Improved isolation of cardiomyocytes by trypsination in addition to collagenase treatment

The present study was undertaken to develop an improved and stabilized method for isolating cardiomycytes from perfused rat heart. Different lots of the commercial collagenases used for isolating cardiomyocytes give variable results both with respect to the total cell yield and the percentage of elongated cells obtained. When trypsin was present both before and during collagenase treatment of the tissues, the performance of the collagenases was improved and stabilized, and a high and stable cell yield (7.5 x 206 cells per heart), and a high percentage of elongated cells (about 70%) was regularly obtained. The cells possessed α1-adrenergic binding sites with binding properties (Bmax = 43.5 fmol/mg protein and Kd 125.5 pmol/l) in agreement with values previously reported. The cells were able to respond functionally, as the cellular uptake of 86Rb+ increased by 18% after α1-adrenoceptor stimulation with phenylephrine. These criteria indicate that the cells were well preserved during the isolation procedure. (au) (10 refs.)