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Biomedical subjects

V I Prosheva

Publications and source records attributed to V I Prosheva.

10 recordsLinked to original sources
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↗
PubMed1989

[Structure of the right muscle atrioventricular valve in the avian heart].

A morphometrical investigation of the right muscle atrioventricular valve in the hearts of 12 adult pigeons and 16 mature hens has been carried out. Qualitative description and designations of separate parts are given. Basing on the results obtained and on the literature data, a hypothesis is advanced that the special construction of the muscle valve, together with the main morpho-functional purpose--closing of the atrioventricular ostium during ventricular contraction--is used also to increase the internal surface of the right ventricle, increasing dimensions of the free wall (the valve is its part) and correspondingly, its contractile ability.

Animals↗
PubMed1986

[Electrophysiologic characteristics of cells of the conducting system in the right atrioventricular valve of the pigeon heart].

Distribution of the APs of Purkinje and pacemaker cells on the atrial and ventricular surfaces of the isolated muscle of the right atrioventricular valve was studied in the pigeon heart. The presence of a constant pacemaker area was found at the atrial side of the valve throughout the extent of its base. Due to the presence of the muscle valve in the right atrioventricular orifice in the bird heart, the "extension" of the pacemaker area of the atrioventricular node and a respective obvious branching of the Purkinje fibers of the atrioventricular bundle seem to take place.

Action Potentials↗
PubMedDate not supplied

[The influence of ecdysteroid fraction from Serratula coronata on transmembrane ionic currents of snail neurons].

Changes of the transmembrane potassium, calcium, and sodium ion currents in isolated neurons of Lymnaea stagnalis snail under the action of ecdysteroid fraction (serpisten) from Serratula coronata L. applied from outside in 0.01 -1000 microg/ml concentrations have been studied using the voltage-clamp technique. It is established for the first time that serpisten non-selectively activates the potassium and calcium ion currents (the currents amplitude increases by 2 - 15%) and reduces nonspecific membrane leakage currents in the entire range of concentrations. The sodium ion current also increased by 4 - 7% under the action of Serpisten in low concentrations (0.01 -10 microg/ml) in comparison with control, but this current decreased by 5 -10% at serpisten concentrations of 100 and 1000 microg/ml. The effects were reversible. The kinetics of currents was not changed under the action of serpisten.

Animals↗
PubMedDate not supplied

[Activation of the right atrioventricular valve in the avian heart].

Using intramural needle electrode, in situ determinations have been made of the moment of activation of the right muscular atrioventricular valve during electrical systole of the heart. In the hen, Gallus domesticus, the electrical activation of the valve was observed 8.8 +/- 1.4 ms (mean QRS duration 25 ms) whereas in the pigeon Columba livia--5 +/- 1 ms (QRS duration 17 ms) after the beginning of ventricular depolarization, i.e. during excitation of the main bulk of the myocardium of the free wall of the right ventricle.

Animals↗
PubMedDate not supplied

[The functional specificity of the cardiac pacemaker system].

On the basis of the own and literature data the original conception on pacemaker system of the heart experimentally is grounded. The new classification of the specialized structure--functional formations in the heart is suggested. The functional specificity of pacemaker system is considered in the comparative-ontogenetic aspect.

Amphibians↗