ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract— Subcellular fractions have been prepared from normal human caudate nucleus and substantia nigra by a standard fractionation technique and the fractions assayed for the following enzymes, which were studied because of their relevance to neurotransmission and pathological change: glutamate decarboxylase (EC 4.1.1.15), choline acetyltransferase (EC 2.3.1.6), acetylcholinesterase (EC 3.1.1.7), acid phosphatase (EC 3.1.3.2) and succinate dehydrogenase (EC 1.3.99.1). The distribution of these enzymes was assessed in relation to the morphology of the fractions as observed by electron microscopy. As with preparations from animal cerebral cortex, acetylcholinesterase and acid phosphatase were found mainly in fractions known to contain plasma membranes, synaptosomal membranes and microsomes. The levels of choline acetyltransferase in fractions from the substantia nigra were too low to measure but, in the caudate nucleus, the enzyme was concentrated in the crude mitochondrial fraction (P2), especially in the P2B and P2C subfractions. A high proportion of the glutamate decarboxylase activity was present in the P2 fractions of the substantia nigra and caudate nucleus and, although the synaptosomal (P2B) fraction contained the enzyme, significant amounts were found in the mitochondrial (P2C) fraction. This may have been due to some contamination of the mitochondria with small synaptosomes. Succinate dehydrogenase showed a conventional bimodal distribution between synaptosomes and mitochondria with a concentration in the latter.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1976.tb05161.x
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