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Query: UMLS:C0034063 (pulmonary edema)
 10,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intravenous injection of oleic acid (OA) induces acute, edematous lung injury resembling some of the features of adult respiratory distress syndrome. One class of inflammatory agents speculated to be mediators of acute lung injury are eicosanoids. We tested the hypothesis that 5-lipoxygenase and cyclooxygenase metabolites of arachidonic acid mediate the pulmonary injury induced by OA. OA (0.1 ml), injected as a bolus into the pulmonary artery (PA) of isolated, Krebs-perfused rabbit lungs, resulted in significant (P less than .05) increases in lung weight (an index of pulmonary edema), maximum airway pressure, perfusate immunoreactive (i) 6-keto PGF1a, and a significant, though minimal, increase in perfusate i-thromboxane B2. No measurable increases were recorded in PA pressure or perfusate i-leukotriene (LT) C4/D4. Neither pretreatment with the LTD4/E4 antagonist, LY171883 (10 microM), nor the 5-lipoxygenase/cyclooxygenase inhibitor, BW755C (100 microM), attenuated the pulmonary edema. However, BW755C abrogated the increase in i6-keto PGF1a. Additionally, administration of exogenous LTD4 (100 nM) into the perfusate produced only a minimal increase in lung weight in the isolated rabbit lungs (n = 4). These results demonstrate that 5-lipoxygenase and cyclooxygenase metabolites do not appear to mediate OA-induced injury in the isolated, Krebs-perfused rabbit lung.
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PMID:Oleic acid induces pulmonary injury independent of eicosanoids in the isolated, perfused rabbit lung. 311 57

Infusion of the oxidant lipid peroxide tert-butyl hydroperoxide (t-bu-OOH) causes pulmonary vasoconstriction and increases vascular permeability in isolated perfused rabbit lungs. We have previously shown that t-bu-OOH stimulates arachidonic acid metabolism, increasing the synthesis of the cyclooxygenase products. The current experiments were designed to determine the role that cyclooxygenase- and lipoxygenase-derived mediators play in the lung injury caused by t-bu-OOH. In the present experiments, we found that t-bu-OOH not only increased the synthesis of the cyclooxygenase-derived products thromboxane and prostacyclin but also increased the synthesis of the lipoxygenase-derived products leukotrienes B4, C4, D4, and E4. To determine the role that these arachidonic acid metabolites play in the increase in pressure and vascular permeability caused by t-bu-OOH, we studied the effect that inhibitors of arachidonic acid metabolism or a leukotriene receptor blocker had on the pulmonary edema. We compared an uninjured control group with 4 groups of lungs given t-bu-OOH: a t-bu-OOH control group; a group pretreated with the cyclooxygenase inhibitor indomethacin (14 microM); a group pretreated with an analogue of arachidonic acid, 5-, 8-, 11-, 14-eicosatetraynoic acid (ETYA) (100 microM), that inhibits both the cyclooxygenase and lipoxygenase pathways; and a group pretreated with the leukotriene receptor antagonist FPL 55712 (38 microM). To produce lung injury, t-bu-OOH (300 microM) was infused throughout the first minute of 4 successive 10-min periods.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The role of cyclooxygenase and lipoxygenase mediators in oxidant-induced lung injury. 314

In addition to activating T and B lymphocytes, interleukin 1 (IL-1) induces several hematologic and metabolic changes typical of host responses to infection and injury. We now report a new biological property, namely, the induction of hypotension. Rabbits given a single intravenous injection of recombinant human IL-1-beta (5 micrograms/kg) rapidly developed decreased systemic arterial pressure, which reached the lowest levels after 50-60 min and slowly returned to pre-IL-1 values after 3 h. Associated with the hypotension, systemic vascular resistance and central venous pressure fell, while cardiac output and heart rate increased. These responses were prevented by ibuprofen given 15 min before the IL-1. A bolus injection of IL-1 followed by a 2-h infusion sustained the hypotension and was associated with leukopenia and thrombocytopenia. Ibuprofen given at the mid-point of the infusion reversed the changes in all hemodynamic parameters, but had no effect on the leukopenia or thrombocytopenia. Tumor necrosis factor (TNF) also induced a shock-like state in rabbits. When the dose of IL-1 or TNF was reduced to 1 microgram/kg, no hemodynamic changes were observed; however, the combination of these low doses of both cytokines resulted in a profound shock-like state including histological evidence of severe pulmonary edema and hemorrhage. Pretreatment with ibuprofen prevented the hemodynamic, leukocyte, and platelet changes induced by the low-dose cytokine combination, and ameliorated the pulmonary tissue damage. These results demonstrate that IL-1, like TNF, possesses the ability to induce hemodynamic and hematological changes typical of septic shock, and that the combination of IL-1 and TNF is more potent than either agent alone. These effects seem to require cyclooxygenase products, and suggest that intravenous cyclooxygenase inhibitors may be of therapeutic value in patients with IL-1/TNF-mediated shock.
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PMID:Interleukin 1 induces a shock-like state in rabbits. Synergism with tumor necrosis factor and the effect of cyclooxygenase inhibition. 325 19

We studied lung clearance of aerosolized technetium-labeled diethylenetriamine pentaacetic acid (99mTcDTPA), plasma concentrations of 6-keto-PGF1 alpha and thromboxane B2, and pulmonary edema as indices of lung injury in rabbits exposed to cigarette smoke (CSE). Forty-six rabbits were randomly assigned to 4 groups: control sham smoke exposure (SS, N = 9), sham smoke exposure ibuprofen-pretreated (SS-I, N = 10), CSE (N = 9), sham smoke exposure ibuprofen-pretreated (SS-I, N = 10), CSE (N = 9), and CSE ibuprofen-pretreated (CSE-I, N = 19). Ibuprofen (cyclooxygenase eicosanoid inhibitor) was administered as a single daily intramuscular injection (25 mg/kg) for 7 days before the experiment. Cigarette or sham smoke was delivered by syringe in a series of 5, 10, 20, and 30 tidal volume breaths with a 15-min counting period between each subset of breaths to determine 99mTcDTPA biological half-life (T1/2). In the ibuprofen pretreated group, CSE caused significant decreases in 99mTcDTPA T1/2 and dynamic lung compliance. Furthermore, these changes in lung function were accompanied by severe injury to type I alveolar cell epithelium, pulmonary edema, and frequently death of the rabbits. These findings suggest that inhibition of the cyclooxygenase pathway before CSE exacerbates lung injury in rabbits.
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PMID:Acute cigarette smoke exposure causes lung injury in rabbits treated with ibuprofen. 331 20

Multiple potentially injurious agents are present in smoke but the importance of each of these agents in producing lung injury as well as the mechanisms by which the lung injury is produced are unknown. In order to study smoke inhalation injury, we developed a synthetic smoke composed of a carrier of hot carbon particles of known size to which a single known common toxic agent in smoke, in this case HCI, could be added. We then exposed rats to the smoke, assayed their blood for the metabolites of thromboxane and prostacyclin, and intervened shortly after smoke with the cyclooxygenase inhibitors indomethacin or ibuprofen to see if the resulting lung injury could be prevented. Smoke exposure produced mild pulmonary edema after 6 h with a wet-to-dry weight ratio of 5.6 +/- 0.2 SEM (n = 11) compared with the non-smoke-exposed control animals with a wet-to-dry weight ratio of 4.3 +/- 0.2 (n = 12), p less than 0.001. Thromboxane B, and 6-keto-prostaglandin F1 alpha rose to 1,660 +/- 250 pg/ml (p less than 0.01) and to 600 +/- 100 pg/ml (p greater than 0.1), respectively, in the smoke-injured animals compared with 770 +/- 150 pg/ml and 400 +/- 100 pg/ml in the non-smoke-exposed control animals. Indomethacin (n = 11) blocked the increase in both thromboxane and prostacyclin metabolites but failed to prevent lung edema.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Ibuprofen prevents synthetic smoke-induced pulmonary edema. 353 56

We examined the mechanism of the bone marrow-induced pulmonary edema in the isolated Ringer-perfused rabbit lung. Bone marrow administration (0.2 ml/kg body wt) increased pulmonary arterial pressure, capillary pressure, arterial resistance, and venous resistance within 2-4 min. Bone marrow also produced marked increases in lung wet weight and the capillary filtration coefficient but at later time points (90-120 min) during the perfusion. Only the triglyceride-containing lipid component of the bone marrow produced increases in pulmonary hemodynamics, lung wet weight, and the capillary filtration coefficient comparable to those observed after bone marrow. Bone marrow and the lipid component of bone marrow both produced increases in venous effluent lipoprotein lipase activity (the enzyme responsible for hydrolysis of triglycerides to free fatty acids). Bone marrow also stimulated the production of thromboxane B2 but not 6-ketoprostaglandin F1 alpha in the perfused lung. Both meclofenamate (1 microM), a cyclooxygenase inhibitor, and U-60,257 (10 microM), a lipoxygenase inhibitor, attenuated the bone marrow-induced pulmonary hemodynamic response, whereas only U-60,257 attenuated the increases in lung wet weight and the capillary filtration coefficient. In conclusion, pulmonary embolization induced by bone marrow results in increases in lung weight and the capillary filtration coefficient in the isolated Ringer-perfused rabbit lung. Pulmonary vasoconstriction is partially dependent on arachidonic acid metabolites but appears to be independent of circulating blood-formed elements. The lipid component of bone marrow or products derived from this component (e.g., free fatty acids and lipoxygenase products) may mediate the bone marrow-induced pulmonary edema.
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PMID:Role of lipids in bone marrow-induced pulmonary edema. 357 Oct 64

A model of increased microvascular permeability pulmonary edema was developed in chronically instrumented unanesthetized sheep using perilla ketone (PK). PK did not cause changes in pulmonary hemodynamics but did cause marked increases in the flow of protein-rich lung lymph. The changes in lung lymph flow were accompanied by radiographic evidence of both interstitial and alveolar pulmonary edema as well as hypoxemia. PK did not cause acute changes in lung mechanics. Dynamic compliance of the lungs and FRC decreased later, concomitant with the changes in lung lymph flow, radiographic evidence for pulmonary edema, and hypoxemia. Resistance to air flow across the lungs and specific conductance did not change significantly after PK infusion. The severity of the radiographic evidence for pulmonary edema observed after PK correlated with the severity of the concomitant hypoxemia and changes in dynamic compliance of the lungs. PK did not cause increases in the concentrations of cyclooxygenase products of arachidonic acid in lung lymph or plasma or changes in blood leukocyte counts. We conclude that PK causes increased lung microvascular permeability pulmonary edema without acute changes in pulmonary hemodynamics. This model permits study of the pathophysiologic aspects of increased lung microvascular permeability without the concomitant functional alterations that complicate most other experimental models of diffuse lung injury.
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PMID:Perilla ketone: a model of increased pulmonary microvascular permeability pulmonary edema in sheep. 368 48

We examined the direct effects of thrombin on pulmonary vasomotor tone in isolated guinea pig lungs perfused with Ringer albumin (0.5% g/100 ml). The injection of alpha-thrombin (the native enzyme) resulted in rapid dose-dependent increases in pulmonary arterial pressure (Ppa) and pulmonary capillary pressure (Ppc), which were associated with an increase in the lung effluent thromboxane B2 concentration. The Ppa and Ppc responses decreased with time but then increased again within 40 min after thrombin injection. The increases in Ppc were primarily the result of postcapillary vasoconstriction. Pulmonary edema as evidenced by marked increases (60% from base line) in lung weight occurred within 90 min after thrombin injection. Injection of modified thrombins (i.e., gamma-thrombin lacking the fibrinogen recognition site or i-Pr2P-alpha-thrombin lacking the serine proteolytic site) was not associated with pulmonary hemodynamic or weight changes nor did they block the effects of alpha-thrombin. Indomethacin (a cyclooxygenase inhibitor), dazoxiben (a thromboxane synthase inhibitor), or hirudin (a thrombin antagonist) inhibited the thrombin-induced pulmonary vasoconstriction, as well as the pulmonary edema. We conclude that thrombin-induced pulmonary vasoconstriction is primarily the result of constriction of postcapillary vessels, and the response is mediated by generation of cyclooxygenase-derived metabolites. The edema formation is also dependent on activation of the cyclooxygenase pathway. The proteolytic site of alpha-thrombin is required for the pulmonary vasoconstrictor and edemogenic responses.
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PMID:Alpha-thrombin-induced pulmonary vasoconstriction. 369 33

It is known that reactive oxygen species cause lung injury in association with activation of arachidonate metabolism. Because metabolites of the cyclooxygenase pathway do not appear to mediate the injury, we considered that the 5-lipoxygenase pathway might be activated and that inhibition of the pathway could interfere with the development of the injury. Thus, we sought to induce an oxidant lung injury and to prevent such injury by inhibiting lipoxygenase pathway or by blocking leukotriene action. In isolated rat lungs, glucose oxidase added to a glucose-containing, cell-free perfusate was used to produce the injurious oxygen species. Lung edema occurred and increased with increasing oxygen tension in the inspired air. Light microscopy of the lung showed perivascular fluid cuffs, and electron microscopy showed endothelial cell damage. Measurements in the lung effluent showed that concentrations of 5-hydroxyeicosatetraenoic acid (5-HETE) and of cyclooxygenase metabolites increased after glucose oxidase administration; BW 755C, U60,257, and FPL 55712 inhibited the glucose-oxidase-induced lung edema. And U60,257 also inhibited the glucose-oxidase-induced increase in 5-HETE without concomitant inhibition of cyclooxygenase metabolites. Thus, glucose oxidase via generation of active oxygen species stimulated the lung 5-lipoxygenase pathway, and inhibitors of 5-lipoxygenase protected against the oxidant lung injury. Further, in these experiments, the injury occurred in the absence of circulating blood cells and was augmented by increasing the inspired oxygen concentration.
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PMID:Leukotriene inhibitors attenuate rat lung injury induced by hydrogen peroxide. 392 81

Polymorphonuclear leukocytes (PMN) are important participants in many models of acute lung edema. Enhanced metabolism of arachidonate is also characteristic of many of these models. We found that PMN and arachidonate, but neither alone, increased alveolar capillary permeability of isolated perfused lungs and increased transfer of albumin across monolayers of endothelial cells cultured on micropore filters. Inhibition of PMN, but not endothelial cyclooxygenase, blunted the edematous process. Neither PMN proteases nor PMN-derived oxidants were involved. The edemagenic activity was not found in supernatants of PMN and arachidonate, and unstable prostaglandins did not alter endothelial albumin transfer. The edemagenic process was not inhibited by blocking leukotriene synthesis, and endothelial albumin transfer was not increased by direct addition of leukotrienes to endothelium. These data demonstrate that PMN and arachidonate can interact to increase endothelial permeability and that PMN cyclooxygenase activity is important for this process. This interaction is of potential significance to the acute inflammatory process in the lung vasculature.
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PMID:Polymorphonuclear leukocyte: arachidonate edema. 392 84


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