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Effect of Exercise on Lipid Metabolism in White Adipose Tissue
Gazdová, Tatiana ; Horáková, Olga (advisor) ; Tauchmannová, Kateřina (referee)
Obesity and old age are more prevalent among the current human population than ever before. Increased fat accumulation and hormonal dysregulation are common hallmarks of both these states. It is well reported that both states are associated with impaired lipolysis and glucose homeostasis as a result of disrupted metabolic pathway signalling. Current research offers exercise as a possible remedy, which could improve substrate handling in obesity and old age. Increased energy expenditure, myokine production, and improved insulin sensitivity are all potential benefits of exercise that could mitigate the health risks associated with obesity and ageing. In this work we aim to explore the effect of acute endurance exercise protocol on lipolytic activity of visceral and subcutaneous white adipose tissue depots of lean and young, obese, and aged mice. By the addition of forskolin, isoproterenol, and insulin into the explant media we hope to assess the functionality of β-adrenergic signalling in our subjects. Post exercise lipolytic rate, measured as non-esterified fatty acid release, increased in both depots in all test groups. Glycerol release did not follow the same pattern. Additionally, lipolytic rate, measured as non-esterified fatty acid release, in visceral adipose tissue was higher in samples from...
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Myocardial beta-adrenergic signaling during adaptation of rats to chronic hypoxia
Hahnová, Klára ; Novotný, Jiří (advisor) ; Ostašov, Pavel (referee)
Endogenous cardiac protection against acute ischemia/reperfusion injury can by increased by cardiac adaptation to various forms of chronic hypoxia. Chronic hypoxia induces a large variety of adaptive changes in the myocardium that could be considered as protective, but the exact mechanism of increased ischemic tolerance is unknown. Different studies suggest that catecholamine release and their effect on -adrenergic signaling after adaptation to chronic hypoxia contributes to cardioprotection. In this study we focused on characterization of -adrenergic receptors ( -ARs) in the myocardium of rats after adaptation to three different hypoxic conditions: 1. intermittent normobaric hypoxia - INH/R (23 h hypoxia, 1 h reoxygenation), 2. intermittent normobaric hypoxia - INH (8 h hypoxia, 16 h normoxia), 3. continuous normobaric hypoxia - CNH (24 h hypoxia). We compared how each hypoxic model affects the total number of -adrenergic receptors and proportion of individual subtypes ( 1-and 2-ARs) in the left and right ventricles compared control normoxic rats. The INH model had apparently no effect on -ARs in either ventricles. On the other hand, adaptation to INH/R and CNH was accompanied by a significant decrease (by about 25%) in the total number of -adrenergic receptors in the right ventricles. Our present...
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Myocardial beta-adrenergic signaling during adaptation of rats to chronic hypoxia
Hahnová, Klára ; Novotný, Jiří (advisor) ; Ostašov, Pavel (referee)
Endogenous cardiac protection against acute ischemia/reperfusion injury can by increased by cardiac adaptation to various forms of chronic hypoxia. Chronic hypoxia induces a large variety of adaptive changes in the myocardium that could be considered as protective, but the exact mechanism of increased ischemic tolerance is unknown. Different studies suggest that catecholamine release and their effect on -adrenergic signaling after adaptation to chronic hypoxia contributes to cardioprotection. In this study we focused on characterization of -adrenergic receptors ( -ARs) in the myocardium of rats after adaptation to three different hypoxic conditions: 1. intermittent normobaric hypoxia - INH/R (23 h hypoxia, 1 h reoxygenation), 2. intermittent normobaric hypoxia - INH (8 h hypoxia, 16 h normoxia), 3. continuous normobaric hypoxia - CNH (24 h hypoxia). We compared how each hypoxic model affects the total number of -adrenergic receptors and proportion of individual subtypes ( 1-and 2-ARs) in the left and right ventricles compared control normoxic rats. The INH model had apparently no effect on -ARs in either ventricles. On the other hand, adaptation to INH/R and CNH was accompanied by a significant decrease (by about 25%) in the total number of -adrenergic receptors in the right ventricles. Our present...
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A study of beta-adrenergic myocardial signaling in spontaneously hypertensive rat of transgenic strain SHR-Tg19
Manakov, Dmitry ; Novotný, Jiří (advisor) ; Nováková, Olga (referee)
β-Adrenergic signalization plays an important role in heart, regulating cardiac frequency and contractility. It is also involved in development of hypertension and heart hypertrophy. Spontaneous hypertensive rat strain is a common model for human essential hypertension, although the origin of blood pressure abnormalities in SHR remains unknown. Dysfunction in the regulation of fatty acid translocase Cd36 was suggested as a link to development of hypertension in SHR. Transgenic strain SHR-Tg19 (also known as SHR-Cd36) was obtained, harboring a wild type of FAT/Cd36. This thesis aimed to investigate key elements of β-adrenergic signaling in the heart of SHR-Tg19 compared to their SHR controls. Expression and distribution of β1- and β2-ARs were measured using radioligand binding and Western blot analysis along with expression of selected G proteins and expression and activity of adenylyl cyclase. Our experiments showed that there were no significant changes in the Gsα and Giα subunits expressions, along with the amount of β1-AR in both left and right ventricles, according to the Western immunoblotting, but radioligand binding showed an increase in the quantity of β-ARs, particularly β2 subtype. Alongside, an increased expression of β2- ARs was observed in the right ventricle. Different...
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