Selective use of calcium chelators enhances the yield of calcium-tolerant myocytes from adult heart.

ABSTRACT

Isolation of viable and functional cells from adult heart remains an intriguing problem for investigators who choose to use the cardiomyocyte model for experimental studies. With a few modifications of the existing procedures we have been able to improve the yield of ventricular myocardial cells from the adult rat heart. Sarcolemmal damage leading to hypercontracture due to Ca2+ loading appears to be the major hindrance to the successful isolation of sufficient number of viable cells. The two crucial steps are found to be the pre-enzymatic perfusion for Ca(2+)-depletion and the final step of Ca(2+)-repletion in extracellular medium for the isolation of Ca(2+)-tolerant myocytes. Inclusion of EGTA and taurine during the initial perfusion of Ca(2+)-free medium and of trypsin during reintroduction of Ca2+ led to a considerable increase in the yield of Ca(2+)-tolerant myocytes. The contraction amplitude and speed of shortening and relaxation of isolated cells were measured using an edge detection device. Selective use of calcium ion chelators appears to have a beneficial effect on the isolation of Ca(2+)-tolerant myocytes.