PubMed Health⌕ Search

Biomedical subjects

V I Kuleshov

Publications and source records attributed to V I Kuleshov.

At least 19 recordsLinked to original sources
PubMed1985

[Miniature currents of the endplates of the muscle fibers of the diaphragm of the rat after inhibition of acetylcholinesterase with galanthamine].

Miniature end-plate currents (MEPC) in rat diaphragm were studied with voltage-clamp technique when synaptic acetylcholinesterase (AChE) was inhibited with different concentrations of galanthamine. The MEPC amplitude and time course were increased progressively with galanthamine concentrations in the range of 3.16 X 10(-8) - 10(-6) g/ml. The decay of MEPC was always exponential. The input resistance of muscle fibres increased. Galanthamine (10(-5) g/ml) produced a curare-like action: the amplitude and duration of MEPC were less as compared with those at galanthamine concentration 10(-6) g/ml, the decay of MEPC became biphasic. During washing out of the drug, the duration of MEPC began to increase and then to diminish, returning to the initial value 3 hours later. The decay of MEPC became exponential. A positive correlation was found between half-decay time and amplitude of MEPC both in the presence and in the absence of anticholinesterase. It is supposed that the functional role of synaptic AChE in limiting the postsynaptic effect of acetylcholine is not so significant as it is usually considered, therefore it is possible to use the parameters of MEPC for the estimation of functional AChE activity.

Acetylcholinesterase↗
PubMed1984

[Treatment of acute pancreatitis patients with functional liver failure].

Methods of extracorporal detoxication hemo- and lymphosorption, intraportal injection of drugs and oxygenated solutions as well as ultraviolet irradiation of auto-blood are included in the routine scheme of treatment of patients with acute pancreatitis. The treatment concerned was used in 77 patients with acute pancreatitis and advanced hepatic insufficiency and resulted in arresting the latter in 43 of the patients. To prevent the development of acute hepatic insufficiency proved to be possible in 20 patients with a destructive form of acute pancreatitis. The intraportal injection of oxygenated solutions against the background of acute experimental pancreatitis contributed to prevention of hypoxia of the liver.

Acute Disease↗
PubMed1983

[Presynaptic action of armin and galantamin on mammalian neuromuscular junction].

Actions of the two cholinesterase inhibitors: armin and galanthaamine on the neuromuscular transmission and on the spontaneous and evoked acetylcholine release were studied in the rat diaphragm. High concentrations (greater than or equal to 10(-6) g/ml) of these agents exhausted the available transmitter store which decreased the quantum content of e. p. p. sin single nerve stimulation. At the repetitive stimulation (10-100 s-1), armin and galanthaamine accelerated the presynaptic depression of e. p. p. s and slowed down the rate of transmitter mobilization. This resulted in a rapid decrease of quantum content and amplitude of e. p. p. s. The found presynaptic deteriorations together with the stationary postsynaptic depolarization may cause the neuromuscular block.

Action Potentials↗
PubMed1983

[Joint action of reversible and irreversible cholinesterase inhibitors on neuromuscular transmission in the rat diaphragm].

Presynaptic effect of compound application of the cholinesterase (ChE) inhibitors of the reversible (galanthamine) and the irreversible (armin) after galanthamine pretreatment has been studied on the neuromuscular transmission at the rat diaphragm. The experiment conditions were regarded as a model of the preventive action of the reversible ChE inhibitors against organism poisoning by the irreversible ChE inhibitors. The quantal content of the end plate potentials (EPP) decreases under the compound action of inhibitors. But under these conditions the EPP amplitude at the single nerve stimulation increases as compared with the control one. The pronounced presynaptic depression and the block of the neuromuscular transmission are observed at the repetitive stimulation (10-50 s-1). The preventive action of galanthamine against the armin poisoning does not relate to presynaptic processes.

Animals↗
PubMed1983

[Effect of armin on frog myelinated nerve fibers].

Study of the action of armin on the nodes of Ranvier in isolated nerve fibers of the frog has demonstrated that armin at concentrations over 4 X 10(-7) M produces the growth of the input resistance of the nodes of Ranvier at the expense of the decreased leakage conduction. At concentrations of 4 X 10(-6) and 4 X 10(-5) armin leads to a shift of the firing level of action potentials towards more positive values.

Action Potentials↗
PubMed1982

[Effect of cholinesterase inhibitors on the electrical excitability of the membrane of frog muscle fiber].

The effects of reversible (galanthamine, eserine) and irreversible organophosphate (armine) cholinesterase inhibitors on excitable muscle fibre membrane of the frog involved elongation of the rise and the half-decay time of the AP (galanthamine and eserine), the critical level of depolarization being shifted to a more negative value. Armine decreased the rise and the half-decay time, the critical level of depolarization being shifted to the positive direction; subsequent rising of the threshold often caused blocking of neuro-muscular transmission during the first minutes of the armine action, pretreatment of preparations with galanthamine (eserine) preventing the threshold increase and armine blocking of transmission. Probably mechanism of these drugs action on the membrane channels is discussed. The negative shift of critical level seems to underlie the protective action of galanthamine and eserine in case of poisoning with irreversible cholinesterase inhibitors.

Action Potentials↗
PubMed1981

[Effect of armin on synaptic transmission in frog neuromuscular preparations].

The action of armin, an organophosphorus inhibitor of cholinesterases, on synaptic transmission parameters was studied by means of intracellular registration of end plate potentials and currents (EPP and EPC) in the frog. On 10-minute exposure the increase in the temporary parameters became manifest provided the drug was administered at a concentration of 10(-6) g/ml and over. EPC reversal potential and cholinoreceptor sensitivity to armin did not change substantially. At a concentration of 10-(-8) g/ml armin exerted a potentiating effect on the frequency of miniature EPP and quantum composition of EPP, while that effect was not related to armin anticholinesterase activity. The presynaptic acetylcholine release was suppressed by high concentration of armin (10(-5) g/ml). Under the conditions cited there was a decrease in the depot of the available transmitter quanta in nerve terminals.

Acetylcholine↗
PubMed1981

[Anticholinesterase properties of benzo(f)quinolinium derivatives].

"In vitro" studies have demonstrated that methyl-p-toluene sulfonates of 1-methyl-(ethyl)-3-aryl-benzo(f)quinolinium are highly efficient inhibitors of cholinesterases, the inhibition constants (Ki) for acetylcholinesterase and butyrylcholinesterase being equal to 2.20 +/- 0.49 and 9.43 +/- 0.39 mkM, respectively. The effect of these inhibitors on the enzyme is of competitive - non-competitive type. A certain role in benzo(f)quinoline binding to acetylcholinesterase apparently belongs to the interaction of substituents in the phenyl nucleus with the anionic sites located outside the active surface of the enzyme.

Cholinesterase Inhibitors↗
PubMedDate not supplied

[Possible methods of evaluating the work capacity of ship operators].

By identifying correlation between physiological changes that develop in work and professional errors of ship operators the complex of informative parameters to be used in assaying ther performance has been determined. The complex includes: latent period of a complex sensorimotor response with a choice, critical frequence of fusion of light oscillations, heart rate, tolerance to static force, pulse arterial pressure and index of a two-minute step-test. With the aid of the complex of clinical, physiological and psychophysiological methods it has been shown that indirect indices of performance of operators in long voyages deteriorate two or three weeks earlier than its direct signs. It has been found that the operator's performance can in principle be quantified. It can be done by taking into consideration changes in the informative indices during a specific operation and contribution of each of them to the integrative evaluation of the operator's performance.

Adaptation, Physiological↗