金属硫蛋白参与碱性成纤维细胞生长因子的心肌细胞保护作用

目的:在培养的乳鼠心肌细胞缺氧/复氧(anoxia/reperfusion,A/R)损伤模型上,观察金属硫蛋白(MT)在碱性成纤维细胞生长因子(bFGF)心肌保护中的作用,探讨bFGF心肌保护作用的可能机制。方法:用bFGF(10^-10、10^-9、10^-8mol/L)及同时应用PD₀₉₈₀₅₉的bFGF(10^-9mol/L)预孵育乳鼠心肌细胞24h,复制心肌细胞A/R损伤模型,光镜下计算细胞存活率,[¹⁰⁹Cd]-血红素饱和法测细胞MT含量,硫代巴比妥酸法测细胞丙二醛(MDA)含量,以自动生化分析仪测培养液乳酸脱氢酶(LDH)活性。结果:bFGF呈浓度依赖地诱导心肌细胞MT生成,10^-10、10^-9、10^-8MbFGF组MT含量分别高于A/R组54%、62%、76%,并拮抗A/R引起的细胞损伤,细胞存活率高于A/R组,细胞乳酸脱氢酶(LDH)及蛋白漏出较少,细胞丙二醛(MDA)含量低于A/R组,而用丝裂素活化蛋白激酶(MAPK)抑制剂PD₀₉₈₀₅₉抑制MT生成则减弱了bFGF的上述细胞保护作用。结论:MT参与了bFGF的心肌保护作用,并与MAPK的介导有关。

Metallothionein involvement in myocardial protection of basic fibroblast growth factor

AIM: To observe whether metallothionein plays a role in cardiac protective effect of basic fibroblast growth factor on anoxic/reperfusion (A/R) injury in cultured cardiomyocytes and study the possible mechanism of cardiac protection by bFGF.METHODS: The present study made the model of myocyte A/R injury after having a 24 h incubation by bFGF( 10-10、10-9、10-s mol/L) and bFGF( 10-9 mol/L) + PD098059 respectively. We measured the levels of MT and MDA in myocytes, and the changes of LDH and protein in cultured medium. We also counted the number of viable cell in groups. RESULTS: The contents of myocardial MT were significantly increased after treatment by bFGF. The levels of MT in I0-l0 mol/L、10-9 mol/L and 10-8 mol/L bFGF treated groups increased 54 %、 62%、 76% respectively, compared with the A/R group, and the number of viable cell were also greatly increased, LDH and protein leakage in cultured medium and MDA contents in myocyte were dramatically decreased in bFGF treated groups. All the protection were completely disappeared with the inhibition of MT production with PD098059, theinhibitor of mitogen- activated protein kinase(MAPK). CONCLUSION: MT involves in the protection of bFGF in cultured cardiomyocytes. It might be related with activation of MAPKase.