Effect of Leptin Pretreatment on Myocardial Ischemic Reperfusion Injury in Type 2 Diabetic Rats

Objective To study the effect of different doses of leptin pretreatment on myocardial ischemic reperfusion injury( MIRI) in type 2 diabetic rats. Methods 60 healthy male SD rats( SPF) were randomly divided into six groups with 10 in each group: normal control group( NC group),DM-sham-operation group,DM-MIRI group,low-dose-leptin group, middle-dose-leptin group,and high-dose-leptin. NC group were fed on basic diet( 4 weeks),and the blood and heart samples were obtained from each rat after 4 weeks. Type 2 diabetic rat models were reconstructed by adopting the method of feeding them on high fat / high sucrose diet( 4 weeks) combined with streptozotocin( 35 mg / kg) intraperitoneal injection. The blood and heart samples were obtained from the DM groups 3 h after reperfusion. The levels of leptin,TNF-α,FBG,FINS,MDA,lipids and HOMA-IR were detected. Results Compared with normal rats,the FBG,FINS,leptin,HOMA-IR,TNF-α, MDA,TG,TC,LDL-C levels of DM-sham-operation group,low-dose-leptin group,middle-dose-leptin group and high-dose-leptin groups were significantly increased( P 0. 05),but HDL-C level was decreased( P 0. 05); Compared with DM-sham-operation group,the FBG,leptin levels of the other four diabetic groups were increased( P 0. 05),the FINS,HOMA-IR of DM-MIRI group and high-dose-leptin group was increased( P 0. 05),the FINS,HOMA-IR of low-dose-leptin group and middle-dose-leptin group was decreased( P 0. 05),the TNF-α and MDA levels of DM-MIRI group were increased( P 0. 05),the TNF-α,MDA and HDL-C levels of the low-dose-leptin group,middle-dose-leptin group and high-dose-leptin group were increased,but the TG,TC,LDL-C levels were decreased( P 0. 05);Compared with DM-MIRI group,the leves of FBG,FINS,leptin,TNF-α,MDA,TG,TC,LDL-C,and HOMA-IR of low-dose-leptin group and middle-dose-leptin group were decreased( P 0. 05),but HDL-C level was increased( P 0. 05). Conclusion Metabolic disorders of insulin resistance and leptin resistance are observed in type 2 diabetic rats with myocardial ischemic reperfusion injury. Certain concentration leptin pretreatment shows protective effects on type 2 diabetic rats with myocardial ischemic reperfusion injury,which can reduce the levels of leptin,TNF-α,MDA and HOMA-IR,thus may reduce the injury by inflammation,oxidative stress,dyslipidemia and insulin resistance.