Effects of liraglutide on 8-OHdG, MDA and SOD of kidney in insulin resistance rats

Objective To observe the effects of liraglutide on 8-OHdG, MDA and SOD of kidney in insulin resistance (IR) rats.Methods According to random number table method, 54 Wistar male rats were divided into normal control group (normal diet) and IR model group (high fat diet). IR was evaluated by hyperinsulinemic euglycemic clamp technique after 8 weeks. After IR rat models were successfully established, the animals in high fat diet group were randomly divided into IR group, intervention group 1 (liraglutide: 100 μg·kg^-1·day^-1), and intervention group 2 (liraglutide: 200 μg·kg^-1·day^-1). After treatment for 2 weeks with liraglutide, SCr, BUN, 24-h urine protein, and 8-OHdG, MDA and SOD in the renal tissues were determined. The morphology and structure in the renal tissues were observed by electron microscope.Results As compared with control group, the levels of SCr, BUN, 24-h urine protein, 8-OHdG, and MDA were significantly increased in IR group (8-OHdG: 32.81±2.96 ng/L vs. 13.30±1.72 ng/L; MDA: 7.7±1.0 nmol/mg vs. 3.3±0.4 nmol/mg, all P<0.05) and the expression of SOD was decreased (175.0±7.7 U/mg vs. 237.1±12.4 U/mg, P<0.05). As compared with the IR group, 24-h urine protein, 8-OHdG and MDA were decreased in intervention group 1 (8-OHdG: 28.54±2.71 ng/L vs. 32.81±2.96 ng/L; MDA: 6.6±1.0 nmol/mg vs. 7.7±1.0 nmol/mg, P<0.05); SCr, BUN, 24-h urine protein, MDA and 8-OHdG were decreased (8-OHdG: 20.06±1.65 ng/L vs. 32.81±2.96 ng/L; MDA: 5.7±0.5 nmol/mg vs 7.7±1.0 nmol/mg, all P<0.05) and SOD was increased in intervention group 2 (216.1±10.6 U/mg vs. 175.0±7.7 U/mg, P<0.05). As compared with the intervention group 1, SCr, BUN, 24-h urine protein, MDA and 8-OHdG were decreased (all P<0.05) and SOD was increased in intervention group 2 (P<0.05).Conclusions Liraglutide could decrease the kidney oxidative stress in a concentration-dependent manner, which may be one of the reasons for the renal injury induced by IR.