Abstract: In this study, the model of early myocardialinfarction(EMI) was Produce by legation of leftanterior descending artery in rat.The artery spasm(CAS) was produced by extermal jugular veininjection of vasopressin (VP). Myocardium of apex and adjoining slice was used to make paraffinsections, then HE and LSAB-Mb staining wereperformed. Results showed: Ih 25 min aftermyocardial infarction, stretch-shape Mb depletionwas obsered in subendocardial myocardium ofaortic ventricle′s frontal wall. As the time of EMIprolonged, stretch-shape Mb depletion extended toepicardial layer. In CAS group, multiply, spotty Mbdepletion was detected. There were more Mbdepletion zones in right heart than that in left heart.The Mb dapletion zones surrounded the CA or werelike grape-clusters along the branches of one largeCA. Thus, Thus,myocardial Mb depletion induced by EMIand CAS had different morphologic peculiarity.LSAB-Mb method could be hoped for the use ofsupplying objectively morphologic evidence tomyocardial ischemia induced by CAS.

Key words: early myocardial infarction, coronary atrery spasm, myoglobin, immunohistochemistry