A NEW MODEL FOR THE RESEARCH INTO RHYTHMIC CONTRACTION ACTIVITY OF CARDIOMYOCYTES IN-VITRO

Heart cells continue to contract rhythmically after isolation and in c ulture in vitro. We describe a model of heart preparation in vitro tha t permits quantitative research on the frequency of contractions of ca rdiomyocytes. The chick embryo heart explants placed on a network of e lastic glass fibers continued beating for months, recorded and analyze d with the methods of computer-assisted image analysis. The efficacy o f this experimental model for the screening of effects of various agen ts on the frequency of contractions was examined by following the effe cts of nifedipine, caffeine, ethanol, and benzamide. The reversibility of the effects and the reproducibility of results were demonstrated q uantitatively. The significance of a mechanical elastic load provided by glass fibers for the preservation of long-lasting contractile activ ity of cardiomyocytes is discussed and the common occurrence of oscill atory contraction processes in various eucaryotic cells is noted.