Reduction of activity, but no decrease in concentration, of erythrocyte Cu,Zn-superoxide dismutase by hyperglycaemia in diabetic patients
✍ Scribed by Kotake, M.; Shinohara, R.; Kato, K.; Hayakawa, N.; Hayashi, R.; Uchimura, K.; Makino, M.; Nagata, M.; Kakizawa, H.; Nakagawa, H.; Nagasaka, A.; Itoh, M.
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 83 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0742-3071
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✦ Synopsis
Cu,Zn-superoxide dismutase(SOD) activity in erythrocytes is affected by various diseases, including diabetes mellitus (DM). We investigated changes in the Cu,Zn-SOD activity compared to changes in the Cu,Zn-SOD concentration in erythrocytes obtained from patients with Type 2 (non-insulin-dependent) diabetes mellitus. Cu,Zn-SOD activity in erythrocytes was significantly lower in Type 2 DM patients than in healthy non-diabetic subjects. The activity correlated negatively with HbA 1c , but not with other indicators of metabolic control, such as fasting blood glucose or plasma cholesterol or triglyceride. However, there was no statistically significant difference in erythrocyte concentration of Cu,Zn-SOD between diabetic and control samples. Concentration did not correlate with enzymatic activity or HbA 1c . These findings indicate that the inactivation of Cu,Zn-SOD activity in erythrocytes of Type 2 DM patients by hyperglycaemia may be slow, because there is a negative correlation between the enzyme activities and HbA 1c levels, but not fasting blood glucose levels. This is consistent with glycosylation of the active site of Cu,Zn-SOD, without any effect of hyperglycaemia on the concentration of Cu,Zn-SOD.