RESUMO
<p><b>OBJECTIVE</b>To investigate the role of superoxide dismutase (SOD) in Adriamycin (ADR)-induced heart failure and the protective effects of Sini decoction (SND).</p><p><b>METHOD</b>SD rats were randomly divided into three groups, control group, heart failure group and SND group. ADR was injected in the rats of heart failure group and SND group by caudal vein. After injection, the rats in SND group were given SND (3.75 g x kg(-1) x d(-1), p.o.). Three weeks later, cardiac function, content of malondialdehyde (MDA) of both myocardium and mitochondria and activity of Cu-Zn SOD and Mn SOD were measured. The mRNA expression of Cu-Zn SOD and Mn SOD were also detected by RT-PCR.</p><p><b>RESULT</b>Compared with control group, LVSP and +/- dp/dt max were obviously decreased, while LVEDP was markedly increased in the heart failure group. The mRNA expression and the activity of Cu-Zn SOD and Mn SOD in heart failure group were obviously lower than that in the controls'. In addition, the MDA content of both myocardium and mitochondria were clearly increased in heart failure rats. In SND-treated rats, the cardiac function, the activity and the mRNA expression of Cu-Zn SOD and Mn SOD were significantly elevated and the content of MDA was reduced, which had no statistic difference with the rats in control group.</p><p><b>CONCLUSION</b>The data suggest that oxidative stress is present in the mitochondria of myocardium in ADR-induced heart failure rats and it can be eased by SND. The mechanism may be closely related to SOD.</p>