[Effect of diethylamine analog of ethmozine on parameters of fast sodium current in normal and depolarized myocardial fibers].

The effect of a diethylamine analog of ethmozine (DAAE) on fast sodium current of normal and depolarized frog atrial trabeculae was studied by means of the double sucrose gap technique. The depolarization of the fibers was produced both by increasing extracellular potassium concentration up to 8 +/- 9 mM and by current passing. The resting potential of normal fibers was within the range of 75-80 mV, and the depolarized one was within 65 +/- 60 mV.

Effect of aprindine on transmembrane currents and contractile force in frog atria.

The effects of aprindine on transmembrane currents in frog (Rana Ridibunda) atrial trabeculae were studied using a voltage clamp technique. Aprindine (1 x 10(-6) g/ml) reduced maximum inward sodium current by 38.6 +/- 7.

[Lidocaine action on the ion currents of normal and depolarized myocardial fibers in membrane potential fixation].

The effect of lidocaine on the transmembrane ion currents of normal and partially depolarized atrial trabecula was studied in the frog by fixation of membrane potential with duoble sucrose bridge. Lidocaine in a concentration below 12 X 10(-4) g/ml produced no effect on the slow input current. Lidocaine decreased the potassium conduction at the membrane potential values below--45 mW, and increased at--30 mW.

[Effect of ethmozine and its diethylamino analog on the slow incurrent and excurrent ion flows of cardiac atrial fibers].

The effects of ethmozine (2 X 10(-5) g/ml) and diethylamine derivative of ethmozine (DAD of ethmozine) (2 X 10(-5) g/ml) on slow inward and outward currents were investigated by means of the voltage clamp method in frog auricular trabeculae. Ethmozine increased the maximal value of the slow inward current by 62 +/- 11% (n = 5) while DAD of ethmozine decreased it by 54 +/- 17% (n = 3). The control value of the slow inward current was restored after 30 min of wash out.

[Antiarrhythmic and electrophysiological properties of etmozin and its diethylamine analog].

Effects of antiarrhythmic drug etmosin and its diethylamine analogue (etmosin DAA) were compared in dogs with the ventricular rhythm disturbances induced by coronary artery ligation according to Harris' method. As demonstrated, both drugs stopped ventricular rhythm disturbances, but etmosin DAA had a more rapid and prolonged effect. Electrophysiological properties of etmosin and etmosin DAA were studied by the method of potential fixation on trabeculae of frog atria.

[Action of a new antiarrhythmia preparation, etmozin, on the contractile force, transmembrane action potential and the rapid incoming sodium flow of the frog atrial muscle].

The mechanism of the effect of ethmosine on the force of contraction, the membrane potential and the rapid incoming sodium flow of the frog atrium was studied by means of microelectrode technique and the method of potential fixation. It has been shown that in a concentration of up to 10(-5) g/ml ethmosine reduces the rate of increase of the foremost front of the action potential by 50%; has no substantial effect on the force of contraction, and on the shape and duration of the transmembrane action potential; inhibits the rapid incoming sodium flow by more than 50% by diminishing maximum conductivity of sodium ions; has no effect on processes of activation, inactivation and reactivation of the sodium flow. A comparison is made between ethmosine and other antiarrhythmic agents in their effect on the force of contraction and the electric parameters of cardiac cells.