Characteristics of prion protein (PrP(Sc)) in the brains of hamsters inoculated serially with a mouse-passaged scrapie strain.

Syrian hamsters were inoculated intracerebrally with a mouse-passaged scrapie strain. After serial passage, the incubation period decreased, but the vacuolar lesion profiles remained unchanged. In immunoblot analysis, accumulated prion protein (PrP) showed hamster PrP characteristics from the first passage. However, immunohistochemical examination revealed a changing pattern of accumulated PrP with each passage. In particular, there were many PrP plaques in the subpial and subependymal region at the third passage, no such plaques having been observed in the same region at the first passage. These results suggest that the species barrier influences not only the incubation period but also the pattern of accumulation of PrP in affected brains.