Cholinesterase, succinic dehydrogenase, nucleic acids, esterase and glutathione reductase in sub-cellular fractions from rat brain

Abstract

Homogenates of rat brain in 0.3 [image]-sucrose were separated by centrifuging into a nuclear fraction, two mitoehondrial fractions, a microsomal and a supernatant fraction. Succinic dehydrogenase and deoxyribonucleic acid were used to assess the contamination of fractions by mitochondria and nuclei, respectively. Of the true cholinesterase, 38% is found in the microsomal fraction with a specific activity 2.6 times that of the homogenate. It was not possible to obtain other fractions free from cholinesterase. The distribution of ribonucleic acid and cholinesterase is different. Esterase (substrate, phenyl butyrate) has a distribution similar to but not identical with that of cholinesterase. The nuclear fraction contains 36% of the pseudocholinesterase, the microsomal fraction 24% and the supernatant fraction 27%. Of the glutathione reductase, 35% is present in the mitoehondrial and 44% in the supernatant fractions.