[Optimization of culture of fetal rat cardiomyocytes in vitro]

Objective To explore the optimal method for in vitro cultivation of SD fetal rat cardiomyocytes. Methods Cardiomyocytes of SD fetal rats from pregnant rats on gestational day 19 were obtained by digesting cardiac tissues with 0.8 g/L trypsin and 0.4 g/L collagenase II. With differential centrifugation and different animal serums (bovine fetal serum or horse serum), we tried to look for the optimal culture conditions. The morphology and beat frequency of cardiomyocytes were observed under an inverted phase-contrast microscope. In addition, the expressions of alpha-sarcomeric actinin (α-SA) and cardiac troponin I (cTnI) in the cultured cardiomyocytes were detected by immunofluorescence staining to identify cardiomyocytes and the purity of these cells after 24, 48, 72 and 96 hours of cultivation. Results After 24 hours of cultivation, we had seen a majority of adherent cells and a few of suspension cells, and also seen some pulsating cardiomyocytes. The positive rates of α-SA and cTnI in the cardiomyocytes of the horse serum-cultured group were obviously higher than those in the bovine fetal serum-cultured group after 48, 72 and 96 hours of cultivation. Conclusion Co-digestion with trypsin and collagenaseII in combination with horse serum cultivation are easier to cultivate fetal rat cardiomyocytes.