96 Cardiomyocyte differentiation : Experience and observations from 2 laboratories

left ventricular rat heart tissue.(9) While the cells do not beat and differ morphologically from isolated adult cardiomyocytes, similarities with primary cardiomyocytes have been reported, specifically in terms of the presence and dynamics of L-type calcium channels, a similar cell membrane lectin binding pattern and comparable G-protein composition associated with ligand stimulated intracellular signalling.(10,11) As such, the H9c2 cell line has been used extensively in research to study the mechanisms of cardiac hypertrophy,(12) oxidative stress,(13,14) ischaemia/ reperfusion (I/R),(15,16) and cardiotoxicity.(17) These cells, however, also have the capacity to adopt features of differentiated skeletal or cardiac muscle upon long term culture with low serum levels,(9,18) and in the case of cardiac specific differentiation, daily treatment with retinoic acid (RA).(19,20)