Papers by Volodymyr Manko
Lesya Ukrainka Eastern European National University Scientific Bulletin. Series: Biological Sciences
Відомо, що сурамін є агоністом ріанодинчутливих Са2+-каналів ендоплазматичного ретикулуму (RyRs).... more Відомо, що сурамін є агоністом ріанодинчутливих Са2+-каналів ендоплазматичного ретикулуму (RyRs). Ми припустили, що він може бути агоністом і мітохондріальних ріанодинчутливих Са2+-каналів (mRyRs). Для перевірки цього припущення досліджено зміни мембранного потенціалу мітохондрій гепатоцитів під впливом сураміну. Сурамін у концентрації 1 мкмоль/л додавали до середовища інкубації, після цього вносили суспензію ізольованих мітохондрій та реєстрували їхній мембранний потенціал. Вимірювання мембранного потенціалу мітохондрій здійснювали з використанням метилтрифенілфосфоніум броміду (ТРМР+) і чутливого до нього електрода. Для ініціації дихання вносили субстрати окиснення сукцинат, піруват або α-кетоглутарат у концентраціях 5 ммоль/л, а для стимуляції окисного фосфорилювання – 320 нмоль АДФ. Установлено, що ефект сураміну на мембранний потенціал мітохондрій залежить від наявності в середовищі інкубації субстратів окиснення та фосфорилювання. За окиснення екзогенного сукцинату під впливом...
Studia Biologica
ȾȿɉɈɄȿɊɈȼȺɇɂɃ ȼɏȱȾ ɋɚ 2+ ɍ ɋȿɄɊȿɌɈɊɇȱ ɄɅȱɌɂɇɂ ɋɅɂɇɇɂɏ ɁȺɅɈɁ ɅɂɑɂɇɄɂ Drosophila melanogaster Ȼɿɨɥɨ... more ȾȿɉɈɄȿɊɈȼȺɇɂɃ ȼɏȱȾ ɋɚ 2+ ɍ ɋȿɄɊȿɌɈɊɇȱ ɄɅȱɌɂɇɂ ɋɅɂɇɇɂɏ ɁȺɅɈɁ ɅɂɑɂɇɄɂ Drosophila melanogaster Ȼɿɨɥɨɝɿɱɧɿ ɋɬɭɞɿʀ 6WXGLD %LRORJLFD x x Ɍɨɦ ʋ x ɋ ± ɍȾɄ ȾȿɉɈɄȿɊɈȼȺɇɂɃ ȼɏȱȾ ɋɚ 2+ ɍ ɋȿɄɊȿɌɈɊɇȱ ɄɅȱɌɂɇɂ ɋɅɂɇɇɂɏ ɁȺɅɈɁ ɅɂɑɂɇɄɂ Drosophila melanogaster Ɍ ȱ ɑɨɪɧɚ 1,2 Ƚ ɏɚɫɚɧ 2 ȼ ȼ Ɇɚɧɶɤɨ 1 1 Ʌɶɜɿɜɫɶɤɢɣ ɧɚɰɿɨɧɚɥɶɧɢɣ ɭɧɿɜɟɪɫɢɬɟɬ ɿɦɟɧɿ ȱɜɚɧɚ Ɏɪɚɧɤɚ ɜɭɥ Ƚɪɭɲɟɜɫɶɤɨɝɨ Ʌɶɜɿɜ ɍɤɪɚʀɧɚ HPDLO tanya#yandexru YYPDQNR#JPDLOFRP 2 ɇɚɰɿɨɧɚɥɶɧɢɣ ɐɟɧɬɪ Ȼɿɨɥɨɝɿɱɧɢɯ ɇɚɭɤ Ɍɚɬɚ ȱɧɫɬɢɬɭɬ Ɏɭɧɞɚɦɟɧɬɚɥɶɧɢɯ Ⱦɨɫɥɿɞɠɟɧɶ ɦ Ȼɚɧɝɚɥɨɪ ȱɧɞɿɹ
International Journal of Physiology and Pathophysiology
Neurophysiology, 1996
The dependence of sodium-calcium exchange current (INacCa)) through the membrane of isolated secr... more The dependence of sodium-calcium exchange current (INacCa)) through the membrane of isolated secretory ceils of Chironornus tarva on pH of the extraceilutar solution was studied with the voltage-clamp technique with intracellular perfusion. INn(Ca) evoked by hyperpolarization of the membrane from-20 to-60 mV was recorded within physiological values of Na ÷ and Ca z÷ gradients. It was established that acidification of extracellular solution from pH 7.2 to 4.0 gradually decreased the amplitude of INl(Ca) with pK'-3.72. In all cases at pH 3.0 an outward current of considerable amplitude emerged in response to membrane hyperpolarization. The reversal of the current occurred at pH around 3.25. A decrease in IN,(Ca) was due to protonation of acid ionogenic groups (quite possibly, of the residues of aspartic or glu~tmic amino acids), which had been involved in binding of cations. Alkalization of extracellular solution from pH 7.2 to 10.0 produced a gradual Increase in the INn(Ca) amplitude; pK' was in the pH range between 9 and 10. The increase in INJ(Ca) in alkaline medium was probably due to the appearance of negatively charged cations at binding sites, which could be carried by deprotonated thiosulfate groups of cysteine residues. This was indicated by the possibility of initial decrease in /Nt~.Ca) under the action of Hg ~+ ions.
Advances in Experimental Medicine and Biology, Feb 1, 2001
Ukrainskii Biokhimicheskii Zhurnal, Sep 1, 2012
Using Clark oxygen electrode, dependence of mitochondrial functions on Ca(2+)-release channels ac... more Using Clark oxygen electrode, dependence of mitochondrial functions on Ca(2+)-release channels activity of Chironomus plumosus L. larvae salivary glands suspension was investigated. Cells were ATP-permeabilized in order to enable penetration of exogenous oxidative substrates. Activation of plasmalemmal P2X-receptors (as well as P2Y-receptors) per se does not modify the endogenous respiration of salivary gland suspension. That is, Ca(2+)-influx from extracellular medium does not influence functional activity of mitochondria, although they are located along the basal part of the plasma membrane. Activation of RyRs intensifies endogenous respiration and pyruvate-malate-stimulated respiration, but not succinate-stimulated respiration. Neither activation of IP3Rs (via P2Y-receptors activation), nor their inhibition alters endogenous respiration. Nevertheless, IP3Rs inhibition by 2-APB intensifies succinate-stimulated respiration. All abovementioned facts testify that Ca2+, released from stores via channels, alters functional activity of mitochondria, and undoubtedly confirm the existence of endoplasmic-mitochondrial Ca(2+)-functional unit in Ch. plumosus larvae salivary glands secretory cells. In steady state of endoplasmic-mitochondrial Ca(2+)-functional unit the spontaneous activity of IP3Rs is observed; released through IP3Rs, Ca2+ is accumulated in mitochondria via uniporter and modulates oxidative processes. Activation of RyRs induces the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to the active state, which is required to intensify cell respiration and oxidative phosphorylation. As expected, the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to inactivated state (i. e. inhibition of Ca(2+)-release channels at excessive [Ca2+]i) limits the duration of signal transduction, has protective nature and prevents apoptosis.
International Journal of Physiology and Pathophysiology, 2015
Fiziologicheskiĭ zhurnal
The parameters of inward current of potential-dependent calcium channels in cells of the upper an... more The parameters of inward current of potential-dependent calcium channels in cells of the upper and lower lobes of the salivary glands in Chironomus larvae have been studied. The current activation thresholds in cells of both types are near -60 mV, but in cells of the upper lobe the current reaches its maximum values at -20 mV, while in cells of the lower lobe at -10 mV. The current density in cells of the upper lobe is approximately 1.3 times higher and the inactivation time constant is 1.62 less than in cells of the lower lobe. Calcium channels in cells of the upper and lower lobes of glands also differ in metabolic dependence: introduction of cAMP, ATP and Mg2+ into cells of the lower gland lobe causes a considerable increase in the current amplitude, while the same action in cells of the upper lobe--its decrease. The current amplitude in the cells of the lower lobe decreases under the influence of nitrendipine and La, Co, Ni, Cd, Zn cations as well as a decrease of the temperatur...
Ukrainskii biokhimicheskii zhurnal
The possible mechanism of transient metals effect on Na(+)-CA2+ exchange of membrane in excitable... more The possible mechanism of transient metals effect on Na(+)-CA2+ exchange of membrane in excitable and non-excitable cells has been examined on the basis of available literature and personal investigation. Different cations of transient metals can either inhibit or stimulate Na(+)-Ca2+ exchange depending on experimental conditions and their own properties. In some conditions these cations can even be translocated by the exchanger. Metal cations with the highest affinity to O-containing protein groups are able to inhibit the activity of exchanger due to the competition with Ca2+ within the transport site. Metal cations with the highest affinity of S-containing protein groups have stimulated the exchanger owing to their effect on the regulatory site. The total effect of different cations in each case is determined by the effectiveness of all these processes (inhibition, translocation and stimulation) which depends on the affinity of the cations to different protein functional groups. I...
Decreasing of Ca2+ content in tissue of salivary gland is caused by ruthenium red, which is known... more Decreasing of Ca2+ content in tissue of salivary gland is caused by ruthenium red, which is known as inhibitor of mitochondria calcium uniporter. This decreasing of Ca2+ content is absent at presence of Ca2+-pump inhibitor eosin Y in incubation medium. But eosin Y doesn’t prevent the ruthenium red effect on Ca2+ content in gland tissue, that was processed by saponin solution. Besides, there is no caffeine effect on Ca2+ content at presence of ruthenium red in incubation medium. As it was shown early caffeine caused increasing of Ca2+ content in gland tissue via, possibly, changes of endoplasmic reticulum Ca2+-pump activity. That is why we suppose that ruthenium red effect on Ca2+ content in gland tissue is caused by inhibition of not only mitochondria Ca2+ uniporter, but lso endoplasmic reticulum Ca2+-pump.
Effect of modification of potential-dependent calcium channels in cells of the upper lobe of the ... more Effect of modification of potential-dependent calcium channels in cells of the upper lobe of the salivary gland in Chironomus larva has been ascertained in the Ca-free medium containing Ca-binding substances (EGTA or EDTA). It is shown that the inward current depends on the sodium transmembrane gradient. The amplitude of the inward sodium current decreases under the influence of verapamil as well as with an increase of external concentration of Ca2+ ions. The metabolic dependence of modified calcium channels as well as the pharmacological sensitivity are unchanged. Tau n of the sodium current through modified calcium channels increases insignificantly comparing with that of the calcium current. Maximum of the current-voltage relationship of the sodium current through modified calcium channels is shifted to a negative side by 10-15 mV as compared with the calcium current through native channels.
Neir̆ofiziologiia = Neurophysiology
Ukrainskii biokhimicheskii zhurnal
The dependence of respiration rate of rat permeabilized acinar pancreacytes on oxidative substrat... more The dependence of respiration rate of rat permeabilized acinar pancreacytes on oxidative substrates concentration was studied at various [Ca2+] - 10-8-10-6 M. Pancreacytes were permeabilized with 50 microg of digitonin per 1 million cells. Respiration rate was measured polarographically using the Clark electrode at oxidation of succinate or pyruvate either glutamate in the presence of malate. Parameters of Michaelis-Menten equation were calculated by the method of Cornish-Bowden or using Eadie-Hofstee coordinates and parameters of Hill equation - using coordinates {v; v/[S]h}. In the studied range of [Ca2+] the kinetic dependence of respiration at pyruvate oxidation is described by the Michaelis-Menten equation, and at oxidation of succinate or glutamate - by Hill equation with h = 1.11-1.43 and 0.50-0.85, respectively. The apparent constant of respiration half-activation (K0.5) did not significantly change in the studied range of [Ca2+] while at 10-7 M Ca2+ it was 0.90 +/- 0.06 mM ...
In the last decade there has been a significant increase of articles related to giant cell transf... more In the last decade there has been a significant increase of articles related to giant cell transformation in different cancers. But it's still unknown what mechanisms are involved in such giant cancer cells. After vinblastine treatment NK/Ly lymphoma cells undergo giant cell transformation with several cytoskeletal and membrane changes. That's why our aim was to evaluate the changes in cellular membrane by permeabilizing it with digitonin. NK/Ly lymphoma cell population was cultivated in vivo by intraperitoneal inoculation of 25 million cells into C57 black 4-month mice. Animal weighting was performed every 24 hours. On day 7-10, when the weight increased by 50-60%, mice were drained. To obtain giant cell population (<17 µm), mice were injected 1% vinblastine solution (maximum 50 µg) 3 days before drainage. Cell suspension (approximately 5*10 6 cells/ml) was washed twice from the ascitic fluid with solution containing КCl – 90.0 mM, NaCl – 15.0 mM, KH 2 PO 4 – 2 mM, MgCl ...
The relationship between cellular metabolism and signalling is an important problem in physiology... more The relationship between cellular metabolism and signalling is an important problem in physiology. Acetylcholine as one of the main secretagogues modulates mitochondrial functions in acinar pancreacytes (Voronina et al., 2002; 2004; 2010), presumably due to increase of ATP hydrolysis or Ca2+-transport into mitochondria. The aim of this work was to investigate mechanisms of acetylcholine analogue, carbamoylcholine (CCh), action on respiration and oxidative phosphorylation of isolated pancreatic acini. Male rats (200-300 g) were anaesthetised with chloroform, decapitated and following the removal of the pancreas suspensions of isolated acini (cell viability ≥ 95%) were obtained (Williams et al., 1978). Oxygen consumption was measured using a Clark electrode at 37°C in a standard extracellular solution (140.0 mM NaCl, 4.7 mM KCl, 1.3 mM CaCl2, 1.0 mM MgCl2, 10.0 mM HEPES, 10.0 mM glucose, 2.5 mg ml-1 BSA and 0.1 mg ml-1 soybean trypsin inhibitor at pH 7.4). Respiration of digitonin-per...
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Papers by Volodymyr Manko