HYDROLASE ACTIVITIES IN BRAIN OF NEUROLOGICAL MUTANTS: CEREBROSIDE GALACTOSIDASE, NITROPHENYL GALACTOSIDE HYDROLASE, NITROPHENYL LUCOSIDE HYDROLASE AND SULPHATASE¹

Abstract

Abstract— The brains of 17‐day‐old quaking and jimpy mice were compared with those of the corresponding normal phenotypes. The concentrations of cerebroside and sulphatide were found to be markedly lower in the affected mutants, while the relative amounts of ceramide and free fatty acid appeared normal. The concentration of cerebroside glactosidase was not significantly abnormal in the jimpy mice but was about 17 per cent lower in quaking mice. In contrast, the relative amount of the enzyme that could be dispersed by sonication was considerably higher in the jimpy animals. It is suggested that this increase is a causative factor in the aetiology of the latter disease. The concentrations of other acid hydrolases were determined, as well as the relative amounts dispersible by sonication. No difference was seen between the phenotypes with NPGalH, NPGluH, and nitrocatechol sulphate hydrolase. An improved solvent system for the TLC detection of ceramide in brain lipids is described.