and discuss model implications. [source] A quantitative analysis of energy intake reported by young menNUTRITION & DIETETICS, Issue 4 2008Selma C. LIBERATO Abstract Aim:, To quantitatively analyse energy intake reported by young men and the accuracy of the Goldberg cut-off method for identifying misreporters. Methods:, This was a cross-sectional study in which: food intake was assessed by a four-day food record; resting metabolic rate was assessed by indirect calorimetry; percentage body fat was measured by dual-energy X-ray absorptiometry; and energy expenditure was assessed by physical activity record completed simultaneously with food intake measurements. Energy intake was analysed by direct comparison of energy intake and energy expenditure and by the Goldberg cut-off. Subjects: 34 healthy men aged 18,25 years. Setting: Queensland University of Technology, Queensland, Australia. Main outcome measures: percentage of misreporters in a group of young men using different methods. Statistical analyses: data are presented as means and standard deviations. The analyses were conducted using Statistic for Windows 5.5 software. Results:, Seven underreporters were identified by direct comparison of energy intake and energy expenditure. The Goldberg cut-off found six out of the seven underreporters identified by direct comparison of energy intake and energy expenditure, but wrongly identified two acceptable reporters as underreporters. The sensitivity and specificity of the Goldberg cut-off method were 0.86 and 0.93, respectively. Conclusions:, Seven out of 34 participants underreported their energy intake. In the absence of physical activity measurements, the Goldberg cut-off method identified underreporters in this group of young men with assessed resting metabolic rate. [source] RESTING METABOLIC RATE AND POST-PRANDIAL THERMOGENESIS BY LEVEL OF AEROBIC POWER IN OLDER ATHLETESCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 4 2004Alessio Sullo SUMMARY 1.,The aim of the present study was to evaluate the resting metabolic rate (RMR) and thermogenic effect of a meal (TEM) in older athletes. 2.,Eighteen older male volunteers were divided into three groups according to their aerobic power related to fat-free mass (FFM) as follows: (i) group I, high aerobic power (Vo2max > 70 mL/kg FFM per min); (ii) group II, moderate aerobic power (Vo2max = 55,70 mL/kg FFM per min); and (iii) group III, low aerobic power (Vo2max < 55 mL/kg FFM per min). 3.,The RMR values, covariated for FFM using analysis of covariance (ancova), were higher in group I (mean (±SEM) 1.09 ± 0.04 kcal/min) than in groups II and III (0.99 ± 0.05 and 0.91 ± 0.03 kcal/min, respectively). Group I had a tendency for higher mean TEM values compared with the other groups, but the differences were not statistically significant for absolute or percentage values. 4.,Master endurance athletes with high aerobic power exhibit a higher RMR than master endurance athletes of similar age and body composition but with lower aerobic power. [source] | |||||||||||||