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Stress of endoplasmic reticulum and its role for the development of adipose tissue inflammation
Zemánková, Kateřina ; Rossmeislová, Lenka (advisor) ; Janovská, Petra (referee)
Endoplasmic reticulum (ER) is a cellular organelle responsible for folding of proteins that are then transported to the various places in the cell or secreted. It is also crucial for the synthesis of triglycerides. Metabolic imbalance leads to ER stress and consequently triggers signaling pathway, which is called unfolded-protein response (UPR). The aim of this pathway is to alleviate ER stress, restore natural homeostasis and prevent death of cell. At the same time however, it activates stress kinases and other factors that may perturb insulin signaling and increase expression of proinflammatory cytokines. These signs are characteristic for human obesity, which is associated with reduced tissue's sensitivity to insulin and is considered as a disease with low level of inflammation. Recent studies have suggested that the source of proinflammatory cytokines in obesity are stressed adipocytes and macrophage infiltrated into adipose tissue. Indeed, it has been demonstrated that stress of endoplasmic reticulum is significantly increased in adipose tissue of obese individuals. Weight loss associated with reduction of adipose tissue mass decreases stress while lowers both, the production of proinflammatory cytokines and insulin resistence. This work aims to collect and discuss these new findings, which...
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New regulatory metabolic factors in patients with obesity and type 2 diabetes mellitus
Matějková, Mirka ; Haluzík, Martin (advisor) ; Flachs, Pavel (referee)
Fibroblast growth factors are proteins with diverse biological function in development, tissue repair, and metabolism. The human FGF gene family consists of 22 members. FGF 19 subfamily includes FGF 19, FGF 21, and FGF 23. They act as systemic factors in an endocrine manner. FGF 19 subfamily requires klotho protein as a cofactor for its action. FGF 19 produced by intestine acts mainly in the liver through FGFR4, where it inhibits bile acid and fatty acid synthesis. FGF 21 is produced by the liver and contributes to the regulation of carbohydrate and lipid metabolism through modulation of glucose uptake in adipocytes. Serum FGF 21 levels are increased in patients with obesity and type 2 diabetes mellitus. Serum FGF 19 levels are on the contrary decreased in patients with obesity and type 2 diabetes mellitus and more probably depend on the nutritional status of the organism than on the glucose metabolism and insulin sensitivity. Key words: type 2 diabetes mellitus, FGF 19, FGF 21, obesity, adipose tissue
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Acipimox during Short-Term Exercise Exerts A Negative Feedback of Growth Hormone on Ghrelin Secretion in Patients with Bulimia Nervosa and in Healthy Women: The Role of Lipolysis
Smitka, Kvido ; Nedvídková, Jara (advisor) ; Kršek, Michal (referee) ; Čáp, Jan (referee)
Title: Acipimox during Short-Term Exercise Exerts A Negative Feedback of Growth Hormone on Ghrelin Secretion in Patients with Bulimia Nervosa and in Healthy Women: The Role of Lipolysis Objective: Eating disorders, such as bulimia nervosa (BN) and anorexia nervosa (AN), are characterized by abnormal eating behavior. The main features of BN are binge-eating and inappropriate compensatory methods to prevent weight gain. The appetite-modulating peptide ghrelin is secreted by the stomach and shows a strong release of growth hormone (GH). A potential GH-ghrelin feedback loop between stomach and the pituitary has been recently reported. Acipimox (Aci), an analogue of nicotinic acid, inhibits lipolysis in adipose tissue (AT) and reduces plasma glycerol and free fatty acids (FFA) levels. Exercise and Aci are stimulators of GH secretion. We suppose that a negative feedback from increased GH levels during exercise may play a role in reducing plasma ghrelin levels. We surmised that altered baseline activity and exercise-induced activation of the sympathetic nervous system (SNS) results in excessive stimulation of lipolysis associated with negative energy balance and may lead to abnormal AT metabolism in patients with BN. Disruption of the gut-brain-AT axis might be involved in the pathogenesis of BN. The...
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The effect of live weight of pigs on the histology of adipose tissue
Žalmánková, Nikola ; Okrouhlá, Monika (advisor) ; Michaela, Michaela (referee)
The main goal of this paper was to evaluate the influence of live weight on both the quantity and the quality of back fat as well as on histology of adipose tissue in pigs. Fourty pigs of PIC genotype and equaly distributed sex were included in this study. The population was then divided into four sub-groups according to their live weight. (Groups: first - under 104.9 kg, second - between 105 kg and 109.9 kg, third - between 110 kg and 114.9 kg, fourth - above 115 kg)
The following indicators of fattening performance were monitored during the study: average daily feed consumption, average weekly feed consumption, average daily weight gain and feed conversion rate. Statistically significant influence was observed only for average daily weight gain which was found to be positively dependent on live weight increases. The smallest average daily weight gain (990.14 g) was observed in group one which at the same time displayed highest feed conversion rate (2.61 kg.kg-1). Subjects in group four, on the other hand, showed the largest average daily weight gain (1159.11 kg) and the lowest feed conversion rate (2.49 kg.kg-1).
Furthermore, development of back fat was periodically monitored via ultrasound examinations at three chosen points of the pigs' anatomy, beginning at four weeks of age and continuing until ten weeks of age. The measurements confirmed that the increases in depth of back fat correlate closely with gains in live weight.
No correlation was proven between other physical characteristics of back fat and changes in live weight. However, measurements showed statistically non-significant increase of coloration of back fat which correlated with weight gains for subjects under 114.9 kg of live weight. As far as tenderness of back fat is concerned, lowest values were found in both upper (74.31 N) and lower (59.61 N) fat in subjects in group two.
No significant influence of live weight on the histology of adipose tissue was found. Nevertheless, measurements showed apparent structural difference between the cut in the higher and lower part of back fat. In upper part of the cut was the highest density of adipose cells (60.27 cells per 1 mm2 at the average cell size of 3430.23) found in group number two. However, in the lower part of the cut was the highest density of adipose cells (63.8 cells per 1 mm2 at the average cell size of 3877.72) found in group number one.
None of the other monitored variables proved to be statistically significant.
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The comparison of fatty acids profile in adipose tissue of pigs with regard to the differently enriched feed with unsaturated fatty acids
Homolková, Dana ; Okrouhlá, Monika (advisor) ; Michaela, Michaela (referee)
This paper deals with a comparison of the profile of fatty acids in adipose tissue pigs with regard to the differently enriched feed of unsaturated fatty acids.
In the theoretical part, the issue is handled using professional literature, supplemented by chapters dealing with the digestive system and digestion.
In the practical part, the experiment was conducted. The experiment was performed at the pig breeding test station at Ploskov near Lány. The experiment included 72 pieces of
slaughter pigs of balanced sex (36 barrows and 36 gilts) final hybrid combinations DanBred.
This paper presents a methodology, under which the test was performed. The pigs were included in the test in the average weight of 29.2 kg and the average age of 70 days. The pigs were fed with a complete feed mixture. The pigs were according on diet divided into six experimental groups with supplemented 4% oil (rapeseed and soybean) and one control group without added oil. In experimental groups were incorporated oil into the feed mixture, for a period of 6, 4 and 2 weeks prior to slaughter. Age and average slaughter weight of pigs at the end of the fattening period was 152 days and 115.8 kg.
From the measurement results, it can be stated that the resulting interaction between the time of application and the type oil used by the addition of has been found in the content of palmitic acid, linoleic acid and alfa linolenic acid, n3 PUFA and n6 PUFA and the ratio of n3 and n6 PUFA and also in oxidation stability, carried out immediately after thawing.
Finally, it is possible to say that the profile of fatty acids contained in the feed is reflected in the profile of fatty acids in adipose tissue. When the rapeseed oil was fed the content of MUFA increaset and when the soybean oil was fed the content of PUFA increaset in the adipose tissue. Time of feeding fatty acids had no content great influence. Thus, from economic point of view the best option seems to be the addition of soybean oil in the diet two weeks before slaughter.
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