Effect of dexmedetomidine on myocardial ischemia-reperfusion injury in rats / 中华创伤杂志

ABSTRACT

Objective To investigate the effect of different doses of dexmedetomidine (DEX) on myocardial ischemia-reperfusion injury (MIRI) in rats.Methods Seventy-five SD male rats weighing between 250 and 300g were divided into sham group,MIRI group,small-dose DEX group,medium-dose DEX group and high-dose group according to the random number table,with 15 rats per group.Threading the left anterior descending coronary artery was done only in sham group,but the MIRI model was produced in the rest groups by ligation of the artery for 30 minutes followed by 120 minutes of reperfusion.Fifteen minutes before the ligation,small-,medium-and high-dose DEX groups were injected 2.5,5 and 10 μg · kg-1 · h-1 of DEX respectively until the end of reperfusion.Instead,an equal volume of normal saline was given in sham and MIRI groups.At the end of reperfusion,five rats in each group were used to determine the myocardial infarct size,and arterial blood samples and myocardial tissues from ten rats in each group were used to measure serum levels of interleukin-1β (IL-β) and serum tumor necrosis factor-α (TNF-α),expression of myocardial nuclear factor kappa B p65 (NF-κB p65) and change of myocardial pathomorphology.Results Myocardial infract size,degree of myocardial pathomorphology structure damage,serum levels of IL-1 β and TNF-αt and expression of myocardial NF-κB p65 in sham group were significantly lower in sham group than other groups (P ＜ 0.05).Above mentioned parameters in small-,medium-and high-dose DEX groups were all significantly decreased compared to MIRI group (P ＜ 0.05),and the decrease was most significant in medium-dose DEX group (P ＜ 0.05).Conclusions DEX can attenuate the MIRI in rats and the possible mechanism is suppressing the release of NF-κB p65,which can reduce serum pro-inflammatory cytokines like TNF-α and IL-1β.And mediumdose DEX exhibits better protective effect.