Edema from cyclooxygenase products of endogenous arachidonic acid in isolated lung

1989 ◽  
Vol 67 (2) ◽  
pp. 846-855 ◽  
Author(s):  
M. R. Littner ◽  
F. D. Lott

We infused A23187, a calcium ionophore, into the pulmonary circulation of dextran-salt-perfused isolated rabbit lungs to release endogenous arachidonic acid. This led to elevations in pulmonary arterial pressure and to pulmonary edema as measured by extravascular wet-to-dry weight ratios. The increase in pressure and edema was prevented by indomethacin, a cyclooxygenase enzyme inhibitor, and by 1-benzylimidazole, a selective inhibitor of thromboxane (Tx) A2 synthesis. Transvascular flux of 125I-albumin from vascular to extravascular spaces of the lung was not elevated by A23187 but was elevated by infusion of oleic acid, an agent known to produce permeability pulmonary edema. We confirmed that A23187 leads to elevations in cyclooxygenase products and that indomethacin and 1-benzylimidazole inhibit synthesis of all cyclooxygenase products and TxA2, respectively, by measuring perfusate levels of prostaglandin (PG) I2 as 6-ketoprostaglandin F1 alpha, PGE2, and PGF2 alpha and TxA2 as TxB2. We conclude that release of endogenous pulmonary arachidonic acid can lead to pulmonary edema from conversion of such arachidonic acid to cyclooxygenase products, most notably TxA2. This edema was most likely from a net hydrostatic accumulation of extravascular lung water with an unchanged permeability of the vascular space, since an index of permeability-surface area product (i.e., transvascular albumin flux) was not increased.

1979 ◽  
Vol 47 (6) ◽  
pp. 1228-1233 ◽  
Author(s):  
D. S. Simon ◽  
J. F. Murray ◽  
N. C. Staub

We evaluated the attenuation of the 122 keV gamma ray of cobalt-57 across the thorax of anesthetized dogs as a method for following the time course of lung water changes in acute pulmonary edema induced by either increased microvascular permeability or increased microvascular hydrostatic pressure. The gamma rays traversed the thorax centered on the seventh rib laterally where the lung mass in the beam path was greatest. Calibration measurements in isolated lung lobes demonstrated the high sensitivity and inherent accuracy of the method over a wide range of lung water contents. In control dogs reproducibility averaged +/-3%. Increased permeability edema led to large rapid increases in the transthoracic gamma ray attenuation (TGA), while increased pressure caused an immediate, modest increase in TGA (vascular congestion) followed by a slow further increase over 2 h. There was a fairly good correlation between the increase in extravascular lung water and the change in TGA. The method is simple, safe, and noninvasive and appears to be useful for following the time course of lung water accumulation in generalized lung edema in anesthetized animals.


1985 ◽  
Vol 58 (4) ◽  
pp. 1092-1098 ◽  
Author(s):  
M. D. Walkenstein ◽  
B. T. Peterson ◽  
J. E. Gerber ◽  
R. W. Hyde

Histological studies provide evidence that the bronchial veins are a site of leakage in histamine-induced pulmonary edema, but the physiological importance of this finding is not known. To determine if a lung perfused by only the bronchial arteries could develop pulmonary edema, we infused histamine for 2 h in anesthetized sheep with no pulmonary arterial blood flow to the right lung. In control sheep the postmortem extravascular lung water volume (EVLW) in both the right (occluded) and left (perfused) lung was 3.7 +/- 0.4 ml X g dry lung wt-1. Following histamine infusion, EVLW increased to 4.4 +/- 0.7 ml X g dry lung wt-1 in the right (occluded) lung (P less than 0.01) and to 5.3 +/- 1.0 ml X g dry wt-1 in the left (perfused) lung (P less than 0.01). Biopsies from the right (occluded) lungs scored for the presence of edema showed a significantly higher score in the lungs that received histamine (P less than 0.02). Some leakage from the pulmonary circulation of the right lung, perfused via anastomoses from the bronchial circulation, cannot be excluded but should be modest considering the low pressures in the pulmonary circulation following occlusion of the right pulmonary artery. These data show that perfusion via the pulmonary arteries is not a requirement for the production of histamine-induced pulmonary edema.


1995 ◽  
Vol 78 (1) ◽  
pp. 64-69 ◽  
Author(s):  
C. A. Hales ◽  
S. Musto ◽  
W. G. Hutchison ◽  
E. Mahoney

Pulmonary edema following smoke inhalation is due to the chemical toxins in smoke and not to the heat. We have shown that acrolein, a common component of smoke, induces pulmonary edema, perhaps via release of leukotrienes. We, therefore, hypothesized that acrolein, a component of smoke from burning cotton, might have a major role in producing pulmonary edema in sheep after cotton smoke inhalation and that BW-755C, a combined cyclo- and lipoxygenase inhibitor, would prevent the edema, whereas indomethacin, a cyclooxygenase inhibitor, would not. In control anesthetized sheep (n = 7), 128 breaths of cotton smoke induced no change in pulmonary arterial pressure but induced increases (P < 0.05) in pulmonary lymph flow from 4.4 +/- 0.8 (SE) to 15 +/- 2.7 ml/h, lymph protein flux from 0.25 +/- 0.08 to 0.80 +/- 0.16 g/h, and blood-corrected wet-to-dry weight ratios from a normal value of 3.8 +/– 0.07 (n = 9) to 4.5 +/- 0.18. Indomethacin (n = 6) did not significantly prevent these changes, whereas BW-755C decreased lung lymph flow change from 5 +/- 1 to 7 +/- 2 ml/h (P = NS), lymph protein flux from 0.25 +/- 0.08 to 0.35 +/- 0.1 g/h (P = NS), and weight-to-dry ratio from normal to 3.9 +/- 2.1 (P = NS). These data suggest leukotrienes may have a role in producing cotton smoke-induced noncardiogenic pulmonary edema.


1994 ◽  
Vol 77 (2) ◽  
pp. 888-895 ◽  
Author(s):  
S. P. Janssens ◽  
S. W. Musto ◽  
W. G. Hutchison ◽  
C. Spence ◽  
M. Witten ◽  
...  

Inhalation of smoke containing acrolein, the most common toxin in urban fires after carbon monoxide, causes vascular injury with non-cardiogenic pulmonary edema containing potentially edematogenic eicosanoids such as thromboxane (Tx) B2, leukotriene (LT) B4, and the sulfidopeptide LTs (LTC4, LTD4, and LTE4). To determine which eicosanoids are important in the acute lung injury, we pretreated sheep with BW-755C (a combined cyclooxygenase and lipoxygenase inhibitor), U-63557A (a specific Tx synthetase inhibitor), or indomethacin (a cyclooxygenase inhibitor) before a 10-min exposure to a synthetic smoke containing carbon particles (4 microns) with acrolein and compared the results with those from control sheep that received only carbon smoke. Acrolein smoke induced a fall in arterial PO2 and rises in peak inspiratory pressure, main pulmonary arterial pressure, pulmonary vascular resistance, lung lymph flow, and the blood-free wet-to-dry weight ratio. BW-755C delayed the rise in peak inspiratory pressure and prevented the fall in arterial PO2, the rise in lymph flow, and the rise in wet-to-dry weight ratio. Neither indomethacin nor U-63557A prevented the increase in lymph flow or wet-to-dry weight ratio, although they did blunt and delay the rise in airway pressure and did prevent the rises in pulmonary arterial pressure and pulmonary vascular resistance. Thus, cyclooxygenase products, probably Tx, are responsible for the pulmonary hypertension after acrolein smoke and to some extent for the increased airway resistance but not the pulmonary edema. Prevention of high-permeability pulmonary edema after smoke with BW-755C suggests that LTB4, may be etiologic, as previous work has eliminated LTC4, LTD4, and LTE4.


1985 ◽  
Vol 59 (3) ◽  
pp. 1019-1025 ◽  
Author(s):  
M. B. Maron

The purpose of this study was to evaluate the usefulness of the intracisternal administration of veratrine as a model of neurogenic pulmonary edema (NPE) in the alpha-chloralose-anesthetized dog. Veratrine (40–60 micrograms/kg) was injected into the cisterna magna of 17 animals, and systemic arterial, pulmonary arterial, and left ventricular end-diastolic (LVEDP) pressures were followed for 1 h. Eleven animals developed alveolar edema. In these animals, systemic arterial pressure increased to 273 +/- 9 (SE) Torr, pulmonary arterial pressure to 74.5 +/- 4.9 Torr, and LVEDP to 42.8 +/- 4.5 Torr, and large amounts of pink frothy fluid, with protein concentrations ranging from 48 to 93% of plasma, appeared in the airways. Postmortem extravascular lung water content (Qwl/dQl) averaged 7.30 +/- 0.46 g H2O/g dry lung wt. Six animals escaped developing this massive degree of edema after veratrine (Qwl/dQl = 4.45 +/- 0.24). These animals exhibited similar elevated systemic arterial pressures (268 +/- 15 Torr), but did not develop the degree of pulmonary hypertension (pulmonary arterial pressure = 52.5 +/- 6.7 Torr, LVEDP = 24.8 +/- 4.0 Torr) observed in the other group. These results suggest that both hemodynamic and permeability mechanisms may play a role in the development of this form of edema and that veratrine administration may provide a useful model of NPE.


1997 ◽  
Vol 82 (4) ◽  
pp. 1040-1045 ◽  
Author(s):  
John Y. C. Tsang ◽  
Michael J. Emery ◽  
Michael P. Hlastala

Tsang, John Y. C., Michael J. Emery, and Michael P. Hlastala. Ventilation inhomogeneity in oleic acid-induced pulmonary edema. J. Appl. Physiol.82(4): 1040–1045, 1997.—Oleic acid causes permeability pulmonary edema in the lung, resulting in impairment of gas-exchange and ventilation-perfusion heterogeneity and mismatch. Previous studies have shown that by using the multiple-breath helium washout (MBHW) technique, ventilation inhomogeneity (VI) can be quantitatively partitioned into two components, i.e., convective-dependent inhomogeneity (cdi) and diffusive-convective-dependent inhomogeneity (dcdi). Changes in VI, as represented by the normalized slope of the phase III alveolar plateau, were studied for 120 min in five anesthetized mongrel dogs that were ventilated under paralysis by a constant-flow linear motor ventilator. These animals received oleic acid (0.1 mg/kg) infusion into the right atrium at t = 0. MBHWs were done in duplicate for 18 breaths every 40 min afterward. Three other dogs that received only normal saline served as controls. The data show that, after oleic acid infusion, dcdi, which represents VI in peripheral airways, is responsible for the increasing total VI as lung water accumulates progressively over time. The cdi, which represents VI between larger conductive airways, remains relatively constant throughout. This observation can be explained by increases in the heterogeneity of tissue compliance in the periphery, distal airway closure, or by decreases in ventilation through collateral channels.


1983 ◽  
Vol 55 (4) ◽  
pp. 1154-1159 ◽  
Author(s):  
Y. K. Ngeow ◽  
W. Mitzner

In this investigation we have studied the effect of increments of pulmonary edema on pulmonary hemodynamics, and physiological and hemodynamic shunt in an isolated lung preparation. Hemodynamic shunt was defined by the slope of the relationship between pulmonary arterial and airway pressures; when the slope decreases, there is a greater degree of shunt. Cardiovascular changes were analyzed using a Starling resistor model of the pulmonary circulation where the effective downstream pressure to flow as seen from the pulmonary artery exceeds the pulmonary venous outflow pressure. This effective downstream pressure is referred to as the critical pressure (Pc), and at low lung inflation the locus of this critical pressure is in extra-alveolar vessels. With 3-4 h of progressive edema to an average of 185% initial lobe weight we found a progressive rise in pulmonary arterial pressure (Ppa) from 12.1 to 21.5 cmH2O. About one-third of this increase in Ppa resulted from an increased Pc and the remainder resulted from an increased resistance upstream from the locus of Pc. These results are consistent with the hypothesis that the interstitial accumulation of fluid creates enough of an increase in interstitial pressure to compress extra-alveolar vessels. There was no significant correlation between the amount of edema and the measured physiologic shunt, but the hemodynamic shunt showed a highly significant correlation. The hemodynamic shunt theoretically measures the extent of obstructed airways and may be a useful index of the degree of pulmonary edema.


1982 ◽  
Vol 242 (5) ◽  
pp. H745-H750 ◽  
Author(s):  
M. M. Krausz ◽  
T. Utsunomiya ◽  
L. L. Levine ◽  
B. Dunham ◽  
D. Shepro ◽  
...  

To test the hypothesis that preservation of circulating platelets would prolong the function of an isolated perfused canine lung lobe, prostacyclin (PGI2) was added to the perfusate. Platelet count in heparinized controls (n = 7) fell to 44,500 platelets/mm3, lower than 136,000 platelets/mm3 seen with 1 microgram/min PGI2 (n = 7, P less than 0.005). Surprisingly, with PGI2, thromboxane B2 (TXB2) the stable product of thromboxane A2 (TXA2), rose from 0.07 to 0.25 ng/ml, a level higher than controls (P less than 0.005). PGI2, in comparison to controls, also led to higher pulmonary arterial pressure, an increase in lobe weight, an increase in wet weight-dry weight ratio, an increase in physiological shunt, and a decrease in compliance (P less than 0.005). Further, with PGI2 there was hemorrhagic edema. Infusion of the PGI2 hydrolysis product 6-keto-prostaglandin F1 alpha (n = 2) led to results similar to controls. Adverse PGI2 effects were eliminated by pretreatment with ibuprofen (12.5 mg/kg, n = 5) or an antiplatelet antibody (n = 6). Infusion of PGI2 into a lobar pulmonary artery of an intact animal was without effect on the lung (n = 2). These results show that platelets exposed to a foreign surface will aggregate and be lost from the circulation. PGI2 prevents platelet loss but not the synthesis of TXA2. This vasoconstrictor is likely to be the cause of pulmonary hypertension and hemorrhagic pulmonary edema.


1987 ◽  
Vol 62 (4) ◽  
pp. 1690-1697 ◽  
Author(s):  
F. W. Cheney ◽  
M. J. Bishop ◽  
E. Y. Chi ◽  
B. L. Eisenstein

We studied the effects of regional alveolar hypoxia on permeability pulmonary edema formation. Anesthetized dogs had a bronchial divider placed so that the left lower lobe (LLL) could be ventilated with a hypoxic gas mixture (HGM) while the right lung was continuously ventilated with 100% O2. Bilateral permeability edema was induced with 0.05 ml/kg oleic acid and after 4 h of LLL ventilation with an HGM (n = 9) LLL gross weight was 161 +/- 13 (SE) g compared with 204 +/- 13 (SE) g (P less than 0.05) in the right lower lobe (RLL). Bloodless lobar water and dry weight were also significantly lower in the LLL as compared with the RLL of the study animals. In seven control animals in which the LLL fractional inspired concentration of O2 (FIO2) was 1.0 during permeability edema, there were no differences in gravimetric variables between LLL and RLL. In eight additional animals, pulmonary capillary pressure (Pc), measured by simultaneous occlusion of left pulmonary artery and vein, was not significantly different between LLL FIO2 of 1.0 and 0.05 either before or after pulmonary edema. We conclude that, in the presence of permeability pulmonary edema, regional alveolar hypoxia causes reduction in edema formation. The decreased edema formation during alveolar hypoxia is not due to a reduction in Pc.


1986 ◽  
Vol 61 (3) ◽  
pp. 1132-1138 ◽  
Author(s):  
G. J. Huchon ◽  
A. Lipavsky ◽  
J. M. Hoeffel ◽  
J. F. Murray

To determine the accuracy of measurements of lung tissue volume (Vlt) by rebreathing acetylene in normal and edematous lungs, we compared gravimetric values of total lung weight (Ql) and extravascular lung water (Qwl) with Vlt in anesthetized control sheep (C) and sheep with hydrostatic pulmonary edema (HPE) or oleic acid-induced permeability pulmonary edema (PPE), five animals each. In eight additional sheep we determined that acetylene solubility in blood (0.117 +/- 0.010 ml X 100 ml-1 X Torr-1) differed significantly from that in lung-blood homogenates (0.095 +/- 0.009 ml X 100 ml-1 X Torr-1, P = 0.0017). The latter value was used in all calculations. In C, Vlt was 194% of Qwl and 98% of Ql; in HPE, Vlt was 144% of Qwl and 87% of Ql; and in PPE, Vlt was 112% of Qwl and 77% of Ql. We conclude that when the lungs are normal, Vlt reasonably measures Ql not Qwl. However in both HPE and PPE, Vlt progressively underestimates Ql and cannot differentiate between increased blood volume and increased Qwl.


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