Abstract:

Objective To monitor the changes of serum interleukin-6(IL-6) and tumor necrosis factor-alpha (TNF-α) levels in the process of myocardial ischemia reperfusion injury(MIRI) in mice and the pretreatment effects of leptin  on them,and to explore the effects of leptin pretreatment on MIRI in mice. Methods Forty males C57BL/6 mice were randomly divided into sham-operation group,MIRI model group
,established by blocking left coronary artery anterior descending branch for 30 min followed by  reperfusion),leptin pretreatment group (Leptin+MIRI group,established by injecting intraperitoneally leptin at 30 min before ischemia）and leptin post-treatment group (MIRI+Leptin group,established by injecting intraperitoneally leptin at 30 min after reperfusion).The blood and heart samples were obtained from each mouse at 3 and 6 h after reperfusion.The serum IL-6 and TNF-α levels and the levels of leptin in cardiac muscle and serum were detected. Results Compared with sham-operation group,the serum IL-6 and TNF-α levels at 3 and 6 h
 in Leptin+MIRI group were significantly increased(P<0.01). Compared with MIRI model group,the srum IL-6 and TNF-α levels at 3 and 6 h in Leptin+MIRI group were signicantly decreased(P<0.01).Compared with sham-operation group,the leptin levels in cardiac muscle and serum at 3 and 6 h in Leptin+MIRI group were significantly increased(P<0.05);compared with MIRI model group,the leptin levels in cardiac muscle and serum at 3 and 6 h in Leptia+MIRI group were significantly decreased(P<0.01).Conclusion Leptin pretreatment c
an reduce the serum IL-6 and TNF-α expressions,thus may have cardiac muscle protection,and leptin pretreatment can alleviate MIRI.

Key words: myocardial ischemia reperfusion injury;leptin;leptin pretreatment;interleukin-6;tumor necrosis factor-alpha