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Biomedical subjects

A I Vislobokov

Publications and source records attributed to A I Vislobokov.

At least 19 recordsLinked to original sources
PubMed2005

Effects of helium-neon laser irradiation and local anesthetics on potassium channels in pond snail neurons.

Intracellular dialysis and membrane voltage clamping were used to show that He-Ne laser irradiation of a pond snail neuron at a dose of 0.7 x 10(-4) J (power density 1.5 x 10(2) W/m2) increases the amplitude of the potential-dependent slow potassium current, while a dose of 0.7 x 10(-3) J decreases this current. Bupivacaine suppresses the potassium current. Combined application of laser irradiation at a dose of 0.7 x 10(-3) J increased the blocking effect of 10 microM bupivacaine on the slow potassium current, while an irradiation dose of 0.7 x 10(-4) J weakened the effect of bupivacaine.

Anesthetics, Local↗
PubMed2004

Activating effect of Tanacetum vulgare L. pectin polysaccharide on ionic channels of neuronal membrane.

The membranotropic effects of TVF tanacetan pectin polysaccharide derived from Tanacetum vulgare L. was studied by the voltage-clamp method on isolated neurons of Lymnaea stagnalis mollusk. TVF in concentrations of 0.1-10.0 microg/ml nonselectively activated the outward potassium and total inward (sodium and calcium) ionic currents (slightly dose-dependently and reversibly increased their amplitude by 5-10%) and decreased nonspecific leakage current.

Animals↗
PubMed2004

[Influence of He-Ne laser irradiation and local anesthetics on potassium channels in the snail neurons].

Using clamp method it had been shown that He-Ne laser irradiation of the snail neurons increases the amplitude of voltage-gated slow potassium currents in dose of 0.7 x 10(-4) (fluence 1.5 x 10(2) Wt/m2) and decreases it in dose 0.7 x 10(-3). Bupivacaine and lidocaine suppressed potassium currents. Laser irradiation in dose 0.7 x 10(-3) enhanced the inhibitory effect of bupivacaine (10 mcM) and in dose 0.7 x 10(-4) it decreased the inhibitory effect of bupivacaine. The results of the study suggest mechanisms of the He-Ne laser irradiation effect in combination with pharmacological substances on ion channels of electrically excitable cells.

Anesthetics, Local↗
PubMed2003

[Effect of the He-Ne laser irradiation on resistance of the isolated heart to the ischemic and reperfusion injury].

The aim of this work was to investigate the myocardial protection against ischemia/reperfusion using low level laser irradiation (LLLI). It has been shown that pulse pressure was higher in the period of post-ischemic reperfusion as compared with the control group. It provided a better restoration of myocardial contractility as well as increasing of coronary flow in the reperfusion period. The amount of ventricular rhythm disorder episodes decreased. These effects of laser application were registered in conditions of coronary flow reduction less than 50%. One of the suggested mechanisms of laser effect is an ATP-sensitive channel activation.

Animals↗
PubMed1993

Cocaine, amphetamine and cathinone, but not nomifensine and pargyline increase calcium inward current in internally perfused neurons.

The influence of cocaine, amphetamine, cathinone, pargyline and nomifensine on inward calcium current was studied using internally perfused neurons of the snail Lymnaea stagnalis. While nomifensine and pargyline inhibited inward calcium current in the concentrations 10(-7)-10(-4) M and did not affect them in the concentrations 10(-9)-10(-8) M, cocaine, amphetamine and cathinone had a biphasic action on inward calcium current, causing activation (10-30 percent) at 10(-9)-10(-7) M, and inhibition at higher concentrations. Only cathinone caused a shift of the I-V characteristics of the membrane along the potential axis. It is suggested that drugs of abuse affect membrane excitability and inward calcium current in neurons directly.

Alkaloids↗
PubMed1991

[The effect of taurine on the electrically controlled ion channels of the somatic membrane of pond snail neurons].

Isolated and internally dialysed neurons from the molluscs Lymnaea stagnalis were investigated under voltage-clamp conditions. The increasing of taurin concentration (from 1.10(-8) to 1.10(-2) mol/l) reduced the calcium inward--and delayed potassium outward currents, and exerted no effect on the fast potassium outward current. Sodium inward current was increased by taurin concentrations 1.10(-8)-1.10(-4) mol/l, and reduced by 1.10(-3)-1.10(-2) mol/l. Membrane leakage currents were reduced by small taurin concentrations and increased by large concentrations.

Animals↗
PubMed1989

[Comparative characteristics of the membrane mechanisms of the action of fenamine and its derivatives on the ion channels of isolated mollusk neurons].

Phenamine (10(-12)-10(-5) M/l) increased by 20-60 per cent the input (sodium and calcium) currents (Iin), the output slow potassium (Ikm) and fast potassium (Ikb) ones, and decreased the currents in higher concentrations. The volt-ampere characteristics of the membrane (VAC) and the curves of stationary inactivation (CSI) shifted along the potentials axis. The phenamine analogue IEM 1365 only decreased the currents leaving the VAC and CSI unaltered. Another analogue IEM 1370 only decreased the Iin whereas VAC and CSI also shifted along the potentials axis. The ion channels seem to be blocked in a decrease of the currents and the membrane surface potential induced with fixed charges seems to change.

Amphetamine↗
PubMed1984

[Dynamics of changes in the neuronal function of the central nervous system under prolonged stimulations].

Mechanisms involved in long-term stimulation of the c. n. s. neurons of different degrees of complexity (cats, molluscs,) were studied. The hypoxic effect and prolonged transmembrane depolarization of a single neuron were used as long-term stimulation. The pattern of electrophysiological properties of neurons was investigated with microelectrode technique, fixation of potential and intracellular dialysis. The experiments showed that the hypoxic effect converted the neuron from the state of excitation into the state of depolarization inhibition. This reaction of the neuron was shown to be connected with the primary activation followed by a slow inactivation of the channels of input current.

Action Potentials↗
PubMed1979

[Effect of etimizol, ethyrasol, and caffeine on the electrical activity of mollusk neurons].

In experiments on Limnae stagnalis neurons, ethymisol increased the AP duration while reducing the trace hyperpolarization and the rate of development of the AP descending phase. Ethymisol (10 mM/1) induced either hyperpolarization of neurons with an increase in membrane resistance or their depolarization (20 mM/1) with a decrease in membrane resistance. A drop in the medium temperature by 2-4 degrees C prevented the hyperpolarization. The ethymisol-induced hyperpolarization seems to be connected with a decrease in membrane permeability for sodium ions in resting conditions and with activation of electrogenic ion transport. The increase of extraneuronal potassium up to 4 mM/1 and depolarization induced by currents of 1-3 nA intensified the ethymisol effects. Ethymisol decreased efflux and influx of ions through membrane thus affecting the AP parameters. The effects of ethymisol also involved an increase of neurons excitability and intensification of synaptic activity. Neither ethyrasol nor caffein exerted these effects.

Action Potentials↗
PubMed1975

[Elektrophysiological parameters of mollusk neurons under the influence of etimizol].

Extracellular application of 5--10 mM/L etimizol exerted a specific effect on the giant neurons of the Coretus corneus isolated nervous system: action potential duration increased significantly, speed of development of its descending phase decreased, as well as the trace hyperpolarization amplitude. The effect was reversible and depended upon the etimizol concentration and the initial functional state of neurons. Etimizol is supposed to decrease the K-+ permeability of neurons' membrane during action potential. Large concentrations of etimizol decrease, probably, the Na+ permeability as well as suggested by reducing maximum of the ascending phase of action potential.

Action Potentials↗