scholarly journals LOCALIZATION OF ADENOSINE TRIPHOSPHATASE ACTIVITY IN PRENEOPLASTIC AND CANCEROUS CELLS OF THE MOUSE SKIN INDUCED BY METHYLCHOLANTHRENE

1968 ◽  
Vol 16 (11) ◽  
pp. 678-687 ◽  
Author(s):  
JÁNOS SUGÁR ◽  
ORSOLYA CSUKA ◽  
JÓZSEF TÓTH
Keyword(s):  
Adenosine Triphosphatase ◽  
Cell Membranes ◽  
Light And Electron Microscopy ◽  
Mouse Skin ◽  
Intercellular Spaces ◽  
Adenosine Triphosphatase Activity ◽  
Dense Deposits ◽  
Membrane Bound ◽  
Cancerous Cells ◽  
Normal Epidermis

The localization of membrane-bound adenosine triphosphatase activity has been studied by both light and electron microscopy in the normal epidermis and in methylcholanthreneinduced preneoplastic alterations, i.e., hyperplasia, papilloma and also in similarly induced cancers of the skin of mice. In normal epidermis, the adenosine triphosphatase activity was seen to be located in contact with all of the cell membranes facing the intercellular spaces. In preneoplastic alterations, the enzyme activity was found along the cell membranes of the basal and suprabasal cells of the epithelial pegs and numerous dense deposits of lead phosphate could be seen on the surfaces of the cytoplasmic processes and in the enlarged intercellular spaces. The intensity of the reaction in preneoplastic conditions was greater than in the normal epidermis. No adenosine triphosphatase activity was observed in the cell membranes facing the basement membrane or in the desmosomes. In carcinoma a less intensive adenosine triphosphatase reaction was present and could be recognized on the surface of only few tumor cells.

scholarly journals PROBLEMS ASSOCIATED WITH THE DEMONSTRATION BY LEAD METHODS OF ADENOSINE TRIPHOSPHATASE ACTIVITY IN RESIDENT PERITONEAL MACROPHAGES AND EXUDATE MONOCYTES OF THE GUINEA PIG

1973 ◽  
Vol 21 (5) ◽  
pp. 488-498 ◽  
Author(s):  
R. E. POELMANN ◽  
W. T. DAEMS ◽  
E. J. VAN LOHUIZEN
Keyword(s):  
Plasma Membrane ◽  
Guinea Pig ◽  
Microscopic Study ◽  
Heterogeneous Nucleation ◽  
Adenosine Triphosphatase ◽  
Peritoneal Macrophages ◽  
Electron Microscopic ◽  
Adenosine Triphosphatase Activity ◽  
Eosinophilic Granulocytes ◽  
Membrane Bound

This cytochemical and electron microscopic study on peritoneal macrophages of the guinea pig has raised doubts concerning the validity of lead methods for the demonstration of plasma membrane-bound adenosine triphosphatase activity. The problems encountered are inherent in the use of lead ions as a capture reagent. The nonenzymatically formed precipitates reflect sites of heterogeneous nucleation specific for certain kinds of cells, e.g., resident peritoneal macrophages, eosinophilic granulocytes and, to a lesser degree, exudate monocytes. This type of precipitation is also catalyzed on the surface of nonbiologic matrices such as latex particles. Enzymatic processes may well occur, but they cannot be distinguished from nonenzymatic processes.

scholarly journals A simple and rapid method for the reversible removal of lipids from a membrane-bound enzyme

1978 ◽  
Vol 169 (2) ◽  
pp. 305-311 ◽  
Author(s):  
S L Goodman ◽  
M Isern de Caldentey ◽  
K P Wheeler
Keyword(s):  
Phosphatase Activity ◽  
Rapid Method ◽  
Adenosine Triphosphatase ◽  
Complete Loss ◽  
Initial Activity ◽  
Experimental Conditions ◽  
Adenosine Triphosphatase Activity ◽  
Ionic Detergent ◽  
Reproducible Method ◽  
Membrane Bound

A simple, rapid and reproducible method for the reversible removal of lipids from a membrane-bound enzyme is described. Essentially, a membrane preparation containing (Na+ + K+)-dependent adenosine triphosphatase was extracted with the non-ionic detergent Lubrol WX in the presence of glycerol, and partial separation of protein from lipid was achieved with the use of only two centrifugations. About 74% of the endogenous phospholipid and 79% of the cholesterol were removed, concomitant with a virtually complete loss of ouabain-sensitive adenosine triphosphatase activity, but with retention of 60-100% of the K+-dependent phosphatase activity. The addition of pure phosphatidylserine re-activated the enzyme to more than 80% of the initial activity, and up to 30% of the protein was recovered. Excess of phosphatidylserine could be washed off the enzyme to give a stable ‘reconstituted’ preparation. The effects of variation in the experimental conditions were examined, and the results are discussed with respect to the possibility of adapting the method to the study of other lipid-dependent enzymes bound to membranes.

scholarly journals ADENOSINE TRIPHOSPHATASE LOCALIZATION IN AMPHIBIAN EPIDERMIS

1966 ◽  
Vol 30 (2) ◽  
pp. 359-379 ◽  
Author(s):  
Marilyn G. Farquhar ◽  
George E. Palade
Keyword(s):  
Cell Membranes ◽  
Light And Electron Microscopy ◽  
Salient Feature ◽  
Cell Junctions ◽  
Intercellular Spaces ◽  
Amphibian Skin ◽  
Fixed Tissue ◽  
Outer Leaflet ◽  
Transport Atpases ◽  
Distal Aspect

The localization of ATPase1 activity has been studied by light and electron microscopy in the epidermis of Rana pipiens, Rana catesbiana, and Bufo marinus. The reaction was carried out on skin (glutaraldehyde-fixed or fresh) sectioned with or without freezing. Best results were obtained with nonfrozen sections of fixed tissue. The incubation mixture was either a Wachstein-Meisel medium, or a modification which approximates assay systems used in biochemical studies of transport ATPases. The reaction product was found localized in contact with the outer leaflet of all cell membranes facing the labyrinth of intercellular spaces of the epidermis. It was absent from: (a) membrane areas involved in cell junctions (desmosomes, zonulae and maculae occludentes); (b) cell membranes facing the external medium (i.e., those on the distal aspect of the ultimate cell layer in s. corneum); (c) cell membranes facing the dermis (those on the proximal aspect of cells in s. germinativum). In the presence of (Na+ + K+) the localization did not change, but the reaction was not appreciably activated. A similar though less intense reaction was obtained with ITP, but not with ADP, AMP, and GP as substrates. The results are discussed in relation to available data on transport ATPases in general, and on the morphology and physiology of amphibian skin in particular. Assuming that the ATPase studied is related to transport ATPase, the findings suggest a series of modifications to the frog skin model proposed by Koefoed-Johnsen and Ussing. The salient feature of this modified model is the localization of the Na+ pump along all cell membranes facing the intercellular spaces of the epidermis.

Factors Affecting the Inhibitor Sensitivity of the Mitochondrial Membrane-Bound Adenosine Triphosphatase Activity

1974 ◽  
Vol 2 (2) ◽  
pp. 205-207 ◽  
Author(s):  
M. PARTIS ◽  
A. D. MITCHELL ◽  
J. WHITEHEAD ◽  
J. F. DONNELLAN ◽  
P. E. LINNETT ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Adenosine Triphosphatase ◽  
Factors Affecting ◽  
Adenosine Triphosphatase Activity ◽  
Membrane Bound
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