Download or read book Mammalian Thermogenesis written by Lucien Girardier and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: an attempt to rationalize these terminological and conceptual difficulties we have considered the origins of mammalian heat production from two different points of view. The scheme depicted in Fig. 1. 1 illustrates the fate of energy in the body as seen by the nutritionist. After allowing for losses of energy in faeces and urine, the metabolizable energy obtained from food is utilized for main taining and increasing body energy content (maintenance, external work, growth and production). The transformation of metabolizable energy into these forms of net energy also involves inevitable energy losses in the form of heat - thermic energy. Similarly, maintaining homeothermy in cold en vironments involves shivering and non-shivering thermogenesis (NST) and the energy costs of assimilating nutrients and retaining net energy results in obligatory heat losses due to diet-induced thermogenesis (DIT). This obligatory DIT is mainly due to the energy cost of protein and fat synthesis but, in addition to this, there is an adaptive component of DIT that helps maintain body energy content (i. e. body weight) by dissipating the metabolizable energy consumed in excess of the requirements for maintenance, growth and production. In Fig. 1. 2, we have converted this nutritionist's scheme (A) into one that A B r-------. . . , I I Production, Growth I I External work I I I I Essential energy expenditure NET BASAL Obligatory 1 I ENERGY Maintenance HEAT heat I FASTING at (BMR) productlpn for t ROC thermoneutrallty homeothermia r.
Download or read book The Evolution of Endothermy From Patterns to Mechanisms written by Elias T. Polymeropoulos and published by Frontiers Media SA. This book was released on 2018-09-14 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metabolic rate is a key ecophysiological factor determining fitness, distribution, survival and reproductive strategies of organisms. The ability to endogenously produce heat and elevate body temperature beyond ambient, has far reaching ecological implications. The diversity of thermogenic mechanisms and strategies employed throughout the animal kingdom is truly phenomenal and one of the greatest biological mysteries. Interestingly, even heat producing plants have been characterised. Over the last several decades, the oversimplified distinction between warm- and cold blooded animals has well and truly been put to rest and the terms “endo- and ectotherm” have been established. Birds and mammals are regarded as endotherms, capable of maintaining high body temperatures within highly precise boundaries. On contrary, in ectothermic organisms ambient temperature governs body temperature and metabolism, encompassing the majority of present day species. However, it has recently become very clear that this distinction is still not accurate enough to describe the vastness of heat generating mechanisms within endo- but also ectotherms. Indeed, a plethora of ectothermic animals display endogenous as well as behavioural means of temperature control and mechanisms for heat generation. There is large diversity in regards to thermoregulatory ability and strategy within endotherms as well, with some groups being classified by separate categories such as basoendotherms and mesotherms. Considerable interest and efforts has been put into the quest to understand the underlying physiological mechanisms leading and facilitating high metabolic rates and body temperatures of endotherms. These mechanisms are far from being exhaustively studied and the evolutionary trajectory leading to high metabolic rates and stable body temperatures is equally, vividly debated. This discussion includes an array of questions and theories surrounding the presence of endothermy in extinct dinosaurs. In addition, a lively debate surrounds the evolutionary drivers promoting the establishment of endothermy with clear support of direct or indirect selective benefits. Within this Research Topic we plan to compile the latest ideas, knowledge and experimental work to elucidate the patterns of the evolution of endothermy and its transition/distinction from ectothermy. The focus is on key physiological mechanisms supporting this transition and contributing to the maintenance of high metabolic rates and body temperature in endotherms, as well as mechanisms for local heterothermy and heat dissipation in ectotherms. These mechanisms and conclusions may be derived from different levels of organisation such as population, taxon, species as well as tissue, cellular or molecular levels. It may also encompass novel experimental or theoretical models testing evolutionary theories of endothermy. A comparative approach is encouraged but not fundamental.
Download or read book Animal Models for the Study of Human Disease written by Belinda A. Henry and published by Elsevier Inc. Chapters. This book was released on 2013-05-29 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Body weight is determined by the balance between energy intake and energy expenditure. Obesity ensues when energy intake exceeds that of energy expenditure. To date, the majority of pharmaco-therapies to control body weight have been directed towards the appetitive limb of this energy balance equation. Very few anti-obesity agents target the manipulation of energy expenditure. The recent unequivocal demonstration that functional brown adipose tissue is present in adult humans has sparked a great deal of interest in developing means to exploit thermogenesis to control body weight. Thermogenesis is defined as the dissipation of energy through the production of heat and occurs in specialised tissues including brown adipose tissue and skeletal muscle. This chapter will highlight a number of animal models that are currently utilised in effort to understand the mechanisms that underpin thermogenesis. It will describe the control of thermogenesis in skeletal muscle and adipose tissue as well as detailing the role of thermogenesis in determining the susceptibility to obesity in a number of distinct animal models.
Download or read book Defining the Mechanisms of Uncoupling Protein 3 induced Thermogenesis and Metabolism in Brown Adipose Tissue written by Sonya Maria Veron and published by . This book was released on 2014 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncoupling proteins (UCPs) constitute a highly conserved subset of mitochondrial solute carriers. Discovered in small rodents in the early 1970's, UCPs and their homologs have since been found in nematodes, plants, birds, and, most recently, in significant depots within humans (Krauss et al. 2005, Van marken Lichtenbelt 2009). Following activation by long chain fatty acids (LCFA, e.g. oleic acid) and reactive oxygen species (ROS, e.g. 4-hydroxynonenal (4HNE)), UCPs form a proton channel within the inner mitochondrial membrane and permit the influx of hydrogen ions from the inter membrane space into the mitochondrial matrix. UCPs effectively uncouple oxidative phosphorylation (OX-PHOS) from ATP generation, resulting in increasing oxygen consumption and dissipating the chemical energy in the form of heat. Found primarily in brown adipose tissue (BAT) of small hibernating mammals, the canonical role of uncoupling protein 1 (UCP1) in mammalian adaptive thermogenesis has been thoroughly studied. However, UCP1 is not the only member of the uncoupling family found within BAT. Also playing a key role in this tissue is uncoupling protein 3 (UCP3), which is a close homolog to UCP1. However, in spite of the fact that UCP3 shares more than 50% amino acid homology and tissue localization with UCP1, the true function UCP3 is very poorly elucidated. Part of the difficulty in determining this function lies in the expression levels of the UCP3 protein, which are hundreds of folds less than UCP1 in this tissue. In addition, their homologous structure makes teasing apart UCP3-specific phenomena from UCP1-mediated mechanisms very difficult using conventional techniques in cell and molecular biology. While UCP1 is almost exclusively found in BAT, UCP3 is expressed primarily in skeletal muscle (SKM), which lacks UCP1 completely (Krauss et al. 2005). Because UCP3 is so enriched in SKM, many studies have focused on its role in that tissue and have then tried to transpose these functions into BAT. As a result, UCP3 has been implicated in facilitating numerous biological processes, including non-adaptive facultative thermogenesis, affecting SKM oxidative capacity by modulating LCFA export, and ameliorating elevated levels of ROS-mediated stress within the tissue via glutathionine (GSH) interacting moieties. Ultimately, however, little consensus exists on the function of UCP3 within SKM, and subsequently, even less is known about its purpose in BAT. Previous data has shown that murine UCP1 has the capacity to bind to itself and form homo-tetramers when expressed in vitro in recombinant E. coli (Hoang T. et al. 2013). Here we show that UCP1 interacts with UCP3 in BAT in vivo, supporting Hoang's research above by showing that UCP1 has the capacity to not only homodimerize but potentially oligomerize with other UCP homologs. While many groups using UCP3-null mice have reported no gross changes in physiologic responses, data previously published in the lab showed that mice lacking UCP3 were protected from potentially fatal hyperthermic effects when administered sympathomimetic agents such as 3,4-Methylenedioxymethamphetamine (MDMA), methamphetamine (METH), lipopolysaccharide (LPS), or norepinephrine (NE) (Mills et al. 2003, Kenaston et al. 2010). This implies that UCP3 plays an intimate role in sympathetic nervous system (SNS) mediated thermogenesis. Based upon the foregoing, the primary goal of the research discussed in this thesis was to elucidate the functions of UCP3 within BAT. In this study, we recapitulated results seen by other students in this lab: that global UCP3-null mice do indeed exhibit a blunted thermogenic response when treated with sympathomimetic agonists. In addition, despite the near-ubiquitous expression of UCP2 throughout the mammalian organism, this UCP is not involved in SNS-mediated thermogenesis (Arsenijevic et al. 2000). Our data shows that UCP3 is vital to the catecholamine-mediated thermogenic responses following sympathomimetic drug administration. When challenged by METH, UCP3-null mice were able to respond, albeit with a blunted increase in body temperature. Furthermore, when challenged by NE, a key neurotransmitter involved in mediating the responses initiated by the SNS following METH exposure, UCP3-null mice were able to mount half the hyperthermic response seen in WT littermates. However, UCP1/UCP3 double-null animals exhibited an almost four-fold hypothermic effect compared to WT littermates when challenged with NE. In addition, UCP1/UCP3 double-null mice were unable to restore body temperatures back to baseline values, an effect seen in all the other genotypes. This implies that UCP3 plays an important role in restoring body temperatures to physiological norms. Therefore, while the mechanism underlying the decreased responsiveness to NE remains unclear, it is clear that whether localized to SKM or BAT, UCP3 is a major player in the mammalian response to SNS-mediated thermogenesis and global thermoregulation.
Download or read book Fires of Life written by Barry Gordon Lovegrove and published by Yale University Press. This book was released on 2019-01-01 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: A groundbreaking argument on how endothermy--arguably the most important innovation in vertebrate evolution--developed in birds and mammals "Vividly narrated and illustrated. . . . Provocative and fascinating for specialists and lay readers alike."--Southeastern Naturalist This pioneering work investigates why endothermy, or "warm-bloodedness," evolved in birds and mammals, despite its enormous energetic costs. Arguing that single-cause hypotheses to explain the origins of endothermy have stalled research since the 1970s, Barry Gordon Lovegrove advances a novel conceptual framework that considers multiple potential causes and integrates data from the southern as well as the northern hemisphere. Drawing on paleontological data; research on extant species in places like the Karoo, Namaqualand, Madagascar, and Borneo; and novel physiological models, Lovegrove builds a compelling new explanation for the evolution of endothermy. Vividly narrated and illustrated, this book stages a groundbreaking argument that should prove provocative and fascinating for specialists and lay readers alike.
Download or read book Temperature Regulation in Humans and Other Mammals written by Claus Jessen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: How do mammals manage to maintain their body temperature within the same narrow range in environments as different as polar regions and hot deserts? This advanced text describes the morphological features and physiological mechanisms by which humans and other mammals maintain their body temperature within a narrow range despite large variations in climatic conditions and internal heat production. Its 19 chapters deal with the physics of heat exchange with the environment, and the autonomic and behavioural mechanisms available to control the loss and production of heat. The neuronal basis of temperature regulation and current concepts of the central nervous interface between temperature signals generated in the body and control mechanisms are examined in detail. This book is of invaluable help for undergraduates, postgraduates, teachers, physicians and scientists.
Download or read book Shivering Thermogenesis in Birds written by Esa Hohtola and published by . This book was released on 1982 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanism, control, evolution and electromyographic correlates.
Download or read book Nutritional Needs in Cold and High Altitude Environments written by Institute of Medicine and published by National Academies Press. This book was released on 1996-05-15 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the research pertaining to nutrient requirements for working in cold or in high-altitude environments and states recommendations regarding the application of this information to military operational rations. It addresses whether, aside from increased energy demands, cold or high-altitude environments elicit an increased demand or requirement for specific nutrients, and whether performance in cold or high-altitude environments can be enhanced by the provision of increased amounts of specific nutrients.
Download or read book Canine and Feline Nutrition E Book written by Linda P. Case and published by Elsevier Health Sciences. This book was released on 2010-05-21 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: How well can you answer pet owners' questions about proper diet and feeding? Canine and Feline Nutrition, 3rd Edition describes the role of nutrition and its effects upon health and wellness and the dietary management of various disorders of dogs and cats. By using the book's cutting-edge research and clinical nutrition information, you'll be able to make recommendations of appropriate pet food and proper feeding guidelines. Pet nutrition experts Linda P. Case, MS, Leighann Daristotle, DVM, PhD, Michael G. Hayek, PhD, and Melody Foess Raasch, DVM, provide complete, head-to-tail coverage and a broad scope of knowledge, so you can help dog and cat owners make sound nutrition and feeding choices to promote their pets' health to prolong their lives. Tables and boxes provide quick reference to the most important clinical information. Key points summarize essential information at a glance. A useful Nutritional Myths and Feeding Practices chapter dispels and corrects common food myths. New clinical information covers a wide range of emerging nutrition topics including the role of the omega-3 and omega-6 fatty acid families in pet health and disease management. Coverage of pet food safety and pet food ingredients includes both commercially and home-prepared foods and provides answers to pet owners’ questions on these topics. Completely updated content reflects the latest findings in clinical nutrition research. Information regarding functional ingredients and dietary supplementation provides a scientifically based rationale for recommending or advising against dietary supplements. Guidelines for understanding pet food formulations and health claims differentiate between "market-speak" and actual clinical benefits for patients, with practice advice for evaluating and selecting appropriate foods.
Download or read book The Adipose Organ written by Saverio Cinti and published by . This book was released on 1999 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Mammals written by Randall W. Davis and published by Springer Nature. This book was released on 2019-11-14 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive book provides new insights into the morphological, metabolic, thermoregulatory, locomotory, diving, sensory, feeding, and sleep adaptations of Cetacea (whales and dolphins), Pinnipedia (seals, sea lions and walrus), Sirenia (manatees and dugongs) and sea otters for an aquatic life. Each chapter reviews the discoveries from previous studies and integrates recent research using new techniques and technology. Readers will gain an understanding of the remarkable adaptations that enable marine mammals to spend all or most of their lives at sea, often while hunting prey at depth.
Download or read book Obesity and Obstetrics written by Tahir A. Mahmood and published by Elsevier. This book was released on 2020-06-06 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: Obesity and Obstetrics, Second Edition, brings together experts to examine the issues and challenges of obesity and obstetrics, also discussing how obesity affects fertility, reproduction and pregnancy. Beginning with the worldwide epidemic of obesity, chapters then go on to review obesity and hyperglycemia of pregnancy, management of labor, interventions to improve care during pregnancy, and long-term impact of maternal obesity. Provides an essential reference on the significant risk of complications during pregnancy, including early pregnancy loss, recurrent miscarriage and fetal developmental abnormalities Builds foundational knowledge on how maternal obesity predisposes offspring to obesity, highlighting that the prevention of childhood obesity begins during pregnancy Assembles critically evaluated chapters focused on obesity and obstetrics to meet the practical needs of obstetricians, endocrinologists and general practitioners
Download or read book Thermogenesis written by and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Temperature Regulation in Mammals and Other Vertebrates written by J. Bligh and published by . This book was released on 1973 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive analysis of the evolutionary progression and the physiology of temperature regulation in vertebrates.
Download or read book Advances in Comparative and Environmental Physiology written by Lawrence C.H. Wang and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: When survival is challenged by the cold, animals react by employing both behavioral and physiological solutions. Depending on the magni tude of the cold stress and the nature of the adjustment, simple avoidance or sophisticated capacity or resistance compensations may be used. Thus, migration, shelter seeking, metabolic and insulative compen sation, torpor, and freezing avoidance and tolerance are successful tac tics used by diverse groups of animals. To understand and appreciate the benefits of these tactics, it is necessary to examine not only the well being of the whole animal but also their basic underlying mechanisms. In ad dition, it is also of fundamental importance to grasp how seasonal cold affects the survivorship and reproductive success of populations when confronted by a general reduction in primary productivity and an elevated energy cost for maintenance (e. g. in endotherms). In this regard, a synthetic overview which integrates aspects of cell biology, biochem istry, physiology, neurobiology, behavior, and population biology should be a fruitful approach in providing a holistic understanding on how animals adapt to cold. The present volume is an attempt to achieve such an overview; its objective is to provide a depth and breadth of coverage that is essential to a full appreciation of animal adaptation to cold. It is the hope of the contributing authors that this book will serve as an effective reference text for all senior undergraduate and graduate students as well as research scientists with an interest in cold physiology.
Download or read book Ecological and Environmental Physiology of Mammals written by Philip C. Withers and published by Oxford University Press. This book was released on 2016-11-10 with total page 685 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mammals are the so-called "pinnacle" group of vertebrates, successfully colonising virtually all terrestrial environments as well as the air (bats) and sea (especially pinnipeds and cetaceans). How mammals function and survive in these diverse environments has long fascinated mammologists, comparative physiologists and ecologists. Ecological and Environmental Physiology of Mammals explores the physiological mechanisms and evolutionary necessities that have made the spectacular adaptation of mammals possible. It summarises our current knowledge of the complex and sophisticated physiological approaches that mammals have for survival in a wide variety of ecological and environmental contexts: terrestrial, aerial, and aquatic. The authors have a strong comparative and quantitative focus in their broad approach to exploring mammal ecophysiology. As with other books in the Ecological and Environmental Physiology Series, the emphasis is on the unique physiological characteristics of mammals, their adaptations to extreme environments, and current experimental techniques and future research directions are also considered. This accessible text is suitable for graduate level students and researchers in the fields of mammalian comparative physiology and physiological ecology, including specialist courses in mammal ecology. It will also be of value and use to the many professional mammologists requiring a concise overview of the topic.
Download or read book Pharmacotherapy of Obesity written by Karl G. Hofbauer and published by CRC Press. This book was released on 2004-06-14 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: Primarily intended for physicians and health care professionals who are treating obese patients, this book explores current and future options for drug treatment of obesity puts them into perspective against available alternative treatments. Distinguished scientists and clinical investigators provide reviews of each individual topic, covering a wide range of subjects from pathophysiology of obesity to the benefits of weight loss. The core sections on pharmacotherapy deal with currently available drugs and drugs in pre-clinical development. These sections are complemented with sections on non-drug treatment and general therapeutic aspects. This design provides an integrated view of therapeutic approaches to the treatment of obesity and its associated syndromes.