Abstract
Excitation and contraction are the two main functions of heart cells. Therefore for studies of physiology and pathophysiology of heart cells, measurement of cell contraction is as important as that of membrane current and action potentials. In addition, measurement of cell contraction provides a simple way for assesing intracellular calcium transients. However, the measurement of single-cell contraction has not been a popular experimental technique, because it requires very specialized instruments, and because the measurement of cell contraction from patch-clamped cells was not quite trivial. In this report, we describe a simple system for video-based measurement of heart cell contraction, which can be used with patch-clamp instruments without difficulty. In this system, motion of the cell is recorded with a CCD video camera attached to the microscope, and the video images are digitized and analysed on a Windows-based PC using ScionImage public domain software. With the aid of software image manipulation using Sobel filter, cell shortening could easily be measured at 1/60 s time-resolution, from patch-clamped single heart cells. Values of the measurements are stored in text-based data files, which can easily be imported into pClamp or spreadsheets for further analysis. Contraction properties of patch-clamped mouse heart cells is also provided as an example of cell analysis using this system. [J Physiol Sci. 2006;56 Suppl:S130]
