Succinic Dehydrogenase, Cytochrome Oxidase and Acid Phosphatase Activities in the Brains of Scrapic-infected Goats and Mice

Abstract

SUMMARY Cytochrome oxidase, succinic dehydrogenase activities and protein contents have been determined in brain slices front goats inoculated with saline or with 1/100 dilutions of ‘drowsy’ strain scrapie brain homogenized in saline from 10−1 to 10−9 (w/v). Activity of the cytochrome oxidase increased in this species with the potency of the inoculum received although only the goats in the 10−1 group showed brain succinic dehydrogenase activities above normal. Cytochrome oxidase, succinic dehydrogenase and acid phosphatase activities and protein contents have been measured in brains of mice infected with a mouse adapted strain of scrapie derived from scrapie Suffolk sheep brain (ME 7). The two mitochondrial enzymes when measured in infected tissue gave activities within the normal range. It is suggested that the enzymic results may give further evidence of strain differences which have already been defined by histopathology. Protein concentrations of brain of goats and mice were unaffected by the presence of the disease. Acid phosphatase activity as well as that of the two mitochondrial enzymes was found to he similar in normal and ME 7-scrapie infected mouse brain. It is concluded that if there is any specific involvement of lysosomes or mitochondria in this form of mouse scrapie such involvement does not seriously affect their enzymic activity.