Objective: To observe the expression and distribution of vascular cell adhesion molecule-1 (VCAM-1) and caspase-3 in myocardium of persons who died from viral myocarditis and to explore its pathogenesis and death mechanism.
Methods: Twenty cases died from viral myocarditis were selected as the experimental group. Ten cases died from traumatic shock and massive hemorrhage shock after traffic accidents were selected as the control group. The sections of myocardium were stained by immunohistochemistry for VCAM-1 and caspase-3, and observed under microscope. The positive expressions of VCAM-1 and caspase-3 of the two groups were compared with each other by image analysis and statistical analysis.
Results: (1) The vascular endothelial cells expressed VCAM-1 with dark-brown colors in the experimental group, and weak expression was observed in the control group. The average optical density in the experimental group was higher than that in the control group (P < 0.05). (2) The caspase-3 positive cells were mostly inflammatory cells around the myocardial vessels with brown-red granules in the experimental group. The positive cell number in the experimental group was higher than that in the control group (P < 0.05).
Conclusion: VCAM-1 may play an important role in the inflammatory cells exudation caused by viral myocarditis, and may provide the reference for diagnosis of viral myocarditis in forensic pathology. However, the myocardial apoptosis mediated by caspase-3 doesn't affect the lethal mechanism in the late stage of viral myocarditis.