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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Strategies to reverse diet- and age-induced obesity and insulin resistance

Lees, Emma Katherine January 2015 (has links)
Ageing and obesogenic diets are two prominent problems in the developed world, as both lead to an increase in body mass and insulin resistance, which can then result in further pathophysiologies, such as type 2 diabetes, cancer and cardiovascular disease. Protein tyrosine phosphatase 1B (PTP1B) contributes to development of body weight gain and insulin resistance through negatively regulating leptin and insulin signalling, respectively. Liver-specific ptp1b deletion from birth improves insulin sensitivity, lipid metabolism and decreases endoplasmic reticulum (ER) stress. However, as a therapy in humans, PTP1B inhibition would target pre-diabetic and diabetic adults; therefore, we investigated the effects of liver-specific inhibition of PTP1B in adult, insulin resistant, obese mice. Restricting the amount of the essential amino acid, methionine, five-fold in the diet, decreases body weight, adiposity and improves insulin sensitivity in young mice. In order to delineate if this would be a feasible treatment in adulthood, we administered the diet to 12-month-old mice with age-induced obesity and insulin resistance and compared its effects to those in 2-month-old mice. As hepatic ptp1b deletion and methionine restriction (MR) both improve hepatic insulin signalling, we investigated if the combined treatment could have additive effects compared to MR alone on whole-body glucose homeostasis. To examine if the effects of MR are methionine-specific or if they would occur with restriction of other EAAs, we compared leucine restriction (LR) to MR in adult mice. Overall, hepatic PTP1B inhibition in adult mice reversed high-fat diet (HFD) -induced glucose intolerance, hepatic lipid accumulation and ER stress. MR administered to 12-month-old adult mice reversed the metabolic effects of ageing back to levels measured in healthy, young, 2-month-old mice. The combination of MR and hepatic ptp1b deletion from birth had no further beneficial effect in male mice, but possibly an additional effect in female mice. MR produced stronger beneficial metabolic effects than LR in mice, suggesting methionine-specific mechanisms may play a role.
2

Metformin in obese children and adolescents : the MOCA Trial

Kendall, Deborah January 2011 (has links)
Background and objective: Childhood obesity is a serious global health problem and it is associated with insulin resistance and significantly increased risk for development of type 2 diabetes and cardiovascular disease. Metformin reduces the risk of developing T2D in adult patients with obesity and insulin resistance. However there is limited and inconclusive data in obese non diabetic children and adolescents. The objective of the Metformin in Obese Children and Adolescents (MOCA trial) was to assess the effect of metformin on body composition, metabolic risk factors and adipokines. Design and methods: The MOCA trial was a six month multi-centre randomized, double-blind placebo-controlled trial of metformin (1.5g daily) in children and adolescents (8-18 years) with insulin resistance and/or impaired glucose tolerance. Auxology, blood pressure measurement and fasting blood tests (insulin, glucose, fasting lipids, ALT, bilirubin, CRP, lactate, resistin, adiponectin, leptin) were performed at baseline, three and six months. A prolonged oral glucose tolerance test was performed at baseline and after six months. Measures of insulin resistance/sensitivity were calculated including HOMA-IR and the adiponectin: leptin (A/L) ratio. Results: 151 obese children participated in the trial (metformin:77, placebo:78). 102 (67.5%) female, 99 (65.6%) post-pubertal, 115 (76.2%) White British and 36 (23.8%) British Asian or Afro-Caribbean. Mean age of participants was 13.7 ±2.3 year and mean BMI-SDS 3.4 (0.5). In regression analysis, controlling for baseline values, sex, ethnicity and pubertal status, metformin had a greater treatment effect over placebo for BMI at three months, that was sustained at six months (-0.25 kg/m2, p=0.01, 95% CI 0.29 to 1.86) and BMI-SDS (-0.1, p=0.01, 95% CI 0.02 to 0.19). Fasting glucose reduced (-0.03 mmol/l, p=0.03) and A/L ratio increased at three months (+0.04, p=0.03), but the improvements were lost at six months. The other measures of insulin sensitivity, metabolic risk factors and concentrations of adipokines did not change with metformin treatment. Conclusions: Metformin therapy for obese children with abnormal insulin glucose status is safe, well tolerated and has a small beneficial treatment effect over placebo for BMI, BMI-SDS, fasting glucose and A/L ratio at three months, with the changes in body composition sustained at six months. A three month course of metformin should be considered by Paediatricians to halt the inexorable rise in BMI-SDS in these children, improve insulin glucose status and act as catalyst and support for more radical change in lifestyle in the individual. Trial register number: ISRCTN 19517475.
3

Studies on fat cell function in human obesity and insulin resistance /

Löfgren, Patrik, January 2005 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.
4

The effect of fetal growth restriction and sex on the development and function of adipose tissue.

Duffield, Jaime Alexandra January 2008 (has links)
A world-wide series of epidemiological studies has demonstrated that there is an association between being born small and the risk of visceral obesity, a more central deposition of subcutaneous fat and insulin resistance in adult life. In the lamb, intrauterine growth restriction (IUGR) results in a low birth weight and an increased visceral fat mass by 45d of postnatal life. In this thesis I have investigated the effect of IUGR on adipose tissue development and function during fetal and early postnatal life in the sheep. IUGR was induced by removal of the majority of endometrial caruncles in non pregnant ewes prior to mating which resulted in the subsequent placental restriction of fetal growth (PR). Fetal blood samples were collected from 116d gestation and visceral perirenal adipose tissue (PAT) collected from PR and control fetuses at 145d. In lambs IUGR was defined as a birth weight less than 2 standard deviations below the mean of a cohort of singleton Merino lambs. Blood samples were collected throughout the first 3 weeks of life and PAT and subcutaneous adipose tissue (SAT) was collected at 21 d. It was determined whether IUGR alters the expression of genes which regulate adipogenesis (IGF1, IGFR1, IGF2, IGFR2, PPARy, and RXRα), adipocyte metabolism (LPL, G3PDH, GAPDH) and adipokine signalling (leptin, adiponectin) in adipose tissue depots before and after birth using qRT-PCR. PR fetuses were hypoglycaemic, hypoinsulinaemic, hypoxic, and had a lower body weight than Control fetuses. The expression of both IGF1 and leptin mRNA in PAT, the major fetal adipose depot, was lower in the PR fetuses, although there was no difference in the expression of other adipokine or adipogenic genes in PAT between PR and control fetuses. Thus restriction of placental and hence fetal substrate supply results in decreased IGF1 and leptin expression in fetal visceral adipose tissue which may alter the functional development of the perirenal fat depot and contribute to altered leptin signalling in the growth restricted newborn and the subsequent emergence of an increased visceral adiposity. At 21d of postnatal life there was no increase in the relative mass of perirenal or subcutaneous fat in IUGR lambs compared with controls. Thus, this study has investigated the effect of IUGR on the development of adipose tissue prior to the development of an obese phenotype. At 21d of life there was a sex specific effect of IUGR on the expression of PPARy and leptin mRNA in perirenal visceral fat such that PPARy and leptin mRNA expression was decreased in male IUGR lambs, but not females. Interestingly PAT mass was greater in females than males, independent of birth weight. Plasma insulin concentrations during the first 24h after birth predicted the size of the adipocytes and expression of adiponectin in visceral adipose tissue in both males and females at 21d. Thus, the nutritional environment before, and immediately after birth, may program adipocyte growth and gene expression in visceral adipose tissue. The differential effect of sex and birth weight on PPARy and leptin expression in visceral fat may be important in the subsequent development of visceral obesity and the insulin resistant phenotype in later life. At 21d of life there was no difference between Control and IUGR lambs in the relative mass of subcutaneous fat, or the expression of PPARy, RXRα, leptin, adiponectin, LPL, G3PDH, and GAPDH in subcutaneous fat at 21d of life. We have shown that the growth of the subcutaneous fat depot is related to plasma glucose, insulin and leptin concentrations, and to the development of perirenal fat. Thus, in contrast to perirenal adipose tissue, the postnatal, but not the fetal nutritional environment, programs subcutaneous adipocyte growth and gene expression. This thesis speculates that there may be a factor secreted from visceral fat that influences the development of the subcutaneous fat depot. At 21d of life there was also an effect of sex, but not IUGR, on the expression of IGF mRNA in adipose tissue. Male lambs had a higher expression of IGF1 mRNA in both PAT and SAT, and a higher expression of IGF1R and IGF2R in SAT compared with female lambs. It is likely that these differences in IGF mRNA levels reflect sexual dimorphism of the GH-IGF axis. When male and female lambs were combined there was a higher expression of IGF1 mRNA in SAT compared with PAT, and a higher expression of IGF2, IGF1R and IGF2R mRNA in PAT compared with SAT. These differences in IGF mRNA expression provide a potential mechanism to explain the sex and depot specific variations in mitogenic potency of IGF1 and proliferative capacities of preadipocytes, the regional variation in adipocyte metabolism, and the difference in incidence of visceral obesity between men and women in adult life. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1347421 / Thesis (Ph.D.) - University of Adelaide, School of Molecular and Biomedical Science, 2008
5

The effect of fetal growth restriction and sex on the development and function of adipose tissue.

Duffield, Jaime Alexandra January 2008 (has links)
A world-wide series of epidemiological studies has demonstrated that there is an association between being born small and the risk of visceral obesity, a more central deposition of subcutaneous fat and insulin resistance in adult life. In the lamb, intrauterine growth restriction (IUGR) results in a low birth weight and an increased visceral fat mass by 45d of postnatal life. In this thesis I have investigated the effect of IUGR on adipose tissue development and function during fetal and early postnatal life in the sheep. IUGR was induced by removal of the majority of endometrial caruncles in non pregnant ewes prior to mating which resulted in the subsequent placental restriction of fetal growth (PR). Fetal blood samples were collected from 116d gestation and visceral perirenal adipose tissue (PAT) collected from PR and control fetuses at 145d. In lambs IUGR was defined as a birth weight less than 2 standard deviations below the mean of a cohort of singleton Merino lambs. Blood samples were collected throughout the first 3 weeks of life and PAT and subcutaneous adipose tissue (SAT) was collected at 21 d. It was determined whether IUGR alters the expression of genes which regulate adipogenesis (IGF1, IGFR1, IGF2, IGFR2, PPARy, and RXRα), adipocyte metabolism (LPL, G3PDH, GAPDH) and adipokine signalling (leptin, adiponectin) in adipose tissue depots before and after birth using qRT-PCR. PR fetuses were hypoglycaemic, hypoinsulinaemic, hypoxic, and had a lower body weight than Control fetuses. The expression of both IGF1 and leptin mRNA in PAT, the major fetal adipose depot, was lower in the PR fetuses, although there was no difference in the expression of other adipokine or adipogenic genes in PAT between PR and control fetuses. Thus restriction of placental and hence fetal substrate supply results in decreased IGF1 and leptin expression in fetal visceral adipose tissue which may alter the functional development of the perirenal fat depot and contribute to altered leptin signalling in the growth restricted newborn and the subsequent emergence of an increased visceral adiposity. At 21d of postnatal life there was no increase in the relative mass of perirenal or subcutaneous fat in IUGR lambs compared with controls. Thus, this study has investigated the effect of IUGR on the development of adipose tissue prior to the development of an obese phenotype. At 21d of life there was a sex specific effect of IUGR on the expression of PPARy and leptin mRNA in perirenal visceral fat such that PPARy and leptin mRNA expression was decreased in male IUGR lambs, but not females. Interestingly PAT mass was greater in females than males, independent of birth weight. Plasma insulin concentrations during the first 24h after birth predicted the size of the adipocytes and expression of adiponectin in visceral adipose tissue in both males and females at 21d. Thus, the nutritional environment before, and immediately after birth, may program adipocyte growth and gene expression in visceral adipose tissue. The differential effect of sex and birth weight on PPARy and leptin expression in visceral fat may be important in the subsequent development of visceral obesity and the insulin resistant phenotype in later life. At 21d of life there was no difference between Control and IUGR lambs in the relative mass of subcutaneous fat, or the expression of PPARy, RXRα, leptin, adiponectin, LPL, G3PDH, and GAPDH in subcutaneous fat at 21d of life. We have shown that the growth of the subcutaneous fat depot is related to plasma glucose, insulin and leptin concentrations, and to the development of perirenal fat. Thus, in contrast to perirenal adipose tissue, the postnatal, but not the fetal nutritional environment, programs subcutaneous adipocyte growth and gene expression. This thesis speculates that there may be a factor secreted from visceral fat that influences the development of the subcutaneous fat depot. At 21d of life there was also an effect of sex, but not IUGR, on the expression of IGF mRNA in adipose tissue. Male lambs had a higher expression of IGF1 mRNA in both PAT and SAT, and a higher expression of IGF1R and IGF2R in SAT compared with female lambs. It is likely that these differences in IGF mRNA levels reflect sexual dimorphism of the GH-IGF axis. When male and female lambs were combined there was a higher expression of IGF1 mRNA in SAT compared with PAT, and a higher expression of IGF2, IGF1R and IGF2R mRNA in PAT compared with SAT. These differences in IGF mRNA expression provide a potential mechanism to explain the sex and depot specific variations in mitogenic potency of IGF1 and proliferative capacities of preadipocytes, the regional variation in adipocyte metabolism, and the difference in incidence of visceral obesity between men and women in adult life. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1347421 / Thesis (Ph.D.) - University of Adelaide, School of Molecular and Biomedical Science, 2008
6

Molecular aspects of the link between obesity, insulin resistance and breast cancer

Weichhaus, Michael Georg January 2010 (has links)
Obesity is a multi-factorial metabolic disease, resulting in increased adipose tissue acquisition by the host. This disease increases the risk for developing co-morbidities, including Metabolic Syndrome and other disorders such as breast cancer. Obesity, and particularly abdominal obesity, is characterised by metabolic changes, including chronically elevated insulin concentrations and aberrant secretion of cytokines released from fat tissue, called adipokines. Epidemiologically, the risk of developing postmenopausal breast cancer is increased in obese individuals. The molecular link between obesity and breast cancer however is not well understood. The study presented here aimed at identifying the molecular mechanisms involved in this link, by testing the hypothesis that high insulin concentration and certain adipokines may promote breast cancer progression and/or breast cancer aetiology. A cell culture system of breast cancer cells and breast epithelial cells was employed to investigate changes in cell proliferation, activation of cell signalling pathways, cell cycle progression and apoptosis after treatment with insulin, leptin, TNF-α, adiponectin and IL-6. In MDA-MB-231 breast cancer cells, insulin treatment did not affect cell proliferation, cell cycle or apoptosis. Conversely, IR-phosphorylation, AKT-phosphorylation and ERK1/2-phosphorylation were all significantly increased. Microarray analysis indicated several important changes in gene expression with insulin treatment. Leptin treatment increased proliferation by 21%. Additional analyses of the effect of leptin indicated that neither the PI3-kinase pathway nor the MAP-kinase pathway was involved in mediating this effect. Treatment with TNF-α increased apoptosis, but did not affect cell proliferation or activation of cell signalling pathways. In MCF-10A breast epithelial cells, cell proliferation increased after insulin treatment by 180%. IR-phosphorylation, AKT-phosphorylation and ERK1/2 phosphorylation were all significantly increased while early apoptosis decreased after insulin treatment. Analysis of cell cycle however did not indicate a change in progression. Microarray analysis indicated that insulin treatment may increase expression of genes related to cancer growth. Leptin treatment increased cell proliferation and also increased ERK1/2-phosphorylation, while AKT-phosphorylation was not affected. Leptin did not change cell cycle progression. TNF-α treatment increased cell proliferation and also increased ERK1/2 phosphorylation, while AKT-phosphorylation was not changed. TNF-α treatment tended to increase apoptosis, the change however was not statistically significant. In SK-BR-3 breast cancer cells, cell proliferation did not change after insulin treatment. IR-phosphorylation and AKT-phosphorylation increased after insulin treatment, while ERK1/2-phosphorylation decreased. Gene expression of cyclin D and cyclin E increased with insulin treatment, while apoptotic rate and cell cycle profile were also not affected. Cell proliferation increased by 115% after treatment with 100 ng/ml leptin. ERK1/2-phosphorylation however decreased, while AKT-phosphorylation tended to increase, but the change was not statistically significant. Cell cycle profile was not affected by leptin treatment, G1-phase however tended to increase, but the change was again not statistically significant. Cell proliferation increased by 59% after 48 h treatment with 10 ng/ml TNF-α. AKT-phosphorylation and ERK1/2-phosphorylation increased with TNF-α treatment. Cell cycle analysis showed a decrease in S-phase and G2-phase, indicative of a decrease in cell cycle progression. These results indicate that none of the examined obesity-related factors is convincingly identified as the main molecular link between obesity and postmenopausal breast cancer. Conversely, all treatments affected each of the cell lines in, at least, one of the examined aspects. This indicates that many of the obesity-related factors may affect breast cancer and that a single breast tumour may utilise a unique combination of those factors to promote growth. All treatments increased proliferation in MCF-10A breast epithelial cells, with additional analysis generally supporting growth promotion. Insulin treatment particularly increased cell proliferation, while leptin and TNF-α increased MAP-kinase signalling. This may indicate that insulin and adipokines may have a higher impact on breast cancer aetiology than on breast cancer progression.
7

Uncaria tomentosa melhora sensibilidade à insulina e inflamação hepática em modelos de camundongos obesos. / Uncaria tomentosa improves insulin sensitivity and hepatic inflammation in obese mice models.

Araujo, Layanne Cabral da Cunha 22 February 2019 (has links)
O balanço energético corporal é mantido através de alterações na ingestão de calorias e no gasto energético. O prolongado balanço energético positivo, em que a ingestão excede o gasto, promove obesidade. A obesidade resulta do aumento de triacilglicerois no tecido adiposo, que também passa a apresentar inflamação de baixo grau crônica. O resultado disso envolve a redução da capacidade de tamponamento dos ácidos graxos livres circulantes e subsequente deposição de gordura em territórios ectópicos como musculatura esquelética e fígado, além de aumentar o risco de desenvolver o diabetes Mellitus tipo 2. Assim, a obesidade é um fator de risco importante para doenças metabólicas e suas comorbidades, dentre elas a doença gordurosa hepática não alcoólica. Uma proposta terapêutica para intervir na obesidade e/ou nas comorbidades associadas é o uso de substancias com ação anti-inflamatória. Considerando a possibilidade de novo uso para alguns produtos liberados para uso e com potencial tóxico já avaliado, foi escolhido avaliar o efeito do fitoterápico Uncaria tomentosa. Para isso, foram utilizados dois modelos de camundongos: (1) obesidade induzida por dieta hiperlipídica (DH), camundongos machos c57bl/6, alimentado com DH por 10 semanas, e (2) camundongo geneticamente obeso, ob/ob. A dose e tempo de tratamento escolhidos basearam-se no resultado da tolerância à insulina determinada inicialmente. Os animais receberam via oral o extrato da UT na dose de 50 mg/kg, uma vez ao dia, por 5 dias consecutivos. Seguindo-se ao tratamento, os animais foram submetidos a testes de tolerância a glicose e insulina, análise do coeficiente respiratório e depois a eutanásia, para retirada do fígado e sangue. O tecido hepático foi submetido a técnicas histológicas para verificar a morfologia e quantificação das gotículas de gordura, extração das proteínas celulares e RNAm para realização de western blot típico e reação em cadeia da polimerase (PCR), respectivamente. Também foi utilizada imunohistoquímica com anticorpo anti-F4/80 para comprovar infiltrado inflamatório. O tratamento com UT reduziu a glicemia de jejum cerca de 15 e 20% nos modelos DH e ob/ob, respectivamente, e a insulimenia para 54% no grupo DH, enquanto no grupo ob/ob houve um aumento de 2 vezes na insulinemia com o uso da UT. Houve uma redução de 22% no índice de massa corpórea (IMC) acompanhada de maior gasto energético com o tratamento no modelo DH. A esteatose hepática foi reduzida em aproximadamente 30% e a presença de infiltrados inflamatórios em 70% em ambos os modelos. Além disso, o grau de fosforilação do IRS1 no resíduo serina foi reduzido em 25% nos camundongos alimentados com DH após tratamento com UT, acompanhando a maior sensibilidade à insulina desses animais em relação aos obesos não tratados. Diante desses resultados, concluímos que o extrato bruto da Uncaria tomentosa melhora a homeostase da glicose e reverte a esteatohepatite incipiente a estatose benigna. O tratamento com Uncaria tomentosa pode ser uma estratégia terapêutica potencial no combate a alterações metabólicas associadas à obesidade como a doença hepática gordurosa não alcoólica (DHGNA) de início imediato. / The body\'s energy balance is maintained through changes in calorie intake and energy expenditure. The prolonged positive energy balance, in which the intake exceeds the expense, promotes obesity. Obesity results from the increase of triacylglycerols in adipose tissue, which also starts to present chronic low-grade inflammation. The result of this involves the reduction of the buffering capacity of circulating free fatty acids and subsequent fat deposition in ectopic territories such as skeletal muscle and liver, as well as increasing the risk of developing type 2 diabetes mellitus. Thus, obesity is an important risk factor for metabolic diseases and their comorbidities, among them non-alcoholic fatty liver disease. A therapeutic proposal to intervene in obesity and/or associated comorbidities is the use of substances with anti-inflammatory action. Considering the possibility of new use for some products released for use and with toxic potential already evaluated, it was chosen to evaluate the effect of the herbal remedy Uncaria tomentosa (UT), popularly known as cat\'s claw. Two models of mice were used: (1) higt fat diet induced obesity (HFD), male mice c57bl / 6, fed HFD for 12 weeks, and (2) genetically obese mice, ob/ob. The dose and time of treatment chosen were based on the initially determined insulin tolerance result. The animals received orally the UT extract at the dose of 50 mg/kg once daily for 5 consecutive days. Following the treatment, the animals were submitted to glucose and insulin tolerance tests, analysis of the respiratory coefficient and then euthanasia, for removal of the liver and blood. Liver tissue was submitted to histological techniques to verify the morphology and quantification of fat droplets, extraction of cellular proteins and mRNA for typical western blot and polymerase chain reaction (PCR), respectively. Immunohistochemistry with anti-F4 / 80 antibody was also used to prove inflammatory infiltrate. Treatment with UT reduced fasting glucose by 15 and 20% in the HFD and ob/ob models respectively, and the insukinemia to 54% in the HFD group, whereas in the ob/ob group there was a 2-fold increase in insulinemia with the use of UT. There was a 22% reduction in body mass index (BMI) accompanied by greater energy expenditure with HFD treatment. Hepatic steatosis was reduced by approximately 30% and the presence of inflammatory infiltrates by 70% in both models. In addition, the degree of IRS1 phosphorylation at the serine residue was reduced by 25% in the mice fed HFD after treatment with UT, following the higher insulin sensitivity of these animals compared to the untreated obese. In view of these results, we conclude that the crude extract of Uncaria tomentosa improves glucose homeostasis and reverts incipient steatohepatitis to benign steatosis. Treatment with Uncaria tomentosa can be a potential therapeutic strategy in the action against obesity-related metabolic alterations such as non-alcoholic fatty liver disease (NAFLD).
8

Structure and function of AMPK : subunit interactions of the AMPK heterotrimeric complex /

Iseli, Tristan. January 2007 (has links)
Thesis (Ph.D.)--University of Melbourne, Dept. , 200. / Typescript. Includes bibliographical references.
9

Die Rolle von Apelin bei Adipositas und gestörter Glukosetoleranz

Krist, Joanna 02 October 2014 (has links)
Apelin ist ein Adipokin, das Einfluß auf die Glukosehomöostase hat und vermutlich eine wichtige Rolle in der Regulation von Adipositas und den damit assoziierten Erkrankungen einnimmt. Die Effekte von Apelin scheinen metabolisch günstig zu sein. In dieser Arbeit wurden zunächst Apelin-Serumkonzentrationen und metabolische Parameter bei 740 Studienteilnehmern bestimmt und in einer Querschnittsstudie (n=629) sowie in drei Interventionsstudien (n=111) dargestellt. In einer Subgruppe (n=161) wurde die mRNA-Expression von Apelin und dessen Rezeptor APJ im viszeralen und subkutanen Fettgewebe bei Patienten mit Typ-2-Diabetes genauer untersucht. Im Rahmen der Interventionsstuden wurde der Einfluß von 12 Wochen körperlichem Training (n=60), 6 Monaten hypokalorischer Mischkost (n=19) und bariatrischer Chirurgie (n=32) auf den Serum-Apelinspiegel sowie Zusammenhänge mit Gewichtsreduktion, verbesserter Insulinsensitivität und subklinischer Inflammation analysiert. Die höchsten Apelin-Serumkonzentrationen fanden sich beim adipösen Typ-2-Diabetiker. Die Apelin-Serumkonzentration korrelierte aber auch unabhängig vom Bodymassindex signifikant mit Parametern für Insulinresistenz und subklinischer Inflammation. Die Apelin-Expression war in den unterschiedlichen Fettgewebsdepots bei normal glukosetoleranten Patienten gleich, beim Typ-2-Diabetiker mit insgesamt höherer Expression überwog sie im viszeralen Fettgewebe. Nach allen Interventionsstudien kam es zur Abnahme der Apelin-Serumkonzentration und korrelierte auch dann signifikant mit einer verbesserten Insulinsensitivität, wenn es zu keiner Gewichtsreduktion kam. Die Apelinkonzentration im Serum sowie die Expression im Fettgewebe ist nicht nur vom Bodymassindex abhängig, sondern steht im direkten Zusammenhang mit Insulinsensitivität und inflammatorischen Prozessen. Die unterschiedliche fettdepotspezifische Regulation unterstreicht die pathogenetische Bedeutung eines „kranken“ viszeralen Fettgewebes in der Entwicklung von Typ-2-Diabetes, wobei Apelin als metabolisch günstiges Adipokin vermutlich eine kompensatorische Rolle einnimmt.
10

Metabolic Effects of Short-Term High-Fat Diet Feeding in Male and Female Mice

Senthil Kumar, Shiva Priya Dharshan 09 January 2014 (has links)
No description available.

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