phagocytosis

(redirected from phagocytized)
Also found in: Dictionary, Thesaurus, Medical.
Related to phagocytized: induced phagocytosis, phagocytosing

phagocytosis:

see endocytosisendocytosis
, in biology, process by which substances are taken into the cell. When the cell membrane comes into contact with a suitable food, a portion of the cell cytoplasm surges forward to meet and surround the material and a depression forms within the cell wall.
..... Click the link for more information.
.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/

Phagocytosis

A mechanism by which single cells of the animal kingdom, such as smaller protozoa, engulf and carry particles into the cytoplasm. It differs from endocytosis primarily in the size of the particle rather than in the mechanism; as particles approach the dimensions and solubility of macromolecules, cells take them up by the process of endocytosis.

Cells such as the free-living amebas or the wandering cells of the metazoa often can “sense” the direction of a potential food source and move toward it (chemotaxis). If, when the cell contacts the particle, the particle has the appropriate chemical composition, or surface charge, it adheres to the cell. The cell responds by forming a hollow, conelike cytoplasmic process around the particle, eventually surrounding it completely. Although the particle is internalized by this sequence of events, it is still enclosed in a portion of the cell's surface membrane and thus isolated from the cell's cytoplasm. The combined particle and membrane package is referred to as a food or phagocytic vacuole. See Vacuole

Ameboid cells of the metazoa also selectively remove foreign particles, bacteria, and other pathogens by phagocytosis. After the foreign particle or microorganism is trapped in a vacuole inside the macrophage, it is usually digested. To accomplish this, small packets (lysosomes) of lytic proenzymes are introduced into the phagocytic vacuole, where the enzymes are then dissolved and activated. See Lysosome

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Phagocytosis

 

the engulfing and absorption of living and nonliving particles by unicellular organisms or specialized cells—phagocytes—in multicellular animals. Phagocytosis was discovered by E. Metchnikoff (I. I. Mechnikov), who traced its evolution and elucidated its function in the defense reactions of the higher animals and man, particularly those related to inflammation and immunity. The process plays a major role in the healing of wounds.

The ability to seize and digest particles, which is the basis of nutrition in primitive organisms, was gradually transferred in the course of evolution to certain specialized cells—initially to the digestive cells and later to some special cells in the connective tissues. In mammals and in man, the neutrophils (that is, micro-phages, or specialized leukocytes) and the reticuloendothelial cells are active phagocytes capable of being transformed into active macrophages. The neutrophils phagocytize small particles, such as bacteria, while macrophages can ingest such larger particles as dead cells and their nuclei and fragments. Marcrophages can also store the negatively charged particles of pigments and of colloidal substances. The ingestion of small colloidal particles is called ultraphagocytosis.

Phagocytosis—a process that requires the expenditure of energy—involves primarily the activity of the cell membrane and intracellular organoids, or lysosomes, which have a high content of hydrolytic enzymes. Phagocytosis proceeds in stages. After a phagocytable particle has attached itself to the cell membrane, an intracellular corpuscle, or phagosome, is formed by invagination of the membrane and the particle. Hydrolytic enzymes enter the phagosome from the surrounding lysosomes and digest the phagocytized particle. Depending on the particle’s physiochemi-cal properties, digestion may be complete or incomplete. In the latter case, a residual corpuscle is formed and may remain in the cell a long time.

REFERENCES

Mechnikov, I. I. Izbrannye biologicheskie proizvedeniia. Moscow, 1950.
Zil’ber, L. A. Osnovy immunologii, 3rd ed. Moscow, 1958.

N. G. KHRUSHCHOV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

phagocytosis

[‚fag·ə‚sī′tō·səs]
(cell and molecular biology)
A specialized form of macropinocytosis in which cells engulf large solid objects such as bacteria and deliver the internalized objects to special digesting vacuoles; exists in certain cell types, such as macrophages and neutrophils.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Our findings provided evidence to suggest the production of ROS during inflammatory response in septic patients as well as morphological alterations of erythrocytes during the inflammatory process, and that this modified cells are phagocytized by macrophages and PMNs.
Consistent with this, we found that AGERAGE signaling devoted to insufficient macrophages infiltration and phagocytized neutrophils on diabetic mice.
The histological changes found in the GFN were increase of endomysial and perimysial connective tissue with inflammation, atrophic and polymorphic fibers, and several fibers phagocytized. In the group only exercised (GN), the analysis of the slides indicated that the rats had changes characterized by increase of the endomysial and perimysial tissue with inflammation and injury sarcolemal, and changes in the muscle fibers, like polymorphic, atrophic and angular fibers (Fig.
After the coverslips fixation process, 200 macrophages were counted in duplicate for each bird to verify the number of macrophages with phagocytized erythrocytes and the number of phagocytized erythrocytes in each macrophage.
Recent findings suggest that silica particles that reach lung parenchyma can be phagocytized by lung macrophages, and thus, activate generation of reactive oxygen species (ROSs) and inflammatory cytokines [4].
CHRONIC GRANULOMATOUS DISEASE: Is an X linked recessive disease characterized by inability of the leukocytes to lyse phagocytized bacteria Patient with recurrent infection of liver, lungs, bone, lymph nodes often due to S.
Inefficient recovery of iron from phagocytized RBCs may also lead to iron deficiency in the body [7].
Microparticles are better phagocytized by the immune cells rather than the nanoparticles as a factor of size [14, 15].
The supernatant was discarded and the cells in 96-well plates were washed with PBS twice to remove the neutral red that was not phagocytized by RAW 264.7 cells.
These blood vessels supply metabolites, vitamins, growth factors, antibodies, and phagocytized cells [17].
However, it is unknown whether sporozoites are phagocytized by DCs or actively invade DCs; it is also unknown whether it is beneficial for the host to elicit immune responses to clear the parasites or for malaria parasites to suppress the host immune responses.
After deposition in the lungs, larger particles are phagocytized by alveolar and airway macrophages [6, 7], but the fine and ultrafine carbon particles remain in the lungs for a longer period of time [8].