We studied the effect of VEGF-A in experimental myocardial infarction on attraction of progenitor cells into the regeneration zone. The appearance of CD34(+)CD45(+) cells known as low-differentiated progenitor cells was observed in the damaged myocardial tissue in the presence of a considerable excess of VEGF-A. These cells can act as precursors of mesenchymal tissues depending on the direction of differentiation.
The relationship between vascular endothelium growth factor (VEGF) and cardiomyocyte oxidative phosphorylation level in experimental myocardial infarction, caused by diathermocoagulation of the periconical ventricular artery, was studied by immunofluorescent microscopy. Staining showed uneven distribution of cytochrome c in the mitochondria in the focus of myocardial infarction 2 h after the operation. After 24 h uneven staining of cardiomyocytes was found in the peri-infarction zone and no staining in the zone of myocardial infarction. This indicated a significant decrease in the level of redox enzymes. This picture persisted till day 14. Intraventricular injection of VEGF to animals led to a significant increase of the immunohistochemical reaction intensity, which reached the peak by day 7. The distribution of immunohistochemical reaction products under conditions of VEGF blocking was about the same as in spontaneous postinfarction reparative restitution. Our data indicated that increase of VEGF concentration in the myocardium maintained and stimulated oxidative phosphorylation in cardiomyocytes during the postinfarction period.