Influence of metallothionein on kidney oxidation of diabetic rats / 第二军医大学学报

ABSTRACT

Objective: To study the effect of metallothionein (MT), a potent antioxidant, on the oxidative stress and NADPH oxidase in kidneys of diabetic rats. Methods: Male SD rats were assigned to the following 3 groups normal control (NC, n=8), diabetes mellitus control (DM, n = 7), diabetes mellitus models treated with MT by lavage (10 g * kg-1 * d-1, DM+MT, n=8). Diabetes in DM group and DM+MT group was induced by intraperitoneal injection of streptozotacin (60 mg/ kg). At 4 weeks after initiating treatment, 24 h urinary protein (24 h UP) and kidney weight/ body weight (KW/BW) were determined in the 3 groups to assess the renal function of rats; malondialdehyde (MDA) was examined with visible spectrophotometry; NADPH oxidase subunits p47phox and p22phox, protein kinase C (PKC)-β, and Angiotensinogen (Ang) were examined by real-time PCR. Results: MDA, 24 h UP and KW/BW in DM group were significantly higher than those in NC group (P<0.05); expression of PKC-β, Ang, and NADPH oxidase subunits p22phox and p47phox mRNA were increased markedly in DM group compared with NC group (P<0.05, P<0.01). 24 h UP, KW/ BW and MDA were significantly lower in DM+MT group compared with DM group (P < 0.05); expression of p47phox, PKC-β and Ang mRNA were significantly decreased in DM+MT group compared with DM group (P<0.05), but the expression of p22phox mRNA in DM and DM+MT groups had no significant changes. Conclusion: MT may lower the oxidase stress on kidney tissues, inhibit the expression of PKC-β and Ang in the kidney, and decrease NADPH oxidase activity, excerting protective effect on the kidney of rats with diabetes mellitus.