Abstract: Objective To study effects of hydrogen saturated saline(HRS) on expressions of apoptosis-related protein Bcl-xL,Bad,Bcl-2,and Bax and on myocardial ischemia-reperfusion injury in rats.Methods Thirty-six healthy male Sprague-Dawley(SD) rats were randomly divided into 3 groups(12 in each group):sham operation group(A),ischemia-reperfusion injury group(B),and HRS-treated group(C).Myocardial ischemia-reperfusion injury model was constructed using conventional method and a two hours reperfusion was performed after the establishment of the model among the rats of the 3 groups,and then the expressions of Bcl-xL,Bad,Bcl-2,and Bax were determeine.Results Compared to those of group C,left ventricular diastolic pressure(LVDP) and maximal first derivative of left ventricular diastolic pressure(LV Dp / dtmax) was significantly higher in group B.The observations with hematoxylin-eosin(HE) staining revealed cardiac cells arranged neatly in group A,obvious myocardial infarction in group B,and significantly reduced scope of infarction of cardiac cells in group C.The expressions of Bcl-xL and Bcl-2m RNA and protein were the highest in group A and the expressions in group C were significantly higher than those in group B(all P<0.05).Bad and Bax mRNA and protein expressions were the lowest in group A and the highest in group B,and the expressions in group C were significantly lower than those in group B(all P<0.05).Conclusion HRS can regulate apoptosis-related protein expressions of Bcl-xL,Bad,Bcl-2,and Bax and effectively reduce myocardial ischemia and reperfusion injury.