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M I Sologub

Publications and source records attributed to M I Sologub.

At least 19 recordsLinked to original sources
PubMed1991

[A new mechanism of action of vasopressin on the neuronal membrane].

It is shown in this work that vasopressin at the concentrations of 1 x 10(-16) to 1 x 10(-6) mol/l decreased statistically significant the amplitude of the electrosensitive sodium and calcium ionic currents of the mollusc's Lymnaea stagnalis neuronal membrane. This peptide increased the amplitude of the fast potassium current at the concentration of 1 x 10(-16) and 1 x 10(-15) mol/l. It decreased the fast potassium current and did not change the slow potassium current at the concentrations more than 1 x 10(-9) mol/l.

Animals↗
PubMed1975

[Bioelectric characteristics of A and B neurons in the mollusc Coretus corneus with different calcium and sodium contents in the medium].

Action potentials (AP) of neurons A and B could be only elicited in the presence of Na-+ ions. An increase in [Ca-++]0 led to depolarization of neurons, enhancement of their excitability, AP, overshoot, of positive afterpotential, AP duration, AP maximal rate of fall (Vf) and to decrease in AP maximal rate of rise (Vr). After addition of CaCl2 up to 50 mmoles into the Ringer solution, the membrane resistance (R) increased. If the [Na-+]0 was equimolarly diminished, R increased up to the [Ca-++]0 30 mmoles, but at greater [Ca-++]0 R fall below the initial value. The regularities were independent of the initial value of resting potential (RP). At high [Ca-++]0 Ca-++ contributed to the generation of the inward current during AP while Na-+ caused an increase in ionic (calcium) membrane permeability at rest. At high [Ca-++]0, Na-+ was also necessary for support of membrane channels which maintained the inward and outward currents during the AP.

Action Potentials↗
PubMed1975

[Bioelectrical characteristics of the membrane of identified Coretus corneus mollusk neurons A and B upon activation and blocking of the electrogenic sodium pump].

Activation of the electrogenic sodium pump by means of increasing concentration of intracellular sodium ions in identified neurons A and B of the mollusc was followed by the hyperpolarization, decrease of the excitability, and depression of the neurons rhythmic activity. Apart from that, the amplitude and the maximal rates of rise of ascending (VB) and descending (VH) phases of action potential (AP) were almost unchanged. The depression of the electrogenic sodium pump activity due to 2,4-DNP and potassium-free medium, led to the depolarization, increase of excitability and frequency of the rhythmic activity, and decrease of AP, VB, and VH. The decrease and increase of the excitability may be explained by the changes of the critical level of depolarization. The decrease of AP, VB and VH may be accounted for by the changes of time parameters of activation and inactivation of sodium and potassium channels which are characteristic for the depolarization effect.

Action Potentials↗
PubMedDate not supplied

[A hypothesis of the possible mechanism of the action of analgesic agents at the neuronal level].

The opiate analgetic promedol and non-opiate analgetics analgin, clonidine, baclofen, tolibut, vasopressin and calcitonin given in adequate doses block the inward electrosensitive sodium transmembrane ionic current of neurons. Like some drugs which do not exhibit any analgetic effect, promedol, analgin, clonidine, vasopressin and calcitonin also block the electrosensitive delayed potassium current. It is assumed that the blocking of the sodium ionic current may be one of the potential analgetic mechanisms at the neuronal level.

Analgesics↗