A new dynamic model system for the study of capture reactions for diffusable compounds in cytochemistry. II. Effect of the composition of the incubation medium on the trapping of phosphate ions in acid phosphatase cytochemistry

1979 ◽  
Vol 11 (2) ◽  
pp. 145-161 ◽  
Author(s):  
A. S. H. De Jong ◽  
T. J. Hak ◽  
P. Van Duijn ◽  
W. Th. Daems
1978 ◽  
Vol 26 (5) ◽  
pp. 331-339 ◽  
Author(s):  
A S de Jong ◽  
T J Hak ◽  
P van Duijn ◽  
W T Daems

A model system is described for the investigation of the dynamics of precipitation processes in a matrix. In this system a solution containing the molecular species to be precipitated and the precipitating medium are pumped along opposite sides of a polyacrylamide film. The solutions flowing continuously along the film, interact and can form a precipitate inside the film. The applicability of the model was tested on the capture reaction for phosphate ions by the Gomori type medium for acid phosphatase. Precipitation of lead phosphate in the film occurred only at a phosphate concentration above a certain value. The dependence of this minimal phosphate concentration on various parameters was studied and the results were compared with values found in earlier model studies and calculations concerning phosphate concentrations that can be built up in lysosomes during the Gomori reaction. The system seems promising for obtaining fundamental data about other cytochemical enzyme trapping reactions as well as for the matrix facotrs involved in bone calcification and shell formation.


1974 ◽  
Vol 22 (2) ◽  
pp. 110-119 ◽  
Author(s):  
C. J. CORNELISSE ◽  
P. VAN DUIJN

A model system developed for the study of diffusion problems in lead salt enzyme cytochemistry served as a basis for the experiments reported in the present paper. Phosphate leakage, which was investigated in polyacrylamide films during incubation in media containing lead, could be expressed by a graphical parameter related to the average displacement of the phosphate ions prior to the onset of lead phosphate precipitation in the films. This parameter can be used as a measure for the efficiency of the capture reaction in cytochemical reactions in tissue sections. The concentration of lead ions, and to a lesser extent that of the phosphate ions, was found to be critical for the degree of phosphate diffusion in this system. Addition of 0.3% of β-glycerophosphate to the lead medium gave increased phosphate diffusion, and trapping was markedly improved by added chloride ions. Raising of the molarity of the acetate buffer resulted in impaired trapping efficiency. Similar findings were made in a parallel study on the kinetics of lead phosphate precipitation in supersaturated solutions with a nephelometric method. The results of the present investigation indicate that the film model system is highly suitable for the study of factors affecting the rapid immobilization of diffusible products of cytochemical reactions.


1990 ◽  
Vol 63 (01) ◽  
pp. 127-132 ◽  
Author(s):  
Michèle Ménard ◽  
Kenneth M Meyers ◽  
David J Prieur

SummaryThe ultrastructure of lysosomes from bovine megakaryocytes (MK) and platelets was characterized using acid phosphatase cytochemistry with beta-glycerophosphate as substrate and cerium as a trapping agent. The technique was easily reproducible; cerium-phosphate precipitates were uniform, readily visualized, and there was a virtual absence of nonspecific reaction product. Acid phosphatase was localized in the trans aspect of the Golgi complex and/or granules of less than 50 nm to 650 nm diameters in MK at all stages of maturation. Forty percent of the MK lysosomes contained inclusions of variable shapes, sizes and electron-density and were classified as secondary lysosomes. Twenty-four percent of the platelet sections contained acid phosphatase-positive granules. Fifty-four percent of these were secondary lysosomes. This is the initial report demonstrating secondary lysosomes in either resting MK or platelets using acid phosphatase cytochemistry. These findings suggest that MK and platelet lysosomes have an intracellular function in resting MK and platelets.


1983 ◽  
Vol 158 (6) ◽  
pp. 2108-2126 ◽  
Author(s):  
M A Horwitz

The interactions between the L. pneumophila phagosome and monocyte lysosomes were investigated by prelabeling the lysosomes with thorium dioxide, an electron-opaque colloidal marker, and by acid phosphatase cytochemistry. Phagosomes containing live L. pneumophila did not fuse with secondary lysosomes at 1 h after entry into monocytes or at 4 or 8 h after entry by which time the ribosome-lined L. pneumophila replicative vacuole had formed. In contrast, the majority of phagosomes containing formalin-killed L. pneumophila, live Streptococcus pneumoniae, and live Escherichia coli had fused with secondary lysosomes by 1 h after entry into monocytes. Erythromycin, a potent inhibitor of bacterial protein synthesis, at a concentration that completely inhibits L. pneumophila intracellular multiplication, had no influence on fusion of L. pneumophila phagosomes with secondary lysosomes. However, coating live L. pneumophila with antibody or with antibody and complement partially overcame the inhibition of fusion. Also activating the monocytes promoted fusion of a small proportion of phagosomes containing live L. pneumophila with secondary lysosomes. Acid phosphatase cytochemistry revealed that phagosomes containing live L. pneumophila did not fuse with either primary or secondary lysosomes. In contrast to phagosomes containing live bacteria, the majority of phagosomes containing formalin-killed L. pneumophila were fused with lysosomes by acid phosphatase cytochemistry. The capacity of L. pneumophila to inhibit phagosome-lysosome fusion may be a critical mechanism by which the bacterium resists monocyte microbicidal effects.


2012 ◽  
Vol 51 (22) ◽  
pp. 12195-12209 ◽  
Author(s):  
Peter Comba ◽  
Lawrence R. Gahan ◽  
Valeriu Mereacre ◽  
Graeme R. Hanson ◽  
Annie K. Powell ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document