Conclusions
Miroslav Holub in Immunology of Nude Mice, 2020
During their short history, a number of endocrine disorders have been described in the nude mice, in many cases dependent on their microbiological status. A general developmental alteration may be the hypothalamic programming in early life, a hypothyroid state, and a delay of female sexual maturation. Thermoregulatory strains are compensated by increased noradrenalin levels which may negatively affect the immune reactions. Nonshivering thermogenesis triggered at all ambient temperatures below the thermoneutrality zone is connected with the development of thermogenic mitochondria in the brown adipose tissue, deiodination of thyroxine and a conspicuous increase of phagocytic and natural killer cell activity. Social behavior seems, however, to be one of the principal solutions of thermoregulatory problems.
Marine Algal Secondary Metabolites Are a Potential Pharmaceutical Resource for Human Society Developments
Se-Kwon Kim in Marine Biochemistry, 2023
Obesity is defined as the unwanted accumulation of body fat and white adipose tissue (WAT), which inhibits the secretion of cytokines in adipose tissue and leads to a variety of other disorders such as diabetes, high cholesterol and stroke (Namvar et al., 2012). Thermogenesis plays an important role in the regulation of the mechanisms of obesity. Similarly, administration of algae to rats reduced plasma leptin and epididymal adipose tissue levels (Grasa-López et al., 2016). In addition, algae significantly reduced adipocyte size, fasting blood sugar and insulin levels in obese rats (Gammone and D’Orazio, 2015). Algae with fucoxanthin inhibited fat absorption and serum triglyceride levels in an in vivo model and have also been shown to have anti-obesity effects in mice (Kang et al., 2012).
Child Versus Adult
Lara Wijayasiri, Kate McCombe, Paul Hatton, David Bogod in The Primary FRCA Structured Oral Examination Study Guide 1, 2017
Temperature homeostasis: Poor temperature regulation in neonates.Large body surface area/volume ratio.High heat loss.Higher thermoneutral temperature (temperature below which an individual is unable to maintain core body temperature) 32 °C for a term infant compared with 28 °C for an adult.Infants <3 months of age cannot shiver.Utilise non-shivering brown fat thermogenesis.
Circadian rhythmicity of body temperature and metabolism
Published in Temperature, 2020
Birds and mammals can increase metabolic heat production when exposed to a cold environment, and this is called cold-induced thermogenesis. Shivering is one form of cold-induced thermogenesis. It is a widespread mechanism of thermogenesis used to prevent the fall of body temperature in a cold environment. It consists of small-amplitude, high-frequency contractions of skeletal muscles. It is employed both by birds [382,392,525–531] and by mammals [532–547], including humans [548–550]. Forms of biological thermogenesis other than shivering are collectively called non-shivering thermogenesis. Birds seem to rely primarily on shivering and, if they exhibit thermoregulatory non-shivering thermogenesis, the muscles themselves are the probable source [392,528–530,551-554]. Mammals, on the other hand, use non-shivering thermogenesis extensively in response to cold stress, and the capacity to use it is strongly affected by acclimation or acclimatization [534,540–543,546,555–578]. Mammalian thermoregulatory non-shivering thermogenesis often relies on the activation of a specialized tissue, brown adipose tissue [579,580].
CORM-401, an orally active carbon monoxide-releasing molecule, increases body temperature by activating non-shivering thermogenesis in rats
Published in Temperature, 2022
Mateus R. Amorim, Roberta Foresti, Djamal Eddine Benrahla, Roberto Motterlini, Luiz G. S. Branco
In this study, we have shown that oral administration of CORM-401 to rats leads to an increase in Tb caused by augmented non-shivering thermogenesis without affecting neither the amount of heat loss through the tail skin nor blood pressure. Thus, the present data are consistent with the notion that delivery of controlled amounts of CO to the body causes an increase in Tb associated with an elevated heat production, indicating that this thermoeffector is specifically activated after systemic CO liberation. Moreover, these thermoregulatory responses were not associated with any significant changes in arterial blood pressure. Non-shivering thermogenesis is defined as an increased metabolic heat production (above the basal metabolism) that is not associated with muscle activity but rather resulting mainly from the increased metabolism of brown fat [25].
Skeletal muscle plasticity and thermogenesis: Insights from sea otters
Published in Temperature, 2022
Traver Wright, Melinda Sheffield-Moore
Although the metabolic rate in resting skeletal muscle is low, it can rapidly increase to support metabolic demand. In skeletal muscle, this increased demand often powers muscle contractions for movement during physical activity, but can also increase for thermogenesis. Increased metabolic heat production can result from shivering (thermogenic muscle contractions that do not support functional movement), or nonshivering thermogenesis. Nonshivering thermogenesis has the advantage of not requiring muscle contraction to increase cellular energy expenditure. Instead, the sequestration of ions in membrane-bound intracellular chambers is made less efficient by “leaky” membranes. This leak requires additional energy expenditure to maintain trans-membrane concentration gradients, and includes proton leak across the inner mitochondrial membrane (where the proton gradient is used to generate ATP) as well as sarcolipin-mediated leak of sequestered calcium from the sarcoplasmic reticulum [4]. Through these mechanisms, skeletal muscle tissue contributes significantly to thermogenesis. Skeletal muscle metabolic capacity must be maintained at a level adequate to support not only thermogenesis, but also peak simultaneous demands for sustained physical activity and cellular maintenance. While increased demand for physical activity (e.g. endurance exercise training) is recognized as the primary work-producing stimulus to upregulate skeletal muscle aerobic capacity, the role of cold exposure is often underappreciated for its ability to stimulate an upregulation of metabolic capacity and thermogenic leak.
Related Knowledge Centers
- Brown Adipose Tissue
- Muscle
- Uncoupling Protein
- Warm-Blooded
- Symplocarpus Foetidus
- NON-Exercise Activity Thermogenesis
- Specific Dynamic Action
- Shivering
- Adenosine Triphosphate
- Thermogenin