scholarly journals Appetite control

2005 ◽  
Vol 184 (2) ◽  
pp. 291-318 ◽  
Author(s):  
Katie Wynne ◽  
Sarah Stanley ◽  
Barbara McGowan ◽  
Steve Bloom

Our understanding of the physiological systems that regulate food intake and body weight has increased immensely over the past decade. Brain centres, including the hypothalamus, brainstem and reward centres, signal via neuropeptides which regulate energy homeostasis. Insulin and hormones synthesized by adipose tissue reflect the long-term nutritional status of the body and are able to influence these circuits. Circulating gut hormones modulate these pathways acutely and result in appetite stimulation or satiety effects. This review discusses central neuronal networks and peripheral signals which contribute energy homeostasis, and how a loss of the homeostatic process may result in obesity. It also considers future therapeutic targets for the treatment of obesity.

2020 ◽  
Vol 21 (16) ◽  
pp. 5715
Author(s):  
Veronica Pena-Leon ◽  
Raquel Perez-Lois ◽  
Luisa Maria Seoane

Mammalian, or mechanic, target of rapamycin (mTOR) signaling is a crucial factor in the regulation of the energy balance that functions as an energy sensor in the body. The present review explores how the mTOR/S6k intracellular pathway is involved in modulating the production of different signals such as ghrelin and nesfatin-1 in the gastrointestinal tract to regulate food intake and body weight. The role of gastric mTOR signaling in different physiological processes was studied in depth through different genetic models that allow the modulation of mTOR signaling in the stomach and specifically in gastric X/A type cells. It has been described that mTOR signaling in X/A-like gastric cells has a relevant role in the regulation of glucose and lipid homeostasis due to its interaction with different organs such as liver and adipose tissue. These findings highlight possible therapeutic strategies, with the gut–brain axis being one of the most promising targets in the treatment of obesity.


2020 ◽  
pp. 2862-2870
Author(s):  
Rebecca Scott ◽  
T.M. Tan ◽  
S.R. Bloom

The gastrointestinal tract is the largest endocrine organ in the body, with its component cells dispersed along its length rather than being clustered in glands. More than 20 gut peptides integrate gastrointestinal function by regulating the actions of the epithelium, muscles, and nerves; they also affect the growth and development of the gut and have a major role in appetite control. They mostly work in an autocrine or paracrine manner. Gastrointestinal hormones include the gastrin–cholecystokinin family, the secretin superfamily, preproglucagon derivatives, the motilin–ghrelin family, the pancreatic polypeptide-fold family, and various other gut peptides. Gastrointestinal and other diseases may cause abnormalities of these gut peptides, for example: (1) achlorhydria (from atrophic gastritis or drug-induced) causes elevation of circulating gastrin; (2) malabsorptive conditions are associated with a decrease in the amount of peptides produced in the affected region, and a compensatory elevation of other peptides; and (3) obesity is associated with orexigenic (appetite-stimulating) and less satiating hormonal changes, and the beneficial effects of bariatric surgery are partly explained through alterations in gut hormones.


2015 ◽  
Vol 21 (3) ◽  
pp. 345-371
Author(s):  
Deryk Stec

Purpose This paper aims to examine how residues of ancient images have influenced one’s perspectives on management. Increased attention has been given to the absence of bodies within discussions of organisations; however, far less attention has been given to the interplay between organisations and images of one’s body. Design/methodology/approach By comparing the perceived benefits of studying sport (e.g. passion, embodiment and action) with the tensions that existed between athletic performances and an ancient image of the body, this paper draws attention to residuals that exist within discussions of organisations. Findings In a context where an image of the body encouraged moderation, the appropriate levels of heat, and the development of an immaterial and eternal soul, athletic performances, which were physical, extreme, focused on the body and generated excessive heat, were often problematic. These problems are then examined within the literature discussing current issues in management. Research limitations/implications Sport has the potential to facilitate one’s understanding of issues that management, consistent with ancient images of the body, has traditionally neglected (i.e. extremes, passion) and the possibilities of using embodied cognition to enhance our understandings of performance, teams and leading are discussed. Social implications As scientists become increasingly concerned about the long-term consequences of the reduced opportunities for cultural programs (sport, art, music, etc.), revisiting one’s assumptions is increasingly important, especially as athletics and philosophy once shared the same physical space. Originality/value By describing how residues from historical images of the body have influenced the thinking about organizing, this paper highlights the connection between the social and the biological and demonstrates how vestiges from the past influence contemporary discussions.


2018 ◽  
Vol 64 (1) ◽  
pp. 173-182 ◽  
Author(s):  
Agatha A van der Klaauw

Abstract BACKGROUND The global rise in the prevalence of obesity and associated comorbidities such as type 2 diabetes, cardiovascular disease, and cancer represents a major public health concern. CONTENT Studies in rodents with the use of global and targeted gene disruption, and mapping of neurocircuitry by using optogenetics and designer receptors exclusively activated by designer drugs (DREADDs) have greatly advanced our understanding of the neural control of body weight. In conjunction with analytical chemistry techniques involving classical immunoassays and mass spectrometry, many neuropeptides that are key to energy homeostasis have been identified. The actions of neuropeptides are diverse, from paracrine modulation of local neurotransmission to hormonal control of distant target organs. SUMMARY Multiple hormones, such as the adipocyte-derived leptin, insulin, and gut hormones, and nutrients signal peripheral energy state to the central nervous system. Neurons in distinct areas of the hypothalamus and brainstem integrate and translate this information by both direct inhibitory/excitatory projections and anorexigenic or orexigenic neuropeptides into actions on food intake and energy expenditure. The importance of these neuropeptides in human energy balance is most powerfully illustrated by genetic forms of obesity that involve neuropeptides such as melanocortin-4-receptor (MC4R) deficiency. Drugs that mimic the actions of neuropeptides are being tested for the treatment of obesity. Successful therapeutic strategies in obesity will require in-depth knowledge of the neuronal circuits they are working in, the downstream targets, and potential compensatory mechanisms.


2018 ◽  
Vol 4 ◽  
Author(s):  
Shi Feng ◽  
Yu Wang

Obesity is a chronic life-threatening disease throughout the world. Available anti-obesity drugs may have hazardous side effects and no long-term safety assurance is in place for patients. In recent decades, alternative natural therapeutics have been intensively investigated. Among them, phytochemicals from citrus fruits have shown tremendous potential to combat obesity through different mechanisms. To date, the most active biological constitutes identified in citrus fruits are flavonoids and p-synephrine. These exert anti-obesity effects through multiple mechanisms, including regulating energy intake and expenditure, regulating lipid metabolism and regulating adipogenesis. In this mini review, a survey focusing on citrus phytochemicals and their anti-obesity activities is presented, together with an update of findings over the last 10 years, including active components and mechanisms of anti-obesity activities.


2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
Keisuke Suzuki ◽  
Channa N. Jayasena ◽  
Stephen R. Bloom

Obesity is one of the major challenges to human health worldwide; however, there are currently no effective pharmacological interventions for obesity. Recent studies have improved our understanding of energy homeostasis by identifying sophisticated neurohumoral networks which convey signals between the brain and gut in order to control food intake. The hypothalamus is a key region which possesses reciprocal connections between the higher cortical centres such as reward-related limbic pathways, and the brainstem. Furthermore, the hypothalamus integrates a number of peripheral signals which modulate food intake and energy expenditure. Gut hormones, such as peptide YY, pancreatic polypeptide, glucagon-like peptide-1, oxyntomodulin, and ghrelin, are modulated by acute food ingestion. In contrast, adiposity signals such as leptin and insulin are implicated in both short- and long-term energy homeostasis. In this paper, we focus on the role of gut hormones and their related neuronal networks (the gut-brain axis) in appetite control, and their potentials as novel therapies for obesity.


2005 ◽  
Vol 85 (4) ◽  
pp. 1131-1158 ◽  
Author(s):  
Sarah Stanley ◽  
Katie Wynne ◽  
Barbara McGowan ◽  
Stephen Bloom

Our knowledge of the physiological systems controlling energy homeostasis has increased dramatically over the last decade. The roles of peripheral signals from adipose tissue, pancreas, and the gastrointestinal tract reflecting short- and long-term nutritional status are now being described. Such signals influence central circuits in the hypothalamus, brain stem, and limbic system to modulate neuropeptide release and hence food intake and energy expenditure. This review discusses the peripheral hormones and central neuronal pathways that contribute to control of appetite.


2017 ◽  
Vol 11 (4) ◽  
pp. 280-284 ◽  
Author(s):  
Kevin G Williams ◽  
Anthony JR Blacker ◽  
Priyadarshi Kumar

Ureteric stents are fundamental to modern-day urological practice. This article aims to chronicle their development over the last century and the key individuals whose efforts have made their development possible. Early stents were ureteric catheters that were exteriorised outside the body and were associated with complications including migration, infection and encrustation. The use of polyethylene stents in humans was first reported by Tulloch in 1952. Polyethylene was thought to be a promising material due to its durability and water-repellent nature. It would, however, suffer the problems that would become associated with stents over the following decades mentioned above. The first silicone ureteric stents were developed in the 1960s by Zimskind and provided prolonged, efficient drainage but were complicated with stent migration. Collars, wings, flanges and barbs were developed to help prevent migration. Finney developed a double ‘pig-tail’ stent in the 1970s which helped to prevent both proximal and distal migration and the modern-day ureteric stent was born. Modern polymers have been developed such as polyurethane or styrene ethylene-butylene (C-flex®). Metal stents have also been used over the last three decades including the Wallstent™, Resonance® and Memokath™ stents. They have shown promising results particularly when long-term relief of ureteric obstruction is needed. Various strategies are available for removal including cystoscopically, stents with a metallic end that can be removed by using a catheter with a magnet at the proximal end, tethered stents that can be removed noninvasively either by the urologist, nurse or even by the patient and dissolvable stents which are in development.


2004 ◽  
Vol 12 (2) ◽  
pp. 217-225 ◽  
Author(s):  
GRAHAM J. DOCKRAY

The obesity epidemic is now widely recognized as a major threat to health in many different countries. Some surgical therapies for obesity are efficacious and indicate that signals from the gastrointestinal tract are capable of exerting beneficial long-term effects on food intake and body weight. The development of non-surgical therapies targeting this system depends on understanding how food, and the absence of food, in the gastrointestinal tract signals to those parts of the brain that regulate feeding behaviour. What can be called gastrointestinal surveillance systems include both nervous pathways linking the gut and brain, and some gut hormones. Nutrient sensing mechanisms within the gastrointestinal tract determine the release of satiety hormones such as cholecystokinin (CCK), or appetite stimulating hormones such as ghrelin, and offer potential therapeutic targets. It seems that CCK and ghrelin both act on the vagus nerve that links the gut to the brain. Examples of interactions between different factors regulating this pathway are discussed. It is argued that sufficient is now known to indicate that this signalling system can provide new targets for the treatment of obesity.


2021 ◽  
Author(s):  
Sissy M Jhiang ◽  
Jennifer A Sipos

Radioiodine (131I) has been used to ablate thyroid tissue not removed by surgery or to treat differentiated thyroid cancer that has metastasized to other parts of the body for the past 80 years. However, the Na+/I- symporter (NIS), which mediates active iodide uptake into thyroid follicular cells, is also expressed in several non-thyroidal tissues. This NIS expression permits 131I accumulation and radiation damage in these non-target tissues, which accounts for the adverse effects of radioiodine therapy. We will review the data regarding the expression, function, and regulation of NIS in non-thyroidal tissues. We will explain the seemingly paradoxical adverse effects induced by 131I: the self-limited gastrointestinal adverse effects in contrast to the permanent salivary dysfunction that is seen after 131I therapy. We propose that prospective studies are needed to uncover the time-course of pathological processes underlying development and progression or ultimate resolution of 131I-induced salivary ductal obstruction and nasolacrimal duct obstruction. Finally, preventive measures and early therapeutic interventions that can be applied potentially to eliminate or alleviate long-term radioiodine adverse effects will be discussed.


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