Immunofluorescent identification of fibronectin and fibrinogen/fibrin in experimental myocardial infarction.

Distribution of fibrinogen/fibrin and fibronectin in regions of experimental myocardial infarction were studied by the immunofluorescence technique. Distinct from normal myocardium 3 and 12 to 24 h after coronary artery ligation infiltration of necrotized cardiomyocytes by fibrinogen/fibrin and plasma fibronectin was detected. Fibrinogen/fibrin and plasma fibronectin constitute "primary matrix" of granulation tissue. On the third day after experimental infarction, synthesis of cellular fibronectin begins. Its content in the extracellular matrix (ECM of granulation tissue significantly increases on days 7 to 15. The amount of fibronectin in the ECM of developing scar tissue dramatically decreases 30 days after infarction, Fibrinogen/fibrin was continually identified in granulation tissue in zones of myocardial infarction. However, its amount in the ECM of developing scar tissue gradually decreased.