Objective      To investigate the effects of St. Thomas Ⅱ solution supplemented with diazoxide (DZ) and fructose-1

6-diphosphate (FDP) on myocardial apoptosis in cryopreserved rat hearts.        Methods      Twenty-four SD rats were randomly divided into 3 groups: control

STH and DF. The isolated hearts were stored at 4 ℃ for 6 h except control group

STH group in St. ThomasⅡ solution and DF group in St. Thomas Ⅱ solution supplemented with DZ and FDP. All hearts were perfused by Lan

gendorff model for 20 min

then changed into isolated working heart model for 10 min. The myocardial cell apoptosis was determined with terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) method. The content of cytosolic malondialdehyde (MDA)

the mitochondrial Ca

2+

concentration ([Ca

2+

]

m

) were detected and the content of cytosolic Cytochrome c (Cyt c) protein by Western blotting was evaluated. The expression of caspase-3 mRNA was evaluated by RT-PCR. The activity of cytosolic caspase-3 was determined with fluorescent assay.        Results      Compared with controls

the levels of apoptotic index

caspase-3 activity and its mRNA content

[Ca

2+

]

m

the content of cytosolic MDA and Cyt c protein were significantly increased in STH group. These parameters of DF group were lower significantly than STH group (P0.01).        Conclusion      Cardioplegic solution supplemented with DZ and FDP could restrain apoptosis of myocardial cells caused by ischemical reperfusion injury.