scholarly journals Evidence for the autophagy of microinjected proteins in HeLA cells.

1977 ◽  
Vol 75 (3) ◽  
pp. 807-817 ◽  
Author(s):  
D W Stacey ◽  
V G Allfrey
Keyword(s):  
Acid Phosphatase ◽  
Fluorescence Microscopy ◽  
Phosphatase Activity ◽  
Hela Cells ◽  
Acid Phosphatase Activity ◽  
Size Fraction ◽  
Cytoplasmic Granules ◽  
Antibody Staining ◽  
Staining Methods ◽  
High Degree

Rhodamine-conjugated proteins were microinjected into living HeLa cells. Fluorescence microscopy was then employed to study their segregation from the cytoplasm into lysosomes. Results obtained in this way were verified when the corresponding unconjugated proteins were localized by autoradiographic, histological, and antibody-staining methods after their microinjection. Most injected proteins were segregated into cytoplasmic granular structures during their removal from cells. As evidence that these were autophagic vacuoles, they were found to contain no detectable acid phosphatase activity upon formation, after which they moved to the juxtanuclear position of lysosomes and appeared to fuse with them. The segregation of microinjected proteins exhibited a high degree of selectivity. The half-times of placement of individual exogenous proteins into cytoplasmic granules varied from 3 h to nearly 3 days, and one protein, hemoglobin, was never observed to enter them. Furthermore, endogenous HeLa proteins in a size fraction near 200,000 daltons were segregated much more rapidly than those in a fraction near 40,000 daltons. In these studies, rapid protein segregation appeared to take place by a mechanism of exclusion of the injected protein from numerous cytoplasmic domains.

Phosphatase Activity of Drosophila Salivary Glands

1948 ◽  
Vol s3-89 (8) ◽  
pp. 415-419
Author(s):  
W. L. DOYLE
Keyword(s):  
Acid Phosphatase ◽  
Enzymatic Activity ◽  
Quantitative Determination ◽  
Salivary Glands ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
The State ◽  
Staining Methods

The phosphatases in the cytoplasm and nuclei of Drosophila salivary glands are better preserved by fixation in absolute acetone than in 85 per cent, alcohol. In whole glands there is relatively little extraction of the enzyme during assay. Phosphatase activity is more resistant to incubation at neutrality than at pH 8.6, but in this material there is sufficient residual enzymatic activity to permit redetermination of alkaline, neutral, or acid phosphatase activity by staining methods after an initial quantitative determination. The state of the membranes of the gland affects the penetration of the substrate sufficiently to limit the activities obtained.

scholarly journals ACID PHOSPHATASE ACTIVITY IN INDIVIDUAL NEURONS DURING CHROMATOLYSIS: A QUANTITATIVE HISTOCHEMICAL STUDY

1970 ◽  
Vol 18 (11) ◽  
pp. 828-833 ◽  
Author(s):  
HILDE E. HIRSCH ◽  
THEODORE OBENCHAIN
Keyword(s):  
Spinal Cord ◽  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Histochemical Study ◽  
Galactosidase Activity ◽  
Fluorogenic Substrates ◽  
Striking Increase ◽  
Staining Methods ◽  
Glucose 6 Phosphate Dehydrogenase

Two fluorogenic substrates, α-naphthyl phosphate and 4-methylumbelliferyl phosphate, were used to measure acid phosphatase activities in individual anterior horn neurons of the monkey spinal cord after section of the sciatic nerve. Although many studies utilizing staining methods have reported a striking increase in acid phosphatase activity during chromatolysis, no significant differences were observed here between the neurons of the operated and unoperated side, despite widespread chromatolysis. β-galactosidase activity was also unchanged, but the marked elevation of glucose 6-phosphate dehydrogenase during the reparative phase was confirmed.

ULTRASTRUCTURAL LOCALIZATION OF A CHARACTERISTIC ACID PHOSPHATASE IN GRANULES OF RABBIT BASOPHILS

1974 ◽  
Vol 22 (12) ◽  
pp. 1092-1104 ◽  
Author(s):  
ATSUSHI KOMIYAMA ◽  
SAMUEL S. SPICER
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Potential Role ◽  
Strong Acid ◽  
Ultrastructural Localization ◽  
Buffy Coat ◽  
Cytoplasmic Granules ◽  
Nitrophenyl Phosphate ◽  
Tris Maleate

Bone marrow basophils incubated in Gomori medium at pH 6.0-6.8 exhibited strong acid phosphatase activity suggestive of a potential role in endocytosis in one-third of the cytoplasmic granules and also in Golgi elements. Buffy coat basophils contained about one-third as many reactive granules. Reaction product was confined to the threadlike component of the larger granules predominant in early basophils and was absent from the denser-type granules predominant in late basophils. In centrioles of basophils acid phosphatase appeared localized between triplet fibers. Reactivity with the Gomori medium was diminished at pH 5.0, absent at pH 8.0 and only slightly decreased with p-nitrophenyl phosphate as substrate. Basophils incubated in Barka-Anderson medium at pH 5.0-6.8 revealed light acid phosphatase activity in the Golgi lamellae but essentially none in cytoplasmic granules. Tris-maleate buffer of the Barka-Anderson medium replacing the sodium acetate of the Gomori medium inhibited the reactivity in the granules. Incubation in media containing NaF, or lacking substrate, eliminated the heavy precipitates in granules and Golgi elements but yielded light, nonenzymatic lead staining in Golgi and tubulovesicular structures and atypical granules present only in buffy coat basophils.

scholarly journals CORRELATION OF ACID PHOSPHATASE ACTIVITY WITH DEGREE OF BACTERIAL INFECTION IN HELA CELLS

1966 ◽  
Vol 14 (2) ◽  
pp. 196-202 ◽  
Author(s):  
HELEN ROLAND JERVIS ◽  
EUGENE H. LABREC
Keyword(s):  
Acid Phosphatase ◽  
Enzymatic Activity ◽  
Phosphatase Activity ◽  
Hela Cells ◽  
Acid Phosphatase Activity ◽  
Virulent Strain ◽  
Shigella Flexneri ◽  
Enzymatic Reaction ◽  
Shigella Flexneri 2A ◽  
And Control

Acid phosphatase activity has been demonstrated in HeLa cells grown in monolayers on coverslips, using the histochemical method of Barka and Anderson. In normal interphase cells variable enzymatic activity may always be demonstrated in a juxtanuclear position. When the culture medium is inoculated with a virulent strain of Shigella flexneri 2a, a certain number of cells in invaded by the organisms. In the presence of one organism, the acid phosphatase activity of the infected cell appears to increase, but as more organisms are found in individual cells, the intensity of the cells enzymatic reaction decreases. Biochemical assays on whole cell monolayers to quantitate this decrease have failed to show a significant change in enzymatic activity between infected and control cultures, possibly due to the high percentage of cells in any culture that were not infected or infected only slightly.

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.

Erythrophagocytosis in the Liver in Hemolytic Anemias

1968 ◽  
Vol 26 ◽  
pp. 184-185
Author(s):  
O. T. Minick ◽  
E. Orfei ◽  
F. Volini ◽  
G. Kent
Keyword(s):  
Acid Phosphatase ◽  
Oxidative Damage ◽  
Phosphatase Activity ◽  
Kupffer Cells ◽  
Acid Phosphatase Activity ◽  
Common Type ◽  
Red Cell ◽  
Cell Fragments ◽  
Reticulo Endothelial System ◽  
Important Site

Hemolytic anemias were produced in rats by administering phenylhydrazine or anti-erythrocytic (rooster) serum, the latter having agglutinin and hemolysin titers exceeding 1:1000.Following administration of phenylhydrazine, the erythrocytes undergo oxidative damage and are removed from the circulation by the cells of the reticulo-endothelial system, predominantly by the spleen. With increasing dosage or if animals are splenectomized, the Kupffer cells become an important site of sequestration and are greatly hypertrophied. Whole red cells are the most common type engulfed; they are broken down in digestive vacuoles, as shown by the presence of acid phosphatase activity (Fig. 1). Heinz body material and membranes persist longer than native hemoglobin. With larger doses of phenylhydrazine, erythrocytes undergo intravascular fragmentation, and the particles phagocytized are now mainly red cell fragments of varying sizes (Fig. 2).

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