Objective: To investigate the protective effects of camelliasaponin C (CS-C) pretreatment on myocardial cell injury induced by anoxia/reoxygenation.
Methods: Myocardial cells were obtained from neonatal SD rats, cultured for 3 to 4 days, added into the wells of a 24-well plate, and were divided randomly into five groups (8 wells for each group): control group, anoxia/reoxygenation (A/R) group, added with anoxia culture fluid for 3 h and then added with imitation reperfusion fluid for 1 h, anoxia preconditioning (AP) group, undergoing anoxia for 10 min before A/R, CS-C pretreated group, added with CS-C 3.75 x 10(-7) mol/L 1 h before A/R, and glibenclamide (Glib) pretreated group, added with CS-C 3.75 x 10(-7) mol/L and Glib 12 microm 1 h before A/R. Trypan blue exclusion was used to detect the viability of the cardiomyocytes, the contents of lactate dehydrogenase (LDH) in the supernatant of culture medium was measured. Electron microscopy was used to observe the ultrastructure of the cardiomyocytes.
Results: The contents of LDH of the A/R group was 57.8 U/L +/- 6.4 U/L, significantly higher than that of the control group (12.3 U/L +/- 1.7 U/L, P < 0.01), and the LDH value of the CS-C group was 39.8 U/L +/- 3.9 U/L, significantly lower than that of the A/R group (P < 0.01), not significantly different from that of the AP group (32.4 U/L +/- 5.2 U/L, P > 0.05), but significantly higher than that of the control group. The cardiomyocyte viability of the A/R group was 51.0% +/- 1.9%, significantly lower than that of the control group (92.0% +/- 2.0%, P < 0.01), the cardiomyocyte viability of the CS-C pretreatment group was 76.4% +/- 3.5%, significantly higher than that of the A/R group (P < 0.01), but not significantly different from that of the AP group (78.0% +/- 2.0%, P > 0.05). The cardiomyocyte ultrastructure of the A/R group was significantly changed, and the changes of cardiomyocyte ultrastructure in the CS-C pretreatment group were significantly attenuated compared with the A/R group. The content of LDH of the Glib group was 55.8 U/L +/- 5.0 U/L, significantly higher than that of the CS-C pretreatment group (P < 0.05), and the cardiomyocyte viability of the Glib group was 54.1% +/- 3.7%, significantly lower than that of the CS-C pretreatment group (P < 0.05), and the damage to the cardiomyocyte ultrastructure in the Glib group was more severe than in the CS-C group.
Conclusion: The cardioprotective effect of CS-C pretreatment is similar to that of anoxia preconditioning and the effective mechanism would be related to the opening of ATP-sensitive K(+) channel. Glib can abolish the cardioprotective effect of CS-C pretreatment.