256 research outputs found
Persoonlijkheid: Een belangrijke factor bij de ontwikkeling, behandeling en de preventie van type 2 diabetes
No full textDe toegenomen incidentie van type 2 diabetes is deels toe te schrijven aan de huidige obesogene leefomgeving. Er bestaan echter grote individuele verschillen in de ontwikkeling van type 2 diabetes. De persoonlijkheid van een individu is in hoge mate bepalend voor de manier waarop een individu omgaat met zijn omgeving. Dit betekent dat de persoonlijkheid van een individu mogelijk ook een bepalende factor zou kunnen zijn bij de ontwikkeling van type 2 diabetes. Wij hebben dit onderzocht in een diermodel met passieve en proactieve ratten. Passieve ratten bleken een grote aanleg hebben voor het ontwikkelen van insulineresistentie terwijl proactieve ratten, zelfs in een obesogene omgeving, gekenmerkt worden door een hoge insulinegevoeligheid. Ook bij de behandeling van type 2 diabetes werden er verschillen gevonden tussen passieve en proactieve ratten. Dit gold zowel voor farmacologische behandeling met een selectieve glucocorticoïd receptor antagonist als voor life style interventie programma’s, met name op het gebied van fysieke activiteit. De studies bevestigen dat de persoonlijkheid van een individu een belangrijke factor is bij de ontwikkeling en behandeling van type 2 diabetes, met name door de interacties van het individu met zijn leefomgeving. We stellen dat de behandeling van type 2 diabetes sterk zou kunnen verbeteren door rekening te houden met de interactie tussen de leefomgeving van de patiënt, zijn of haar persoonlijkheid en uiteraard de bijbehorende fysiologische kenmerken
The Role of Leptin in the Regulation of Energy Balance and Adiposity
Get PDFSince its discovery, leptin (a 167-amino acid product of the OB gene) has quickly moved to the forefront as an important hormone for regulation of energy balance. It closes a feedback loop from adipose tissue to hypothalamic neuropeptide-containing neural circuitry involved in regulation of food intake and neuroendocrine/autonomic outflow. While increased central leptin signalling reduces adiposity via a reduction in food intake, it also has remarkable metabolic effects that promote leanness, independent of food intake. These include: (i) increased energy expenditure, (ii) in-place degradation of fat, and (iii) increased thermogenesis. Hypothalamic neurones that synthesize corticotropin releasing hormone and melanocortins (i.e. α-melanocyte-stimulating hormone and agouti-related protein) are likely effector pathways that mediate the anorexigenic and metabolic effects of leptin. Activation of sympathetic outflow (via neuropeptidergic effector pathways of central leptin) to a number of tissues that store fat might be an important mechanism through which these peripheral metabolic effects are elicited. It is proposed that these peripheral metabolic effects contribute to the satiating properties of leptin.
Neurobiology of the metabolic syndrome: An allostatic perspective
Get PDFThe metabolic syndrome is a cluster of more or less related metabolic and cardiovascular derangements including visceral obesity, insulin resistance, blood and tissue dislipidemia, high blood pressure and it is often associated with neuroendocrine and immunological dysregulations. The aetiology of this syndrome is clinically highly relevant because it predisposes to life-threatening complications, such as Diabetes Mellitus, kidney failure, cardiovascular disease, and certain types of cancer. Contributing factors include a sedentary life-style combined with increased dietary fat intake and psychosocial stress. From a biological viewpoint, however, the metabolic syndrome can be considered as a maladaptive consequence of an initially successful adaptation to high environmental demands. As opposed to pre-historic times — when environmental demands were usually energy-costly (e.g., fight/flight/hunt) and nutritional resource often inadequate — energy-utilizing actions serve no longer an optimal solution to deal with environmental demands of current human society. This paper describes the interactions between psychosocial stress and nutrition and how these may affect emotional and metabolic components of the metabolic syndrome. A deeper understanding of these interactions is necessary to come to effective treatment and prevention of the metabolic syndrome in the future.
Distinct Effects of Short Chain Fatty Acids on Host Energy Balance and Fuel Homeostasis With Focus on Route of Administration and Host Species
Get PDFAccumulating evidence implicates gut-microbiota-derived metabolites as important regulators of host energy balance and fuel homeostasis, the underlying mechanisms are currently subject to intense research. In this review, the most important executors, short chain fatty acids, which both directly and indirectly fulfill the interactions between gut microbiota and host will be discussed. Distinct roles of individual short chain fatty acids and the different effects they exert on host metabolism have long been overlooked, which compromises the process of clarifying the sophisticated crosstalk between gut microbiota and its host. Moreover, recent findings suggest that exogenously administered short chain fatty acids affect host metabolism via different mechanisms depending on the routes they enter the host. Although these exogenous routes are often artificial, they may help to comprehend the roles of the short-chain-fatty-acid mechanisms and signaling sites, that would normally occur after intestinal absorption of short chain fatty acids. Cautions should be addressed of generalizing findings, since different results have appeared in different host species, which may imply a host species-specific response to short chain fatty acids
Parkinson's disease medication alters small intestinal motility and microbiota composition in healthy rats
Get PDFParkinson's disease (PD) is known to be associated with altered gastrointestinal function and microbiota composition. To date, the effect of PD medication on the gastrointestinal function and microbiota, at the site of drug absorption, the small intestine, has not been studied, although it may represent an important confounder in reported microbiota alterations observed in PD patients. To this end, healthy (non-PD) wild-type Groningen rats were employed and treated with dopamine, pramipexole (in combination with levodopa-carbidopa), or ropinirole (in combination with levodopa-carbidopa) for 14 sequential days. Rats treated with dopamine agonists showed a significant reduction in small intestinal motility and an increase in bacterial overgrowth in the distal small intestine. Notably, significant alterations in microbial taxa were observed between the treated and vehicle groups; analogous to the changes previously reported in human PD versus healthy control microbiota studies. These microbial changes included an increase in Lactobacillus and Bifidobacterium and a decrease in Lachnospiraceae and Prevotellaceae. Markedly, certain Lactobacillus species correlated negatively with levodopa levels in the systemic circulation, potentially affecting the bioavailability of levodopa. Overall, the study highlights a significant effect of PD medication intrinsically on disease-associated comorbidities, including gastrointestinal dysfunction and small intestinal bacterial overgrowth, as well as the gut microbiota composition. The results urge future studies to take into account the influence of PD medication per se when seeking to identify microbiota-related biomarkers for PD. IMPORTANCE Parkinson's disease (PD) is the second most common neurodegenerative disorder and is known to be associated with altered gastrointestinal function and microbiota composition. We previously showed that the gut bacteria harboring tyrosine decarboxylase enzymes interfere with levodopa, the main treatment for PD (S. P. van Kessel, A. K. Frye, A. O. El-Gendy, M. Castejon, A. Keshavarzian, G. van Dijk, and S. El Aidy, Nat Commun 10:310, 2019). Although PD medication could be an important confounder in the reported alterations, its effect, apart from the disease itself, on the microbiota composition or the gastrointestinal function at the site of drug absorption, the small intestine, has not been studied. The findings presented here show a significant impact of commonly prescribed PD medication on the small intestinal motility, small intestinal bacterial overgrowth, and microbiota composition, irrespective of the PD. Remarkably, we observed negative associations between bacterial species harboring tyrosine decarboxylase activity and levodopa levels in the systemic circulation, potentially affecting the bioavailability of levodopa. Overall, this study shows that PD medication is an important factor in determining gastrointestinal motility and, in turn, microbiota composition and may, partly, explain the differential abundant taxa previously reported in the cross-sectional PD microbiota human studies. The results urge future studies to take into account the influence of PD medication on gut motility and microbiota composition when seeking to identify microbiota-related biomarkers for PD.</p
Obesity and anorexia
No full textEating disorders frequently develop during adolescence or early adulthood. Much attention is paid to anorexia nervosa (AN) and bulimia nervosa (BN), both eating disorders that are more likely to be found in females than in males (Hoek, 2006). As of now, it is estimated that AN and BN affect about 3% of young women with nearly twice this number having eating problems that do not reach diagnostic thresholds. Consequences of these eating disorders can be devastating and far-reaching. For example, individuals suffering from AN or BN frequently go into remission, and about 5 to 10% of them die due to complications such as heart and kidney failure (Casiero and Frishman, 2006; Hoek, 2006). According to the DSM-IV criteria, AN is characterized by self-starvation, and a refusal to maintain a minimally normal body weight. Bulimia nervosa is characterized by repeated binge-eating episodes, which are usually followed by self-induced vomiting, intake of laxatives and diuretics, or other medications aimed at induction of weight loss. Eating disorders are frequently found to occur with other psychiatric disorders such as depression, addiction, and anxiety. Furthermore, individuals suffering from AN and BN often have a disturbed perception of body shape and weight, and judge themselves as too fat (Ruuska et al., 2005). Another frequently mentioned eating disorder on the other side of the spectrum is binge eating disorder (BED). According to the DSM-IV criteria, BED subjects have binges at least twice a week over a period of six months or more. Each binge is characterized by ingesting a large amount of food at a high feeding rate, and continues far beyond the normal sensation of satiety. Binge eating disorder is commonly associated with obesity, and - as opposed to AN and BN subjects - BED obese individuals are generally quite aware of their fat state (Gromel et al., 2000). In fact, they frequently feel stigmatized as such (Puhl et al., 2007). Since obesity is considered a general medical condition according to the International Classification of Diseases (ICD), and no consistent psychological syndrome is associated with it, it has not been classified in the DSM-IV. However, reports nevertheless suggest that obese individuals already at adolescence are frequently depressed according to the DSM-IV criteria (McElroy et al., 2004; Sjoberg et al., 2005)
Ethanol-induced c-Fos expression in rat lines selected for low and high alcohol consumption
Get PDFSelectively bred rat lines, developed to model genetic contributions to alcohol abuse, include the Indiana alcohol-preferring (P) and alcohol-nonpreferring (NP) lines, and the Alko-Alcohol (AA) and Alko-Nonalcohol (ANA) lines. Preferring and nonpreferring lines were compared in their response to intraperitoneal injection of either ethanol or isotonic saline using c-Fos expression as a marker of neuronal activity. Although line differences were noted in several brain regions, the principal finding was that alcohol-nonpreferring lines (NP and ANA) displayed greater c-Fos expression in the locus coeruleus (LC) relative to the alcohol-preferring lines (P and AA) following injection of 3.0 g ethanol/kg. These data point to the LC as an area which may play a role in the differences in voluntary ethanol consumption between rat lines genetically bred for low and high ethanol preference
Involvement of the brain melanocortin system in energy homeostasis
Get PDFIn dit proefschrift is getracht nader inzicht te krijgen in de anatomie van het MC systeem en hoe dit systeem de energie balans beïnvloedt. Dit is gedaan aan de hand van diverse proefdierstudies. Zoals vermeld is niet helemaal bekend welke neuronen door het MC worden
aangeschakeld. .... Zie: Samenvatting
The fire of life:applications and implications
Get PDFIn onze samenleving komen overgewicht, obesitas, en daarmee gepaard gaande metabole stoornissen in toenemende mate voor. Waarschijnlijk spelen beschikbaarheid van te veel lekker en ongezond eten en te weinig lichaamsbeweging hierbij een rol. Onderzoek naar de mechanismen die betrokken zijn bij regulatie van energiebalans is daarom van groot belang aangezien dit ook inzicht kan geven in het ontstaan van stoornissen hierin. Het onderzoek beschreven in dit proefschrift is een zoektocht naar de rol van fysieke inspanning en metabole snelheid in bovengenoemde processen. Het eerste gedeelte van dit proefschrift beschrijft validatie van de dubbel-gelabeld water methode in muizen en mensen. Deze methode is uitermate geschikt om metabole snelheid te bepalen onder vrij-levende condities. Diverse aspecten aangaande toepassing en analyse zijn hierbij onderzocht. In het tweede gedeelte werd de rol van fysieke inspanning als persoonskenmerk onderzocht bij muizen. Volwassen hoogactieve muizen bleken ongevoelig te zijn voor ontwikkeling van obesitas, wanneer ze werden blootgesteld aan een hoog vet/suiker dieet - een eigenschap die controle muizen wel bezitten. Deze dieet-geinduceerde obesitas- resistentie in de hoog-actieve muizen bleek te worden opgeheven wanneer hun moeders eveneens werden blootgesteld aan een hoog vet/suiker dieet tijdens de zwangerschap en lactatiefase. Deze ombuiging van obesitas resistentie naar obesitas gevoeligheid en geassocieerde stoornissen in de hyperactieve muizen door perinatale dieet invloeden is waarschijnlijk het gevolg van recombinatie van obesogene eigenschappen die wederom tot expressie komen door epigenetische veranderingen tijdens foetale ontwikkeling. Homologe mechanismen zouden een rol kunnen spelen bij de snelle toename van de obesitas prevalentie in onze maatschappij.
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