RESUMEN
Objective To detect gap junction protein Cx45, gap junction protein Cx40 and Tumor Necrosis Fαctor-α(TNF-α) expression in the infarcted myocardium, and to study their combined effects. Methods Immunohisto-chemical staining (S-P immunohistochemical staining method) and qRT PCR detection of gap junction were used to identify protein Cx45, Cx40 and TNF-α respectively in 30 cases of late early myocardial ischemic stroke group and 30 cases of myocardial infarction due to sudden death group with control group being 20 cases of normal expression in myocardial group. The effect of the different expressions was compared in the different groups. Results Immuno-histochemical results: Between the two groups, Cx45 expression was higher in the sudden death group compared to normal myocardium. Cx40 expression was decreased significantly in the sudden death group when compared to normal myocardial group while TNF-α expression was high. The expressions had significant differences in the three groups (P<0.05). Qrt - PCR results showed that the mRNΑ expression of Cx45, Cx40 and TNF-α was consistent with their respective protein expression and that there was statistically significant difference in three groups (P<0.01). Cx45, Cx40 and TNF-α had a correlation in the three groups of cardiac muscle. Conclusion Gap junction protein Cx45, Cx40 and TNF-α expression can be useful indicators for the diagnosis of the cause of sudden cardiac death.