Select dietary fatty acids attenuate cardiopulmonary dysfunction during acute lung injury in pigs

1995 ◽  
Vol 269 (6) ◽  
pp. H2090-H2099 ◽  
Author(s):  
M. J. Murray ◽  
M. Kumar ◽  
T. J. Gregory ◽  
P. L. Banks ◽  
H. D. Tazelaar ◽  
...  

We examined the effect of substituting linoleic acid (LA) with eicosapentaenoic acid (EPA) and gamma-linolenic acid (gamma-LA), precursors of trienoic and monoenoic eicosanoids, respectively, on acute lung injury (ALI). Three groups (n = 8/group) of pigs were fed enteral diets containing LA (diet A), EPA (diet B), or EPA+gamma-LA (diet C) for 8 days. ALI was then induced with a 0.1 mg/kg bolus of Escherichia coli endotoxin followed by a continuous infusion for 4 h (0.075 mg.kg-1.h-1). Pulmonary arterial and capillary wedge pressures, cardiac index (CI), arterial blood gases, arterial O2 content, and plasma thromboxane B2 (TxB2) were measured. Arterial PO2 decreased at 20 min in animals fed diet A. This change was attenuated with diets B and C. The EPA- and EPA + gamma-LA-enriched diets attenuated the fall in O2 delivery at 20 min, an improvement that was sustained throughout the 4-h study period with the EPA+gamma-LA-enriched diet only. This improvement in O2 delivery was due not only to the improved arterial PO2, but also to the maintenance of CI at 20 min in animals fed diets B and C and throughout the 4-h study period in animals fed diet C. At 4 h, TxB2 increased 10-fold over baseline in animals fed diet A, whereas in animals fed diets B and C the increase was only 3-fold. These decreased TxB2 levels in animals fed diets B and C correlate with an attenuation in the increase in pulmonary vascular resistance that was observed at 20 min after endotoxin infusion in animals fed diet A. These data suggest that specialized enteral diets enriched in EPA+gamma-LA improve gas exchange and O2 delivery, presumably in part through a modification of TxB2 production with a decrease in pulmonary vascular resistance and an increase in CI, during ALI.

1998 ◽  
Vol 85 (3) ◽  
pp. 1079-1085 ◽  
Author(s):  
Basil O. Ibe ◽  
Sue Hibler ◽  
J. Usha Raj

Eight near-term fetal lambs were studied acutely in utero to determine role of platelet-activating factor (PAF) in the regulation of vasomotor tone in systemic and pulmonary circulations in the immediate perinatal period. Four fetal lambs were studied predelivery and 2 h postdelivery to determine circulating PAF levels. Aortic and pulmonary arterial pressures and cardiac output were measured continuously, and systemic and pulmonary vascular resistances were calculated. Left pulmonary arterial blood flow was also measured in four fetal lambs. After delivery and oxygenation, circulating PAF levels fell significantly. When WEB-2170, a specific PAF-receptor antagonist, was infused to block effect of endogenous PAF in the eight near-term fetal lambs, systemic vascular resistance fell 30% but pulmonary vascular resistance fell dramatically by 68%. Specificity of WEB-2170 was tested in juvenile lambs and was found to be very specific in lowering vasomotor tone only when tone was elevated by action of PAF. Our data show that endogenous PAF levels in the fetus contribute to maintain a high basal systemic and pulmonary vasomotor tone and that a normal fall in circulating PAF levels after birth and oxygenation may facilitate fall in pulmonary vascular resistance at birth.


2016 ◽  
Vol 82 (3) ◽  
pp. 266-270
Author(s):  
Matthew B. Bloom ◽  
Derek Serna-Gallegos ◽  
Mark Ault ◽  
Ahsan Khan ◽  
Rex Chung ◽  
...  

Pleural effusions occur frequently in mechanically ventilated patients, but no consensus exists regarding the clinical benefit of effusion drainage. We sought to determine the impact of thoracentesis on gas exchange in patients with differing severities of acute lung injury (ALI). A retrospective analysis was conducted on therapeutic thoracenteses performed on intubated patients in an adult surgical intensive care unit of a tertiary center. Effusions judged by ultrasound to be 400 mL or larger were drained. Subjects were divided into groups based on their initial P:F ratios: normal >300, ALI 200 to 300, and acute respiratory distress syndrome (ARDS) <200. Baseline characteristics, physiologic variables, arterial blood gases, and ventilator settings before and after the intervention were analyzed. The primary end point was the change in measures of oxygenation. Significant improvements in P:F ratios (mean ± SD) were seen only in patients with ARDS (50.4 ± 38.5, P = 0.001) and ALI (90.6 ± 161.7, P = 0.022). Statistically significant improvement was observed in the pO2 (31.1, P = 0.005) and O2 saturation (4.1, P < 0.001) of the ARDS group. The volume of effusion removed did not correlate with changes in individual patient's oxygenation. These data support the role of therapeutic thoracentesis for intubated patients with abnormal P:F ratios.


1961 ◽  
Vol 200 (2) ◽  
pp. 287-291 ◽  
Author(s):  
M. Harasawa ◽  
S. Rodbard

The effects of tetraethylammonium chloride (TEAC) and aminophylline on the pulmonary vascular resistance were studied in thoracotomized dogs. Pulmonary arterial blood flow and pressure, and systemic blood pressure were measured simultaneously. Both drugs showed marked hypotensive effects on the systemic vessels. In every instance pulmonary arterial pressures and blood flows were reduced by TEAC given via the pulmonary artery and increased by aminophylline. However, the calculated pulmonary vascular resistance remained essentially unchanged in all experiments. These data challenge the concept that the pulmonary vessels respond to these drugs by active vasodilatation


2016 ◽  
Vol 38 (4) ◽  
pp. 1354-1364 ◽  
Author(s):  
Yan Zhao ◽  
Min Zhang ◽  
Ren-Ping Xiong ◽  
Xing-Yun Chen ◽  
Ping Li ◽  
...  

Background/Aims: Although it has been reported that somatostatin (SOM) upregulated the level of 90-kD heat shock protein (Hsp90), which participates in the inflammatory regulation by its client proteins, such as glucocorticoid receptor (GR), it remains unclear if it has a protective role against acute lung injury (ALI). Methods: ALI model was established by the injection of oleic acid (OA) into the tail vein of mice. Lung injury was assessed by histological analysis, lung water content and arterial blood gases. The levels of Hsp90 and GR, the binding capacity and the affinity of GR were examined. Results: It was showed that pretreatment with SOM significantly increased Hsp90 levels and alleviated lung injuries in OA-injected mice. Furthermore, SOM increased the GR expression and improved the affinity of the GR in animals with lung injury. However, little alteration was found in the maximum binding capacity of the GR in mice with or without SOM. Conclusion: The data indicate SOM exerts a protective effect by increasing Hsp90 abundant and further enhancing the affinity of the GR. The beneficial effects of SOM treatment provide a new strategy for modulation of GR efficiency and alleviation of acute lung injury.


1965 ◽  
Vol 208 (1) ◽  
pp. 130-138 ◽  
Author(s):  
G. J. A. Cropp

The resistance to blood flow in the pulmonary circulation of dogs (PVR) increased when their lungs were ventilated with 95–100% oxygen and were perfused with blood that recirculated only through the pulmonary circulation; the systemic circulation was perfused independently. This increase in PVR occurred even when nerves were cut or blocked but was abolished by inhaled isopropylarterenol aerosol. Elevation of intra-alveolar Po2 without increase in pulmonary arterial blood Po2 was sufficient to increase pulmonary vascular resistance. The pulmonary venules or veins were thought to be the likely site of the constriction. These reactions were qualitatively similar to those produced by injection of serotonin or histamine into the pulmonary circulation. The time course of the response and failure to obtain it when the blood was perfused through the remainder of the body before it re-entered the pulmonary circulation are compatible with a theory that high intra-alveolar O2 tension activates a vasoconstrictor material in the pulmonary parenchyma.


1990 ◽  
Vol 69 (1) ◽  
pp. 345-352 ◽  
Author(s):  
A. H. Stephenson ◽  
R. S. Sprague ◽  
T. E. Dahms ◽  
A. J. Lonigro

Thromboxane (Tx) has been suggested to mediate the pulmonary hypertension of phorbol myristate acetate- (PMA) induced acute lung injury. To test this hypothesis, the relationship between Tx and pulmonary arterial pressure was evaluated in a model of acute lung injury induced with PMA in pentobarbital sodium-anesthetized male mongrel dogs. Sixty minutes after administration of PMA (20 micrograms/kg iv, n = 10), TxB2 increased 10-fold from control in both systemic and pulmonary arterial blood and 8-fold in bronchoalveolar lavage (BAL) fluid. Concomitantly, pulmonary arterial pressure (Ppa) increased from 14.5 +/- 1.0 to 36.2 +/- 3.5 mmHg, and pulmonary vascular resistance (PVR) increased from 5.1 +/- 0.4 to 25.9 +/- 2.9 mmHg.l-1.min. Inhibition of Tx synthase with OKY-046 (10 mg/kg iv, n = 6) prevented the PMA-induced increase in Tx concentrations in blood and BAL fluid but did not prevent or attenuate the increase in Ppa. OKY-046 pretreatment did, however, attenuate but not prevent the increase in PVR 60 min after PMA administration. Pretreatment with the TxA2/prostaglandin H2 receptor antagonist ONO-3708 (10 micrograms.kg-1.min-1 iv, n = 7) prevented the pressor response to bolus injections of 1-10 micrograms U-46619, a Tx receptor agonist, but did not prevent or attenuate the PMA-induced increase in Ppa. ONO-3708 also attenuated but did not prevent the increase in PVR. These results suggest that Tx does not mediate the PMA-induced pulmonary hypertension but may augment the increases in PVR in this model of acute lung injury.


1985 ◽  
Vol 249 (3) ◽  
pp. H570-H576 ◽  
Author(s):  
S. J. Soifer ◽  
R. D. Loitz ◽  
C. Roman ◽  
M. A. Heymann

The factors responsible for maintaining the normally low pulmonary blood flow and high pulmonary vascular resistance in the fetus are not well understood. Since leukotrienes are potent pulmonary vasoconstrictors in many adult animal species, we determined whether leukotrienes were perhaps involved in the control of the fetal pulmonary circulation by studying the effects of putative leukotriene end organ antagonists in two groups of fetal lambs. In six fetal lambs studied at 130-134 days gestation, FPL 55712 increased pulmonary blood flow by 61% (P less than 0.05) and reduced pulmonary vascular resistance by 45% (P less than 0.05). There was a small increase in heart rate but no changes in pulmonary and systemic arterial pressures and systemic arterial blood gases. In six other fetal lambs studied at 130-140 days gestation, FPL 57231 increased pulmonary blood flow by 580% (P less than 0.05) and decreased pulmonary vascular resistance by 87% (P less than 0.05). Pulmonary and systemic arterial pressures decreased (P less than 0.05), and heart rate increased (P less than 0.05). Leukotriene end organ antagonism significantly increases fetal pulmonary blood flow and decreases pulmonary vascular resistance. Leukotrienes may play a role in the physiological control of the fetal pulmonary circulation.


1985 ◽  
Vol 249 (2) ◽  
pp. H351-H357 ◽  
Author(s):  
R. F. Lodato ◽  
J. R. Michael ◽  
P. A. Murray

To characterize quantitatively the relationships among pulmonary vascular pressures (P) and cardiac output (Q) in conscious dogs, multipoint plots of pulmonary arterial (PAP), pulmonary capillary wedge (PCWP), PAP - PCWP, and left atrial (LAP) pressure versus Q were generated by graded constriction of the thoracic inferior vena cava (IVC) to vary Q. Slopes and extrapolated pressure intercepts from linear regression fits to the P/Q plots were determined for three inspired oxygen tensions: normoxia, hyperoxia, and hypoxia. During normoxia (arterial Po2 87 +/- 1 Torr), the extrapolated pressure intercepts for PAP, PCWP, and PAP - PCWP were virtually 0 mmHg, and for LAP, substantially negative (-5.5 +/- 1.1 mmHg; P less than 0.01). Hyperoxia (Po2 365 +/- 28 Torr) had no effect on any of the P/Q plots. In contrast, hypoxia (Po2 51 +/- 1 Torr) significantly increased the intercepts (P less than 0.01) as well as the slopes (P less than 0.05) of PAP and PAP - PCWP versus Q, but produced only minor changes in PCWP and LAP versus Q. These hypoxia-induced changes in intercepts, perhaps related to changes in critical closing pressures, demonstrate the limitations of pulmonary vascular resistance calculations (quotient of pressure gradient and Q) in quantifying changes in pulmonary vasomotor tone. In this way, the IVC constriction technique provides a more complete description of P/Q relationships than that permitted by simple calculations of pulmonary vascular resistance. We conclude that this technique can be utilized to investigate the effects of other physiological and pharmacological interventions on pulmonary vasomotor tone in conscious dogs.


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