["Micro-lead" technic for recording ion currents through the membranes of individual myocardial cells]

Patch-voltage-clamp method has been used for registration of the fast inward current in single heart muscle cells. Ionic current were measured on a small patch of membrane which is of about 1/200-1/300 of the total cell surface (diameter of patch is of about 5 micrometer). To correct the distortions of raw signal caused by the stray capacity in feedback of current-voltage converter and adjustable increasing of high-frequency gain was used. This allows one to shorten the net time of transient process in response to switching the command potential up to 30 microseconds. The channel population in membrance patch of micrometer in diameter is, on the one hand, large enough to record directly the integral ionic current and is, on the other hand, small enough for fluctuations of ionic current to be pronounced. This circumstance permits the method to be applied for ionic current investigations both by the classical methods and by statistical analysis.