RESUMO
Objective To investigate the effects of propofol on the changes in myocardial Toll-like receptor 4 (TLR-4)and TNF-αand NF-κb protein expressions in ischemia-reperfusion injury (I/R).Methods Thirty healthy male SD rats weighing 250-320 g were randomly divided into 3 groups (n=10 for each):Group A,sham operation;Group B,I/R;and Group C,propofol + I/R.In Groups B and C myocardial I/R was induced by occlusion of the left anterior descending artery (LAD)for 30 min,followed by 120 min reperfusion.In Group C propofol was given intravenously 1 0 min before myocardial ischemia,followed by continuous infusion of propofol at 5 mg/(kg·h)until the end of 120 min reperfusion.In Groups A and B normal saline instead of propofol was given. The myocardial tissues were taken at the end of 120 min;ultrastructural changes of myocardial cells were observed under X-ray electron microscope and the expressions of TLR-4 mRNA as well as TNF-αand NF-κb protein were determined.Results Ultrastructural observation under electron microscope showed significantly worsened damage in myocardial tissue structure and mitochondria in Groups B and C compared with Group A.The myocardial expressions of TLR-4 and TNF-αand NF-κb protein were significantly higher in Groups B and C than in control Group A.The myocardial expressions of TLR-4 and TNF-αand NF-κb protein were down-regulated in Group C compared with Group B.Conclusion Intravenous injection of propofol can protect against myocardial damage.Propofol can suppress the increase in myocardial TLR-4 and TNF-αand NF-κb protein expressions induced by I/R.