[Fibronectin and fibrinogen/fibrin at the focus of an experimental myocardial infarct].

The content of fibrinogen/fibrin, plasma and cellular fibronectin, the 1st type collagen, laminin and skeletal muscle myosin in the zone of experimental myocardial infarction was studied by the immunofluorescent method. The infiltration of the necrotized cardiomyocytes with fibrinogen/fibrin and plasma fibronectin was observed 3 hours and later after coronary artery ligation. Fibrinogen/fibrin and plasma fibronectin form a "primary matrix" of the granulation tissue in which the fibers of the 1st type collagen are being formed. Cellular fibronectin starts to be synthesized 3 days after the infarct development and its content in the extracellular matrix (ECM) of the granulation tissue increases 7-15 days after the infarction. The amount of the fibronectin in ECM of the scar tissue decreases 30 days after the infarct. Fibrinogen/fibrin is always found in the granulation tissue replacing the myocardial infarction but its content in ECM decreases during the scar formation.