The novel environment of a metabolic cage can be stressful for rodents, but few studies have attempted to quantify this stress-response. Therefore, we determined the effects on mean arterial pressure (MAP) and heart rate (HR), of placing mice of both sexes in metabolism cages for 2 days. After surgical implantation of a carotid artery catheter mice recovered individually in standard cages for 5 days. Mice then spent 2 days in metabolism cages. MAP and HR were monitored in the standard cage on Day 5 and in metabolism cages on Days 6-7. MAP increased by 18±3 and 22±4 %, while HR increased by 27±4 and 27±6 %, in males and females, respectively, during the first hours after cage switch. MAP decreased to baseline in the fourth and eighth h following metabolism cage switch in males and females, respectively. However, HR remained significantly elevated in both sexes during the entire two-day period in metabolism cages. Females had lower MAP than males both pre- and post- metabolism cage switch, but there were no sex differences in HR. These results demonstrate sustained changes in cardiovascular function when mice are housed in metabolism cages, which could potentially affect renal function., C. C. Hoppe ... [et al.]., and Obsahuje seznam literatury
Protein kinase C (PKC) appears to play a significant role in the signal transduction of cardiac growth and development. The aim of this study was to determine changes in the total PKC activity and the expression of PKC isoforms α, δ and ε in the rat heart that was affected by pressure overload imposed at postnatal day (d) 2. Three groups of Wistar rats were employed for the experiment: rats submitted to the abdominal aortic constriction (AC), sham-operated controls (SO) and intact controls. Animals were sacrificed at d2, d3, d5 and d10. The total PKC activity was measured by the incorporation of 32P into histone IIIS and the expression of PKC was analyzed by immunoblotting in the homogenate of the left ventricular myocardium and in the cytosolic, membrane-enriched (105 × g) and nuclear-cytoskeletalmyofilament- enriched (103 × g) fractions. We observed the significant transient increase in both the total PKC activity and the expression of all isoforms at d5 (the 3rd day after the operation) in the cardiac homogenate of AC rats as compared with SO animals. Aortic constriction did not significantly affect the distribution of activity and isoform abundance among individual cellular fractions except for PKCδ, which increased significantly at d10 in the cytosolic fraction at the expense of the membraneenriched fraction. It is concluded that PKCα, PKCδ and PKCε undergo transient upregulation associated with the accelerated cardiac growth induced by pressure overload imposed in the very early postnatal period., B. Hamplová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Hypertriglyceridemia is an important marker of increased levels of highly atherogenic rem nant -like particles. The importance of lowering plasma levels of triglycerides (TG) has been called into question many times, but currently it is considered an integral part of residual cardiovascular risk reduction strategies. Lifestyle changes (improved diet and increased physical activity) are effective TG lowering measures. Pharmacological treatment usually starts with statins, although associated TG reductions are typically modest. Fibrates are currently the drugs of choice for hyperTG, frequently in c ombination with statins. Niacin and omega -3 fatty acids improve control of triglyceride levels when the above measures are inadequately effective. Some novel therapies including anti- sense oligonucleotides and inhibitors of microsomal triglyceride transfer protein have shown significant TG lowering efficacy. The current approach to the management of hypertriglyceridemia is based on lifestyle changes and, usually, drug combinations (statin and fibrate and/or omega -3 fatty acids or niacin)., M. Vrablík, R. Češka., and Obsahuje bibliografii
TRH-like peptides are characterized by substitution of basic amino acid histidine (related to authentic TRH) with neutral or acidic amino acid, like glutamic acid, phenylalanin e, glutamine, tyrosine, leucin, valin, aspartic acid and asparagine. The presence of extrahypothalamic TRH-like peptides was reported in peripheral tissues including gastroin testinal tract, placenta, neural tissues, male reproductive system and certain endocrine tissues. Work deals with the biological function of TRH-like peptides in different parts of organisms where various mechanisms may serve for realisation of biological function of TRH-like peptides as negative feedback to the pituitary exerted by the TRH-like peptides, the role of pEEPam such as fertilization-promoting peptide, the mechanism influencing the proliferative ability of prostatic tissues, the neuroprotective and antidepressant function of TRH-like peptides in brain and the regulation of thyroid status by TRH-like peptides., R. Bílek, M. Bičíková, L. Šafařík., and Obsahuje bibliografii a bibliografické odkazy
Tumor necrosis factor a (TNFa) was found to be significantly increased in skeletal muscles and retroperitoneal fat of obese insulin-resistant Koletsky rats as compared to control Wistar rats. This increase was accompanied by a depression of insulin receptor protein tyrosine kinase (PTK) activity. Neither the insulin-binding capacity nor insulin receptor affinity were related to this TNFa increase in these tissues. In the liver, no significant changes of TNFa content and only a lowering of insulin-binding capacity were found. It is concluded that an increased TNFa content in muscles and fat (but not in the liver) contributes to insulin resistance by lowering insulin receptor protein tyrosine kinase activity, while other insulin receptor characteristics (insulin-binding capacity and affinity of insulin receptors to the hormone) do not seem to be influenced by this factor., A. Hřebíček, M. Rypka, Z. Chmela, J. Veselý, M. Kantorová, V. Golda., and Obsahuje bibliografii
The aim of our study was to evaluate the potential differences in blood pressure (BP) profile in subjects with different forms of primary aldosteronism (PA). Simultaneously, we studied the effects of PA treatment on BP curve. We therefore monitored 24-hour ambulatory blood pressure values in 22 subjects with aldosterone-producing adenoma (APA), 22 subjects with idiopathic hyperaldosteronism (IHA) and 33 subjects with essential hypertension (EH) as controls. We found a significantly attenuated nighttime systolic BP decline in the APA group (P=0.02). Patients with IHA had lower nighttime systolic BP values (P=0.01) and also a diastolic BP decline (P=0.02) during the night in comparison with EH. We did not detect any significant differences in BP profile characteristics between APA and IHA. Specific treatment of primary aldosteronism (adrenalectomy, treatment with spironolactone) led to the normalization of the BP curve with a marked BP decline. Our study thus demonstrates a blunted diurnal BP variability in patients with primary aldosteronism the specific treatment of which normalized previously attenuated nocturnal BP fall., T. Zelinka, J. Widimský., and Obsahuje bibliografii
The aim of our study was to develop a model producing obese mice in early adulthood (4-6 weeks) based on their over-nutrition during fetal and early postnatal development. The fertilized dams of the parental generation were fed the standard diet supplemented with high-energy nutritional product Ensure Plus during gestation and lactation. De livered weanlings were then fed with standard or supplemented diet and assessed for body fat deposits using EchoMRI at the ti me of early and late adulthood. Maternal over-feeding during th e period before weaning had the most significant effect on obesity development in the filial generation. In weanlings, signific antly higher body fat deposits and average body weight were recorded. Later, further significant increase in percentage of body fat in both male and female mice was observed. Withdrawal of the Ensure Plus supplement caused a decrease in the percentage of body fat in part of the filial generation. In offspring fed the standard diet, higher fat deposits persisted till the time of late adulthood. We conclude that this diet-induced obesity model might be used in exploration of the effects of elevated body fat on physiological functions of various organ systems during juvenile and early adulthood periods of life of a human being., J. Kubandová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy