Objective:To investigate the effects of different heat shock preconditioning intensities on cultured neonatal rat cardiomyocytes injured by oxidative-stress. Methods:Primary culture cardiomyocytes of neonatal rats pretreated with heat shock. 0.5 mmol/L(final concentration)H2O2 was added into the culture medium to mimic oxidative stress. Cardiomyocytes were divided into five groups:control group,H2O2 group,mild heat shock pretreatment group with 15 min heat shock at 42℃ and recovered 12 h before H2O2 treatment,moderate heat shock pretreatment group with 45 min heat shock at 42℃ before H2O2 treatment,severe heat shock pretreatment group with 90 min heat shoch before H2O2 treatment. Cell viabilities were analyzed by MTT. The apoptosis rate was evaluated with flow cytometry. The contents of superoxide dismutase(SOD),malonaldehyde(MDA) in cardiomyocytes and lactate dehydrogenase(LDH) in culture solution were measured. Results:Compared with normal control group,cell viabilities and the contents of SOD in the H2O2 group decreased significantly(P < 0.01),whereas,the apoptosis rate,the contents of LDH and MDA in the H2O2 group increased significantly(P < 0.01); Compared with the H2O2 group,cell viabilities and the contents of SOD in the mild heat shock prereatment group and moderate heat shock pretrentment group increased significantly(P < 0.01),whereas the apoptosis rate the contents of LDH and MDA in the mild heat shock pretreatment group and moderate heat shock pretreatment group decreased significantly(P < 0.01). The consequence of the severe heat shock prefreatment group and the H2O2 group were not different obviously(P > 0.05); Compared with the moderate heat shock prereatment group,cell viabilities and the contents of SOD in the mild pretreatment group and severe pretreatment group decreased significantly(P < 0.01),whereas the apoptosis rate and the contents of MDA in the mild pretreatment group and severe pretreatment group increased significantly(P < 0.01). The contents of LDH increased significantly too(P < 0.05,P < 0.01). Conclusion:Heat shock pretreatment can protect primary cultured rat cardiomyocytes injured by H2O2. Different effects would be created on cardiomyocytes by different heat shock preconditioning intensities.
徐少华,龙明智,章海燕,陈磊磊.不同强度热休克预处理对氧化应激所致乳鼠心肌细胞损伤的影响[J].南京医科大学学报(自然科学版英文版),2008,28(3):341-345.