Aim To investigate the damage of mitochondria in HUVECs cells by iron overload and the role of ADMA/eNOS/DDAHⅡ in it.Methods HUVECs cells were cultured and randomly divided into normal control (Ctrl) group, dextran iron (Iron) group and L-arginine (L-Arg) group.After 48 h, the survival rate of cells was detected by MTT assay;ADMA content and DDAHⅡactivity were measured by HPLC method;the expression of eNOS was determined by Western blot;LDH activity, MDA and NO content, and mitochondrial permeability transition pores(mPTP) openness were determined by colorimetric assay;ROS generation, mitochondrial membrane potential and apoptosis were determined by flow cytometry.Results After 48 h treatment with iron, the survival rate of HUVECs significantly decreased, while the activity of LDH in culture medium increased.The results showed that ADMA and MDA content significantly increased, NO content, DDAHⅡactivity, and the expression of eNOS markedly decreased, the generation of ROS was evidently elevated, mitochondrial membrane potential was lost apparently, mPTP openness was obvious, and the apoptosis of the HUVECs were worsened.However, as ADMA physiological antagonist, L-Arg significantly attenuated the above effects of iron.Conclusion Iron overload could damage mitochondrial function by eNOS and induce the apoptosis of HUVECs, in which ADMA/DDAHⅡ mechanism may also be engaged.

Aim To investigate the relationship be-tween the cardioprotection of apigenin ( Api ) from an-oxia/reoxygenation ( A/R) injury and Bcl-2 pathway. Methods H9 c2 cardiomyocytes were cultured and di-vided into normal control group, A/R group, Api pre-treatment group ( Api ) , Api + Bcl-2 inhibitor group ( Api + ABT-737 ) . Expression of Bcl-2 was deter-mined by Western blot,and cell viability was measured by MTT method. LDH, SOD, GSH-Px, MDA activity were determined by chromometry. ROS generation, mi-tochondrial membrane potential and apoptosis were de-termined by flow cytometry. Results 25h after apige-nin precondition,the expression of Bcl-2 was upregulat-ed in cardiomyocytes ( P <0. 01 ) . In the group pre-treated with 40 μmol · L-1 apigenin before A/R, the activity of LDH in culture medium decreased; the ac-tivity of intracellular SOD, GSH-Px increased; the content of MDA and ROS generation decreased; cell viability increased; mitochondrial membrane potential could be more stable and cell apoptosis decreased ( P<0. 01 ) . However, all these protective effects were attenuated significantly in the group pretreated with apigenin and Bcl-2 inhibitor ABT-737 . Conclusion The effect of apigenin against A/R injury in cardiomyo-cytes involves Bcl-2 pathway, and at least partly de-pends on its effect on upregulating the expression of Bcl-2 .