Effects of Dynamic and Static Loads on the Concentration of Sodium and Potassium in Murine Skeletal Muscles.

The effects of dynamic and static load on the intracellular concentrations of sodium [Formula: see text] and potassium (K+i) in m. soleus and m. biceps, respectively, were studied in mice. Both dynamic (swimming for 60 min) and static (hanging on the grid for 40 min) load led to a 2-fold increase in [Formula: see text] level, a decrease in K+i concentration by 25-35%, and 3-4-fold increase in the [Formula: see text] ratio. These effects of dynamic and static loads on the studied parameters remained unchanged in mice subjected to regular physical exercise (swimming or hanging on the grid for 1 h a day over 4 weeks). Our results suggest that dissipation of sodium and potassium transmembrane gradients during physical exercise can be considered as a factor of regulation of functional activity of skeletal muscles, which includes changes in transcription and translation of myokines observed previously.

Post-exercise Endothelium-Dependent Vasodilation Is Dependent on Training Status.

The effect of training status on post-exercise flow-mediated dilation (FMD) is not well characterized. We tested the hypothesis that the more trained the subjects, the lower the reduction in FMD after an acute bout of aerobic exercise. Forty-seven men (mean ± SD, age: 20.1 ± 1.2 years, body mass: 75.5 ± 5.1 kg, height 178.1 ± 5.4 cm) were divided into five groups with different training characteristics (sedentary, two different groups of active subjects, two different groups of well-trained subjects - runners and weightlifters). Brachial artery FMD (blood pressure cuff placed around the arm distal to the probe with the proximal border adjacent to the medial epicondyle; 5 min at a pressure of 220 mmHg) was assessed before and during 3 min immediately after a bout of cycling exercise at a relative intensity of 170 bpm [(physical work capacity (PWC170)]. At baseline, a progressive increase in FMD was observed in the participants with the higher training status, if the training remained moderate. Indeed, FMD was reduced in runners and weightlifters compared to those who were moderately trained. After PWC170, FMD did not significantly change in sedentary and highly trained runners, significantly increased in the two groups of active subjects but significantly decreased in highly trained weightlifters. These results showed that endothelium-dependent vasodilation evaluated using brachial FMD is maintained or improved following acute aerobic exercise in moderately trained participants, but not in well-trained participants, especially if they are engaged in resistance training.

Search for Intracellular Sensors Involved in the Functioning of Monovalent Cations as Secondary Messengers.

Maintenance of non-equilibrium Na+ and K+ distribution between cytoplasm and extracellular medium suggests existence of sensors responding with conformational transitions to the changes of these monovalent cations' intracellular concentration. Molecular nature of monovalent cation sensors has been established in Na,K-ATPase, G-protein-coupled receptors, and heat shock proteins structural studies. Recently, it was found that changes in Na+ and K+ intracellular concentration are the key factors in the transcription and translation control, respectively. In this review, we summarize results of these studies and discuss physiological and pathophysiological significance of Na+i,K+i-dependent gene expression regulation mechanism.

Level of Interleukins IL-6 and IL-15 in Blood Plasma of Mice after Forced Swimming Test.

We measured the concentrations of IL-6 and IL-15 in blood plasma of mice at different terms after forced swimming, taking into account exercise intensity and preliminary training. It was shown that training was an important factor affecting blood plasma level of IL both at rest and after single forced swimming: in trained animals, the concentration of both myokines increased immediately after swimming, while in untrained animals, this increase was observed only after 5 h. Changes in cytokine production against the background of training can be associated with various factors, including neuroendocrine mechanisms, stress, modification of intracellular signaling, as well as reorganization of transcriptional mechanisms in muscle fibers. The most important factor is shift in the ratio of monovalent cations (sodium and potassium) in the cytoplasm.

[The improvement of the abilities to maintain motor coordination and equilibrium in the students presenting with the functional disorders of the musculoskeletal system by introducing the elements of therapeutic physical training into the structure of academic schedule of physical education]. / Sovershenstvovanie navykov koordinatsii i ravnovesiya u studentov s narusheniyami oporno-dvigatel'nogo apparata za schet vklyucheniya elementov lechebnoi fizicheskoi kul'tury v strukturu akademicheskikh zanyatii po fizicheskomu vospitaniyu.

The problem of deterioration of the health status in the university students at present remains as topical as it was before being a major cause of impaired working capacity, disability and/or poor social adaptation of the large number of graduates. It has been proposed to introduce a class of therapeutic physical training (TPT) into the schedule of physical education for the students. AIM: The objective of the present study was to evaluate the effectiveness of the formation of the skills needed to maintain motor coordination and equilibrium in the students presenting with the functional disorders of the musculoskeletal system (MSS) including scoliosis by the introduction of the elements of therapeutic physical training into their academic schedules. MATERIAL AND METHODS: The main study group was comprised of 32 students (men) at the age of 18-19 years presenting with the disorders of the musculoskeletal system (type III scoliosis, osteochondropathy, and osteochondrosis). The students of this group received a curriculum aimed at improving their motor skills with the emphasis laid on the selected elements of therapeutic physical training. The control group was composed of 17 students without disorders of the musculoskeletal system who attended the physical education classes following the traditional program. The coordination abilities and balance skills were evaluated based on the analysis with the use of the Stabilan-1 stabilographic apparatus. In addition, the stability test and the Romberg test with open and closed eyes were performed. RESULTS: The results of the study give evidence that the introduction of the elements of therapeutic physical training into the structure of academic schedule of physical education for the students suffering from diseases of the musculoskeletal system has beneficial effect on the parameters of stability and the general ability to maintain the posture and balance. Specifically, in the beginning of the academic year, the students of the main study group presenting with the locomotor problems (the scatter of the manifest disorders in the frontal and sagittal planes, the mean amplitude and velocity of fluctuations of the center of pressure, the area of the projection of the center of pressure displacements as well as the quality of the equilibrium function that characterizes the ability to maintain the posture) were significantly different from the respective characteristics in the control group (p<0,05). After the course of therapeutic physical training given during the academic year, the scatter of the manifestations in the frontal and sagittal planes as well as the role of the visual control in the maintenance of balance decreased significantly. CONCLUSION: The present study has demonstrated that the introduction of the elements of therapeutic physical training into the structure of academic schedule of physical education for the students presenting with the functional disorders of the locomotor apparatus exerts the positive influence on the parameters characterizing stability and the ability to maintain the posture as well as equilibrium at large. Such beneficial effect is apparent in the form of reduction of the amplitude and velocity of fluctuations of the centre of pressure, the decrease in the area of projection of its displacements, and the improvement of the quality of the equilibrium function that characterizes the ability to maintain the posture. Moreover, the ratio of spreading in the frontal and sagittal planes decreases, and the role of the visual control in the maintenance of equilibrium becomes diminished. The results of the study give grounds for recommending the introduction of the elements of therapeutic physical training into the learning process of students presenting with diseases of the musculoskeletal system.

Identification of Proteins Whose Interaction with Na+,K+-ATPase Is Triggered by Ouabain.

Prolonged exposure of different epithelial cells (canine renal epithelial cells (MDCK), vascular endothelial cells from porcine aorta (PAEC), human umbilical vein endothelial cells (HUVEC), cervical adenocarcinoma (HeLa), as well as epithelial cells from colon carcinoma (Caco-2)) with ouabain or with other cardiotonic steroids was shown earlier to result in the death of these cells. Intermediates in the cell death signal cascade remain unknown. In the present study, we used proteomics methods for identification of proteins whose interaction with Na+,K+-ATPase is triggered by ouabain. After exposure of Caco-2 human colorectal adenocarcinoma cells with 3 µM of ouabain for 3 h, the protein interacting in complex with Na+,K+-ATPase was coimmunoprecipitated using antibodies against the enzyme α1-subunit. Proteins of coimmunoprecipitates were separated by 2D electrophoresis in polyacrylamide gel. A number of proteins in the coimmunoprecipitates with molecular masses of 71-74, 46, 40-43, 38, and 33-35 kDa was revealed whose binding to Na+,K+-ATPase was activated by ouabain. Analyses conducted by mass spectroscopy allowed us to identify some of them, including seven signal proteins from superfamilies of glucocorticoid receptors, serine/threonine protein kinases, and protein phosphatases 2C, Src-, and Rho-GTPases. The possible participation of these proteins in activation of cell signaling terminated by cell death is discussed.

[Secretory Function of Skeletal Muscles: Producing Mechanisms and Myokines Physiological Effects].

Skeletal muscle cells secrete a variety of hormones and cytokines, which are referred to as myokines. Different modes of exercise are the main factor of myokines producing. The myokines expression level is increased in an exponential fashon proportional to the length of exercise and the amount of muscle mass engaged in the exercise. These myokines are described to communicate with cells in an autocrine/ paracrine manner. Thus it ensures the maintenance of homeostasis and adaptarion to physical stress. This myokines role is provided by a vriety of effects. It is assumed that exercise increases myokines transcription via signaling systems that are activated in response to a decrease in the partial pressure of oxygen, increasing the concentration of [Ca²âº] i and AMP. Significant prospects have the myokines investigation of the role in the different disorders correction. So now accumulated enough data for myokines consideration as a single functional system, which plays an important role in the adaptation mechanisms to the habitual exrcise.

[INTERACTION EPITHELIUM AND SMOOTH MUSCLE IN THE WALLS OF THE AIRWAYS IN THE NORMAL CONDITIONS AND WHEN FORMING OF HYPERREACTIVITY].

In the present study was to investigate the effect epithelium on the tone smooth muscle of the airways of guinea pigs under physiological conditions and when forming of experimental asthma. It was found that the amplitude of contractile responses decreased by histaminergic, and serotonergic effects in the presence of epithelium in the control group. Influence epithelium dilatation adrenergic reactions depended on the type of pretreatment factors. The amplitude of the relaxation was reduced in the case of pre-treatment with a solution of potassium, the amount of dilation increased by pretreatment with histamine. The impact of epithelium on contractile responses of smooth muscles disappeared when forming of hyperreactivity.

[PHYSIOLOGICAL COORDINATION OF MOTOR ACTIONS IN PAIR OF DANCE].

With an increase of sports qualification dancers are developing asymmetry of parameters of bioelectric activity and hemodynamic of the legs. For beginners sportsmen are characteristic coordination of movements performed individually, while highly skilled dancers better coordination of movements, performed in tandem. For the average skill level of athletes characteristically is overvoltage vegetative-vascular system. All of the above allows us to consider the formation of skills in ballroom dancing as a functional system in which a sense of balance and coordination are determining for the skill level of athletes, linked to the information field of the visual and vestibular reception, to the organization of the contractile activity of muscles and vegetative-vascular maintenance activities. An essential component of this physiological system is the formation of asymmetry, which depends on the sex of the partner and defines its role in the pair.

[Physiological Basis of the Improvement of Movement Accuracy with the Use of Stabilographic Training with Biological Feedback].

We studied the physiological parameters of ball hitting by volleyball players in unsupported position and opportunities for their improvement by training with biological feedback. Physiological and biomechanical parameters of a direct attack hit from supported position correlate with biomechanical features ofjump shots. At the same time, the physiological basis of accuracy of shots consists of the improvement of trunk and arm movement coordination in the flight phase, the factors of intramuscular and intermuscular coordination of the hitting arm and the change in the displacement of the center of pressure. The use of computer stabilography training with biological feedback helps to optimize physiological and biomechanical parameters of physical actions in unsupported position, which ultimately causes an increase in the accuracy of jump hitting of the ball. The obtained results open the prospects for applying the method of computer stabilography to improve the performance of accuracy-targeted actions in unsupported position in various sports.

Cation-chloride cotransporters: regulation, physiological significance, and role in pathogenesis of arterial hypertension.

This review summarizes the data on the functioning of carriers providing electroneutral symport of sodium, potassium, and chloride (Na(+),K(+),2Cl(-) cotransport), potassium and chloride (K(+),Cl(-) cotransport), and sodium and chloride (K(+),Cl(-) cotransport) as well as molecular mechanisms of the regulation of these carriers and their physiological significance. We emphasized the involvement of chloride-coupled carriers in the regulation of cell volume and intracellular chloride concentration and novel data on the role of ubiquitous isoform of Na(+),K(+),2Cl(-) cotransporter NKCC1 in regulation of vascular smooth muscle contraction and activity of GABA(A) receptors. Finally, we analyzed the data on activation of NKCC1 in patients with essential hypertension and its role in the long-term maintenance of elevated systemic blood pressure and myogenic response in microcirculatory beds.

[Age, gender and individually-typological characteristics of reaction to acute hypoxic exposure].

Individual pequliarities of hypoxic resistance, assessed by the response of cardiorespiratory system to acute normobaric hypoxia (10% O2), were studied in healthy subjects. Age changes in dynamics of blood oxygen saturation after the acute hypoxia are shown at level of separate sites curve SpO2 (phases of a delay, decrease and lifting). It is established, that at children sensitivity to acute hypoxia above, than at teenagers, and at teenagers above, than at adults. Higher lability of mental processes, sympathetic activity, and personal anxiety are associated with choleric temperament. Cholerics are characterized by slower restoration of blood oxygen saturation after the acute hypoxia compared with sanguine persons that we consider an indication of less hypoxic tolerance of the first group. We have developed the complex algorithm, dynamics describing dependence oxygen saturation in various phases of the hypoxic test, which can be used as a universal method of an estimation hypoxic stability at different groups of the population.

Physiological and biomechanical characteristics of the kick and goal techniques of football players.

Physiological and biomechanical characteristics of the kick and goal technique in football were studied in athletes of different qualification. The formation of technological skills of football players kicking the ball from the standard position requires coordinated movements and high differentiation of muscular activity.

Contractile reactions of guinea pig airway smooth muscles in the presence of stannum oxide nanosized particles.

Contractile reactions of the guinea pig airway smooth muscles in the presence of stannum dioxide nanosized particles were studied. Contractile reactions to cholinergic and histaminergic stimulation were potentiated by inhalations of nanoparticle aerosol and by exposure of isolated smooth muscle segments to nanoparticle suspension.

[Influence of nanosize particles of cobalt ferrite on contractile responses of smooth muscle segment of airways].

Contractile responses of airways segments of porpoises inhaling nanopowder CoFe2O4 were stidued by means of a mechanographic method. Inhalation of the nanosize particles of CoFe2O4 in vivo and in vitro testing the nanomaterial on isolated smooth muscles led to potentiation histaminergic, cholinergic contractile activity in airways of porpoises and to strengthening of adrenergic relaxing answers. Nanosize particles vary amplitude of hyperpotassium reductions in smooth muscle segments of airways similarly to the effect of depolymerizing drug colchicine.

Effect of nanodisperse ferrite cobalt (CoFe2O4) particles on contractile reactions in guinea pigs airways.

The effect of nanopowder CoFe(2)O(4)on contractile responses of smooth-muscle segments of guinea pigs airways was studied by mechanography. Both in vivo inhalation of nanopowder aerosol or in vitro application of nanopowder to isolated airway segments increased the amplitude of contractile responses to histamine and potentiated the dilatory reaction to adrenergic salbutamol.

Specific adrenergic responses of smooth muscles in the vascular wall of guinea pig pulmonary arteries during ovalbumin sensitization.

The adrenergic contractile responses of smooth muscles in the vascular wall of guinea pig pulmonary arteries were studied during ovalbumin sensitization. Sensitization was followed by inhibition of contractile responses to an alpha-adrenoceptor agonist mesatone, prevented endothelium-derived relaxation, and potentiated the contractile response to isoproterenol. Administration of a beta-adrenoceptor agonist isoproterenol potentiated the increase in mechanical strain of smooth muscles in the pulmonary artery precontracted with high-potassium Krebs solution. Removal of the endothelium had no effect on the contractile response of smooth muscle segments from the pulmonary artery of intact and sensitized guinea pigs to b-adrenergic influences. The contractile responses of smooth muscles of the pulmonary artery are associated with activity of the cAMP-dependent signal system and play a role in the pathogenesis of ventilation-perfusion disturbances during atopic inflammation.

[Definition of parameters of the condition of oxidizing stress in smooth muscle cells under influence of exogenous nitroso-glutatyon in vitro].

Influence of exogenous nitroso-glutatyon on intensity of oxidizing processes in smooth muscles of colon and bronchial tubes in intact and atopic sensitised porpoises (guinea pigs) was studied. In sensitised porpoises, antioxidant protection has been initially reduced against the background of increased maintenance of products of oxidizing that reflects a picture of oxidizing damage and can be associated with an inflammatory process. In incubation with nitroso-glutatyon, a decrease in activities of syperoxiddismutase and catalase is marked and, in sensitised animals, this effect has been expressed to a lesser degree. Syperoxiddismutase and catalase are antioxidant for the enzymes participating in protection of cells from free-radical damage. A dose-dependence decrease in activity catalase and syperoxiddismutase is defined by a parity of the enzymes participating in disintegration of nitrosoglutatyon and the enzymes which have kept antioxidant activity.

[Na+,K+,2Cl(-)-cotransport and chloride permeability of the cell membrane in mezaton and histamine regulation of electrical and contractile activity in smooth muscle cells from the guinea pig ureter].

Influence of Na+,K+,2Cl(-)-cotransport and chloride permeability of the cell membrane on electrically-induced action potential and contraction of smooth muscle cells from guinea pig ureter was examined with the methods of the double sucrose gap junction. Mesatone (10 microM) and histamine (10 microM) induced prolongation of the action potential and elevation of smooth muscle cell contraction, whereas hyperosmic medium (+150 mM sucrose), and recovery of solution osmolality in hyposmic condition (70 mM NaCl) after a single contraction. Inhibitor Na+,K+,2Cl(-)-cotransport bumetanide (10 microM) and chloride permeability blockers niflumic acid (10-100 microM) and SITS (10-500 microM) attenuated stimulating effects of mesatone, histamine and hyperosmic medium. In opposite to adenylate cyclase activation with forskolin (1 microM), guanylate cyclase activation with sodium nitroprusside (SN, 100 microM) decreased both inhibitory action of bumetanide, niflumic acid and activating effects of mesatone, histamine on action potential and elevation contraction of smooth muscle cells. Influence of forskolin rather and not SN on AP and SMC C was inhibited with tetraethylammonium (5 mM). These results suggest that influence of Na+,K+,2Cl(-)-cotransport on electrical and contractil properties of ureter smooth muscle cells is mediated by stimulation of Ca(2+)-activated chloride permeability of the cell membrane and modulated by intracellular cGMP, but not triggered by Ca2+ release from sarcoplasmic reticulum.

[Features of the pharmacosensitivity of smooth muscles of the lesser circulation circle artery walls in rabbits].

Features of the pharmacological sensitivity of smooth muscles in the walls of arteries of the lesser circulation circle in rabbits with respect to cholinergic, histaminergic, and adrenergic agents, as well as the influence of endothelium on the realization of contractile response to these agents have been investigated in rabbits. A special feature in the cholinergic relaxation of smooth muscles of a pulmonary artery is a two-componential character of the dose dependence. The low-threshold component of the relaxant action of pilocarpine exhibits the endothelium-dependent character. An important feature of the contractile reaction to histaminergic action is a direct contractile effect of histamine, which is not observed in vessels of the greater circulation circle. Endothelium produces an inhibiting effect on the histaminergic contractility. The basic feature in the response to adrenergic action is the beta-adrenergic contractility effect. Activation of the cAMP-dependent alarm system in smooth muscles of the pulmonary arteries leads to a constrictive effect. The established features of the pharmacological sensitivity of smooth muscles of the artery walls of the lesser circulation circle are important for the clinical pharmacology.