Teptin G.M.,Kazan Federal University |
Mamedova L.E.,Kazan Federal University |
Kim Z.F.,Kazan Medical University
Radiophysics and Quantum Electronics | Year: 2011
We present the results of an experimental study of the low-amplitude cardiac signals without temporal and spatial averaging. The characteristics of the fluctuation and quasi-periodic components of the low-amplitude signals are determined statistically reliably for the first time. The results of the studies of the periodic and quasi-periodic components obtained from the long-term measurement data are reported. It is found that the structure of the frequency characteristics of low-amplitude signals has pronounced temporal variability in the neighboring cardiac cycles. © 2011 Springer Science+Business Media, Inc.
Khaertdinov N.N.,Kazan Federal University |
Ahmetshina D.R.,Kazan Federal University |
Zefirov A.L.,Kazan Medical University |
Sitdikova G.F.,Kazan Federal University
Biologicheskie Membrany | Year: 2012
Hydrogen sulfide (H2S) is an endogenously synthesized gaseous molecule which along with nitric oxide and carbon monoxide induces a number of effects in cardiovascular system in normal and pathological conditions. In the present study the effects and underlying mechanisms of H2S donor, sodium hydrosulfide (NaHS), on isometric force of frog myocardium contraction were studied. NaHS in the concentration of 100 μM induced a negative inotropic effect and decreased the maximal velocity of contraction and relaxation of isolated ventricle strips. The substrate Of H2S synthesis L-cystein (200 μM and 1 mM) induced the same effect and the inhibitors of cystationin y-lyase, H2S-producing enzyme in heart, ß-cyanoalanin (500 μM) and propargylglycine (500 μM) increased the amplitude of contraction. Inhibition of cystationin y-lyase by ß-cyanoalanin prevented the negative inotropic effect of L-cystein. After inhibition of adenylate cyclase by MDL12,330A (3 μM) or phosphodiesterases by IBMX (200 μM) effect of NaHS was lesser than in control. In the presence of membrane-penetrating analogous of cAMP, 8Br-cAMP (100 μM) and pCPT-cAMP (100 μM), negative inotropic effect of NaHS completely retained. The effect of NaHS significantly decreased after preliminary application of the NO donor, SNAP (10 μM), and did not change after inhibition of NO-synthases by LNAME ( 100 μM). The obtained data suggest the possibility of endogenous synthesis of H2S in frog myocardium and regulation of its contractility by activation of phosphodiesterases hydrolyzing cAMP, which leads to a decrease of activation of cAM P-dependent protein kinases and phosphorylation of voltage-dependent L-type Ca-channels. As the result, a reduction of calcium entry into cardiomyocytes decreases the contractility of frog myocardium.
Akhmadeev N.R.,Kazan Medical University |
Miftahof R.,Arabian Gulf University
International Journal of Design and Nature and Ecodynamics | Year: 2010
A biomechanical model of the human stomach is proposed, that is based on detailed biological data of the structure and function of the organ. The process of electromechanical conjugation and the spread of the electromechanical wave along the stomach wall were analyzed numerically. Results revealed patterns of stress-strain distribution in the organ. Thus the fundus, the body and the antrum of the organ always experience biaxial stress-strain states, while the cardia and the pylorus undergo uniaxial loading. The circular smooth muscle layer produced greater total forces throughout in comparison to the outer longitudinal smooth muscle layer. The body of the organ along the lesser curvature and the cardia-fundus areas were overstressed compare to other regions. Although the theoretical results resemble qualitatively patterns of electrical and mechanical activity observed in vivo and in vitro there is currently no affirmative experimental evidence to provide a detailed quantitative comparison of the results. © 2010 WIT Press.
Malomouzh A.I.,Russian Academy of Sciences |
Nurullin L.F.,Russian Academy of Sciences |
Arkhipova S.S.,Russian Academy of Sciences |
Nikolsky E.E.,Kazan Medical University
Muscle and Nerve | Year: 2011
In this study we demonstrate expression of the N-methyl-D-aspartate receptor NR1 subunit in the rat neuromuscular junction of skeletal muscles of different functional types (extensor digitorum longus, soleus, and diaphragm muscles) using fluorescence immunocytochemistry. Electron microscopic immunocytochemistry has shown that the NR1 subunit is localized solely on the sarcolemma in the depths of the postsynaptic folds. These findings suggest participation of the glutamatergic signaling system in functioning of the adult mammalian neuromuscular junction. © 2011 Wiley Periodicals, Inc.
Zalyalova Z.A.,Kazan Medical University
Zhurnal Nevrologii i Psihiatrii imeni S.S. Korsakova | Year: 2014
The most frequent causes of disability of patients with neurological diseases are motor disorders in the upper motor neuron lesion caused by the damage of the brain and/or the spinal cord that resulted in the formation of spastic paresis and paralysis. The correct understanding of the pathophysiological basis of clinical presentations of the upper motor neuron lesion will allow to chose the most adequate and prognostically successful methods of treatment. Currently, treatment with botulotoxin can be considered as such a method. This method in the combination with non-pharmacological rehabilitation decreases the activity of phasic and tonic stretching reflexes, associated contractions, synkinesia, spastic dystonia and spasticity that leads to the increase in muscle elasticity, mobility of extremities, reduction of pain, joint stiffness and soft tissue deformation that, in its turn, can increase the independence of the patient from any help. © 2014, Media Sphera. All rights reserved.