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Further observations on histochemical changes in scrapie mouse brain

1968; Elsevier BV; Volume: 78; Issue: 4 Linguagem: Inglês

10.1016/0021-9975(68)90048-0

1532-3129

A. Mackenzie, Angela Wilson, P.F. Dennis,

Vector-Borne Animal Diseases

In a previous paper, histochemical alterations were described in scrapie mouse brains in respect of the glycoside hydrolases, β-glucuronidase (β-GUR) and N-acetyl-β-D-glucosaminidase (β-GAM). In examinations of further scrapie mouse brains altered β-GUR and β-GAM activities have been consistently confirmed and, in addition, significant increase in β-galactosaminidase (β-GALAM) was demonstrated. Post-incubation coupling methods used for α-glucosidase (α-GUS), β-glucosidase (β-GUS) and β-galactosidase (β-GALAS) detected no significant activity of these enzymes in either normal or scrapie brains. Abnormal accumulations of PAS-positive material were demonstrated in the brain and spinal cord of mice affected with advanced clinical scrapie. Comparative histochemical tests were made on the brains of normal mice and of mice experimentally infected with louping ill, yellow fever and Herpes simplex as well as on those of mice with scrapie. Morphological changes in the brains of mice with the experimental encephalitides were compared with the lesions of scrapie. In addition, methods for the demonstration of fat, astrocytic hypertrophy, PAS-positive material and activity of specific enzymes were carried out to establish further criteria in the comparative pathology of the various diseases. The viral encephalitides examined resembled scrapie in showing accumulations of PAS-positive material and pronounced β-GUR activity, but the distribution of these changes varied. Differences between scrapie and the encephalitides occurred in respect of morphological lesions, accumulation of fat, astrocytic hypertrophy, and in β-GAM and β-GALAM enzyme activity.