scholarly journals Regulation of arachidonic acid metabolism by macrophage activation.

1982 ◽  
Vol 155 (4) ◽  
pp. 1148-1160 ◽  
Author(s):  
W A Scott ◽  
N A Pawlowski ◽  
H W Murray ◽  
M Andreach ◽  
J Zrike ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Macrophage Activation ◽  
Peritoneal Macrophages ◽  
Arachidonic Acid Metabolism ◽  
Prostaglandin Synthesis ◽  
Activated Macrophages ◽  
Synthetic Enzymes ◽  
Oxygenated Products

Levels of zymosan-induced arachidonic acid (20:4) metabolism by peritoneal macrophages elicited with inflammatory agents and resident macrophages were similar. Thyioglycollate (THIO)-elicited macrophages represented the exception; however, the diminished metabolism by these cells was reproduced by exposing resident cells to 5 mg/ml THIO broth in vitro. In contrast, reduced prostaglandin synthesis by macrophages from mice variously treated with the immunologic agents, Corynebacterium parvum or Bacille Calmette Guérin (BCG), closely correlated with enhanced antitoxoplasma activity, one measure of macrophage activation. This relationship, although not causative, suggested that the capacity for 20:4 metabolism is a function of the macrophage activation state. Modulation of macrophage 20:4 metabolism in vivo apparently required factors in addition to lymphocyte-derived products. Treatment of resident macrophages in vitro with BCG lymphokine was without effect on 20:4 release or prostaglandin synthesis. Activated macrophages from animals inoculated i.p. with C. parvum exhibited reduced 20:4 release and also failed to metabolize 70% of the 20:4 released in response to a zymosan stimulus. Consequently, the quantities of 20:4 metabolites formed were significantly less than expected from 20:4 release. These activated macrophages displayed greatly reduced synthesis of prostacylcin and leukotriene C compared with other 20:4 metabolites. It appeared that factors that regulate macrophage 20:4 metabolism influence the level of the inducible phospholipase and synthetic enzymes for specific 20:4 oxygenated products.

scholarly journals Macrophage oxygen-dependent antimicrobial activity. III. Enhanced oxidative metabolism as an expression of macrophage activation.

1980 ◽  
Vol 152 (6) ◽  
pp. 1596-1609 ◽  
Author(s):  
H W Murray ◽  
Z A Cohn
Keyword(s):  
Antimicrobial Activity ◽  
Oxidative Metabolism ◽  
Macrophage Activation ◽  
Systemic Infection ◽  
Peritoneal Macrophages ◽  
H2o2 Production ◽  
Oxygen Intermediates ◽  
Cultivation In Vitro

The capacity of 15 separate populations of mouse peritoneal macrophages to generate and release H2O2 (an index of oxidative metabolism) was compared with their ability to inhibit the intracellular replication of virulent Toxoplasma gondii. Resident macrophages and those elicited by inflammatory agents readily supported toxoplasma multiplication and released 4-20X less H2O2 than macrophages activated in vivo by systemic infection with Bacille Calmette-Guérin or T. gondii, or by immunization with Corynebacterium parvum. Immunologically activated cells consistently displayed both enhanced H2O2 production and antitoxoplasma activity. Exposure to lymphokines generated from cultures of spleen cells from T. gondii immune mice and toxoplasma antigen preserved both the antitoxoplasma activity and the heightened H2O2 release of toxoplasma immune and immune-boosted macrophages, which otherwise were lost after 48-72 h of cultivation. In vitro activation of resident and chemically-elicited cells by 72 h of exposure to mitogen- and antigen-prepared lymphokines, conditions that induce trypanocidal (5) and leishmanicidal activity (14), stimulated O2- and H2O2 release, and enhanced nitroblue tetrazolium reduction in response to toxoplasma ingestion. Such treatment, however, failed to confer any antitoxoplasma activity, indicating that intracellular pathogens may vary in their susceptibility to macrophage microbicidal mechanisms, including specific oxygen intermediates. In contrast, cocultivating normal macrophages with lymphokine plus heart infusion broth for 18H rendered these cells toxoplasmastatic. This in vitro-acquired activity was inhibited by scavengers of O2-, H2O2, OH., and 1O2, demonstrating a role for oxidative metabolites in lymphokine-induced enhancement of macrophage antimicrobial activity. These findings indicate that augmented oxidative metabolism is an consistent marker of macrophage activation, and that oxygen intermediates participate in the resistance of both in vivo- and vitro-activated macrophages toward the intracellular parasite, T. gondii.

scholarly journals Biological and Inflammatory Effects of Antigen 5 from Polybia paulista (Hymenoptera, Vespidae) Venom in Mouse Intraperitoneal Macrophages

Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 850
Author(s):  
Murilo Luiz Bazon ◽  
Luis Gustavo Romani Fernandes ◽  
Isabela Oliveira Sandrini Assugeni ◽  
Lucas Machado Pinto ◽  
Patrícia Ucelli Simioni ◽  
...  
Keyword(s):  
Peritoneal Macrophages ◽  
In Vivo Studies ◽  
M2 Macrophage ◽  
No Production ◽  
Activated Macrophages ◽  
In Vitro Production ◽  
Polybia Paulista ◽  
Antigen 5

The social wasp Polybia paulista (Hymenoptera, Vespidae) is highly aggressive, being responsible for many medical occurrences. One of the most allergenic components of this venom is Antigen 5 (Poly p 5). The possible modulation of the in vitro immune response induced by antigen 5 from P. paulista venom, expressed recombinantly (rPoly p 5), on BALB/c mice peritoneal macrophages, activated or not with LPS, was assessed. Here, we analyzed cell viability changes, expression of the phosphorylated form of p65 NF-κB subunit, nitric oxide (NO), proinflammatory cytokines production, and co-stimulatory molecules (CD80, CD86). The results suggest that rPoly p 5 does not affect NO production nor the expression of co-stimulatory molecules in mouse peritoneal macrophages. On the other hand, rPoly p 5 induced an increase in IL-1β production in non-activated macrophages and a reduction in the production of TNF-α and MCP-1 cytokines in activated macrophages. rPoly p 5 decreased the in vitro production of the phosphorylated p65 NF-κB subunit in non-activated macrophages. These findings suggest an essential role of this allergen in the polarization of functional M2 macrophage phenotypes, when analyzed in previously activated macrophages. Further investigations, mainly in in vivo studies, should be conducted to elucidate Polybia paulista Ag5 biological role in the macrophage functional profile modulation.

Platelet inhibition by aspirin is diminished in patients during carotid surgery: a form of transient aspirin resistance?

2004 ◽  
Vol 92 (07) ◽  
pp. 89-96 ◽  
Author(s):  
David Payne ◽  
Chris Jones ◽  
Paul Hayes ◽  
Sally Webster ◽  
A. Naylor ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
Platelet Inhibition ◽  
Aspirin Resistance ◽  
Arachidonic Acid Metabolism ◽  
Significant Rise ◽  
Control Group

SummaryThe majority of patients who suffer peri-operative thromboembolic complication while undergoing vascular procedures do so despite taking aspirin. This study examined the antiplatelet effect of aspirin during surgery in patients undergoing carotid endarterectomy (CEA). Fifty patients undergoing CEA were standardised to 150 mg aspirin daily for ≥2 weeks. Platelet aggregation in response to arachidonic acid (AA) was measured in platelet rich plasma prepared from blood taken prior to, during, and at the end of surgery. Spontaneous platelet aggregation was also studied, as was the role of physiological agonists (ADP, collagen, thrombin, and epinephrine) in mediating the in vivo and in vitro responses to AA. Eighteen patients undergoing leg angioplasty, also on 150 mg aspirin, without general anaesthesia, served as a control group. In the CEA patients aggregation induced by AA (5 mM) increased significantly from 7.6 ± 5.5% pre-surgery to 50.8 ± 29.5% at the end of surgery (p <0.0001). Aggregation to AA was even greater in samples taken mid-surgery from a sub-set of patients (73.8 ± 7.2%; p = 0.0001), but fell to 45.9 ± 7.4% by the end of surgery. The increased aggregation in response to AA was not due to intra-operative release of physiological platelet agonists since addition of agents that block/neutralise the effects of ADP (apyrase; 4 µg/ml), thrombin (hirudin; 10 units/ml), or epinephrine (yohimbine; 10 µM/l) to the samples taken at the end of surgery did not block the increased aggregation.The patients undergoing angioplasty also showed a significant rise in the response to AA (5 mM), from 5.6 ± 5.5% pre-angioplasty to 32.4 ± 24.9% at the end of the procedure (p <0.0001), which fell significantly to 11.0 ± 8.1% 4 hours later. The antiplatelet activity of aspirin, mediated by blockade of platelet arachidonic acid metabolism, diminished significantly during surgery, but was partially restored by the end of the procedure without additional aspirin treatment.This rapidly inducible and transient effect may explain why some patients undergoing cardiovascular surgery remain at risk of peri-operative stroke and myocardial infarction.

Aging and dietary modulation of elastase and interleukin-1 beta secretion

1995 ◽  
Vol 268 (1) ◽  
pp. R208-R213 ◽  
Author(s):  
J. G. Cannon ◽  
M. A. Fiatarone ◽  
M. Meydani ◽  
J. Gong ◽  
L. Scott ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Cell Function ◽  
Interleukin 1 ◽  
Lipid Peroxide ◽  
Arachidonic Acid Metabolism ◽  
Interleukin 1 Beta ◽  
Tension Development ◽  
Age Related

Aging is associated with diminished immune function that may stem from alterations in arachidonic acid metabolism and lipid peroxidation. This study sought to determine if dietary modification of fatty acids influenced neutrophil and monocyte secretion after an in vivo inflammatory stress in older human subjects. Volunteers participated in protocols that forced their quadriceps muscles to lengthen during tension development (eccentric stress). These protocols can cause inflammatory foci in the muscle as well as alterations in circulating leukocyte function. In this study, in vivo neutrophil degranulation was assessed by plasma elastase concentrations, and mononuclear cell function was assessed by interleukin-1 beta (IL-1 beta) secretion in vitro. In response to eccentric stress, older subjects (> 60 yr old) taking a placebo had no apparent elastase response, whereas those taking fish oil supplements responded with a 142% increase in plasma elastase (P = 0.011), similar to responses of younger reference subjects (< 33 yr old) taking no supplement. Overall, elastase responses correlated with individual plasma arachidonic acid-to-eicosapentaenoic acid ratios (r = -0.881, P = 0.004). Thus apparent age-related differences in elastase release were reconciled by individual differences in fatty acid nutriture. No significant temporal changes in urinary lipid peroxide excretion or IL-1 beta secretion were observed; however, age-associated differences were found.

The molecular biology of mammalian arachidonic acid metabolism

1991 ◽  
Vol 260 (2) ◽  
pp. L13-L28 ◽  
Author(s):  
E. Sigal
Keyword(s):  
Arachidonic Acid ◽  
Acid Metabolism ◽  
Recombinant Dna ◽  
Biological Activities ◽  
Biological Effects ◽  
Arachidonic Acid Metabolism ◽  
Bioactive Metabolites ◽  
Wide Range

The metabolism of arachidonic acid by cyclooxygenase and lipoxygenase enzymes results in a wide range of oxidized products with potent biological activities. These metabolites, which include the prostaglandins and leukotrienes, have been implicated in the pathogenesis of a variety of inflammatory diseases. Research over the last decade has focused primarily on the elucidation of the chemical structure of the metabolites and their biological effects in vitro and in vivo. Recently, research on the enzymes that produce these bioactive metabolites through oxidization of arachidonic acid has intensified. Recombinant DNA techniques have enabled investigators to determine the nucleotide sequences for several of the enzymes in the arachidonic acid cascade. The resulting cDNAs are now being used to further investigate the biochemical and biological features of arachidonic acid metabolism. The purpose of this paper is to review how the cDNAs for these enzymes were obtained, what information they convey, and how they are being applied in current research.

scholarly journals Arachidonic acid metabolism and the adhesion of human polymorphonuclear leukocytes to cultured vascular endothelial cells

Blood ◽  
1983 ◽  
Vol 62 (4) ◽  
pp. 889-895 ◽  
Author(s):  
MR Buchanan ◽  
MJ Vazquez ◽  
MA Jr Gimbrone
Keyword(s):  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Endothelial Cell ◽  
Polymorphonuclear Leukocytes ◽  
Acid Metabolism ◽  
Arachidonic Acid Metabolism ◽  
Vascular Endothelial ◽  
Endothelial Monolayers

Abstract Polymorphonuclear leukocytes (PMN) adhere to the vascular endothelial lining in vivo and to the surfaces of cultured endothelial cells in vitro, but the mechanisms of these cellular interactions remain unclear. Arachidonic acid metabolites, both cyclooxygenase- and lipoxygenase-derived, have been shown to influence PMN locomotion, secretion, and adhesion to artificial surfaces. To determine whether such mediators also are involved in regulating PMN-endothelial cell interactions, we have examined the effects of prostacyclin and various inhibitors of arachidonic acid metabolism on the adherence of radiolabeled PMN to cultured bovine aortic endothelial cells. Confluent endothelial monolayers were incubated with washed suspensions of radiolabeled human PMN (which contained less than 1% platelet contamination) at 37 degrees C for 30 min, then subjected to a standardized wash procedure and the number of adherent leukocytes determined radiometrically. Under basal conditions, i.e., in the absence of exogenous activating stimuli, 4,163 +/- 545 PMN adhered per square millimeter of endothelial surface (mean +/- SEM, n = 12). This basal adhesion (which corresponds to approximately 4–5 leukocytes per endothelial cell) was unaffected when the leukocytes and endothelial monolayers were pretreated with cyclooxygenase inhibitors (100 microM aspirin or 1–5 microM indomethacin) or PGI2 (10(-9)-10(6) M). Thus, basal PMN-endothelial adhesion in this in vitro model system does not appear to be dependent on endogenous cyclooxygenase derivatives of arachidonate or to be sensitive to inhibition by exogenous prostacyclin. In contrast, leukocyte adhesion was significantly reduced by pretreatment with 5,8,11,14- or 4,7,10,13-eicosatetraynoic acid, 0.5- 5 mM sodium salicylate, or 10–1,000 microM indomethacin, antiinflammatory agents that can interfere with the metabolism of arachidonic acid via non-cyclooxygenase-dependent mechanisms. These observations may be relevant to the interactions of circulating PMN with vascular endothelium under both physiologic and pathophysiologic conditions in vivo.

Diethylcarbamazine (DEC): immunopharmacological interactions of an anti-filarial drug

Parasitology ◽  
1992 ◽  
Vol 105 (S1) ◽  
pp. S49-S60 ◽  
Author(s):  
R. M. Maizels ◽  
D. A. Denham
Keyword(s):  
Immune Response ◽  
Arachidonic Acid ◽  
Acid Metabolism ◽  
Arachidonic Acid Metabolism ◽  
Host Factors ◽  
Pathogenic Organism ◽  
Rapid Clearance ◽  
Existing Data

SUMMARYAnti-parasitic drugs may achieve their therapeutic effect either by direct activity against the pathogenic organism, or by altering host factors which lead to parasite killing. In this review, we discuss the evidence for an indirect mode of action for one major anti-filarial drug, diethylcarbamazine (DEC). The interpretation most consistent with existing data is that DEC alters arachidonic acid metabolism in microfilariae and in host endothelial cells. These changes may result in vasoconstriction and amplified endothelial adhesion leading to immobilization of microfilarial parasites, enhanced adherence and cytotoxic activity by host platelets and granulocytes. These events would represent activation of the innate, non-specific immune system, independent of the adaptive, antigen-specific, immune response. This model explains the paradox between rapid clearance in vivo and the lack of an in vitro effect, as well as the efficacy of DEC in non-immune animals.

scholarly journals CELL-MEDIATED IMMUNITY AGAINST BESNOITIA AND TOXOPLASMA IN SPECIFICALLY AND CROSS-IMMUNIZED HAMSTERS AND IN CULTURES

1974 ◽  
Vol 139 (3) ◽  
pp. 560-580 ◽  
Author(s):  
Richard L. Hoff ◽  
J. K. Frenkel
Keyword(s):  
Macrophage Activation ◽  
Cell Formation ◽  
Lymphoid Cells ◽  
Cell Populations ◽  
Cell Mediated Immunity ◽  
Activated Macrophages ◽  
Specific Effects ◽  
Giant Cell Formation

The capacity of hamster peritoneal cell populations to control viability and growth of Besnoitia and Toxoplasma organisms was assessed in vivo and in vitro. Immunized hamsters reduced the homologous organisms 100- to 10,000-fold over a 5-day period, but the heterologous infection increased 100- to 1,000-fold in numbers, similar as in the nonimmune controls. Passively administered antibody was ineffective although lytic cofactors were supplied by hamsters. In cultures, peritoneal cells from Besnoitia-immune hamsters delayed the growth of homologous parasites to an average of 38.5 h per division; however, in Toxoplasma-immune and nonimmune cells, Besnoitia divided every 12.8 h. Specificity of immunity was pronounced against both infections. With cross-infections, Toxoplasma-immune cultures did not effectively delay Besnoitia growth; however, Besnoitia-immune cultures reduced Toxoplasma growth by one-half. Co-cultivation experiments demonstrated that specifically committed lymphocytes could instruct macrophages to reduce the homologous organism 10-fold, whereas heterologous organisms were reduced only 2-fold. Lymphocyte supernatants initiated hypersensitivity as indicated by macrophage activation and giant cell formation in culture. However, these supernatants did not transfer infection immunity. Lymphokines could account for the hypersensitivity phenomena, but cell-mediated infection immunity in this model required close lymphocyte-macrophage proximity. These studies indicate that a number of distinct processes including delayed hypersensitivity, macrophage activation, and specific cellular immunity are acting simultaneously during latent Besnoitia infection of hamsters. All three processes are mediated by lymphoid cells and appear to be specifically induced. Although activated macrophages develop some heightened nonspecific capabilities, these were several orders of magnitude below the specific effects.

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