Objective To investigate the relationship between the protective mechanism of dexmedetomidine(Dex)against myocardial ischemia-reperfusion(I/R)injury and cuproptosis.Methods The Langendorff models were con-structed using SD rats(I/R group),which were divided into 4 groups according to different interventions during reperfusion as:sham group,I/R group,Dex group and Dex+ES-Cu group.The left ventricular peak pressure(LVSP)of the rats in the above four groups were continuously monitored in the immediate pre-ischemic period(T0),30 min of reperfusion(T1),60 min reperfusion(T2),90 min reperfusion(T3),2 h of reperfusion(T4).Left ventricular end-diastolic pressure(LVEDP),heart rate(HR),maximum rate of rise of left ventricular pressure(+dp/dtmax)and maximum rate of drop.Subsequently,the extent of myocardial infarction was shown by 1%triphenyltetrazoliumchloride(TTC)staining,and the degree of myocardial fibrosis was assessed by Sirius red staining;Myocardial enzyme profiles,oxidative stress and inflammation indexes were detected by ELISA;Copper ions were detected by copper ion detection kit in myocardial tissues;ATF3,SPI1 and FDX1 protein level expres-sion was detected by Western blot.Results Compared with the sham-operated group,the extent of myocardial in-farction and fibrosis increased in the I/R group(P＜0.05),the level of serum MDA,IL-6,IL-1β,and TNF-α was elevated(P＜0.05),and the activity of SOD and GSH-Px decreased(P＜0.05).The Dex group significantly alleviated the above changes in the I/R group,and compared with the Dex group,in the Dex+ES-Cu group myocardi-al tissue copper ion content at the end of perfusion was increased(P＜0.05).Both ATF3 and SPI1 protein were in-creased and FDX1 protein was decreased(P＜0.05).Conclusions Dex can regulate copper metabolism and improve myocardial ischemia-reperfusion injury(MI/RI)resulted from oxidative stress and inflammation in rat model.