[Mechanism of postextrasystolic potentiation of the myocardium].

Combined effects of poststimulation and postextrasystolic potentiation (PESP) were studied in the rat papillary muscles. The constant PESP augmentation of isometric force triggered by extrasystolic stimulus was shown for 2-8 poststimulatory potentiated contractions. The PESP was not dependent upon the Ca2+ concentration within the 0.

[The theory of regulation of the contraction force of the heart muscle].

A model of rhythmoinotropic phenomena in the heart muscle is elaborated. Kinetics of calcium flowing in intracellular pools of cardiomyocytes is described by differential equations. Dimensionless values (portions) serve as equation coefficients.

[Modeling the effect of rhythm on the strength of myocardial contraction].

A linear three-pool model of rhythm-inotropic phenomena in the cardiac muscle is proposed. Dynamics of accumulation and liberation of calcium from intracellular pools is described by differential equations. It has been shown by numerical experiments that rhythm-inotropic phenomena in the normal cardiac muscle and under cardiac insufficiency can be described qualitatively in terms of the concept on calcium recirculation in intracellular pools.

[The effect of neutotropic substances on motor excitation in dogs induced by amizil].

The motor activity of dogs was quantitatively recorded before and after the intramuscular injection of amizyl (2 mg/kg). Amizyl was found to induce hyperactivity for 2-3 hours. Galanthamine (3 mg/kg) blocked the effect of amizyl.