RESUMO
Objective To determine the effects of Sodium Nitroprusside ( SNP) , superoxide dismutase ( SOD) and catalase ( CAT ) on the expression of catalytic subunit of the DNA-dependent protein kinase ( DNA-PKcs ) and Ku70/80 heterodimer in cardiomycyte H9C2, as well as their expression in the myocardial tissues of SD rats . Methods H9C2 cells were co-cultured with SNP at concentreations of 10, 20 and 40 mmol/L for 6 hours, SD rats were injected with normal saline , SNP, SNP+SOD, SNP+CAT or SNP+SOD+CAT.Western blot and immuno-histochemistry assay were used to examine DNA-PKcs and Ku70/80 protein expression respectively .Results The expression of DNA-PKcs and Ku70/80 increased in H9C2 cells co-cultured with SNP when compared with control group, but they were be decreased when treated with SOD or/and CAT.The expression of DNA-Pkcs and Ku70/80 in myocardial tissues of experimental groups were higher than the control .Conclusions Radical scavengers may play a role as a protective effect for sodium nitroprusside related injury in cardiac myocytes .