A cheap, simple and fast procedure of building an infusion swivel is described for both short- and long-term experiments in rats. To assemble the swivel, plastic laboratory syringe elements, needles and a three-way stopcock are used. The swivel avoids cannula-kinking and permits animals free movement inside the cage. In addition, the gadget presented is inexpensive enough to make it disposable. Further advantages of the self-made infusion swivel depend on its disposability, it is time-saving, simplifies blood sampling or administration of drugs and prevents contamination, when using radiolabelled products. The haemodynamics and metabolism of rats subjected to restraint stress or ether-anaesthetized rats significantly differ from those of conscious freely moving animals. Whereas restraint stress provoked a more pronounced increase of blood pressure and heart rate, ether anaesthesia induced a 19% rise in serum glucose. Thus, the device described in this study provides more physiological experimental conditions.

• MeSH
• časové faktory MeSH
• fyzické omezení MeSH
• katetrizace přístrojové vybavení   MeSH
• krevní glukóza MeSH
• krevní tlak MeSH
• krysa rodu Rattus MeSH
• monitorování fyziologických funkcí ekonomika   přístrojové vybavení   MeSH
• pohoda zvířat MeSH
• potkani Wistar MeSH
• srdeční frekvence MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• krevní glukóza MeSH

• MeSH
• kardiovaskulární fyziologické jevy * MeSH
• kardiovaskulární systém patofyziologie   MeSH
• lidé MeSH
• oxid dusnatý fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• kongresy MeSH
• souhrny MeSH
• Názvy látek
• oxid dusnatý MeSH

Plant hormones, also called phytohormones, are small signaling molecules regulating a wide range of growth and developmental processes. These unique compounds respond to both external (light, temperature, water, nutrition, or pathogen attack) and internal factors (e.g., age) and mediate signal transduction leading to gene expression with the aim of allowing plants to adapt to constantly changing environmental conditions. Within the regulation of biological processes, individual groups of phytohormones act mostly through a web of interconnected responses rather than linear pathways, making elucidation of their mode of action in living organisms quite challenging. To further progress with our knowledge, the development of novel tools for phytohormone research is required. Although plenty of small molecules targeting phytohormone metabolic or signaling pathways (agonists, antagonists, and inhibitors) and labeled or tagged (fluorescently, isotopically, or biotinylated) compounds have been produced, the control over them in vivo is lost at the time of their administration. Caged compounds, on the other hand, represent a new approach to the development of small organic substances for phytohormone research. The term "caged compounds" refers to light-sensitive probes with latent biological activity, where the active molecule can be freed using a light beam in a highly spatio/temporal-, amplitude-, or frequency-defined manner. This review summarizes the up-to-date development in the field of caged plant hormones. Research progress is arranged in chronological order for each phytohormone regardless of the cage compound formulation and bacterial/plant/animal cell applications. Several known drawbacks and possible directions for future research are highlighted.

• Klíčová slova
• caged compound, chemical biology, photochemistry, photoremovable protecting group, phytohormone, plant physiology,
• MeSH
• fyziologická adaptace MeSH
• regulátory růstu rostlin * MeSH
• rostlinné buňky MeSH
• rostliny * MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• regulátory růstu rostlin * MeSH

Hypoxia is characterized as insufficient oxygen delivery to tissues and cells in the body and is prevalent in many human physiology processes and diseases. Thus, it is an attractive state to experimentally study to understand its inner mechanisms as well as to develop and test therapies against pathological conditions related to hypoxia. Animal models in vivo fail to recapitulate some of the key hallmarks of human physiology, which leads to human cell cultures; however, they are prone to bias, namely when pericellular oxygen concentration (partial pressure) does not respect oxygen dynamics in vivo. A search of the current literature on the topic revealed this was the case for many original studies pertaining to experimental models of hypoxia in vitro. Therefore, in this review, we present evidence mandating for the close control of oxygen levels in cell culture models of hypoxia. First, we discuss the basic physical laws required for understanding the oxygen dynamics in vitro, most notably the limited diffusion through a liquid medium that hampers the oxygenation of cells in conventional cultures. We then summarize up-to-date knowledge of techniques that help standardize the culture environment in a replicable fashion by increasing oxygen delivery to the cells and measuring pericellular levels. We also discuss how these tools may be applied to model both constant and intermittent hypoxia in a physiologically relevant manner, considering known values of partial pressure of tissue normoxia and hypoxia in vivo, compared to conventional cultures incubated at rigid oxygen pressure. Attention is given to the potential influence of three-dimensional tissue cultures and hypercapnia management on these models. Finally, we discuss the implications of these concepts for cell cultures, which try to emulate tissue normoxia, and conclude that the maintenance of precise oxygen levels is important in any cell culture setting.

• Klíčová slova
• animal model, cell culture, hypoxia, in vitro model, normoxia, oxygen concentration, partial pressure, pericellular oxygen,
• MeSH
• buněčné kultury metody   MeSH
• fyziologie buňky * MeSH
• hypoxie * MeSH
• kyslík metabolismus   MeSH
• lidé MeSH
• studie proveditelnosti MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• kyslík MeSH

A heart rate biofeedback system consisting of a JPR 12 minicomputer (12 bit, 4 K), of input devices (an electronic circuit triggered by the EEG R-waves or a photoelectric ear lobe pulse detector and of output devices (a feedback indicator of successful or unsuccessful heart rate control during the preceding time interval, the teletype and the paper tape punch) is described. The actual heart rate is measured and compared with levels differing from the average by a preselected number of pulses/min. When a preset criterion is met, the levels are shifted automatically. In control session shuffled data from the preceding experimental session are used for feedback.

• MeSH
• biofeedback (psychologie) fyziologie   MeSH
• lidé MeSH
• psychofyziologie přístrojové vybavení   MeSH
• srdeční frekvence * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• cévní rezistence MeSH
• dospělí MeSH
• fyziologická adaptace MeSH
• hemodynamika * MeSH
• hodnoty glomerulární filtrace MeSH
• kardiovaskulární fyziologické jevy * MeSH
• krevní objem MeSH
• krevní tlak MeSH
• ledviny fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• minutový srdeční výdej MeSH
• ortostatická hypotenze patofyziologie   MeSH
• postura těla * MeSH
• regionální krevní průtok MeSH
• srdeční frekvence MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Thermoregulation in control subjects and cold-adapted winter swimmers was examined during 1 h of cold water immersion (13 C). It was found that the thermoregulatory functions of winter swimmers differ from those of non-cold-adapted subjects. As evident from the relationship between rectal temperature and the magnitude of cold thermogenesis, in controls a significant part of cold thermogenesis during the early phase of cooling was induced by changes in peripheral temperature input, while in the late phase of cooling it was the central temperature input which was mainly engaged in induction of cold thermogenesis. In winter swimmers the magnitude of cold thermogenesis was solely related to changes in rectal temperature, indicating the predominance of the central temperature input in activation of heat production mechanisms. The thermoregulatory threshold for induction of cold thermogenesis was lowered (by 0.34 C), but the apparent hypothalamic thermosensitivity was the same as in non-cold-adapted subjects. These differences are indicative of adaptation of thermoregulatory control centres. Additionally, the activity of thermoregulatory effectors was also changed. Shivering was induced later during cooling (after 40 min) in winter swimmers than in controls, which suggests an important participation of non-shivering thermogenesis in the early thermogenic response. Winter swimmers also showed bradycardia and a greater reduction in plasma volume during cooling. The data indirectly indicate restriction of heat loss from the body. Only a non-significant increase in quantity of subcutaneous fat was observed in winter swimmers. Thus, winter swimmers were able to survive a significantly greater temperature gradient between body and environment than non-cold-adapted subjects by modifying the sensory functions of hypothalamic thermoregulatory centres to lower heat loss and produce less heat during cold exposure. Additionally, the capacity of the total cold thermogenesis due to potentiation of non-shivering heat production was also increased. Heat produced due to thermogenic action of adrenaline may represent more than a quarter of the total cold thermogenesis. In conclusion, the data suggest that winter swimmers exhibit metabolic, hypothermic and insulative types of cold adaptation.

• MeSH
• adrenalin krev   MeSH
• dospělí MeSH
• fyziologická adaptace fyziologie   MeSH
• hemodynamika fyziologie   MeSH
• katecholaminy fyziologie   MeSH
• krevní tlak fyziologie   MeSH
• lidé MeSH
• nízká teplota MeSH
• noradrenalin krev   MeSH
• objem plazmy fyziologie   MeSH
• plavání fyziologie   MeSH
• srdeční frekvence fyziologie   MeSH
• tělesná teplota fyziologie   MeSH
• termoregulace fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adrenalin MeSH
• katecholaminy MeSH
• noradrenalin MeSH

The cold pressor test (CPT) triggers in healthy subjects a vascular sympathetic activation and an increase in blood pressure. The heart rate (HR) response to this test is less well defined, with a high inter-individual variability. We used traditional spectral analysis together with the non-linear detrended fluctuation analysis to study the autonomic control of HR during a 3-min CPT. 39 healthy young subjects (23.7+/-3.2 years, height 180.4+/-4.7 cm and weight 73.3+/-6.4 kg) were divided into two groups according to their HR responses to CPT. Twenty subjects have a sustained increase in HR throughout the test with reciprocal autonomic interaction, i.e. increase in sympathetic activity and decrease vagal outflow. In the 19 remainders, HR decreased after an initial increase, with indication of involvement of both sympathetic and vagal outflow. Baseline evaluation of the subjects revealed no difference between the two groups. Nevertheless, a higher sympathetic activity at the skin level during CPT was present in the group with decreased HR. Further studies are needed to explain why healthy subjects react differently to the CPT and if this has potential clinical implications.

• MeSH
• časové faktory MeSH
• dospělí MeSH
• fyziologická adaptace MeSH
• kardiovaskulární systém inervace   MeSH
• krevní tlak MeSH
• lidé MeSH
• lineární modely MeSH
• mladý dospělý MeSH
• modely kardiovaskulární MeSH
• nelineární dynamika MeSH
• nervus vagus fyziologie   MeSH
• nízká teplota * MeSH
• srdeční frekvence * MeSH
• sympatický nervový systém fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A ubiquitous property of bacteria is their ability to move toward more suitable environments, which can also facilitate host-associated activities like colonization and offer the cell several benefits such as bacteria moving towards a favorable gradient or away from a harmful gradient is known as chemotaxis. Bacteria achieve this by rotating flagella in clockwise and anticlockwise directions resulting in "run" and "tumble." This ability of bacteria to sense and respond to any type of change in the environmental factors like pH, osmolarity, redox potential, and temperature is a standard signal transduction system that depends on coupling proteins, which is the bacterial chemotaxis system. There are two architectures for the coupling proteins in the chemotaxis system: CheW and CheV. Typically, a signal transduction system for chemotaxis to form a core signaling complex couples CheA activity to chemoreceptor control: two CheW coupling protein molecules span a histidine kinase CheA dimer and two chemoreceptors (also known as methyl-accepting chemotaxis protein, MCP) trimers of dimers which further transfer the signal to the flagellar motor through CheY. The current review summarizes and highlights the molecular mechanism involved in bacterial chemotaxis, its physiological benefits such as locating suitable nutrients and niches for bacterial growth, and various assay techniques used for the detection of chemotactic motility.

• Klíčová slova
• Bacteria, Chemotaxis, Motility, Run, Tumble,
• MeSH
• Bacteria * metabolismus   genetika   MeSH
• bakteriální proteiny metabolismus   genetika   MeSH
• chemotaxe * fyziologie   MeSH
• flagella fyziologie   MeSH
• fyziologie bakterií * MeSH
• MCP systém metabolismus   MeSH
• signální transdukce MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• bakteriální proteiny MeSH
• MCP systém MeSH

The interval model training has been more recommended to promote aerobic adaptations due to recovery period that enables the execution of elevated intensity and as consequence, higher workload in relation to continuous training. However, the physiological and aerobic capacity adaptations in interval training with identical workload to continuous are still uncertain. The purpose was to characterize the effects of chronic and acute biomarkers adaptations and aerobic capacity in interval and continuous protocols with equivalent load. Fifty Wistar rats were divided in three groups: Continuous training (GTC), interval training (GTI) and control (CG). The running training lasted 8 weeks (wk) and was based at Anaerobic Threshold (AT) velocity. GTI showed glycogen super-compensation (mg/100 mg) 48 h after training session in relation to CG and GTC (GTI red gastrocnemius (RG)=1.41+/-0.16; GTI white gastrocnemius (WG)=1.78+/-0.20; GTI soleus (S)=0.26+/-0.01; GTI liver (L)=2.72+/-0.36; GTC RG=0.42+/-0.17; GTC WG=0.54+/-0.22; GTC S=0.100+/-0.01; GTC L=1.12+/-0.24; CG RG=0.32+/-0.05; CG WG=0.65+/-0.17; CG S=0.14+/-0.01; CG L=2.28+/-0.33). The volume performed by GTI was higher than GTC. The aerobic capacity reduced 11 % after experimental period in GTC when compared to GTI, but this change was insignificant (19.6+/-5.4 m/min; 17.7+/-2.5 m/min, effect size = 0.59). Free fatty acids and glucose concentration did not show statistical differences among the groups. Corticosterone concentration increased in acute condition for GTI and GTC. Testosterone concentration reduced 71 % in GTC immediately after the exercise in comparison to CG. The GTI allowed positive adaptations when compared to GTC in relation to: glycogen super-compensation, training volume performed and anabolic condition. However, the GTI not improved the aerobic performance.

• MeSH
• aerobióza fyziologie   MeSH
• anaerobní práh fyziologie   MeSH
• běh fyziologie   MeSH
• fyziologická adaptace fyziologie   MeSH
• glukosa metabolismus   MeSH
• glykogen metabolismus   MeSH
• játra fyziologie   MeSH
• kondiční příprava zvířat fyziologie   MeSH
• kortikosteron metabolismus   MeSH
• kosterní svaly fyziologie   MeSH
• krysa rodu Rattus MeSH
• kyseliny mastné neesterifikované metabolismus   MeSH
• potkani Wistar MeSH
• tělesná hmotnost fyziologie   MeSH
• testosteron metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• glukosa MeSH
• glykogen MeSH
• kortikosteron MeSH
• kyseliny mastné neesterifikované MeSH
• testosteron MeSH