Superoxide Anion‐Generating Activities of Macrophages as Studied by Using Cytochalasin E and Lectins as Synergistic Stimulants for Superoxide Release

Abstract

Treatment of macrophages with cytochalasin E in combination with a lectin was found to stimulate the generation of superoxide anions (021 very efficiently. The macrophages stimulated with concanavalin A, phytohemagglutinin or wheat germ agglutinin released superoxide, but cells pretreated with cytochalasin E released much greater amounts of superoxide, without notable lag time, upon stimulation with the lectin.Wheat germ agglutinin was found to be the most efficient stimulant among the lectins tested.Superoxide generation in guinea pig macrophages was shown to be dependent largely on cytoplasmic glucose metabolism and to some extent on mitochondrial respiration, since the superoxide release was largely but not totally inhibited by 2-deoxyglucose and to a lesser extent by antimycin A or KCN.The method presented is sensitive and allows rapid assay of the superoxide-generating activity with only 1-5 x 105 macrophages for a single determination.In application of this technique, elevation of the superoxide-generating activity was shown with macrophages elicited by chemical inflammation or those obtained from mice after treatment with tubercle bacilli.

Hydrogen peroxide metabolism in human monocytes during differentiation in vitro.

“…When the monocyte enters noninflamed tissue, its capacity to produce reactive oxygen intermediates may involute to resemble that of the resident peritoneal macrophage of the mouse (28,29). During the remainder of the cell's lifespan, the remarkable capacity to secrete large amounts of O2 and H202 may be reinduced by inflammatory mediators (23,(29)(30)(31). The above hypothesis contains key elements that have not yet been tested.…”

“…The production of these reactive oxygen intermediates is of considerable interest, in view of mounting evidence for their involvement in some of the antimicrobial (21)(22)(23)(24) and antitumor (25)(26)(27) been activated by exposure to inflammatory agents or lymphocyte mediators, their capacity to secrete these substances increases toward the high levels observed with human blood monocytes (23,(29)(30)(31). We hypothesized, therefore, that the ability of the blood monocyte to secrete large amounts of O2 and H202 might (a) normally involute during its maturation into a macrophage; and (b) that this capacity might be retained or regained in the presence of lymphocyte mediators.…”

Organic Carbonates from Natural Sources

“…Another type of important effect of 39 on cells is the induction of superoxide anion (O 2 – ) release. Generation of O 2 – in guinea pig and human polymorphonuclear leukocytes by treatment with 39 was investigated by Nakagawara and colleagues in 1975 and 1976, respectively, while similar effects on O 2 – production in human monocytes , and macrophages were also observed. In addition, 39 also stimulates rat Kupffer cells, human neutrophils, and eosinophils and neutrophils of guinea pigs to release O 2 – .…”

Generation of Reactive Oxygen Species (ROS) by Harmful Algal Bloom (HAB)-Forming Phytoplankton and Their Potential Impact on Surrounding Living Organisms

“…ROS generation by C. marina increases in response to extracellular stimuli, such as lectins [ 191 , 218 ]. After binding to the cell surface carbohydrate moieties, lectins induce various cellular signaling pathways, leading to the enhancement of ROS generation in leukocytes [ 301 , 302 ]. C. marina might possess such pathways regulating ROS generation in response to lectin stimuli, as found in leukocytes.…”