Virus-induced damage of the myocardial cell.

A total of 330 male 3-week-old mice of the N.M.R.I./Han. strain were infected with the M-variant of the EMC (encephalomyocarditis) virus by subcutaneous inoculation of 0.25 ml of the virus suspension diluted 1:500. Animals were killed at 4- or 6-hour intervals, respectively, and groups of 2 to 8 hearts were taken for virological, morphological, and biochemical studies. Before the 8th hour after the inoculation, no virus and no pathological cell changes could be detected in the hearts; it is assumed, therefore, that there first takes place an extracardiac virus cultiplication. The virus content in the hearts increases from the 12th to the 30th ahour and subsequently maintains that level. Also from the 12th to the 30th hour, electron microscopy reveals increasing damage of the myocardial cells, the course of which is described. In most instances following virus-induced damage of the myocardial cells, the onset of alterations of the blood and lymph capillaries and damage to the interstitial cells were observed...