Comparative histomorphology between isoproterenol-induced early lesions and postmortem artifacts in the rat heart

Isoproterenol-induced early myocardial lesions were compared histomorphologically to commonly observed postmortem artifacts in the rat hearts which were collected up with 40 min after death. Isoproterenol-induced early lesions were characterized by multifocal myocardial eosinophilia restricted to the inner one third of the left ventricle and septum. These very early lesions were similar to the artifacts which were also characterized by myocardial eosinophilia and increased with time after death. The dilation of intercellular spaces which was also an artifact occurred at 40 min. Contraction bands, fragmentation of fibers and inflammatory cellular infiltration noted only in the isoproterenol-induced lesions were the differentiating criteria from artifacts. The postmortem artifacts were not observed in the hearts fixed immediately after death.