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.

scholarly journals ELECTRON MICROSCOPIC LOCALIZATION OF GLYCOPROTEINS IN PITUITARY CELLS OF DUCK AND QUAIL

1971 ◽  
Vol 19 (12) ◽  
pp. 775-797 ◽  
Author(s):  
ANDRÉE TIXIER-VIDAL ◽  
RENÉE PICART
Keyword(s):  
Endoplasmic Reticulum ◽  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Secretory Granules ◽  
Periodic Acid ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
Gonadotropic Cells ◽  
Dense Bodies

Structures demonstrating the presence of glycoproteins, acid phosphatase activity and OsO4 impregnation were localized by means of the electron microscope in duck and in quail pituitary cells. Two methods for the electron microscopic demonstration of glycoproteins were used: a chromic acid-phosphotungstic acid mixture on glycol-methacrylate-embedded tissues, and the periodic acid-thiocarbohydrazide-silver proteinate technique. Both methods showed glycoproteins in the following sites: ( a) the secretory granules in three types of cells (A, B, C) which are part of the seven different cells of the avian pituitary; ( b) the several kinds of dense bodies which are richer in reaction product than the secretory granules. A correlation with previous studies on similar species of birds is helpful in identifying each of the three positive types of cells as thyrotropic cell (A), prolactin cell (B) and gonadotropic cell (C). The presence of glycoproteins within the Golgi saccules (on condensing granules) was found with the periodic acid-thiocarbohydrazide-silver proteinate method in these gonadotropic cells only. In gonadotropic and thyrotropic cells, acid phosphatase activity is weak in the inner Golgi saccules and strong in the "Golgi Endoplasmic Reticulum Lysosomes" system, in the lysosomes, in the dense bodies and in the vacuolated dense bodies. The structures which are richest in glycoproteins are also those which have the most acid phosphatase activity. On the contrary, OsO4-stained structures in duck gonadotropic cells (nuclear pericisterna, rough endoplasmic reticulum, cisternae and outer Golgi saccules) have no glycoproteins or acid phosphatase activity.

scholarly journals LOCALIZATION OF ACID PHOSPHATASE ACTIVITY AND SECRETION MECHANISM IN RABBIT PANCREATIC B-CELLS

1966 ◽  
Vol 14 (3) ◽  
pp. 233-246 ◽  
Author(s):  
SYDNEY S. LAZARUS ◽  
BRUNO W. VOLK ◽  
HERBERT BARDEN
Keyword(s):  
Acid Phosphatase ◽  
B Cells ◽  
B Cell ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Secretory Granules ◽  
Secretory Product ◽  
Cell Cytoplasm ◽  
Single Membrane ◽  
Pancreatic B Cells

Utilizing formaldehyde- or glutaraldehyde-fixed tissue and Gomori's lead method it was found by optical microscopy that rabbit pancreatic islet cell acid phosphatase activity is present in discrete, mostly perinuclear foci and that this distribution differs from that of the aldehyde fuchsin-positive secretory granules which are densely packed at the capillary pole of the cell. Electron microscopically lead reaction product was noted in dense bodies, as well as in structures thought to be Golgi vacuoles and vesicles, it was also present in the innermost of the Golgi cisternae, and at the periphery of adjacent single membrane-limited bodies whose origin can be traced from the proximal cisternae. These latter bodies in routinely prepared, osmium-fixed material show finely granular content, which is in contrast to the electron-dense, central body seen in secretory granules that appear to originate from endoplasmic reticulum. B-cell cytoplasm contained additional numerous, single membrane-limited vacuoles with pale content. These are thought also to represent secretion vacuoles but with insulin secretory product in a different physical or chemical state. The lack of acid phosphatase activity in B-cell secretion vacuoles, the dissimilarities in fine structure between the content of secretory elements and that of the Golgi-derived granular body, together with previous evidence that alteration in B-cell functional state does not result in altered number or distribution of acid phosphatase active elements in B-cell cytoplasm, indicate a lack of relationship between acid phosphatase and secretory granule formation or release in pancreatic B-cells. It is also hypothesized that the secretory vacuole with central dense granule may be a storage form while the pale vacuole is the one which liberates its content to the intercellular space.

Cellular mechanisms of periostracum formation in Physa spp. (Mollusca: Pulmonata)

1978 ◽  
Vol 56 (11) ◽  
pp. 2299-2311 ◽  
Author(s):  
G. M. Jones ◽  
A. S. M. Saleuddin
Keyword(s):  
Endoplasmic Reticulum ◽  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Rough Endoplasmic Reticulum ◽  
Acid Phosphatase Activity ◽  
Homogeneous Material ◽  
Cellular Mechanisms ◽  
Phenoloxidase Activity ◽  
Enzyme Substrate ◽  
Mantle Edge

The periostracum comprises an external lamella, 13 nm thick, and one sublamellar layer. Periostracal cells secrete the lamella as preformed periostracal units. The mantle edge gland (meg) produces most of the sublamellar layer. A sequence of formation of periostracal units within the periostracal cells is suggested. Homogeneous inclusions, possibly Golgi derived, fuse into larger, irregular inclusions. Within these inclusions, three-layered membranes, 7 nm thick, arise from the homogeneous material. The membranes fuse in pairs to form the five-layered, 13-nm periostracal units. Acid phosphatase activity has been localised al the surfaces of the periostracal units and might be involved in modifying the units prior to their discharge. Phenoloxidase and polyphenols have been localised in the meg, suggesting that this region is responsible for periostracal sclerotisation. Phenoloxidase activity is present in Golgi, rough endoplasmic reticulum, and apical secretory inclusions in cells in the anterior two-thirds of the meg. Polyphenols are present in apical secretory inclusions, particulary in three or four cells in the posterior meg. This distribution may suggest that phenoloxidase is incorporated into all levels of the sublamellar layer and that sclerotisation occurs subsequently when the enzyme substrate is presented.

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