المؤلفون: Ramos, Julian Andro P., Ducker, Kagan J., Riddell, Hugh, Girard, Olivier, Landers, Grant J., Brade, Carly J.

المصدر: International Journal of Sports Physiology & Performance; May2024, Vol. 19 Issue 5, p435-442, 8p

مصطلحات موضوعية: SKIN temperature, STATISTICAL models, BODY temperature regulation, DATA analysis, ENVIRONMENTAL monitoring, RESEARCH funding, ENDURANCE sports, PERSPIRATION, DESCRIPTIVE statistics, EXERCISE intensity, CYCLING, ATHLETES, HUMIDITY, BODY temperature, HYDRATION, PHYSICAL fitness, RESEARCH methodology, INTRACLASS correlation, STATISTICS, ATHLETIC ability, TEMPERATURE, ANTHROPOMETRY, HUMAN comfort, CONFIDENCE intervals, WARMUP, REGRESSION analysis, TIME

مستخلص: Purpose: Precooling (PreC) may only benefit performance when thermal strain experienced by an individual is sufficiently high. We explored the effect of mixed-method PreC on 20-km cycling time-trial (CTT) performance under 3 different apparent temperatures (AT). Methods: On separate days, 12 trained or highly trained male cyclists/triathletes completed six 20-km CTTs in 3 different ATs: hot-dry (35 °C AT), moderately hot-humid (40 °C AT), and hot-humid (46 °C AT). All trials were preceded by 30 minutes of mixed-method PreC or no PreC (control [CON]). Results: Faster 2.5-km-split completion times occurred in PreC compared with CON in 46 °C AT (P =.02), but not in 40 °C AT (P =.62) or 35 °C AT (P =.57). PreC did not affect rectal and body temperature during the 20-km CTT. Skin temperature was lower throughout the CTT in PreC compared with CON in 46 °C AT (P =.01), but not in 40 °C AT (P = 1.00) and 35 °C AT (P = 1.00). Heart rate had a greater rate of increase during the CTT for PreC compared with CON in 46 °C AT (P =.01), but not in 40 °C AT (P =.57) and 35 °C AT (P = 1.00). Ratings of perceived exertion (P <.001) and thermal comfort (P =.04) were lower for PreC compared with CON in 46 °C AT only, while thermal sensation was not different between PreC and CON. Conclusion: Mixed-method PreC should be applied prior to 20-km CTTs conducted in hot-humid conditions (≥46 °C AT). Alternatively, mixed-method PreC may be a priority in moderately hot-humid (∼40 °C AT) conditions but should not be in hot-dry (∼35 °C AT) conditions for 20-km CTT. [ABSTRACT FROM AUTHOR]

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المؤلفون: Hinostroza, Fernando^1,2,3,4 (AUTHOR), Araya-Duran, Ingrid⁵ (AUTHOR), Piñeiro, Alejandro⁶ (AUTHOR), Lobos, Isabel⁶ (AUTHOR), Pastenes, Luis⁶ (AUTHOR) lpastenes@ucm.cl

المصدر: Scientific Reports. 7/2/2024, Vol. 14 Issue 1, p1-9. 9p.

مصطلحات موضوعية: *TRANSCRIPTION factors, *BODY temperature regulation, *GENE expression, *TOADS, *PHYSIOLOGICAL adaptation, *TADPOLES, *ANIMAL navigation

مصطلحات جغرافية: CHILE

مستخلص: Environmental temperature strongly influences the adaptation dynamics of amphibians, whose limited regulation capabilities render them susceptible to thermal oscillations. A central element of the adaptive strategies is the transcription factors (TFs), which act as master regulators that orchestrate stress responses, enabling species to navigate the fluctuations of their environment skillfully. Our study delves into the intricate relationship between TF expression and thermal adaptation mechanisms in the Rhinella spinulosa populations. We sought to elucidate the dynamic modulations of TF expression in prometamorphic and metamorphic tadpoles that inhabit two thermally contrasting environments (Catarpe and El Tatio Geyser, Chile) and which were exposed to two thermal treatments (25 °C vs. 20 °C). Our findings unravel an intriguing dichotomy in response strategies between these populations. First, results evidence the expression of 1374 transcription factors. Regarding the temperature shift, the Catarpe tadpoles show a multifaceted approach by up-regulating crucial TFs, including fosB, atf7, and the androgen receptor. These dynamic regulatory responses likely underpin the population's ability to navigate thermal fluctuations effectively. In stark contrast, the El Tatio tadpoles exhibit a more targeted response, primarily up-regulating foxc1. This differential expression suggests a distinct focus on specific TFs to mitigate the effects of temperature variations. Our study contributes to understanding the molecular mechanisms governing thermal adaptation responses and highlights the resilience and adaptability of amphibians in the face of ever-changing environmental conditions. [ABSTRACT FROM AUTHOR]

المؤلفون: Da Luz, Marina Pagliai Ferreira¹ (AUTHOR) marina_pagliai@hotmail.com, Maia, Caroline Marques^2,3 (AUTHOR), Puoli Filho, José Nicolau Próspero¹ (AUTHOR)

المصدر: Journal of Applied Animal Welfare Science. Jul-Sep2024, Vol. 27 Issue 3, p477-486. 10p.

مصطلحات موضوعية: *HORSE health, *BODY temperature regulation, *HORSES, *SHOW horses, *RECREATION areas, *HORSE shows

مستخلص: Rolling is a natural behavior of equids that is beneficial to their well-being. However, more intensive domestic environments offer fewer opportunities for animals to roll, neglecting its importance. We believe that the inclusion of recreational areas for animals, containing substrates and conditions that encourage the occurrence of natural behaviors, is essential to promote their well-being. Therefore, we evaluated the preference of horses (Equus caballus; n = 8) and mules (E. asinus x E. caballus; n = 8) for different rolling substrates (sand, grass, manure), and the influence of this behavior on thermoregulation after exercise. Horses rolled preferentially on grass, whereas mules preferred sand, both of which were cooler substrates when compared to manure. In addition, the temperature of the animals significantly reduced after rolling. Thus, horses and mules must roll for thermoregulation after exercise, choosing cooler and more efficient substrates for heat dissipation. The differences in preferences between mules and horses showed particularities between the equine species and its hybrid, which is important for management that is focused more on the individual animal. [ABSTRACT FROM AUTHOR]

المؤلفون: Vyas, Rashmi¹, Rana, Pratiksha², Sharma, Shafali³, Malik, Asifa Ikhlaq³, Bahuguna, Khushboo⁴, Rawat, Deepti⁵

المصدر: Journal of Cardiovascular Disease Research (Journal of Cardiovascular Disease Research). 2024, Vol. 15 Issue 6, p842-848. 7p.

مصطلحات موضوعية: *CHILDREN'S hospitals, *BODY temperature regulation, *MOTHERS, *PREMATURE infants, *JUDGMENT sampling

مصطلحات جغرافية: UNITED Kingdom

مستخلص: Introduction: Thermoregulation refers to the ability to maintain a stable internal body temperature regardless of external conditions. In neonates, particularly preterm infants, thermoregulation is critical due to several factors. Objective: To assess the knowledge on thermoregulation among the mothers of under five children in selected hospitals, Dehradun (UK),To assess the practise of thermoregulation among the mothers of under five children in selected hospitals, Dehradun (UK),To assess the Effectiveness of planned teaching programme on knowledge and practice regarding thermoregulation among the mothers of under five children in selected hospitals, Dehradun (UK). Methodology-The researchers have used A Quasi Experimental Research Design (One group Pre-test and Post-test).Non Probability Purposive sampling technique was used.80 Mothers who fullfill the inclusion criteria were included in the study In the present study the below scales were used to collect the data. Structured Questionnaire and observational checklist was used to assess the Effectiveness of planned teaching programme on knowledge and practice regarding thermoregulation among the mothers of under five children in selected hospitals, Dehradun (UK). Conclusion: The planned teaching programme significantly improved the knowledge and practices of thermoregulation among mothers of under-five children. Educating mothers on thermoregulation techniques is crucial for reducing temperature-related health issues in children, thereby improving their overall health outcomes. [ABSTRACT FROM AUTHOR]

المؤلفون: Keipert, Susanne¹, Gaudry, Michael J.¹, Kutschke, Maria¹, Keuper, Michaela¹, Dela Rosa, Margeoux A. S.², Yiming Cheng^3,4,5, Monroy Kuhn, José M.⁶, Laterveer, Rutger¹, Cotrim, Camila A.², Giere, Peter⁷, Perocchi, Fabiana^3,4,5, Feederle, Regina⁸, Crichton, Paul G.², Lutter, Dominik⁶, Jastroch, Martin¹ martin.jastroch@su.se

المصدر: Science. 6/7/2024, Vol. 384 Issue 6700, p1111-1117. 7p. 4 Diagrams.

مصطلحات موضوعية: *BROWN adipose tissue, *BODY temperature regulation, *UNCOUPLING proteins, *BODY temperature, *THERMAL stresses, *ADIPOSE tissues

مستخلص: Brown adipose tissue (BAT) is a heater organ that expresses thermogenic uncoupling protein 1 (UCP1) to maintain high body temperatures during cold stress. BAT thermogenesis is considered an overarching mammalian trait, but its evolutionary origin is unknown. We show that adipose tissue of marsupials, which diverged from eutherian mammals ~150 million years ago, expresses a nonthermogenic UCP1 variant governed by a partial transcriptomic BAT signature similar to that found in eutherian beige adipose tissue. We found that the reconstructed UCP1 sequence of the common eutherian ancestor displayed typical thermogenic activity, whereas therian ancestor UCP1 is nonthermogenic. Thus, mammalian adipose tissue thermogenesis may have evolved in two distinct stages, with a prethermogenic stage in the common therian ancestor linking UCP1 expression to adipose tissue and thermal stress. We propose that in a second stage, UCP1 acquired its thermogenic function specifically in eutherians, such that the onset of mammalian BAT thermogenesis occurred only after the divergence from marsupials. [ABSTRACT FROM AUTHOR]

المؤلفون: Wen, Xueping¹ (AUTHOR), Song, Yufei¹ (AUTHOR), Zhang, Mei² (AUTHOR) fjnan@simm.ac.cn, Kang, Yiping² (AUTHOR), Chen, Dandan² (AUTHOR), Ma, Hui² (AUTHOR), Nan, Fajun² (AUTHOR), Duan, Yanan² (AUTHOR) duanyanan@simm.ac.cn, Li, Jingya^1,2 (AUTHOR) duanyanan@simm.ac.cn

المصدر: Biomolecules (2218-273X). Jun2024, Vol. 14 Issue 6, p618. 21p.

مصطلحات موضوعية: *BODY temperature regulation, *WEIGHT gain, *UNCOUPLING proteins, *OBESITY, *INSULIN sensitivity, *FAT cells, *METABOLIC disorders, *ADIPOSE tissues

مستخلص: Recent studies increasingly suggest that targeting brown/beige adipose tissues to enhance energy expenditure offers a novel therapeutic approach for treating metabolic diseases. Brown/beige adipocytes exhibit elevated expression of uncoupling protein 1 (UCP1), which is a thermogenic protein that efficiently converts energy into heat, particularly in response to cold stimulation. Polyphenols possess potential anti-obesity properties, but their pharmacological effects are limited by their bioavailability and distribution within tissue. This study discovered 18a, a polyphenol compound with a favorable distribution within adipose tissues, which transcriptionally activates UCP1, thereby promoting thermogenesis and enhancing mitochondrial respiration in brown adipocytes. Furthermore, in vivo studies demonstrated that 18a prevents high-fat-diet-induced weight gain and improves insulin sensitivity. Our research provides strong mechanistic evidence that UCP1 is a complex mediator of 18a-induced thermogenesis, which is a critical process in obesity mitigation. Brown adipose thermogenesis is triggered by 18a via the AMPK-PGC-1α pathway. As a result, our research highlights a thermogenic controlled polyphenol compound 18a and clarifies its underlying mechanisms, thus offering a potential strategy for the thermogenic targeting of adipose tissue to reduce the incidence of obesity and its related metabolic problems. [ABSTRACT FROM AUTHOR]

المؤلفون: Xu, X.^1,2 (AUTHOR), Wang, J.^1,2 (AUTHOR), Lv, K.^1,2 (AUTHOR), Jin, H.^1,2 (AUTHOR), Li, M.^1,2 (AUTHOR) 20190035@wzu.edu.cn, Liu, J.^1,2 (AUTHOR)

المصدر: European Zoological Journal. Jun2024, Vol. 91 Issue 1, p406-419. 14p.

مصطلحات موضوعية: *SPARROWS, *BODY temperature regulation, *GLUTATHIONE peroxidase, *DRINKING (Physiology), *SUPEROXIDE dismutase, *ANTIOXIDANTS

مستخلص: Global warming has become an undeniable fact, and the frequent occurrence of extremely hot weather is a serious challenge to the survival of animals. As one of the most active components of the ecosystem, birds are sensitive to the constant changes in the climate and environment. To investigate the physiological responses of Eurasian tree sparrows (Passer montanus) to acute heat stress, various thermogenic parameters of the birds, which included resting metabolic rate (RMR), body mass, body temperature, water intake, and liver cellular metabolic capacity, were measured after exposure to 42°C for different times. The antioxidant response of Eurasian tree sparrows to heat stress was investigated by measuring the lipid oxidation indexes and related antioxidant oxidase activities in the serum and liver. Body temperature and water intake were significantly increased after 2 h of heat stress and lasted until the end of the heat stress (12 h). In contrast, RMR was significantly decreased after 2 h of heat stress. At the cellular level, liver COX activity was significantly increased during heat stress from 2 h to 6 h. Additionally, there was a significant increase in MDA content and superoxide dismutase (SOD) and catalase (CAT) activity levels in the serum. The glutathione peroxidase (GSH-PX) activity in the liver was significantly decreased after 2 h of heat stress. Our results indicated that heat production decreased while heat dissipation increased in Eurasian tree sparrows exposed to acute heat stress. At the same time, the internal antioxidant defense system of the birds was activated to counteract the damage caused by high temperatures. Therefore, it was reasonable to speculate that Eurasian tree sparrows might be resistant to high temperatures to the extent that they can maintain normal life activities through the regulation of thermogenic and antioxidant systems under acute heat stress. [ABSTRACT FROM AUTHOR]

المؤلفون: Leith, Noah T.¹ (AUTHOR) noah.leith@slu.edu, Miller, Em A.¹ (AUTHOR), Fowler‐Finn, Kasey D.¹ (AUTHOR)

المصدر: Functional Ecology. Jun2024, Vol. 38 Issue 6, p1344-1356. 13p.

مصطلحات موضوعية: *INSECT reproduction, *BODY temperature regulation, *COLD-blooded animals, *SCALE insects, *BODY temperature, *ATMOSPHERIC temperature, *THERMAL tolerance (Physiology), *ANIMAL sexual behavior

مستخلص: Temperature influences nearly all aspects of fitness. However, reproduction is often more thermally sensitive than survival. Thermoregulation must maintain performance in both components of fitness to buffer populations from environmental change.We assessed the fitness benefits of thermoregulation in Enchenopa binotata treehoppers. Under realistic mesocosm conditions, we quantified fine‐scale microclimates using 3D‐printed operative temperature models. We then compared operative temperatures to treehopper body temperatures and translated patterns of thermoregulation into variation in survival and reproduction. We also assessed two thermoregulatory mechanisms: precise microclimate choice and heat‐escape behaviours. Finally, we applied our results to evaluate if arthropod thermoregulation is accurately characterized by two theoretical models commonly used to simulate responses to environmental change.We found substantial thermal variation at fine spatial scales relevant to insects: at a single point in time, temperatures within 30‐cm‐tall plants spanned ranges up to 19°C (23–42°C).Lethal operative temperatures were common when air temperatures were high. However, heat escapes allowed treehoppers to almost entirely avoid lethal temperatures.By contrast, individuals thermoconformed in the absence of lethal operative temperatures. This finding suggests that precise microclimate choice imposes high costs due to thermal uncertainty at fine spatial scales. Furthermore, given the narrow range of temperatures in which reproduction occurs, thermoregulation is unlikely to maintain reproduction.Thermoregulation was most effective in the lowest‐quality and most spatially variable thermal habitats. Treehopper thermoregulation therefore more closely follows cost–benefit models of thermoregulation compared to models that account for inhibited movement at extreme temperatures.Overall, even if thermoregulation can prevent lethal heat stress, it may have limited capacity to buffer arthropods and other small ectotherms from environmental change if it cannot maintain reproductive performance. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

المؤلفون: Paul, Kailey D.¹ (AUTHOR), Jiménez, Ana Gabriela¹ (AUTHOR) ajimenez@colgate.edu

المصدر: Journal of Experimental Zoology: Part A Ecological & Integrative Physiology. Jun2024, Vol. 341 Issue 5, p606-614. 9p.

مصطلحات موضوعية: *SLED dogs, *BODY temperature regulation, *BASAL metabolism, *AEROBIC capacity, *BODY temperature, *ENDURANCE athletes

مستخلص: Regulation of internal body temperature (Tb), or thermoregulation, is an evolutionarily conserved trait that places demand on basal metabolic rate of endothermic animals. Across species, athletes generate increased quantities of heat in comparison to their nonathletic counterparts and, therefore, must mediate physiological unbalance by upregulating the effectiveness of their heat dissipation abilities. Canine athletes are no exception to this phenomenon, however, with literature denoting body temperatures lower than nonathletic canines, it is clear they must possess adaptations to mitigate this demand. With VO2 max measurements of more than 200 mL/kg/min in sled dogs with mild training to 300 mL/kg/min in highly trained animals, sled dogs are a prime example of athleticism in canines. Seeking to determine correlations between Tear and body mass, morphology, and age of canine athletes, core body temperature (Tb) was measured with an instant ear thermometer, using Tear as a correlate before and after a 2‐mile run. In addition, we employed thermal imaging analysis to capture body‐wide heat dissipation patterns in sled dogs, and focused on thermal variation of mouth (Tmouth), nose (Tnose), and eyes (Teye). Furthermore, we looked at correlations between thermal variability across these four tissues and head morphology of each dog. Tear was consistently the highest temperature across all tissues measured, with a 1.5°C increase between pre‐ to postexercise (p < 0.001). Thermal imaging revealed significant positive correlations between Tmouth and body mass 15 min postexercise (p = 0.0023) as well as significantly negative correlations between Tnose and body mass at before exercise (p = 0.0468), Teye and nose length after run (p = 0.0076), and Tmouth and nose length after run (p = 0.0110). As body temperature rises during exercise, it becomes increasingly important to regulate blood flow throughout the body to supply working tissues with oxygen. This demand is offset by the role of the snout in evaporative cooling through panting, functioning as a prime location for heat dissipation and therefore maintaining significant relationships with many other vascularized tissues. Research Highlights: As body temperature rises during exercise, it becomes increasingly important to regulate blood flow throughout the body to supply working tissues with oxygen. This demand is offset by the role of the snout in evaporative cooling through panting, functioning as a prime location for heat dissipation. [ABSTRACT FROM AUTHOR]

المؤلفون: Jones, Scott A.¹ (AUTHOR), Ruprecht, Jonathan J.¹ (AUTHOR), Crichton, Paul G.² (AUTHOR), Kunji, Edmund R.S.¹ (AUTHOR) ek@mrc-mbu.cam.ac.uk

المصدر: Trends in Biochemical Sciences. Jun2024, Vol. 49 Issue 6, p506-519. 14p.

مصطلحات موضوعية: *MITOCHONDRIAL proteins, *BODY temperature regulation, *BROWN adipose tissue, *PURINE nucleotides, *UNCOUPLING proteins, *MITOCHONDRIAL membranes

مستخلص: Uncoupling protein 1 (UCP1, SLC25A7) is a mitochondrial carrier that facilitates thermogenesis in brown adipose tissue (BAT) by dissipating the protonmotive force and is a potential target for therapeutics against metabolic disease. Recent cryo-electron microscopy (cryo-EM) structures of human UCP1 have provided molecular insights into pH-dependent purine nucleotide inhibition of thermogenesis in BAT. UCP1 has the structural fold of members of the SLC25 mitochondrial carrier family, suggesting a related mechanism involving conformational changes, required to initiate proton conductance. The chemical uncoupler 2,4-dinitrophenol (DNP), which binds weakly to UCP1, does not induce conformational changes and retains a proton-impermeable state. Analysis of the structural features reveals potential molecular components of an activation mechanism of UCP1 in thermogenesis. In mitochondria, the oxidation of nutrients is coupled to ATP synthesis by the generation of a protonmotive force across the mitochondrial inner membrane. In mammalian brown adipose tissue (BAT), uncoupling protein 1 (UCP1, SLC25A7), a member of the SLC25 mitochondrial carrier family, dissipates the protonmotive force by facilitating the return of protons to the mitochondrial matrix. This process short-circuits the mitochondrion, generating heat for non-shivering thermogenesis. Recent cryo-electron microscopy (cryo-EM) structures of human UCP1 have provided new molecular insights into the inhibition and activation of thermogenesis. Here, we discuss these structures, describing how purine nucleotides lock UCP1 in a proton-impermeable conformation and rationalizing potential conformational changes of this carrier in response to fatty acid activators that enable proton leak for thermogenesis. [ABSTRACT FROM AUTHOR]