Objective:To investigate the effect of enhanced external counterpulsation(EECP)on serum nitric oxide(NO)

malondialdehyde(MDA) and superoxide dismutase(SOD) in patients with coronary heart disease(CHD) and its mechanism.Methods:The serum NO

MDA and SOD levels of 54 cases of CHD and 20 normal controls were tested.Patients were divided into EECP group(30cases) and medication group(24 cases).The serum concentrations of NO

MDA and SOD of each group before and after treatment were compared for the correlation analysis.Results:Before treatment

compared with the normal controls

the serum levels in CHD patients were as follows.NO were much lower(P<0.05)

MDA were much higher(P<0.01)

and SOD were much lower(P<0.05).After 6 weeks medication treatment or 3 courses EECP treatment

compared with the levels before treatment

the serum levels in CHD patients EECP group were as follows.NO increased significantly(P<0.05)

MDA decreased significantly(P<0.05)

and SOD increased significantly(P<0.05);while there was only slight changes of NO

MDA and SOD in medication group without significant difference(P>0.05).Correlation analyses showed that in EECP group

there was negative correlation between NO and SOD(r=-0.47

P<0.01);positive correlation between NO and SOD(r=0.39

P<0.05);negative correlation between MAD and SOD(r=-0.41

P<0.05).Conculusion:The blood vessel endothelium function was disordered and lipid peroxidation was enhanced in CHD patients.EECP treatment can regulate blood vessel endothelium function by improving the release of NO and relieve lipid peroxidation by reducing the production of MDA or increasing the production of SOD.The results may be useful in further study of EECP mechanism of treating CHD.