scholarly journals Costly steroids: egg testosterone modulates nestling metabolic rate in the zebra finch

2007 ◽  
Vol 3 (4) ◽  
pp. 408-410 ◽  
Author(s):  
Michael Tobler ◽  
Jan-Åke Nilsson ◽  
Johan F Nilsson
Keyword(s):  
Metabolic Rate ◽  
Competitive Ability ◽  
Resting Metabolic Rate ◽  
Taeniopygia Guttata ◽  
Energetic Costs ◽  
Offspring Performance ◽  
Nestling Growth ◽  
Prenatal Testosterone ◽  
Yolk Hormones ◽  
Resting Metabolism

The transfer of non-genetic resources from mother to the offspring often has considerable consequences for offspring performance. In birds, maternally derived hormones are known to influence a variety of morphological, physiological and behavioural traits in the chick. So far, the range of these hormonal effects involves benefits in terms of enhanced growth and competitive ability as well as costs in terms of immunosuppression. However, since yolk hormones can enhance growth and begging activity, high levels of these hormones may also involve energetic costs. Here, we show experimentally that elevated levels of prenatal testosterone increase resting metabolic rate in nestling zebra finches ( Taeniopygia guttata ). Surprisingly, however, elevation of prenatal testosterone did not result in higher growth rates and, thus, differences in resting metabolism do not seem to be linked to nestling growth. We conclude that apart from immunosuppressive effects, high levels of egg steroids may also entail costs in terms of increased energy expenditure.

scholarly journals Metabolic reduction after long-duration flight is not related to fat-free mass loss or flight duration in a migratory passerine

2020 ◽  
Vol 223 (19) ◽  
pp. jeb215384
Author(s):  
Alexander R. Gerson ◽  
Joely G. DeSimone ◽  
Elizabeth C. Black ◽  
Morag F. Dick ◽  
Derrick J. Groom
Keyword(s):  
Metabolic Rate ◽  
Mass Loss ◽  
Body Mass ◽  
Lean Mass ◽  
Migratory Birds ◽  
Resting Metabolic Rate ◽  
Fat Free Mass ◽  
Flight Duration ◽  
Long Duration ◽  
Resting Metabolism

ABSTRACTMigratory birds catabolize large quantities of protein during long flights, resulting in dramatic reductions in organ and muscle mass. One of the many hypotheses to explain this phenomenon is that decrease in lean mass is associated with reduced resting metabolism, saving energy after flight during refueling. However, the relationship between lean body mass and resting metabolic rate remains unclear. Furthermore, the coupling of lean mass with resting metabolic rate and with peak metabolic rate before and after long-duration flight have not previously been explored. We flew migratory yellow-rumped warblers (Setophaga coronata) in a wind tunnel under one of two humidity regimes to manipulate the rate of lean mass loss in flight, decoupling flight duration from total lean mass loss. Before and after long-duration flights, we measured resting and peak metabolism, and also measured fat mass and lean body mass using quantitative magnetic resonance. Flight duration ranged from 28 min to 600 min, and birds flying under dehydrating conditions lost more fat-free mass than those flying under humid conditions. After flight, there was a 14% reduction in resting metabolism but no change in peak metabolism. Interestingly, the reduction in resting metabolism was unrelated to flight duration or to change in fat-free body mass, indicating that protein metabolism in flight is unlikely to have evolved as an energy-saving measure to aid stopover refueling, but metabolic reduction itself is likely to be beneficial to migratory birds arriving in novel habitats.

scholarly journals 0139 Associations of Actigraphic Sleep Parameters with Maximal Oxygen Consumption and Resting Metabolism in Well-Functioning Older Adults

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A54-A55
Author(s):  
A J Alfini ◽  
A A Wanigatunga ◽  
J A Schrack ◽  
S Wanigatunga ◽  
J Li ◽  
...  
Keyword(s):  
Older Adults ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Cardiorespiratory Fitness ◽  
Resting Metabolic Rate ◽  
Maximal Oxygen Consumption ◽  
Sleep Onset ◽  
Community Dwelling ◽  
Wrist Actigraphy ◽  
Resting Metabolism

Abstract Introduction Both poor sleep and poor cardiorespiratory fitness are common in older age and associated with negative health outcomes. Additionally, among older adults, higher resting metabolic rate (RMR) has been associated with increased morbidity and mortality risk. To evaluate whether, and in what ways, sleep may affect these relationships, we investigated the association of actigraphic sleep indices with cardiorespiratory fitness and RMR in older adults. Methods We studied 393 community-dwelling participants in the Baltimore Longitudinal Study of Aging (mean age 73.5±10.3 years, 52% women) who completed 6.7±0.9 nights of wrist actigraphy, RMR testing, and a maximal graded exercise test. Primary predictors included mean actigraphic total sleep time (TST, minutes), sleep efficiency (SE, %), wake after sleep onset (WASO, minutes), and average wake bout length (WBL, minutes). Cardiorespiratory fitness, as measured by maximal oxygen consumption (V O2MAX; ml/kg/min), and RMR (kcal/day) were the primary outcomes. Results After adjustment for age, sex, race, body mass index, comorbidity index, and depressive symptoms, longer WBL was associated with lower V O2MAX (β=-0.12, 95% confidence interval (CI)=-0.20, -0.04), greater WASO was associated with lower V O2MAX (β=-0.09, 95% CI=-0.17, -0.01), and greater SE was associated with higher V O2MAX (β=0.12, 95% CI=0.03, 0.20). In addition, longer TST was associated with lower RMR (β=-0.10, 95% CI=-0.19, -0.01) and longer WBL was linked to higher RMR (β=0.12, 95% CI=0.04, 0.21). Conclusion In well-functioning older adults, indices of greater wakefulness after sleep onset are linked with poorer cardiorespiratory fitness and higher resting metabolism, while longer and more efficient sleep are associated with better fitness and lower resting metabolic rate. Our findings suggest that sleep disturbance may be linked to disrupted energy homeostasis, evidenced by excessive energy expenditure at rest and inefficient energy utilization in response to maximal demands. Prospective analyses are necessary to determine the nature of these associations. Support This study was supported in part by National Institute on Aging (NIA) grants R01AG050507 and T32-AG027668, the NIA Intramural Research Program (IRP), and Research and Development Contract HHSN-260-2004-00012C.

EFFECTS OF WINTER ACCLIMATIZATION ON RESTING METABOLISM OF BEEF COWS

1975 ◽  
Vol 55 (4) ◽  
pp. 619-625 ◽  
Author(s):  
B. A. YOUNG
Keyword(s):  
Metabolic Rate ◽  
Body Condition ◽  
Fat Body ◽  
Resting Metabolic Rate ◽  
Beef Cows ◽  
The Body ◽  
Early Winter ◽  
Naturally Occurring ◽  
Downward Shift ◽  
Resting Metabolism

Twelve pregnant beef cows in average or fat body condition were overwintered in either heated housing (18 C) or outside and exposed to the naturally occurring cold winter conditions (5 to −10 C during early winter, 0 to −48 C during mid-winter). The housed and half of the outside cows were provided with woodshavings as bedding. In November (early winter) and again in January (mid-winter) metabolic measurements were made on each cow (22 h postfeeding) while exposed to test temperatures of −30, 0 and + 30 C. After adjusting for differences in body weight (kg3/4 basis), metabolic rate was not significantly influenced by either the body condition or by the availability of bedding. Metabolic rates were elevated in all cows when exposed to −30 C but, as evident from the decreases in rectal temperature, the housed cows were unable to maintain homeothermy during the tests at −30 C. Metabolic acclimatization occurred in the cows kept outside resulting in an increased resting metabolism and downward shift in their thermoneutral zone. Resting metabolic rate (22 h postfeeding) and the temperature of its occurrance were estimated by regression analysis to be 3.13 kcal/h.kg3/4 at about 30 C for the housed cows, and for the cows kept outside 3.71 and 4.29 kcal/h.kg3/4 at 17.4 and 12.7 C during early and mid-winter, respectively.

Energetic costs of digestion in Australian crocodiles

2011 ◽  
Vol 59 (6) ◽  
pp. 416 ◽  
Author(s):  
C. M. Gienger ◽  
Christopher R. Tracy ◽  
Matthew L. Brien ◽  
S. Charlie Manolis ◽  
Grahame J. W. Webb ◽  
...  
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Body Mass ◽  
Rapid Growth ◽  
Metabolic Response ◽  
Standard Metabolic Rate ◽  
Specific Dynamic Action ◽  
Energetic Costs ◽  
Resting Metabolism ◽  
Crocodylus Porosus

We measured standard metabolic rate (SMR) and the metabolic response to feeding in the Australian crocodiles, Crocodylus porosus and C. johnsoni. Both species exhibit a response that is characterised by rapidly increasing metabolism that peaks within 24 h of feeding, a postfeeding metabolic peak (peak O2) of 1.4–2.0 times SMR, and a return to baseline metabolism within 3–4 days after feeding. Postfeeding metabolism does not significantly differ between species, and crocodiles fed intact meals have higher total digestive costs (specific dynamic action; SDA) than those fed homogenised meals. Across a more than 100-fold range of body size (0.190 to 25.96 kg body mass), SMR, peak O2, and SDA all scale with body mass to an exponent of 0.85. Hatchling (≤1 year old) C. porosus have unexpectedly high rates of resting metabolism, and this likely reflects the substantial energetic demands that accompany the rapid growth of young crocodilians.

Nutrient pattern of unsaturated fatty acids and vitamin E increase resting metabolic rate of overweight and obese women

2020 ◽  
pp. 1-9
Author(s):  
Habib Yarizadeh ◽  
Leila Setayesh ◽  
Caroline Roberts ◽  
Mir Saeed Yekaninejad ◽  
Khadijeh Mirzaei
Keyword(s):  
Vitamin E ◽  
Metabolic Rate ◽  
Unsaturated Fatty Acids ◽  
Resting Metabolic Rate ◽  
Blood Parameters ◽  
Cross Sectional Study ◽  
Obese Women ◽  
Cross Sectional ◽  
Dietary Nutrients ◽  
Nutrient Patterns

Abstract. Objectives: Obesity plays an important role in the development of chronic diseases including cardiovascular disease and diabetes. A low resting metabolic rate (RMR) for a given body size and composition is a risk factor for obesity, however, there is limited evidence available regarding the association of nutrient patterns and RMR. The aim of this study was to determine the association of nutrient patterns and RMR in overweight and obese women. Study design: This cross-sectional study was conducted on 360 women who were overweight or obese. Method: Dietary intake was assessed using a semi-quantitative standard food frequency questionnaire (FFQ). Nutrient patterns were also extracted by principal components analysis (PCA). All participants were evaluated for their body composition, RMR, and blood parameters. Result: Three nutrient patterns explaining 64% of the variance in dietary nutrients consumption were identified as B-complex-mineral, antioxidant, and unsaturated fatty acid and vitamin E (USFA-vit E) respectively. Participants were categorized into two groups based on the nutrient patterns. High scores of USFA-vit E pattern was significantly associated with the increase of RMR (β = 0.13, 95% CI = 0.79 to 68.16, p = 0.04). No significant associations were found among B-complex-mineral pattern (β = −0.00, 95% CI = −49.67 to 46.03, p = 0.94) and antioxidant pattern (β = 0.03, 95% CI −41.42 to 22.59, p = 0.56) with RMR. Conclusion: Our results suggested that the “USFA-vit E” pattern (such as PUFA, oleic, linoleic, vit.E, α-tocopherol and EPA) was associated with increased RMR.

Validation of Equations for the Prediction of Resting Metabolic Rate in Sri Lankan Adults

2019 ◽  
Vol 9 (10) ◽  
pp. p9462
Author(s):  
Pathima Fairoosa ◽  
Indu Waidyatilaka ◽  
Maduka de Lanerolle-Dias ◽  
Pujitha Wickramasinghe ◽  
Pulani Lanerolle
Keyword(s):  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Sri Lankan
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