ABSTRACT
AIM: To set the model of rat bone marrow me se nchymal stem cells (BMMSCs) that differentiate into cardiomyocytes and observe t he connection structure between cells. METHODS: BMMSCs were isolated by adhering to culture plates and cultured in vitro to expand. Induction of BMMSCs to differentiate into cardi omyo cytes was conducted by treating the cells with 5-aza. Immunocytochemical stainin g was used to identify sarcomeric actin and intercalated disc-like structure wh en the cells were cultured for additional 1 week, 2 or 3 weeks, respectively. RESULTS: Sarcomeric actin positive cells were observed in 1 week , 2 or 3 weeks after 5-aza treatment. Some cells stained positive for connexin4 3 at 1 week and 2 weeks after 5-aza treatment, with brown pellet located disper sively around nucleus. 3 weeks after 5-aza treatment, connexin43 positive cells s howed brown pellet arranging in thready structure around nucleus, such structure could be seen between very few cells which was similar to intercalated disc-lik e structure in normal heart tissue. CONCLUSION: During the process of BMMSCs differentiating into ca rdiomyocytes, intercalated disc-like structure is gradually formed with increas e in culture time and cell density.