Cardiac and pancreatic lesions in guinea pigs infected with encephalomyocarditis. EMC, virus

Abstract

Cardiac and pancreatic lesions were observed in guinea pigs infected with 2 variants (B and D) of encephalornyocarditis (EMC) virus. Cardiac changes were characterized by focal myocardial necrosis and subsequent replacement by immature granulation tissue. and the pancrcatic ones by vacuolar degeneration of acinar cells. In the electron microscopic esaminatioiis. tlie affected cardiornyocytes showed intracellular oedema. swelling andlor partial destruction of mitochondria, and distortion and disruption of myofihrils. Intracellular vacuolization and dilatation of roughsurfaced endoplasniic reticulurn (rER) were conspicuous in the damaged pancreatic acinar cells. In addition, intracisternal granules were found in dilated rER with a high frequency. These changes were common to animals infected with the B and D variants. On the contrary, B cell alterations: i.e. degranulation and degeneration of insulin granules, were detected only in animals infected with the D variant.