OBJECTIVE: To determine the effects of reacting cortisol on ischemic preconditioning (IPC). METHODS: Thirty rabbits were randomized into ischemic preconditioning (IPC) group, etomidate (Etom) group, ischemic/reperfusion (IR) group, methylprednisolone (MP) group and a control group. The ratios of infarction size versus risk area (Infarct/Risk) were calculated. The elevations of serum CK activity and cTnI concentrations as well as serum cortisol concentrations were measured. RESULTS: The ratios of Infarct/Risk were 5.9%+/-2.8% for IPC, 11.3%+/-3.6% for Etom, 26.8%+/-4.5% for IR and 18.2%+/-3.7% for MP. The elevations of serum CK activity (U/L) were 255+/-89 for IPC, 314+/-160 for Etom, 855+/-371 for IR and 768+/-404 for MP, the elevations of serum cTnI concentrations (microg/L) were 3.6+/-0.6 for IPC, 5.9+/-2.0 for Etom, 8.1+/-3.6 for IR and 6.1+/-2.3 for MP. Those indicators among groups are all significantly different (P<0.01). Cortisol reacting was markedly diminished in Etom group. CONCLUSION A blunted cortisol reaction can markedly undermine the benefit of ischemic preconditioning, methylprednisolone show a certain myocardial protection. Cortisol may play an important role in the IPC process.
Animals ; Creatine Kinase, MB Form ; blood ; Etomidate ; therapeutic use ; Female ; Ischemic Preconditioning, Myocardial ; Male ; Methylprednisolone ; therapeutic use ; Myocardial Reperfusion Injury ; blood ; prevention & control ; Rabbits ; Random Allocation