Computer programs to facilitate the estimation of time-dependent drug effects on ion channels

The programs I-VOC and I-ROC have been designed to facilitate the analysis of drug effects on currents through ion channels in the cell membrane, measured by means of voltage-clamp. They are written in Igor Pro (WaveMetrics) and read exported files or raw data files generated by the Pulse (HEKA Electronic) or pClamp (Axon Instruments) programs. With I-VOC, the sweeps of current through voltage-operated ion channels can be quantified within six time ranges, and current run-down can be corrected for after the currents are fitted during the control period. Linear leak current can be subtracted even when the P/n method is not used. The results are plotted and tabulated. With I-ROC, an analogous program, receptor-operated currents can be quantified, the peak current or rate of desensitization can be fitted and run-down corrected for. Chart-like data can be converted to a sweep-like format. Several procedures are incorporated for rapid graphical data presentation. These programs accelerate and improve the estimation of drug effects on ion channels.