6-ketoprostaglandin-f1-alpha and Pulmonary-Edema

The role of prostanoids in modulating respiratory syncytial virus (RSV) infection is unknown. We found that RSV infection in mice increases production of prostaglandin I(2) (PGI(2)). Mice that overexpress PGI(2) synthase selectively in bronchial epithelium are protected against RSV-induced weight loss and have decreased peak viral replication and gamma interferon levels in the lung compared to nontransgenic littermates. In contrast, mice deficient in the PGI(2) receptor IP have exacerbated RSV-induced weight loss with delayed viral clearance and increased levels of gamma interferon in the lung compared to wild-type mice. These results suggest that signaling through IP has antiviral effects while protecting against RSV-induced illness and that PGI(2) is a potential therapeutic target in the treatment of RSV.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Antibodies, Viral; Cytochrome P-450 Enzyme System; Disease Models, Animal; Epoprostenol; Female; Gene Deletion; Interferon-alpha; Interferon-beta; Interferon-gamma; Intramolecular Oxidoreductases; Lung; Male; Mice; Mice, Transgenic; Pulmonary Edema; Pulmonary Surfactant-Associated Protein A; Pulmonary Surfactant-Associated Protein B; Receptors, Epoprostenol; Respiratory Mucosa; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Signal Transduction; Weight Loss

The authors recently demonstrated that methylene blue (MB), an inhibitor of the nitric oxide (NO) pathway, reduces the increments in pulmonary capillary pressure, lung lymph flow and protein clearance in endotoxaemic sheep. In the present study, the authors examined whether MB influences pulmonary haemodynamics and accumulation of extravascular lung water (EVLW) by mechanisms other than the NO pathway. Sixteen awake, chronically-instrumented sheep randomly received either an intravenous injection of MB 10 mg x kg(-1) or isotonic saline. Thirty minutes later, all sheep received an intravenous infusion of Escherichia coli endotoxin 1 microg x kg(-1) for 20 min and either an intravenous infusion of MB 2.5 mg x kg(-1) x h(-1) or isotonic saline for 6 h. MB markedly attenuated the endotoxin-induced pulmonary hypertension and right ventricular failure, and reduced the accumulation of EVLW. Moreover, MB reduced the increments in plasma thromboxane B2 and 6-keto-prostaglandin F1alpha, and abolished the febrile response. However, MB had no effect on the changes in circulating neutrophils, serum hyaluronan, and total haemolytic activity of the alternative complement pathway. The authors conclude that in sheep, methylene blue attenuates the endotoxin-induced pulmonary hypertension and oedema, at least in part, by inhibiting the cyclo-oxygenase products of arachidonic acid. This is a novel effect of methylene blue in vivo.

Topics: 6-Ketoprostaglandin F1 alpha; Analysis of Variance; Animals; Disease Models, Animal; Endotoxins; Extravascular Lung Water; Female; Lung; Male; Methylene Blue; Probability; Prostaglandin-Endoperoxide Synthases; Pulmonary Circulation; Pulmonary Edema; Random Allocation; Reference Values; Sensitivity and Specificity; Sheep; Thromboxane B2

The role of liver in the respiratory dysfunction associated with acute pancreatitis has been evaluated. For this purpose, an experimental necrohemorrhagic pancreatitis was induced in rats by intraductal administration of 3.5% sodium taurocholate. Additionally, a portocaval shunt was performed before induction of acute pancreatitis to prevent the initial passage through the liver of substances released by the pancreas. Twelve hours after the induction of pancreatitis, increases in lung prostacyclin and thromboxane B2 synthesis, decreased lung superoxide dismutase activity, and increases in plasma phospholipase A2 activity were found. In addition, inflammatory injury was evidenced in lung by histopathological analysis. The portocaval shunt was able to prevent the metabolic changes and ameliorate the inflammatory process in the lung, suggesting that the liver plays an active role in the systemic inflammatory response to acute pancreatitis.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Lipase; Liver; Lung; Male; Pancreas; Pancreatitis; Phospholipases A; Phospholipases A2; Portacaval Shunt, Surgical; Pulmonary Edema; Rats; Rats, Sprague-Dawley; Superoxide Dismutase; Thromboxane B2

Phosgene, a toxic gas widely used as an industrial chemical intermediate, is known to cause life-threatening latent noncardiogenic pulmonary edema. Mechanisms related to its toxicity appear to involve lipoxygenase mediators of arachidonic acid (AA) and can be inhibited by pretreatment with drugs that increase adenosine 3',5'-cyclic monophosphate (cAMP). In the present study, we used the isolated buffer-perfused rabbit lung model to investigate the mechanisms by which cAMP protects against phosgene-induced lung injury. Posttreatment with dibutyryl cAMP (DBcAMP) was given 60-85 min after exposure by an intravascular or intratracheal route. Lung weight gain (LWG) was measured continuously. AA metabolites leukotriene (LT) C4, LTD4, and LTE4 and 6-ketoprostaglandin F1 alpha were measured in the perfusate at 70, 90, 110, 130, and 150 min after exposure. Tissue malondialdehyde and reduced and oxidized glutathione were analyzed 150 min postexposure. Compared with measurements in the lungs of rabbits exposed to phosgene alone, posttreatment with DBcAMP significantly reduced LWG, pulmonary arterial pressure, and inhibited the release of LTC4, LTD4, and LTE4. Intratracheal administration of DBcAMP was more effective than intravascular administration in reducing LWG. Posttreatment also decreased MDA and protected against glutathione oxidation observed with phosgene exposure. We conclude that phosgene causes marked glutathione oxidation, lipid peroxidation, release of AA mediators, and increases LWG. Posttreatment with DBcAMP attenuates these effects, not only by previously described inhibition of pulmonary endothelial or epithelial cell contraction but also by inhibition of AA-mediator production and a novel antioxidant effect.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Arachidonic Acids; Bucladesine; Glutathione; In Vitro Techniques; Injections, Intravenous; Intubation, Intratracheal; Leukotrienes; Male; Malondialdehyde; Organ Size; Phosgene; Proteins; Pulmonary Edema; Rabbits

Hyperpermeability is the crux of pathogenesis of sudden lung edema in many pulmonary disorders, especially in acute lung injury and acute respiratory distress syndrome (ARDS). Using our modified method for assessment of pulmonary vascular permeability, we observed the effects of xanthine with xanthine oxidase (X-XO) perfused in rat pulmonary artery and the protection of vasoactive intestinal polypeptide (VIP) against the injury of pulmonary vascular permeability. After addition of xanthine oxidase in the perfusate reservoir containing xanthine, 125I-albumin leak index (125I-ALI) was remarkably increased while peak airway pressure (Paw) showed no significant increase, and perfusion pressure of pulmonary artery (Ppa) and lung wet/dry weight ratio (W/D) were only slightly increased. Xanthine plus xanthine oxidase also increased thromboxane B2 (TX B2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) in the perfusate. Treatment with VIP obviously reduced or totally prevented all signs of injury. Simultaneously, VIP also diminished or abolished the associated generation of arachidonate products. The results indicated that VIP has potent protective activity against injury of pulmonary vascular permeability and may be a physiological modulator of inflammatory damage to vascular endothelium associated with toxic oxygen metabolites.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Antioxidants; Capillary Permeability; Lung; Male; Pulmonary Edema; Rats; Rats, Sprague-Dawley; Thromboxane B2; Vasoactive Intestinal Peptide; Xanthine Oxidase; Xanthines

Hyperpermeability is a crux of pathogenesis of sudden lung edema in many pulmonary disorders, especially in acute lung injury and adult respiratory distress syndrome (ARDS). Using our modified method for assessment of pulmonary vascular permeability, we observed the effects of xanthine with xanthine oxidase (X-XO) perfused in rat pulmonary artery and the protection of vasoactive intestinal polypeptide (VIP) against the injury of pulmonary vascular permeability. After addition of xanthine oxidase in the perfusate reservoir containing xanthine, 125I-albumin leak index (125IALI) was remarkably increased while peak airway pressure (Paw) was not significantly increased, and perfusion pressure of pulmonary artery (Ppa) and lung wet/dry weight ratio (W/D) were only slightly increased. Xanthine plus xanthine oxidase also increased thromboxane B2 (TX B2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) in the perfusate. Treatment with VIP obviously reduced or totally prevented all signs of injury. Simultaneously, VIP also diminished or abolished the associated generation of arachidonate products. The results indicated that VIP has potent protective activity against injury of pulmonary vascular permeability and may be a physiological modulator of inflammatory damage to vascular endothelium associated with toxic oxygen metabolites.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Capillary Permeability; Free Radical Scavengers; Male; Pulmonary Artery; Pulmonary Edema; Rats; Rats, Sprague-Dawley; Thromboxane B2; Vasoactive Intestinal Peptide; Xanthine; Xanthine Oxidase; Xanthines

Bronchial arterial (BA) perfusion could modify pulmonary arterial (PA) ischemia-reperfusion (IR) injury by promoting clearance of peribronchial edema or limiting edema formation through maintenance of pulmonary vessel integrity via bronchopulmonary anastomotic or pulmonary vasa vasorum flow. The purpose of this study was to determine the effect of BA perfusion on IR injury in isolated sheep lungs. In 12 lungs (BA++) the BA was perfused throughout 30 min of PA ischemia and 180 min of reperfusion. In 12 lungs (BA-+) BA perfusion was begun with PA reperfusion, and in 15 lungs (BA--) the BA was never perfused. After 180 min, extravascular lung water was less (P < 0.05) in BA++ and B-+ lungs [4.70 +/- 0.16 and 4.57 +/- 0.18 g/g blood-free dry lung (bfdl)] than in BA-- lungs (5.23 +/- 0.19 g/g bfdl). The reflection coefficient for albumin was greater (P < 0.05) in BA++ and BA-+ (0.57 +/- 0.06 and 0.75 +/- 0.03) than in BA-- lungs (0.44 +/- 0.04). The filtration coefficient in BA++ and BA-+ lungs (0.016 +/- 0.006 and 0.015 +/- 0.006 g.min-1 x mmHg-1 x kg-1) was not different from that in BA-- lungs (0.025 +/- 0.006 g.min-1 x mmHg-1 x kg-1). These results suggest that BA perfusion decreased reperfusion edema by attenuating the increase in pulmonary vascular permeability caused by IR injury. Moreover the result in BA-+ lungs suggests that the protective effect was mediated by BA perfusion of PA vasa vasorum rather than bronchopulmonary anastomotic flow, which was trivial compared with PA blood flow.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Bronchi; Bronchial Arteries; Capillary Permeability; Extravascular Lung Water; Ischemia; Lung; Lymphatic System; Pulmonary Circulation; Pulmonary Edema; Regional Blood Flow; Reperfusion Injury; Respiration, Artificial; Sheep; Thromboxane B2; Water-Electrolyte Balance

Perfusion redistribution (PR) after acute oleic acid (OA) lung injury may be the result of changes in the tissue concentration ratio of thromboxane (Tx) and prostacyclin (A. H. Stephenson et al. J. Appl. Physiol. 73: 2126-2134, 1992). We tested this hypothesis by determining whether the Tx mimetic U-46619 would mimic PR caused by cyclooxygenase inhibition with meclofenamate and whether the Tx receptor antagonist ONO-3708 would inhibit PR even in the presence of meclofenamate. Measurements of regional pulmonary blood flow (PBF) and lung water concentration were made with the nuclear medicine imaging technique of positron emission tomography. Measurements were made at baseline and 2 h after OA. At baseline, the spatial distribution of PBF was similar in all experimental groups. Two hours after OA, fractional PBF was reduced to the edematous lung in all groups given OA, but the magnitude of change was greater in those groups receiving meclofenamate or U-46619 compared with the change in the group given OA only. Thus, although the Tx mimetic produced the same amount of PR as meclofenamate, Tx inhibition did not prevent PR after meclofenamate. Therefore, the ratio of Tx to prostacyclin per se is not the critical determinant of PR.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; 6-Ketoprostaglandin F1 alpha; Animals; Cyclooxygenase Inhibitors; Dogs; Extravascular Lung Water; Image Processing, Computer-Assisted; Lung; Meclofenamic Acid; Oleic Acid; Oleic Acids; Prostaglandin Endoperoxides, Synthetic; Pulmonary Circulation; Pulmonary Edema; Pulmonary Gas Exchange; Receptors, Thromboxane; Thromboxane A2; Thromboxane B2; Tomography, Emission-Computed; Vasoconstriction

Exposure of isolated perfused rabbit lungs (IPL) to ischemia-reperfusion causes a transient increase in pulmonary arterial (PA) pressure at the onset of reperfusion. Because thromboxane A2 (TxA2) is a potent vasoconstrictor, we hypothesized that it may contribute to the ischemia-reperfusion-induced pressor response. To evaluate this hypothesis, we exposed IPL perfused with a cell-free solution to 40 min of warm ischemia followed by reperfusion and measured perfusate immunoreactive thromboxane B2 (iTxB2) and 6-ketoprostaglandin F1 alpha (i6-keto-PGF1 alpha). We observed that ischemia-reperfusion IPL compared with controls had an increase in PA pressure (40.2 +/- 4.8 vs. 9.3 +/- 0.3 mmHg, P < 0.05), lung edema (29.3 +/- 6.3 vs. -0.2 +/- 0.2 g, P < 0.05), iTxB2 perfusate levels (155 +/- 22 vs. < 50 pg/ml, P < 0.05), and i6-keto-PGF1 alpha (436 +/- 33 vs. 61 +/- 16 pg/ml, P < 0.05). In ischemia-reperfusion IPL, infusion of SQ 29548 (10(-6) M), a specific TxA2/prostaglandin H2 receptor antagonist, attenuated the PA pressor response and the degree of edema. We conclude that pulmonary hypertension associated with ischemia-reperfusion results in part from pulmonary release of TxA2. Furthermore, TxA2 directly through membrane effects or indirectly through hydrostatic mechanisms increases the severity of ischemia-reperfusion-induced lung edema.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Blood Pressure; Bridged Bicyclo Compounds, Heterocyclic; Fatty Acids, Unsaturated; Hydrazines; Hypertension, Pulmonary; In Vitro Techniques; Ischemia; Lung; Organ Size; Pulmonary Circulation; Pulmonary Edema; Rabbits; Radioimmunoassay; Receptors, Thromboxane; Reperfusion Injury; Thromboxane A2; Thromboxane B2; Thromboxanes; Vasoconstriction

Thromboxanes (Txs) were implicated as possible participants in the altered microvascular permeability of acute lung injury when the Tx synthase inhibitor, OKY-046, was reported to prevent pulmonary edema induced by phorbol myristate acetate (PMA). Recently, however, we found that OKY-046, at a dose just sufficient to block Tx synthesis in intact dogs, did not prevent PMA-induced pulmonary edema but rather merely reduced it modestly. The present study was designed to explore other mechanisms whereby OKY-046 might prevent PMA-induced pulmonary edema. The finding that 5-lipoxygenase (5-LO) metabolites of arachidonic acid were increased within the lung after PMA administration, coupled with the report that OKY-046 inhibited slow-reacting substance of anaphylaxis formation, permitted formulation of the hypothesis that OKY-046, at a dose in excess of that required to inhibit Tx synthesis, inhibits the formation of a product(s) of 5-LO and, thereby, prevents edema formation. In vehicle-pretreated pentobarbital-anesthetized male mongrel dogs (n = 4), PMA (20 micrograms/kg i.v.) increased pulmonary vascular resistance (PVR) from 4.4 +/- 0.3 to 26.3 +/- 8.8 mmHg.l-1 x min (P < 0.01) and extravascular lung water from 6.7 +/- 0.5 to 19.1 +/- 6.2 ml/kg body wt (P < 0.05). Concomitantly, both TxB2 and leukotriene B4 (LTB4) were significantly increased in the lung. Pretreatment with OKY-046 (100 mg/kg i.v., n = 8) prevented PMA-induced increases in TxB2, LTB4, and pulmonary edema formation but did not prevent the increase in PVR.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Arachidonate 5-Lipoxygenase; Cardiac Output; Dogs; Extravascular Lung Water; Leukocyte Count; Leukotriene B4; Male; Methacrylates; Oxygen; Pulmonary Edema; Tetradecanoylphorbol Acetate; Thromboxane-A Synthase; Thromboxanes

For the past half-century, several high molecular weight compounds have been used for volume expansion during cardiopulmonary resuscitation. However, the effectiveness and side effects of these different expanders are varied. We have compared plasma, pentastarch, and a new product, pentafraction, for effective plasma volume expansion before and after tissue injury with endotoxin administration. In each group, eight range ewes instrumented with a Swan-Ganz, arterial, and venous catheters, and lung and flank lymphatic cannulas were compared. Each group received 15 ml/kg of either 6% pentafraction, 6% pentastarch, or plasma followed two hours later by 1.5 micrograms/kg/0.5 hr E. Coli endotoxin over 30 min. Data were collected for an additional 24 hr after endotoxin administration. Our results indicated a plasma volume expansion in all three groups. However, the prior administration of pentafraction significantly attenuated the increase in the lung lymph flow and early evaluation of systemic vascular resistance noted with endotoxin in comparison to the other two groups.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Blood Pressure; Capillary Permeability; Disease Models, Animal; Hydroxyethyl Starch Derivatives; Lymph; Molecular Weight; Pulmonary Edema; Sheep; Shock, Septic; Thromboxane B2

We tested the preventive effects of catalase, an enzymatic scavenger of hydrogen peroxide, or dimethyl sulfoxide (DMSO), a hydroxyl radical scavenger, on intravenous alloxan-induced lung edema in four groups of pentobarbital sodium-anesthetized, ventilated dogs for 3 h: saline (20 ml.kg-1.h-1) infusion alone (n = 5), alloxan (75 mg/kg) + saline infusion (n = 5), catalase (150,000 U/kg) + alloxan + saline infusion (n = 5), or DMSO (4 mg/kg) + alloxan + saline infusion (n = 5). Catalase or DMSO significantly prevented the increase in plasma thromboxane B2 and 6-keto-prostaglandin F1 alpha over 3 h after alloxan and the accumulation of extravascular lung water after 3 h [3.95 +/- 0.52 (SE) g/g with catalase, 3.06 +/- 0.42 g/g with DMSO] but not early pulmonary arterial pressor response. An electron microscopic study indicated that catalase or DMSO significantly reduced the endothelial cellular damages after alloxan. These findings strongly suggest that hydrogen peroxide and hydroxyl radical are major mediators responsible for intravenous alloxan-induced edematous lung injury in anesthetized ventilated dogs.

Topics: 6-Ketoprostaglandin F1 alpha; Acute Disease; Alloxan; Animals; Blood Pressure; Catalase; Dimethyl Sulfoxide; Dogs; Endothelium; Free Radical Scavengers; Free Radicals; Leukocyte Count; Microscopy, Electron; Platelet Count; Pulmonary Alveoli; Pulmonary Circulation; Pulmonary Edema; Pulmonary Wedge Pressure; Thromboxane B2

We have proposed that endogenous prostacyclin opposes the vasoconstriction responsible for redistribution of regional pulmonary blood flow (rPBF) away from areas of increased regional lung water concentration (rLWC) in canine oleic acid- (OA) induced acute lung injury (D. P. Schuster and J. Haller. J. Appl. Physiol. 69: 353-361, 1990). To test this hypothesis, we related regional lung tissue concentrations of 6-ketoprostaglandin (PG) F1 alpha and thromboxane (Tx) B2 in tissue samples obtained 2.5 h after administration of OA (0.08 ml/kg iv) to rPBF and rLWC measured by positron emission tomography. After OA only (n = 16), rLWC increased in dependent lung regions. Some animals responded to increased rLWC by redistribution of rPBF away from the most edematous regions (OA-R, n = 6), whereas others did not (OA-NR, n = 10). In another six animals, meclofenamate was administered after OA (OA-meclo). After OA, tissue concentrations of 6-keto-PGF1 alpha were greater than TxB2 in all groups, but concentrations of 6-keto-PGF1 alpha were not different between OA-R and OA-NR animals. TxB2 was increased in the dependent regions of animals in both OA-R and OA-NR groups compared with controls (no OA, n = 4, P < 0.05). The tissue TxB2/6-keto-PGF1 alpha ratio was smaller in controls and OA-NR in which no perfusion redistribution occurred than in OA-R and OA-meclo in which it did occur. This TxB2/6-keto-PGF1 alpha ratio correlated significantly with the magnitude of perfusion redistribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Blood Gas Analysis; Body Water; Dogs; Eicosanoids; Hemodynamics; Meclofenamic Acid; Oleic Acid; Oleic Acids; Perfusion; Pulmonary Circulation; Pulmonary Edema; Thromboxane A2; Tomography, Emission-Computed

It has been suggested that the von Willebrand factor antigen (vWF:Ag) may be a clinical marker for pulmonary endothelial cell injury. An ELISA was developed for the measurement of rat vWF:Ag. Rat lungs were isolated and perfused with a recirculating, blood-free, physiologic salt solution. Circulating levels of vWF:Ag and the eicosanoids thromboxane B2 (TXB2) and prostaglandin 6-keto F1-alpha (6-keto PGF1 alpha) were measured before and after different forms of insult. The addition of phospholipase C (PLC) or hydrogen peroxide (H2O2) to the perfusate caused lung damage as manifested by pulmonary artery pressure increase and pulmonary edema. This was paralleled by significant release of vWF:Ag, TXB2, and 6-keto PGF1 alpha. Increased hydrostatic pressure caused pulmonary edema without vWF:Ag and eicosanoid release. The addition of vasopressin to the perfusate caused vWF:Ag release but no lung injury and no release of eicosanoids. It is concluded that in the rat model, vWF:Ag release is a nonspecific marker for lung injury.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Enzyme-Linked Immunosorbent Assay; Hydrogen Peroxide; Hydrostatic Pressure; In Vitro Techniques; Lung; Male; Pulmonary Edema; Rats; Rats, Inbred Strains; Thromboxane B2; Type C Phospholipases; Vasopressins; von Willebrand Factor

We analyzed edema fluid in two cases of reexpansion pulmonary edema during thoracotomy. High value of the fluid to plasma protein concentration ratio indicates an increase in pulmonary microvascular permeability. There were marked increases in polymorphonuclear leukocyte (PMN) count and concentration of PMN-elastase in edema fluid. There were also increases in concentrations of thromboxane B2 and 6-keto-PGF1-alpha in both edema fluid and plasma. These findings strongly suggest that the mechanism of reexpansion pulmonary edema is an inflammatory response and that PMNs in the reexpanded lung may play a role in the increase in permeability.

Topics: 6-Ketoprostaglandin F1 alpha; Acute Disease; Adolescent; Adult; Exudates and Transudates; Female; Humans; Inflammation; Pancreatic Elastase; Proteins; Pulmonary Atelectasis; Pulmonary Edema; Thromboxane B2

Perfusion of isolated rabbit lungs with hydrogen peroxide (H2O2, 3 x 10(-5) M) raised the overflow of thromboxane B2 (TXB2) and the perfusion pressure. H2O2 induced oedema formation and endothelial distress, as evidenced by an increased production of 6-oxo-prostaglandin F1 alpha (6-oxo-PGF1 alpha). Endothelial cell death did not occur since there was no release of lactate dehydrogenase. The thromboxane A2 (TXA2)-synthase inhibitor/receptor antagonist ridogrel (R68070) further enhanced 6-oxo-PGF1 alpha output, while inhibiting TXB2 release. Ridogrel prevented the rise in pulmonary artery pressure and oedema formation. These data indicate that TXA2 is probably involved in the acute pulmonary pressor response and concomitant oedema formation induced by H2O2. In order to assess the functional activity of the pulmonary endothelium, the uptake of 5-hydroxytryptamine (5-HT) was measured before and 15 min after exposure to H2O2. As the H2O2-induced effects were not associated with any change in the uptake of 5-hydroxytryptamine (5-HT), we conclude that the endothelial injury was reversible or that the 5-HT uptake was not sensitive enough to evaluate the integrity of the pulmonary endothelium during oxidant-induced injury.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Blood Pressure; Cell Death; Endothelium, Vascular; Female; Hydrogen Peroxide; L-Lactate Dehydrogenase; Lung; Pentanoic Acids; Pulmonary Edema; Pyridines; Rabbits; Serotonin; Thromboxane A2; Thromboxane-A Synthase

Interleukin-2 (IL-2) produces toxicity characterized by generalized edema within 24 hours. This study tests whether the rate of IL-2 administration modulates the onset of edema and examines thromboxane (Tx) and neutrophils as possible mediators of this event. Recombinant human IL-2, 10(5) U (n = 7), 10(6) U (n = 9), or vehicle (n = 8) were given to anesthetized rats intravenously during a period of 1 hour. At 6 hours edema, as measured by increase in wet to dry weight (w/d) ratio, was present in the heart, liver, and kidney, with 10(5) U IL-2 and in the lung, heart, liver and kidney, with 10(6) U IL-2, relative to values with vehicle-infused controls (all p less than 0.05). With a 1-hour infusion of 10(6) U IL-2, there was an increase in plasma thromboxane (Tx)B2 level to 1290 +/- 245 pg/mL, higher than 481 +/- 93 pg/mL in control rats (p less than 0.05); lung polymorphonuclear leukocyte (PMN) sequestration of 53 +/- 7 PMN/10 higher-power fields (HPF) relative to 23 +/- 2 PMN/10 HPF in controls (p less than 0.05); and increased bronchoalveolar lavage (BAL) fluid protein concentration of 1970 +/- 210 micrograms/mL relative to 460 micrograms/mL in controls (p less than 0.05). When 10(6) U IL-2 was given as a 1-minute intravenous bolus (n = 9), edema was not demonstrated, plasma TxB2 levels were similar to controls, there was no leukosequestration, and BAL protein levels were normal. These data indicate that a constant infusion but not the rapid bolus administration of IL-2 produces in rats multiple-system organ edema, increased plasma TxB2, sequestration of PMNs, and microvascular permeability. These findings may explain the early toxicity seen in patients given high-dose IL-2 in cancer treatment.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Bronchoalveolar Lavage Fluid; Edema; Heart Diseases; Infusions, Intravenous; Injections, Intravenous; Interleukin-2; Kidney Diseases; Liver Diseases; Male; Neutrophils; Pulmonary Edema; Rats; Rats, Inbred Strains; Recombinant Proteins; Thromboxane A2; Thromboxane B2

Results from previous studies indicate that injury in isolated rat lungs perfused with buffer containing phorbol myristate acetate (PMA) and rat neutrophils (PMNs) is dependent on the production of reactive oxygen species and thromboxane (Tx) A2. The purpose of this study was to determine whether the lung or the PMN was the source of TxA2 required to produce lung injury in this model. Prostanoid synthesis by rat lungs or PMNs was inhibited selectively by pretreatment of either rats or isolated PMNs with aspirin (100 mg/kg p.o. or 100 microM, respectively). Unbound aspirin was removed from the lungs and PMNs before use in experiments. Lungs from vehicle-pretreated rats that were perfused with PMA and untreated PMNs exhibited increases in weight, lavage fluid albumin content and TxB2 production with respect to lungs perfused with PMA but no PMNs. Increases in these markers were prevented when cyclooxygenase from either the lungs or the PMNs was inhibited. These results indicate that TxA2 is produced by both PMNs and by lung cells in this preparation, and that TxA2 production by both of these sources is required for the manifestation of edema.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Aspirin; Cyclooxygenase Inhibitors; Lung; Male; Neutrophils; Oxygen; Pulmonary Edema; Rats; Rats, Inbred Strains; Tetradecanoylphorbol Acetate; Thromboxane B2

To verify the presence of the constitutional abnormality implicated in the pathogenesis of high-altitude pulmonary edema (HAPE), we evaluated the hemodynamic responses to hypoxia, hypobaria, and exercise in HAPE-susceptible subjects (HAPE-S). HAPE-S were five males with a history of HAPE. Five healthy volunteers who had repeated experiences of mountain climbing without any history of altitude-related problems served as controls. HAPE-S showed much greater increase in pulmonary vascular resistance index (PVRI) than the control subjects, resulting in a much higher level of pulmonary arterial pressure (Ppa), under both acute hypoxia of 15% O2 (Ppa = 29.0 +/- 2.8 vs. 17.8 +/- 0.3 Torr, P less than 0.05) and acute hypobaria of 515 Torr (32.3 +/- 2.8 vs. 19.1 +/- 0.8 Torr, P less than 0.05). Also, PVRI in HAPE-S exhibited a tendency to increase even during light exercise with supine bicycle ergometer (50 W), whereas PVRI in the control subjects significantly decreased, so that HAPE-S showed a greater increase in Ppa (delta Ppa = 16.0 +/- 1.5 vs. 4.9 +/- 1.1 Torr, P less than 0.001) and a greater decrease in arterial oxygen tension (17.8 +/- 4.7 vs. 5.6 +/- 1.7 Torr, P less than 0.05). We thus conclude that HAPE-S have a constitutional abnormality, which can be evaluated at low altitude, in the pulmonary circulatory responses to possible causative factors of HAPE such as hypoxia, hypobaria, and exercise.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Altitude Sickness; Atmospheric Pressure; Atrial Natriuretic Factor; Blood Gas Analysis; Disease Susceptibility; Hemodynamics; Humans; Hypoxia; Male; Physical Exertion; Pulmonary Edema; Thromboxane B2

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.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Female; Ibuprofen; Lung; Lung Diseases; Male; Nicotiana; Organometallic Compounds; Pentetic Acid; Plants, Toxic; Pulmonary Alveoli; Pulmonary Edema; Rabbits; Smoke; Technetium; Technetium Tc 99m Pentetate; Thromboxane B2; Time Factors

Neutropenia was produced in goats by injection of either nitrogen mustard, (1.5 mg/kg) or hydroxyurea (200 mg X kg-1 X day-1). A nitrogen mustard (M + E) group (n = 6), a hydroxyurea (H + E) group (n = 5), and a control (E) group (n = 7) were given 1-h infusions of endotoxin (5 micrograms/kg total dose), then monitored for up to 5 h. Postmortem extravascular lung water (EVLW) was significantly higher in the M + E group (14.2 +/- 4.4 ml/kg) and the E group (11.9 +/- 3.9 ml/kg) when compared with a normal control (6.6 +/- 1.3 ml/kg) group that did not receive endotoxin. EVLW in a group made neutropenic with nitrogen mustard (6.7 +/- 1.3 ml/kg) and the H + E (7.9 +/- 1.5 ml/kg) groups were not statistically different from each other or from normal controls. Circulating neutrophil counts averaged 32 +/- 42 cells/microliter in the M + E group and 180 +/- 210 cells/microliter in the H + E group. Only minimal histological changes were seen in the H + E group, but the E and M + E lungs had severe pulmonary edema. We conclude that neutrophils are not required for increased EVLW and decreased arterial O2 partial pressure after endotoxin infusion, and hydroxyurea prevents at least part of the pulmonary edema after endotoxin by a mechanism that is not neutrophil dependent.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Blood Pressure; Blood Proteins; Body Water; Cardiac Output; Endotoxins; Escherichia coli; Goats; Hydroxyurea; Leukocyte Count; Mechlorethamine; Neutrophils; Oxygen; Pulmonary Artery; Pulmonary Edema; Pulmonary Wedge Pressure; Thromboxane B2

In a previous study, we demonstrated that a non-toxic concentration of phorbol myristate acetate (PMA) produced edema in isolated rat lungs which were coperfused with neutrophils (PMN). In this study, we examined whether prostaglandins or thromboxane were responsible for increases in pressure and/or edema in this preparation. In lungs perfused with PMA (14 ng/ml) and PMN (1 X 10(8], significantly greater amounts of thromboxane B2 (TxB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) were produced than in controls. Relative lung weights and increases in perfusion pressure correlated with concentrations of TxB2 and 6-keto-PGF1 alpha that were produced. Indomethacin (10 microM) or Dazmegrel (10 microM) retarded the increase in perfusion pressure and prevented the increase in relative lung weight induced by PMA and PMN. When lungs were perfused with a high concentration of PMA (57 ng/ml) in the absence of added PMN, lungs also become edematous. Compared to controls, concentrations of TxB2 and 6-keto-PGF1 alpha were elevated in media collected from this preparation. As with lungs perfused with PMN and PMA, increases in pressure and relative weights of lungs perfused with PMA (57 ng/ml) correlated with the concentrations of TxB2 that were detected in perfusion media. Although indomethacin (10 microM) and Dazmegrel (50 microM) retarded the increase in perfusion pressure in this preparation, they only partially attenuated the increase in lung weight. These results suggest that, depending on the concentration, PMA can produce lung injury via different mechanisms. Thromboxane does not seem to be required for the genesis of edema induced by a high concentration of PMA in the absence of perfused neutrophils; however, it appears to play an obligatory role in the pathogenesis of edema induced by a low concentration of PMA in the presence of PMN.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Imidazoles; Indomethacin; Lung; Male; Neutrophils; Organ Size; Perfusion; Pressure; Pulmonary Edema; Rats; Rats, Inbred Strains; Tetradecanoylphorbol Acetate; Thromboxane B2; Thromboxane-A Synthase

Inhalation injury was induced in chronically instrumented sheep (n = 9) by insufflating them with smoke from burning cotton cloth. Sham animals (n = 9) were insufflated with air. There were no temporal changes in any measured parameter of the sham animals. Smoke induced a depression in PaO2. There was a threefold elevation in protein-rich pulmonary lymph which was sustained for over 48 hours. The lymph-to-plasma oncotic pressure ratio was increased. The cardiac index, left atrial pressure, and pulmonary arterial pressure remained unchanged in both groups. After smoke inhalation, the interstitial levels of neutrophils increased while interstitial antiprotease activity was depressed. The lung lymph concentration of 6-keto prostaglandin F1a, the major metabolite of prostacyclin, was increased. These data suggest that the pulmonary injury following smoke inhalation is the result of an increase in lung microvascular permeability to protein with resultant pulmonary edema. The mechanisms responsible for these changes appear to be related to direct injury to the tracheobronchial tree by cytotoxic agents in the smoke; polymorphonuclear leukocytes; and, possibly, eicosanoids.

Topics: 6-Ketoprostaglandin F1 alpha; alpha-Macroglobulins; Animals; Burns, Inhalation; Capillary Permeability; Cardiac Output; Female; Lung; Lung Injury; Lymph; Neutrophils; Pulmonary Edema; Sheep; Smoke; Thromboxane B2; Time Factors

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)

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Drug Evaluation, Preclinical; Epoprostenol; Germ-Free Life; Hemodynamics; Hydrochloric Acid; Ibuprofen; Indomethacin; Lung; Male; Pulmonary Edema; Rats; Rats, Inbred Strains; Smoke; Thromboxane B2

The effects of methylprednisolone, F(ab')2 fragments of human gamma globulins and rosmarinic acid, an inhibitor of complement activation, were tested on endotoxin-induced haemodynamic and haematological changes in the rabbit. Their effects were compared with complement depletion by cobra venom factor (CVF) pretreatment. The results provide further evidence for the role of complement activation and the concomitant triggering of the arachidonic acid cascade in the early phase of shock. The formation of vasoactive prostanoids (prostacyclin and thromboxane A2), the arterial hypotension and the thrombocytopenia were largely dependent on the presence of the intact complement system. F(ab')2 fragments (150 mg kg-1, i.v.) diminished the second fall in blood pressure to some extent but failed to alter any of the other endotoxin-induced changes. Methylprednisolone (40 mg kg-1, i.v.) given 10 min before endotoxin significantly reduced the activation of complement, the second rise of prostacyclin and the secondary hypotension, but was without effect on the early thromboxane peak of the haematological features of endotoxin shock. Rosmarinic acid (20 mg kg-1, i.v.) may be of potential interest for treatment of septic shock, since the drug suppressed the endotoxin-induced activation of complement, the formation of prostacyclin, both hypotensive phases, the thrombocytopenia and the concomitant release of thromboxane A2. The role of leukocytes and their arachidonic acid metabolites in plasma exudation deserves further investigation, because leukopenia and pulmonary oedema were not complement-dependent and were not affected by any of the treatments. Our results indicate that drugs, interfering with complement activation and/or prostaglandin biosynthesis, may be beneficial in endotoxin shock, provided that they are administered at an early stage.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Blood Pressure; Cinnamates; Complement Activation; Depsides; Elapid Venoms; Endotoxins; Hemodynamics; Hemolysis; Immunoglobulin Fab Fragments; In Vitro Techniques; Leukocyte Count; Methylprednisolone; Platelet Count; Pulmonary Edema; Rabbits; Rosmarinic Acid; Thromboxane B2

Hyperoxia and infused granulocytes act synergistically in producing a nonhydrostatic high-permeability lung edema in the isolated perfused rabbit lung within 4 h, which is substantially greater than that seen with hyperoxia alone. We hypothesized that the interaction between hyperoxia and granulocytes was principally due to a direct effect of hyperoxia on the lung itself. Isolated perfused rabbit lungs that were preexposed to 2 h of hyperoxia (95% O2-5% CO2) prior to the infusion of unstimulated granulocytes (under normoxic conditions) developed significant nonhydrostatic lung edema (P = 0.008) within 2 h when compared with lungs that were preexposed to normoxia (15% O2-5% CO2) prior to granulocyte perfusion. The edema in the hyperoxic-preexposed lungs was accompanied by significant increases in bronchoalveolar lavage (BAL) protein, BAL granulocytes, BAL thromboxane and prostacyclin levels, perfusate chemotactic activity, and lung lipid peroxidation. These findings suggest that the synergistic interaction between hyperoxia and granulocytes in producing acute lung injury involves a primary effect of hyperoxia on the lung itself.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Biomechanical Phenomena; Bronchi; Cell Count; Chemotaxis; Granulocytes; In Vitro Techniques; Lipid Peroxides; Lung; Lung Diseases; Oxygen; Pulmonary Alveoli; Pulmonary Edema; Rabbits; Therapeutic Irrigation; Thromboxane B2

To determine if vascular abnormalities in preterm neonates might be related to vasoactive prostaglandins, stable prostacyclin (6-KPGF1 alpha) and thromboxane A2 (T X B2) metabolites in arterial blood were measured at less than or equal to 6 hours after birth and at 24, 48, and 72 hours using a radioimmunoassay. Neonates of less than 32 weeks gestation (N = 26) were diagnosed as having either the idiopathic respiratory distress syndrome (IRDS, N = 15) or pulmonary edema (PE, N = 11), and were also grouped according to the presence or absence of intracranial hemorrhage (ICH, N = 11) or patent ductus arteriosus (PDA, N = 10). Initial plasma 6-KPGF1 alpha was greater in neonates with ICH (0.23 +/- 0.04 ng/ml, mean +/- SE) than without ICH (0.11 +/- 0.04, p less than 0.05). Neonates with both ICH and IRDS (N = 8) had significantly elevated T X B2 at all sampling times compared to neonates with IRDS and no ICH (N = 7). Both T X B2 and 6-KPGF1 alpha increased with time in those with major ICH. Among neonates without ICH, 7 with IRDS had higher initial 6-KPGF1 alpha (0.19 +/- 0.07 ng/ml) and lower T X B2 (0.15 +/- 0.04 ng/ml) than 8 with PE (0.04 +/- 0.01 and 0.37 +/- 0.09 ng/ml, respectively). The initial 6-KPGF1 alpha (0.024 + 0.003 ng/ml), measured in neonates with PE and without PDA or ICH (N = 6), was significantly less than the corresponding value in the other neonates (0.201 +/- 0.036 ng/ml) (N = 20).

Topics: 6-Ketoprostaglandin F1 alpha; Cerebral Hemorrhage; Ductus Arteriosus, Patent; Humans; Infant, Newborn; Infant, Premature, Diseases; Pulmonary Edema; Respiratory Distress Syndrome, Newborn; Thromboxane B2; Thromboxanes

Plasma concentrations of 6-oxo-prostaglandin F1 alpha (6-oxo-PGF1 alpha) and thromboxane B2 (TXB2) were measured by radioimmunoassay in arterial blood before and after injections of the complement activator, cobra venom factor (CVF). During the control period, the concentration of 6-oxo-PGF1 alpha, which gives the sum of prostacyclin plus 6-oxo-PGF1 alpha, and TXB2 were, respectively, less than 20 pg ml-1 and 70 +/- 15 pg ml-1. Intravenous injections of CVF induced dose-dependent, reversible elevations in the plasma levels of both prostanoids. The time courses for the increases of 6-oxo-PGF1 alpha and TXB2 paralleled the arterial hypotension and thrombocytopenia, suggesting the existence of a causal relationship between these parameters. The results further support our hypothesis that complement-dependent formation of arachidonic acid metabolites contributes to some of the haemodynamic and haematological changes occurring during endotoxin shock.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Complement Activation; Elapid Venoms; Epoprostenol; Female; Hematocrit; Leukocyte Count; Male; Platelet Count; Prostaglandins; Pulmonary Edema; Rabbits; Radioimmunoassay; Thromboxane A2

This study examined the effect of acute endotoxemia on hypoxic pulmonary vasoconstriction (HPV) in awake sheep. Thirteen sheep were chronically instrumented with Silastic catheters in the pulmonary artery, left atrium, jugular vein, and carotid artery; with a Swan-Ganz catheter in the main pulmonary artery; with a chronic lung lymph fistula; and with a tracheostomy. Base-line HPV was determined by measuring the change in pulmonary vascular resistance (PVR) while sheep breathed 12% O2 for 7 min. Concentrations of immunoreactive 6-keto-PGF1 alpha and thromboxane B2 (TXB2) were measured in lung lymph during the hypoxic challenge. Escherichia coli endotoxin (0.2-0.5 micrograms/kg) was infused intravenously. Four hours after endotoxemia, HPV was measured. In five sheep, meclofenamate was infused at 4.5 h after endotoxemia and HPV measured again. During the base-line hypoxic challenge, PVR increased by 36 +/- 9% (mean +/- SE). There was no significant change in lung lymph 6-keto-PGF1 alpha or TXB2 levels with hypoxia. Twelve of the 13 sheep showed a decrease in HPV 4 h after endotoxemia; the mean change in PVR with hypoxia was -8 +/- 5%, which was significantly (P less than 0.05) reduced compared with base-line HPV. The infusion of meclofenamate at 4.5 h after endotoxin did not restore HPV.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Consciousness; Endotoxins; Escherichia coli; Lymph; Meclofenamic Acid; Oxygen; Pulmonary Artery; Pulmonary Edema; Pulmonary Veins; Sheep; Thromboxane B2; Vasoconstriction

We tested the effects of OKY-046, a selective thromboxane synthetase inhibitor, on endotoxin-induced lung injury in unanesthetized sheep in order to evaluate the role of thromboxane (Tx) in this injury. Escherichia coli endotoxin (1 microgram/kg) infusion produced a biphasic response. The early period (Phase 1) was a transient pulmonary hypertension. The late period (Phase 2) was a more prolonged period characterized by a marked high flow of lung lymph with a high concentration of protein, suggesting increased pulmonary vascular permeability. During Phase 1, there were remarkable increases in TxB2 and 6-keto-PGF1 alpha concentrations in lung lymph and in plasma samples obtained from the pulmonary artery (PA) and the left atrium (LA). The increase in plasma TxB2 level of the LA was greater than that of the PA. During Phase 2, TxB2 levels returned to the baseline values, whereas 6-keto-PGF1 alpha levels remained elevated. Pretreatment with OKY-046 prevented the pulmonary hypertension and increases in TxB2 levels during Phase 1. However, OKY-046 had little effect on lung lymph balance during Phase 2. We conclude that the early pulmonary hypertension induced by endotoxin is mediated mainly by release of TxA2 from the lungs, and TxA2 is not attributed to the increased pulmonary permeability during the late period.

Topics: 6-Ketoprostaglandin F1 alpha; Acrylates; Animals; Blood Gas Analysis; Body Fluids; Consciousness; Endotoxins; Escherichia coli; Hemodynamics; Hydrogen-Ion Concentration; Hypertension, Pulmonary; Leukocyte Count; Lung; Methacrylates; Oxidoreductases; Platelet Count; Pulmonary Edema; Sheep; Thromboxane B2; Thromboxane-A Synthase

Active oxygen species can cause lung injury. Although a direct action on endothelial cells is proposed, the possibility exists that they might cause injury via mediators. We considered that active oxygen species would stimulate the generation of cyclooxygenase metabolites, which then alter pulmonary vasoreactivity and cause edema. We chemically produced hydrogen peroxide by adding glucose oxidase to a plasma- and cell-free, but beta-D-glucose-containing, solution, which perfused isolated rat lungs. Addition of glucose oxidase to the perfusate caused a marked decrease in pulmonary vasoreactivity, accompanied by an increase in the concentrations of prostacyclin, thromboxane A2, and prostaglandin F2 alpha. Pretreatment with catalase, a specific scavenger of hydrogen peroxide, preserved pulmonary vasoreactivity, inhibited the increase of the concentration of the measured prostaglandins, and prevented edema formation. Indomethacin effectively blocked lung prostaglandin production but neither prevented the decrease in vasoreactivity nor inhibited edema formation. From these data we conclude that hydrogen peroxide impaired pulmonary vasoreactivity and subsequently caused edema. Despite the fact that hydrogen peroxide stimulated lung prostaglandin production, cyclooxygenase-derived products neither caused the decrease in vasoreactivity nor the development of edema.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Glucose Oxidase; Hydrogen Peroxide; In Vitro Techniques; Lung; Male; Organ Size; Prostaglandin-Endoperoxide Synthases; Prostaglandins F; Pulmonary Edema; Rats; Rats, Inbred Strains; Thromboxane B2

The effects of synthetic platelet-activating factor (PAF) on guinea pig lung were examined in isolated lungs perfused with platelet-free Krebs-Ringer solution. When PAF (1 microgram) was injected into the pulmonary artery (PA), it markedly increased airway pressure (maximal increase, 84.7%) and moderately raised PA pressure (maximal increase, 22.8%). The same dose also provoked a massive (29-fold) release of thromboxane B2 (TXB2), the stable metabolite of TXA2, into the perfusate, beginning before the increases in airway and PA pressures. The concentration of 6 keto-PGF1 alpha, the stable metabolite of prostacyclin, also increased (to 5 times control levels) about 70 s after peak release of TXB2. Indomethacin completely blocked TXB2 release, reduced the magnitude of airway pressure increase by 79%, and shortened its duration, as well as the duration of the PA pressure rise. Larger concentrations of PAF (3 and 10 micrograms) produced even greater increments in airway and PA pressures, but these were only moderately attenuated by indomethacin. Also, PAF increased extravascular lung water, as evidenced by increases in wet/dry lung weight and lung/body weight ratios. In a concentration of 0.1 microgram, PAF had no effects on airway or PA pressures, nor did it stimulate TXB2 or 6-keto-PGF1 alpha release. Lyso-PAF was similarly ineffective. We conclude that PAF induces airway constriction, pulmonary hypertension, and pulmonary edema in guinea pig lung independently of platelets. These effects are associated with stimulated synthesis of TXA2, but the mechanisms of their production remain to be determined.

Topics: 6-Ketoprostaglandin F1 alpha; Airway Resistance; Animals; Blood Platelets; Female; Guinea Pigs; Indomethacin; Lung; Perfusion; Platelet Activating Factor; Pressure; Pulmonary Edema; Thromboxane B2; Vascular Resistance

Prostacyclin (PG I2) generated by vascular endothelium is a strong antiaggregating substance. As platelet aggregation and release of humoral factor(s) have been reported to be crucial in the pathogenesis of acute lung injury following pulmonary microembolization, PG I2 could have a protective effect against microembolic lung vascular injury. Following unilateral microembolization, we have observed a large increase in the filtration coefficient in the nonembolized lung with a significant increase in 6-keto PG F1 alpha, the stable metabolite of PG I2, in arterial blood. The pretreatment with indomethacin (10 mg/kg) prevented the increase in 6-keto PG F1 alpha and potentiated the lung injury after microembolization. Exogenously administered PG I2 (20 ng/kg/min) prevented completely the increase in the filtration coefficient without any effects on hemodynamics, although these effects of indomethacin and PG I2 did not relate to their effects on platelet aggregation. Based on these results, we could conclude that prostacyclin could play an important role in preserving cell integrity of the lung and in prevention of increased lung vascular permeability following pulmonary microembolization.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Capillary Permeability; Dogs; Epoprostenol; Female; Hemodynamics; Indomethacin; Male; Platelet Aggregation; Platelet Count; Pulmonary Circulation; Pulmonary Edema; Pulmonary Embolism

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Blood Platelets; Blood Pressure; Dogs; Epoprostenol; Ibuprofen; Inhalation; Kinetics; Leukocyte Count; Lung; Pulmonary Edema; Respiration; Thrombocytosis; Thromboxane B2