Energy metabolism, thermogenesis and body mass regulation in Brandt's voles (Lasiopodomys brandtii) during cold acclimation and rewarming

2006 ◽  
Vol 50 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Xue-Ying Zhang ◽  
De-Hua Wang
2009 ◽  
Vol 82 (5) ◽  
pp. 549-560 ◽  
Author(s):  
François Vézina ◽  
Magali Petit ◽  
Deborah M. Buehler ◽  
Anne Dekinga ◽  
Theunis Piersma

1998 ◽  
Vol 201 (8) ◽  
pp. 1065-1072 ◽  
Author(s):  
R K Suarez

Mass-specific rates of aerobic metabolism VO2/Mb) scale in inverse proportion to body mass (Mb). Thus, small hummingbirds display the highest VO2/Mb known among vertebrates. Among all animals, higher VO2/Mb values are known only in flying insects. The high body-mass-specific rates of metabolism seen in hummingbirds are made possible by high lung O2 diffusing capacities, cardiac outputs, ratios of capillary surface area to muscle fiber surface area, mitochondrial volume densities, cristae surface densities and concentrations of enzymes involved in energy metabolism. Current evidence from control analyses of O2 transport through the respiratory and cardiovascular systems and of metabolic fluxes through pathways of energy metabolism indicates shared control of maximum flux rates among multiple steps (i.e. the absence of single rate-limiting steps). This supports the suggestion that functional capacities at each step in linear pathways or processes are matched to each other, and provides an explanation for why the up-regulation of functional capacities has occurred at virtually all steps in the evolution of the smallest vertebrate homeotherms. Flying insects make use of a tracheal system for O2 transport and, like hummingbirds, possess a highly up-regulated biochemical machinery for substrate oxidation. Studies of hummingbirds and honeybees reveal closer matches between biochemical flux capacities and maximum physiological flux rates than in animals capable of lower maximum VO2/Mb. It is proposed that the upper limits to functional capacities set the upper limit to VO2/Mb. This upper limit to aerobic metabolic rate may contribute, along with other factors, towards establishing the lower limit to vertebrate homeotherm size.


2016 ◽  
Vol 2 ◽  
pp. 73-77
Author(s):  
Andrzej Nowak ◽  
Elżbieta Czkwianianc

2020 ◽  
Vol 21 (22) ◽  
pp. 8606
Author(s):  
Shogo Moriwaki ◽  
Yuki Narimatsu ◽  
Keisuke Fukumura ◽  
Eiko Iwakoshi-Ukena ◽  
Megumi Furumitsu ◽  
...  

RFamide-related peptide-3 (RFRP-3), the mammalian ortholog of avian gonadotropin-inhibitory hormone (GnIH), plays a crucial role in reproduction. In the present study, we explored the other functions of RFRP-3 by investigating the effects of chronic intracerebroventricular infusion of RFRP-3 (6 nmol/day) for 13 days on energy homeostasis in lean male C57BL/6J mice. The infusion of RFRP-3 increased cumulative food intake and body mass. In addition, the masses of brown adipose tissue (BAT) and the liver were increased by the administration of RFRP-3, although the mass of white adipose tissue was unchanged. On the other hand, RFRP-3 decreased O2 consumption, CO2 production, energy expenditure, and core body temperature during a short time period in the dark phase. These results suggest that the increase in food intake and the decrease in energy expenditure contributed to the gain of body mass, including the masses of BAT and the liver. The present study shows that RFRP-3 regulates not only reproductive function, but also energy metabolism, in mice.


2019 ◽  
Vol 160 (39) ◽  
pp. 1554-1562
Author(s):  
Julianna Bircher ◽  
Eszter Kótyuk ◽  
Renáta Cserjési ◽  
Andrea Vereczkei ◽  
Zsolt Rónai ◽  
...  

Abstract: Introduction and aim: Earlier results in the literature suggest that overweight subjects show weaker performance in executive function tasks as compared to normal weight people. Dopaminergic system is strongly linked to executive functions, body mass regulation and ingestion. The aim of the present study was to examine the possible relationship between DRD4 VNTR 7-repeat allele, body mass index and Stroop performance in a healthy adult population, and to draw psychogenetic conclusions. Method: 152 subjects without diabetic or psychiatric history participated in the study. Along with non-invasive DNA sampling, demographic, weight and height data were collected. The participants also solved the computerized Stroop task. 11 subjects belonged to the underweight (mean body mass index = 17.9 kg/m2), 98 subjects to the normal (mean body mass index = 21.8 kg/m2), and 43 subjects to the overweight (mean body mass index = 28.9 kg/m2) category. After grouping participants according to their body mass index and DRD4 VNTR genotype, we compared their mean performance to investigate the possible psychogenetic associations. Results: Body mass index and stimuli type showed significant interaction on error number (p = 0.045): subjects with normal body mass index made significantly less error as compared to under- and overweight subjects in incongruent trials. The 7-repeat allele carriers made tendentiously more errors than non-carriers. Normal weight people made less error – independently from their genotype –, while subjects with either low or high BMI carrying the 7-repeat allele made more errors compared to non-carriers. Conclusion: Under- and overweight subjects perform weaker where inhibition is necessary in the task. This may reflect their reactions to food-related situations. Orv Hetil. 2019; 160(39): 1554–1562.


Sign in / Sign up

Export Citation Format

Share Document