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Liao S, Tan S, Jiang M, Wen J, Liu J, Cao J, Li M, Zhao Z. Temperature determines the shift of thermal neutral zone and influences thermogenic capacity in striped hamsters. Integr Zool 2023; 18:353-371. [PMID: 36056589 DOI: 10.1111/1749-4877.12678] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The thermoneutral zone (TNZ) reflects the adaptation of mammals to their natural habitat. However, it remains unclear how TNZ shifts in response to variations in ambient temperature. To test the hypothesis that ambient temperature plays a key role in determining TNZ variations between seasons, we measured metabolic rate, body temperature, and cytochrome c oxidase (COX) activity of several visceral organs in striped hamsters (Cricetulus barabensis) either acclimated to semi-natural conditions over a year, or subjected to a gradual decrease in mean temperature from 30 ± 1°C to -15 ± 1°C. The TNZ range in striped hamsters differed seasonally, with a wider TNZ and a lower lower-critical temperature in winter compared to summer. The hamsters showed a considerable leftward shift of lower-critical temperature from 30°C to 20°C after the ambient temperature of acclimation from 30°C down to -15°C, whereas the upper-critical temperature of TNZ remained fixed at 32.5°C. The resting metabolic rate in thermoneutral zone (RMRt), nonshivering thermogenesis (NST), and COX activity of brown adipose tissue, liver, skeletal muscle, brain, and kidneys, increased significantly in hamsters acclimated at lower ambient temperatures. Following acute exposure to 5°C and -15°C, hamsters acclimated to 32.5°C had significantly lower maximal NST and lower serum thyroid tri-iodothyronine (T3 ) levels compared to those kept at 23°C. These findings suggest that acclimation to the upper-critical temperature of TNZ impairs the hamsters' thermogenic capacity to cope with extreme cold temperature. Reduced ambient temperature was mainly responsible for the leftward shift of TNZ in striped hamsters, which reflects the adaptation to cold environments.
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Affiliation(s)
- Shasha Liao
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Song Tan
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China.,CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Meizhi Jiang
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Jing Wen
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Jinsong Liu
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Jing Cao
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Ming Li
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Zhijun Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China.,Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou, China
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Zhao Z, Yang R, Li M, Bao M, Huo D, Cao J, Speakman JR. Effects of ambient temperatures between 5 and 35 oC on energy balance, body mass and body composition in mice. Mol Metab 2022; 64:101551. [PMID: 35870706 PMCID: PMC9382332 DOI: 10.1016/j.molmet.2022.101551] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 11/17/2022] Open
Abstract
Background Considerable attention is currently focused on the potential to switch on brown adipose tissue (BAT), or promote browning of white adipose tissue, to elevate energy expenditure and thereby reduce obesity levels. These processes are already known to be switched on by cold exposure. Yet humans living in colder regions do not show lower levels of obesity. This could be because humans shield themselves from external temperatures, or because the resultant changes in BAT and thermogenesis are offset by elevated food intake, or reductions in other components of expenditure. Scope of Review We exposed mice to 11 different ambient temperatures between 5 and 35 °C and characterized their energy balance and body weight/composition. As it got colder mice progressively increased their energy expenditure coincident with changes in thyroid hormone levels and increased BAT activity. Simultaneously, these increases in expenditure were matched by elevated food intake, and body mass remained stable. Nevertheless, within this envelope of unchanged body mass there were significant changes in body composition – with increases in the sizes of the liver and small intestine, presumably to support the greater food intake, and reductions in the level of stored fat – maximally providing about 10% of the total elevated energy demands. Major Conclusions Elevating activity of BAT may be a valid strategy to reduce fat storage even if overall body mass is unchanged but if it is mostly offset by elevated food intake, as found here, then the impacts may be small. Male and female mice were exposed to 11 different ambient temperatures between 5 and 35 °C. As it got colder mice increased both energy expenditure and food intake. Increased energy expenditure was coincident with increased THs and BAT activity. Stored fat was considerably reduced in colder conditions, providing about 10% of the elevated energy requirements. Elevating activity of BAT may be a valid strategy to reduce fat storage.
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Affiliation(s)
- Zhijun Zhao
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang 325035, China.
| | - Rui Yang
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Min Li
- Shenzhen key laboratory of metabolic health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Menghuan Bao
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Daliang Huo
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Jing Cao
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - John R Speakman
- Shenzhen key laboratory of metabolic health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK; State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100100, China.
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Switching off the furnace: brown adipose tissue and lactation. Mol Aspects Med 2019; 68:18-41. [DOI: 10.1016/j.mam.2019.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 06/12/2019] [Indexed: 12/31/2022]
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Kagya-Agyemang JK, Vaanholt LM, Hambly C, Król E, Mitchell SE, Speakman JR. Limits to sustained energy intake XXVIII: Beneficial effects of high dietary fat on lactation performance in mice. J Exp Biol 2018; 221:jeb.180828. [DOI: 10.1242/jeb.180828] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/20/2018] [Indexed: 12/22/2022]
Abstract
Maximal animal performance may be limited by the ability of animals to dissipate heat; the heat dissipation limitation (HDL) theory. Since diets vary in the incidental heat produced during digestion (specific dynamic action, SDA), the HDL theory predicts lactating female mice consuming diets with lower SDA should have increased reproductive performance. Dietary fat has a lower SDA than dietary carbohydrate. Female mice were fed low (LF), medium (MF) or high fat (HF) diets (10%, 45% and 60% energy from fat respectively) from days 4-18 of lactation. HF and MF-fed mice weaned significantly heavier litters than LF mice. This was because they not only consumed more energy (metabolisable energy intake, Emei; HF:306.5±25.0, MF:340.5±13.5 kJ d−1) at peak lactation, but also delivered more milk energy to their pups (milk energy output, Emilk: 203.2±49.9, 229.3±42.2 kJ d−1 respectively) than the LF-fed mice (Emei =266.7±4.5, Emilk =164.60±30.59 kJ d−1). This effect was greater than predicted from the SDA of the different diets combined with a mathematical model based on the HDL theory. Fatty acid profiles of the diets, milk and pups, showed significant correlations between the profiles. Besides reduced SDA, HF and MF-fed mice were probably able to directly transfer absorbed dietary fat into milk, reducing the heat production of lactogenesis, and enabling them to perform better than expected from the HDL model. In summary, HF and MF diets had beneficial effects on reproductive performance compared to the LF diet because they enabled mice to generate milk more efficiently with less incidental heat production.
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Affiliation(s)
- J. K. Kagya-Agyemang
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- College of Agriculture Education, University of Education, Winneba, P.O. Box 40, Mampong-Ashanti, Ghana
| | - L. M. Vaanholt
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - C. Hambly
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - E. Król
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - S. E. Mitchell
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - J. R. Speakman
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- State key laboratory of molecular developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing China
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Zhao XY, Zhang JY, Cao J, Zhao ZJ. Oxidative Damage Does Not Occur in Striped Hamsters Raising Natural and Experimentally Increased Litter Size. PLoS One 2015; 10:e0141604. [PMID: 26505889 PMCID: PMC4624642 DOI: 10.1371/journal.pone.0141604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 10/09/2015] [Indexed: 12/21/2022] Open
Abstract
Life-history theory assumes that animals can balance the allocation of limited energy or resources to the competing demands of growth, reproduction and somatic maintenance, while consequently maximizing their fitness. However, somatic damage caused by oxidative stress in reproductive female animals is species-specific or is tissue dependent. In the present study, several markers of oxidative stress (hydrogen peroxide, H2O2 and malonadialdehyde, MDA) and antioxidant (catalase, CAT and total antioxidant capacity, T-AOC) were examined in striped hamsters during different stages of reproduction with experimentally manipulated litter size. Energy intake, resting metabolic rate (RMR), and mRNA expression of uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) and UCP3 in skeletal muscle were also examined. H2O2 and MDA levels did not change in BAT and liver, although they significantly decreased in skeletal muscle in the lactating hamsters compared to the non-reproductive group. However, H2O2 levels in the brain were significantly higher in lactating hamsters than non-reproductive controls. Experimentally increasing litter size did not cause oxidative stress in BAT, liver and skeletal muscle, but significantly elevated H2O2 levels in the brain. CAT activity of liver decreased, but CAT and T-AOC activity of BAT, skeletal muscle and the brain did not change in lactating hamsters compared to non-reproductive controls. Both antioxidants did not change with the experimentally increasing litter size. RMR significantly increased, but BAT UCP1 mRNA expression decreased with the experimentally increased litter size, suggesting that it was against simple positive links between metabolic rate, UCP1 expression and free radicals levels. It may suggest that the cost of reproduction has negligible effect on oxidative stress or even attenuates oxidative stress in some active tissues in an extensive range of animal species. But the increasing reproductive effort may cause oxidative stress in the brain, indicating that oxidative stress in response to reproduction is tissue dependent. These findings provide partial support for the life-history theory.
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Affiliation(s)
- Xiao-Ya Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Ji-Ying Zhang
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jing Cao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Zhi-Jun Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
- * E-mail:
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