The localization of enzyme activities in the rat brain.
Studies with rat brain illustrate the usefulness of formol-calcium-fixed tissue for studying both enzymatic "chemoarchitectonics" and intracellular organelles. Unembedded frozen sections and polyvinyl alcohol-embedded sections may be used to demonstrate the activities of DPNH-tetrazolium reductase localized in mitochondria and ergastoplasm, TPNH-tetrazolium reductase localized in mitochondria, ATPase (and/or apyrase or ADPase) in cell membranes, and acid phosphatase in lysosomes.(1) Among the observations recorded are: (1) the presence of lysosomes in all cells of the brain; (2) the presence of numerous large lysosomes near the nuclei of capillary endothelial cells; (3) a polarized arrangement of large lysosomes in epithelial cells of the ependyma and choroid plexus; (4) the presence of ATPase activity in the cell membranes of some neurons; (5) the presence of either an apyrase or combination of ATPase and ADPase in the cell membranes of neuroglia and capillaries; (6) the presence of both DPNH- and TPNH-tetrazolium reductase activities in neuroglia; (7) the presence of DPNH- and TPNH-tetrazolium reductase activities in mitochondria and of DPNH-tetrazolium reductase activity in Nissl substance. The possible functional significance of these localizations is briefly discussed, as is their relation to "quantitative histochemistry" data available in the literature.
D000135:Acid Phosphatase; D000251:Adenosine Triphosphatases; D000818:Animals; D015703:Antigens, CD; D001081:Apyrase; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane; D002831:Choroid Plexus; D004721:Endoplasmic Reticulum; D004798:Enzymes / Q000378:metabolism*; D006651:Histocytochemistry; D008247:Lysosomes; D008928:Mitochondria; D010088:Oxidoreductases; D051381:Rats
D015703:Antigens, CD; D004798:Enzymes; D010088:Oxidoreductases; D000135:Acid Phosphatase; D000251:Adenosine Triphosphatases; D001081:Apyrase; C067869:CD39 antigen
BRAIN/metabolism; ENZYMES/metabolism