A. N. Verkhratskii

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Block of sodium currents by allapinine (diterpene alkaloid with strong antiarrhythmic properties) was investigated in isolated, voltage-clamped trigeminal neurons of a rat and single ventricular myocytes of a neonatal rat. Allapinine (in micromolar concentrations) produced a 70-90% decrease of the sodium current amplitude without any changes in(More)
Cytosolic free calcium [( Ca2+]in) was measured using fura-2 in isolated cultured ventricular myocytes of neonatal rat. Exposure of the cardiomyocyte to a solution in which all Na+ have been replaced by impermeable cations results in a 400-600 nmol/l increase of [Ca2+]in. This increase is followed by a slow decrease to the initial level. A decrease of the(More)
The effects were investigated of allapinine, diterpene alkaloid on ionic currents in voltage-clamped trigeminal neurons and cardiomyocytes isolated from rats. Allapinine application was found to exert an inhibitory effect on inward tetrodotoxin-sensitive sodium currents without changing their voltage dependence. Potential differences between the mechanisms(More)
Using indo-1- and fura-2-based microfluorometry for measuring the cytoplasmic free calcium concentration ([Ca2+] in ), the properties of caffeine-induced Ca2+ release from internal stores were studied in rat cultured central and peripheral neurons, including dorsal root ganglion (DRG) neurons, neurons from then. cuneatus, CA1 and CA3 hippocampal regions,(More)
The effect of a drop of extracellular pH on the fast and slow sodium currents (INaf and INas) was studied in the rat isolated perfused ventricular myocytes. The shift of the extracellular pH value from 7.4 to 5.0 caused a disappearance of INaf. If the fast sodium current was blocked by external tetrodotoxin (10(-6) mol/l) or inactivated by the shift of the(More)
Dual wavelength microfluorometry was used to measure the cytoplasmic free calcium concentration [( Ca2+]in) in single cultured cells from ventricular myocytes of neonatal rats loaded with the indicator fura-2. At 2.5 nmol/l extracellular Ca2+ in the resting cells [Ca2+]in was between 80 and 110 nmol/l. Sometimes, spontaneous low-frequency (approximately 0.1(More)
Thin cardiac slices (100-200 microns) from newborn (1-14 days old) rat heart ventricles were used for patch clamp recordings. High resistance seals (10-50 GOhms) between patch-clamp pipettes and the membrane of cardiac cells as well as classical patch-clamp configurations can be achieved on this preparation without any enzymatic treatment of tissue.(More)
In isolated, cultured neonatal rat ventricular myocytes calcium current was investigated by whole-cell patch clamp technique. The shift of holding potential values from -100-80 mV to -40 mV caused no significant changes in calcium current potential-dependent and kinetic properties. No calcium current component with preferential steady-state inactivation at(More)