Abstract:

Abstract:Objective To explore the effect of trimetazidine on myocardial structure injury induced by pyran adriamycin and to clarify the protective effect   of trimetazidine on.the changes of  myocardial structure and its mechanism.Methods 36 Wistar rats were randomly divided into control group,model group and treatment group.The rats in model group and treatment group were injected with pyran doxorubicin 2.5 mg/kg(concentration 2 g/L)　by the caudal vein  once a week.The rats in control group were injected with  equivalent normal saline  for 6 weeks.The  rats in treatment group were intragastricly infused with  trimetazidine 5.4 mg/kg/d one day before making the model.The rats in control group and model group were injected with equivalent normal saline  for 8 weeks.At the end of the experiment,the  myocardial enzymes in serum of the rats in various groups were measured.The morphology of myocardium tissue was detected by light microscope and electron microscope.Results  Compared with model group,the levels of myoglobin,troponin I and alanine transaminase(ALT) of the rats in treatment group were significantly decreased（P<0.05）.Under  light microscope the  myocardium of the rats in model group   arranged disorderly,the structure was severely damaged,emyocardial was seen，the myofilament was dissolved;the myocardium of the rats in treatment group  arranged in order，the structure was nearly integrated，partial dissolution and fracture were found.Under  electron microscope in model group the myocardial muscle bundle dissolved,fractured and  disappeared,and the mitochondria was decreased, and the cytoplasmic matrix cavitation was seen;the  cardiomyocytes sarcomeres of the rats in treatment group arranged in order, local myofilaments were reduced slightly,the  surrounding mitochondria were oval and arranged in parallel between the muscle bundles.Conclusion Trimetazidine has protective effect on the  cardiomyocyte injury caused by pyran adriamycin,and its mechanism may be related to decreasing the injury of mitochondria and myocytes.

Key words: trimetazidine, pyran adriamycin, mitochondria, myocardial enzyme；myocardial structure