EARLY DEVELOPMENT OF ENCEPHALOMYOCARDITIS (EMC) VIRUS-INDUCED ORCHITIS IN SYRIAN-HAMSTERS

Lesions associated with encephalomyocarditis (EMC) virus in the testes of Syrian hamsters were investigated. Histopathologic changes were fi rst detectable by light microscopy at 3 days postinoculation (DPI). Im munohistochemically, virus antigens were detected in the cytoplasm of germ cells and Sertoli cells in some seminiferous tubules beginning at 2 DPI. The following ultrastructural changes were observed: 1) swelli ng of mitochondria and dilatation of endoplasmic reticulum in germ cel ls, 2) large number of residual bodies in seminiferous tubules, 3) agg regates of virus-like particles in the cytoplasm of degenerated cells and tubular lumen, 4) condensation of cytoplasm and dilatation of endo plasmic reticulum in Sertoli cells, and 5) degenerative changes in cap illary endothelial cells.