The impact of two different passive recovery durations, two and three minutes, between sets of repeated sprint skating ability (RSSA) test on skating speed, speed decrement (Sdec), and heart rate (HR) response of ice hockey forwards (n = 12) and defensemen (n = 7) were determined. Six sets of 3 × 80 m sprint, with two-minute passive recovery between two consecutive sets, were performed in RSSA-2. A three-minute passive recovery period between two consecutive sets was allowed in RSSA-3. Skating speed, Sdec, and HR were measured in all tests. Subjects skated faster (p < 0.05) in most of the RSSA-3 sets than the corresponding set of RSSA-2. Defensemen were slower (p < 0.05) than forwards in most of the cases. The Sdec was higher in defensemen than in forwards, although the difference was significant occasionally. No difference in peak HR and minimum HR between forwards and defensemen was found. RSSA-3 is beneficial over RSSA-2 in both forwards and defensemen by increasing speed. Defensemen are slower and show early fatigability than forwards, and no difference in HR response was noted between forwards and defensemen. This study concludes that three-minute recovery is beneficial over two-minute recovery by increasing skating speed, although Sdec and HR response neither vary significantly between RSSA-2 and RSSA-3, nor between forwards and defensemen.

• Klíčová slova
• fatigue index, field test, heart rate, movement pattern, performance decrement, skating performance,
• MeSH
• bruslení * MeSH
• hokej * MeSH
• lidé MeSH
• únava MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The aim of this study was to determine the effects of two different rest periods, 2 min and 3 min, between consecutive sets of a repeated sprint skating ability (RSSA) test, on the skating ability of ice hockey players. Two RSSA tests, RSSA-2 and RSSA-3, were assessed on 24 ice hockey players. In RSSA-2, six sets of 3 × 80 m sprint skating, with 2 min passive recovery between two consecutive sets was allowed. In RSSA-3, the recovery period between the sets was 3 min. Average speed, average heart rate (HRaver), peak heart rate (HRpeak), blood lactate concentration ([BLa]), and rate of perceived exertion (RPE) were measured in both RSSA-2 and RSSA-3 tests. In all the sets, except set 1, the average speed of the subjects was significantly (p < 0.05) higher in RSSA-3 than the respective set in RSSA-2. Average HR and RPE were higher in RSSA-2 than RSSA-3 in most of the sets. For any given set, no difference in HRpeak was noted between RSSA-2 and RSSA-3. Post-sprint (Set 6) [BLa] was significantly (p < 0.05) higher in RSSA-3 than RSSA-2. This study concludes that the 3 min rest period is more beneficial than the 2 min rest period, for (1) increasing skating speed and (2) reducing overall cardiac workload and perceived fatigue.

• Klíčová slova
• average heart rate, average speed, blood lactate concentration, peak heart rate, rate of perceived exertion, speed decrement,
• MeSH
• bruslení * MeSH
• hokej * MeSH
• kyselina mléčná MeSH
• lidé MeSH
• odpočinek MeSH
• srdeční frekvence MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina mléčná MeSH

It is widely accepted that sympathetic nervous system plays a crucial role in the development of hypertension. On the other hand, the role of adrenal medulla (the adrenomedullary component of the sympathoadrenal system) in the development and maintenance of high blood pressure in man as well as in experimental models of hypertension is still controversial. Spontaneously hypertensive rats (SHR) are the most widely used animal model of human essential hypertension characterized by sympathetic hyperactivity. However, the persistence of moderately elevated blood pressure in SHR subjected to sympathectomy neonatally as well as the resistance of adult SHR to the treatment by sympatholytic drugs suggests that other factors (including enhanced activity of the adrenomedullary hormonal system) are involved in the pathogenesis of hypertension of SHR. This review describes abnormalities in adrenomedullary hormonal system of SHR rats starting with the hyperactivity of brain centers regulating sympathetic outflow, through the exaggerated activation of sympathoadrenal preganglionic neurons, to the local changes in chromaffin cells of adrenal medulla. All the above alterations might contribute to the enhanced release of epinephrine and/or norepinephrine from adrenal medulla. Special attention is paid to the alterations in the expression of genes involved in catecholamine biosynthesis, storage, release, reuptake, degradation and adrenergic receptors in chromaffin cells of SHR. The contribution of the adrenomedullary hormonal system to the development and maintenance of hypertension as well as its importance during stressful conditions is also discussed.

• MeSH
• dřeň nadledvin metabolismus   patofyziologie   MeSH
• hormony metabolismus   MeSH
• hypertenze genetika   metabolismus   patofyziologie   MeSH
• krevní tlak genetika   MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• potkani inbrední SHR MeSH
• sympatický nervový systém patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• hormony MeSH

We adapted a radioligand receptor binding assay for measuring insulin levels in unknown samples. The assay enables rapid and accurate determination of insulin concentrations in experimental samples, such as from insulin-secreting cells. The principle of the method is based on the binding competition of insulin in a measured sample with a radiolabeled insulin for insulin receptor (IR) in IM-9 cells. Both key components, radiolabeled insulin and IM-9 cells, are commercially available. The IR binding assay was used to determine unknown amounts of insulin secreted by MIN6 β cell line after stimulation with glucose, arginine, ornithine, dopamine, and serotonin. The experimental data obtained by the IR binding assay were compared to the results determined by RIA kits and both methods showed a very good agreement of results. We observed the stimulation of glucose-induced insulin secretion from MIN6 cells by arginine, weaker stimulation by ornithine, but inhibitory effects of dopamine. Serotonin effects were either stimulatory or inhibitory, depending on the concentration of serotonin used. The results will require further investigation. The study also clearly revealed advantages of the IR binding assay that allows the measuring of a higher throughput of measured samples, with a broader range of concentrations than in the case of RIA kits. The IR binding assay can provide an alternative to standard RIA and ELISA assays for the determination of insulin levels in experimental samples and can be especially useful in scientific laboratories studying insulin production and secretion by β cells and searching for new modulators of insulin secretion.

• Klíčová slova
• Binding assay, Insulin receptor, Insulin secretion, Radioligand, Secretagogue, β Cells,
• MeSH
• arginin metabolismus   MeSH
• beta-buňky metabolismus   MeSH
• buněčné linie MeSH
• dopamin metabolismus   MeSH
• glukosa metabolismus   MeSH
• inzulin analýza   metabolismus   MeSH
• krysa rodu Rattus MeSH
• Langerhansovy ostrůvky metabolismus   MeSH
• lidé MeSH
• myši MeSH
• ornithin metabolismus   MeSH
• potkani Wistar MeSH
• radioimunoanalýza metody   MeSH
• radioligandová zkouška metody   MeSH
• sekrece inzulinu * MeSH
• serotonin metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• arginin MeSH
• dopamin MeSH
• glukosa MeSH
• inzulin MeSH
• ornithin MeSH
• serotonin MeSH

PURPOSE: The aim of this study was to assess the diagnostic value of catecholamines and their O-methylated metabolites in vitreous humor samples in identifying antemortem cold exposure and fatal hypothermia in the forensic casework. METHODS: A total of 80 autopsy cases (40 hypothermia fatalities and 40 cases in which hypothermia as the main or contributory cause of death was excluded) were selected for this study. Catecholamines and their O-methylated metabolites were measured in urine and vitreous humor samples collected at autopsy. RESULTS: Urine catecholamine and their O-methylated metabolite concentrations were significantly higher in hypothermia-related deaths. On the other hand, measurements in vitreous humor samples did not reveal statistically significant differences between hypothermia-related deaths and controls. CONCLUSIONS: Globally considered, our findings seem to suggest that, contrary to urine catecholamines and their O-methylated metabolites, vitreous levels of these compounds appear to be of limited value in characterizing human antemortem stress reactions due to cold exposure and can hardly be used in the forensic setting to support the diagnosis of hypothermia.

• Klíčová slova
• Catecholamines, Hypothermia, Metanephrines, Postmortem biochemistry, Vitreous humor,
• MeSH
• adrenalin metabolismus   MeSH
• dopamin analogy a deriváty   metabolismus   MeSH
• dospělí MeSH
• hypotermie diagnóza   metabolismus   MeSH
• katecholaminy metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• metanefrin metabolismus   MeSH
• mladý dospělý MeSH
• noradrenalin metabolismus   MeSH
• normetanefrin metabolismus   MeSH
• posmrtné změny MeSH
• senioři MeSH
• sklivec metabolismus   MeSH
• soudní patologie MeSH
• studie případů a kontrol MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 3-methoxytyramine MeSH Prohlížeč
• adrenalin MeSH
• dopamin MeSH
• katecholaminy MeSH
• metanefrin MeSH
• noradrenalin MeSH
• normetanefrin MeSH

BACKGROUND: Chronic hemodynamic overloading leads to heart failure (HF) due to incompletely understood mechanisms. To gain deeper insight into the molecular pathophysiology of volume overload-induced HF and to identify potential markers and targets for novel therapies, we performed proteomic and mRNA expression analysis comparing myocardium from Wistar rats with HF induced by a chronic aorto-caval fistula (ACF) and sham-operated rats harvested at the advanced, decompensated stage of HF. METHODS: We analyzed control and failing myocardium employing iTRAQ labeling, two-dimensional peptide separation combining peptide IEF and nano-HPLC with MALDI-MS/MS. For the transcriptomic analysis we employed Illumina RatRef-12v1 Expression BeadChip. RESULTS: In the proteomic analysis we identified 2030 myocardial proteins, of which 66 proteins were differentially expressed. The mRNA expression analysis identified 851 differentially expressed mRNAs. CONCLUSIONS: The differentially expressed proteins confirm a switch in the substrate preference from fatty acids to other sources in the failing heart. Failing hearts showed downregulation of the major calcium transporters SERCA2 and ryanodine receptor 2 and altered expression of creatine kinases. Decreased expression of two NADPH producing proteins suggests a decreased redox reserve. Overexpression of annexins supports their possible potential as HF biomarkers. Most importantly, among the most up-regulated proteins in ACF hearts were monoamine oxidase A and transglutaminase 2 that are both potential attractive targets of low molecular weight inhibitors in future HF therapy.

• Publikační typ
• časopisecké články MeSH