The contrast of immunohistochemical studies of myocardial fibrinogen and myoglobin in early myocardial ischemia in rats

In this study, an animal model of early myocardial ischemia (EMI) was established by ligating the left anterior descending coronary artery of rats. The experimental animals were divided into five groups according to different intervals of MI (15, 30min, 1, 2, and 3h) and one control group. Tissues from the apex of the myocardium and the adjacent myocardium were taken for paraffin sections, followed by hematoxylin-eosin and streptavidin-biotin-peroxidase complex (SABC) staining. Results showed that the myoglobin (Mb) depletion and the fibrinogen (Fg) staining increase were detected in the 30min MI group. The wavy-like increasing extension of the size and the intensity of the Mb depletion and the Fg staining intensification from the subendocardial to the subepicardial cells were observed along with the prolongation of the ischemic period. Both changes had similar patterns and sensitivity, except Fg was less reliable than Mb as it is more easily contaminated by blood. After overcoming blood contamination, the SABC-Fg technique will provide a new method for the diagnosis of EMI.