scholarly journals LOCALIZATION OF ACID PHOSPHATASE ACTIVITY IN RAT PANCREATIC ACINAR CELLS: A LIGHT AND ELECTRON MICROSCOPIC STUDY

1965 ◽  
Vol 13 (4) ◽  
pp. 301-303 ◽  
Author(s):  
HAROLD J. SOBEL ◽  
ERNA AVRIN
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Acid Phosphatase Activity ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Electron Microscopic

scholarly journals An Electron Microscopic Study of Erythrophagocytosis

1960 ◽  
Vol 7 (2) ◽  
pp. 329-334 ◽  
Author(s):  
Edward Essner
Keyword(s):  
Plasma Membrane ◽  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Microscopic Study ◽  
Hela Cells ◽  
Acid Phosphatase Activity ◽  
Ascites Hepatoma ◽  
Electron Microscopic ◽  
Intracellular Digestion ◽  
Physicochemical State

The present study describes a submicroscopic surface fragmentation of erythrocytes which occurs in the ascitic fluid of rats bearing the Novikoff ascites hepatoma. The resulting fragments attach to the surface of macrophages and are phagocytized by pseudopod formation. Plasma membrane in the region of these phagocytosis vacuoles appears to condense into electron-opaque material, suggesting an alteration in its physicochemical state. Stages in intracellular digestion of intact erythrocytes or small fragments within the phagocytosis vacuoles are illustrated; no particles resembling ferritin are observed. The phagocytosis vacuoles possess high levels of acid phosphatase activity. They may be called phagosomes, a type of lysosome. There is no indication of a connection between phagosomes and other formed cytoplasmic organelles. Small vacuoles of the order of 80 mµ in diameter, which may represent pinocytosis vacuoles, are present in the cytoplasm and some appear to be in contact with the phagosome membrane, reminiscent of observations of Rose with HeLa cells.

scholarly journals CYTOLOGICAL STUDIES ON TWO FUNCTIONAL HEPATOMAS

1962 ◽  
Vol 15 (2) ◽  
pp. 289-312 ◽  
Author(s):  
Edward Essner ◽  
Alex B. Novikoff
Keyword(s):  
Endoplasmic Reticulum ◽  
Acid Phosphatase ◽  
Golgi Apparatus ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Secretory Granules ◽  
Dynamic State ◽  
Secretory Product ◽  
Electron Microscopic ◽  
Golgi Membranes

The Reuber hepatoma H-35 and Morris hepatoma 5123 have been studied by electron microscopy and by cytochemical staining methods for a number of phosphatases. These studies emphasize the resemblances of the two tumors to rat liver, but they also indicate distinctive features in each of the three tissues. Secretory product accumulates within the cisternae of the Golgi apparatus that dilate to form the Golgi vacuoles. The vacuoles apparently separate, and secretory material undergoes further condensation within them. These "secretory vacuoles" possess acid phosphatase activity and may thus be considered lysosomes. The membranes of the Golgi apparatus are without acid phosphatase activity but show high levels of thiaminepyrophosphatase activity. The endoplasmic reticulum also hydrolyzes thiaminepyrophosphate but at a lower rate; it hydrolyzes the diphosphates of uridine, guanosine, and inosine rapidly. These observations and the electron microscopic images are consistent with the view that the cytomembranes are in a dynamic state of flux, movement, and transformation in the living cell, and that smooth surfaced derivatives of the endoplasmic reticulum become refashioned into the Golgi membranes as the Golgi membranes are being refashioned into those that delimit secretory vacuoles. The variations encountered in the two hepatomas are described. The electron microscope literature dealing with the relations of the Golgi apparatus to secretory granules, on the one hand, and the endoplasmic reticulum, on the other, is reviewed briefly.

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