Objective To establish endoplasmic reticulum stress induced-apoptotic model by tunicamycin in cultured neonatal rat cardiomyocytes.

Methods Neonatal rat cardiomyocytes in primary culture were exposed to tunicamycin of different concentrations. MTT assay and flow cytometry analysis were applied to measure cardiomyocyte viability. Western blot was used to examine the expression levels of GRP78 and CHOP.

Results Cell viability was time and concentration-dependently decreased. The treatment of tunicamycin produced 42.8±5.8% of apoptotic population in cardiomyocytes. The levels of GRP78 and CHOP significantly upregulated at 6 h. After tunicamycin treatment for 24 h, the upregulation of GRP78 and CHOP reached the maxium.

Conclusion We successfully constructed tunicamycin-induced apoptotic model in cultured neonatal rat cardiomyocytes. The optimal concentration and time of tunicamycin treatment was 100 ng/ml, 72 h, respectively.