당뇨병 환자 단핵구의 Manganese Superoxide Dismutase ( Mn - SOD ) 활성도에 관한 연구

/A Background: Free radical injury is one of the environmental factors related to the development of diabetes mellitus. Oxidative injury may also have a role in the development of diabetic microangiopathy by promoting peroxidation of lipids. Superoxide dismutase(SOD) is one of the most important enzymes of the reactive oxygen scavanger system as it acts on the first and the rate limiting step. To investigate the possible role of SOD in the genesis of microangiopathy, we measured the Mn-SOD activity in monocytes in patients with IDDM and NIDDM, with and without retinopathy. Methods : Thirteen patients with insulin dependent diabetes mellitus(IDDM), 13 patients with non-insulin dependent diabetes mellitus(NIDDM) and 14 healthy controls were studied. Peripheral mononuclear cells were isolated and the SOD activity was measured at basal state and after culture with r-interferon(20units/ml, 100units/ ml) for 24 hours. Results : There were no significant differences in basal and r-interferon stimulated Mn-SOD activities among IDDM, NIDDM and healthy controls. However, when we divided the diabetic patients into two groups, those with and without retinopathy, the activity of the Mn-SOD was significantly lower in diabetic patients with retinopathy at both basal and r-interferon stimulated state than those without retinopathy(all p< 0.05). Conclusion : These results suggest that decreased mononeuclear cell Mn-SOD activities might be related to the development of diabetic retinopathy.