Effect of endotoxin on diaphragm lymph contamination in unanesthetized sheep

1987 ◽  
Vol 62 (2) ◽  
pp. 706-710 ◽  
Author(s):  
R. E. Drake ◽  
S. J. Allen ◽  
J. C. Gabel ◽  
J. Katz ◽  
G. A. Laine
Keyword(s):  
Plasma Protein ◽  
Concentration Ratio ◽  
Protein Concentration ◽  
Mediastinal Lymph Node ◽  
Base Line ◽  
Plasma Protein Concentration ◽  
Lymph Vessels ◽  
Time Period ◽  
Afferent Lymph ◽  
Lung Lymph

The preparation for collecting lung lymph from sheep caudal mediastinal lymph node (CMN) efferent vessels is widely used to study the effects of endotoxin on lung microvascular permeability. However, there are nonpulmonary lymph vessels that drain into the CMN along with the afferent lymph vessels from the lung. Thus CMN lymph is a mixture of lymph from the lung and diaphragm lymph vessels as well as from other nonpulmonary lymph vessels. We studied the effect of 0.5–1.0 microgram/kg Escherichia coli endotoxin on the flow rates in diaphragm and CMN efferent lymph vessels (Qdi and QCMN, respectively) in unanesthetized sheep. For the time period between 2 and 5.5 h after endotoxin QCMN was increased from its base line of 7.2 +/- 4.4 (SD) to 17.3 +/- 10.6 ml/h and the lymph-to-plasma protein concentration ratio (L/PCMN) had increased from 0.68 +/- 0.11 to 0.81 +/- 0.06. During the same time period, Qdi was 4.5 +/- 3.1 ml/h compared with 1.0 +/- 0.8 ml/h at base line and the diaphragm lymph-to-plasma protein concentration ratio (L/Pdi) was 0.92 +/- 0.07 (base line = 0.74 +/- 0.15). The increases in flow rate and protein concentration were significant for each type of vessel (P less than 0.05). We conclude that the period of increased QCMN and L/PCMN after endotoxin is associated with an increase in Qdi and L/Pdi. Thus, it is difficult to determine how much of the CMN lymph response comes from the lungs and how much comes from diaphragm lymph vessels.

Comparison of afferent and efferent lung lymph in the sheep

1988 ◽  
Vol 64 (6) ◽  
pp. 2340-2347 ◽  
Author(s):  
D. E. McClure ◽  
W. J. Weidner
Keyword(s):  
Plasma Protein ◽  
Concentration Ratio ◽  
Protein Concentration ◽  
Interstitial Fluid ◽  
Mediastinal Lymph Node ◽  
Pressure Ratio ◽  
Base Line ◽  
Plasma Protein Concentration ◽  
Afferent Lymph ◽  
Lung Lymph

Efferent lymph collected from the caudal mediastinal lymph node (CMN) in the sheep lung lymph fistula model has been reported to represent free pulmonary interstitial fluid. Studies that utilize this model assume that nodal transit does not alter the composition of lymph. We collected afferent lymph from the tracheobronchial node (TBN) while simultaneously collecting CMN efferent lymph in acutely prepared sheep. We compared afferent and efferent lymph protein concentrations (CA and CE) and changes in flow rates (QLA and QLE) during base line and periods of elevated left atrial pressure (Pla). As a result of elevated Pla, QLA and QLE increased and the afferent lymph-to-plasma protein concentration ratio (CA/Cp) and the efferent lymph-to-plasma protein concentration ratio (CE/Cp) fell. The CA/Cp was significantly lower than the CE/Cp during base line (0.67 vs. 0.80) and periods of elevated Pla (0.41 vs. 0.61). Although we cannot exclude regional permeability differences, the difference between CA/Cp and CE/Cp is most likely due to the concentration of lymph within the CMN. Our data suggest nodal modification of CA is correlated with the afferent lymph-to-plasma colloid osmotic pressure ratio (pi A/pi p) and further suggest that nodal alteration of lymph during elevated Pla is due to the influence of decreased pi A/pi p at the blood-to-lymph barrier. We conclude that afferent lymph is a more accurate representation of lung free interstitial fluid because collection of pulmonary afferent lymph obviates the complications introduced by the CMN. Studies utilizing efferent lymph may have overestimated lung microvascular permeability in the acute sheep preparation.

Hindlimb and lung lymph flows during prolonged exercise

1993 ◽  
Vol 75 (2) ◽  
pp. 633-638 ◽  
Author(s):  
G. Coates ◽  
H. O'Brodovich ◽  
G. Goeree
Keyword(s):  
Steady State ◽  
Surface Area ◽  
Vascular Resistance ◽  
Plasma Protein ◽  
Concentration Ratio ◽  
Protein Concentration ◽  
Plasma Protein Concentration ◽  
Efferent Duct ◽  
Exercise Period ◽  
Lung Lymph

We performed experiments to determine the effect of 2h of exercise on hindlimb lymph flow (QL) and protein concentration in sheep. We compared these results with the lung QL response to long-term exercise. Eleven sheep with catheters in an efferent duct of a prefemoral lymph node and 12 sheep with chronic lung lymph catheters exercised at 2.5–3.0 km/h for up to 2h (lung lymph: range 45–120 min, mean 80 min;hindlimb lymph: range 75–120 min, mean 110.5 min). Cardiac output approximately doubled. Pulmonary vascular resistance decreased by 42%, and systemic vascular resistance decreased by 35%. There were small increases in calculated pulmonary microvascular and arterial pressures. During steady-state exercise, lung QL doubled and the lung lymph-to-plasma protein concentration ratio decreased by 16%. There was an immediate fivefold increase in hindlimb QL, and the hindlimb lymph-to-plasma protein concentration ratio decreased by 26%. Hindlimb QL decreased to a constant 130% above baseline during the last 30 min of exercise. We conclude that the marked increase in hindlimb QL early in exercise is secondary to a massaging effect in working muscles. The steady-state increases in QL toward the end of the exercise period in both lung and hindlimb are secondary to both increased surface area and pressure in the pulmonary and systemic microvascular circulations. Our data suggest that in the lung the major factor determining QL is increased vascular surface area.

Lung lymph and free interstitial fluid protein composition in sheep with edema

1976 ◽  
Vol 230 (6) ◽  
pp. 1650-1653 ◽  
Author(s):  
CR Vreim ◽  
PD Snashall ◽  
RH Demling ◽  
NC Staub
Keyword(s):  
Plasma Protein ◽  
Protein Concentration ◽  
Interstitial Fluid ◽  
Protein Composition ◽  
Lymph Flow ◽  
Base Line ◽  
Interstitial Edema ◽  
Plasma Protein Concentration ◽  
Free Interstitial ◽  
Lung Lymph

In 10 anesthetized sheep with mild or moderate pulmonary edema we determined whether the protein composition of lung lymph is representative of free interstitial fluid. We measured protein concentration and albumin fraction in 1-mul samples of plasma, lung lymph, and free interstitial fluid. We also measured lung lymph flow. In five sheep with edema caused by increased pulmonary microvascular pressure, the average (+/- 1 SE) plasma protein concentration was 6.0 +/- 0.4 g/100 ml, lung lymph 3.4 +/- 0.2, and interstitial fluid 3.1 +/- 0.3. Lymph flow increased from an average base-line value of 9.4 ml/h to 43.4 ml/h during edema. Average albumin fractions in lymph and interstitial fluid were 0.56 +/- 0.02 and 0.50 +/- 0.01, respectively, compared with 0.44 +/- 0.01 for plasma. In five sheep with increased-permeability edema, average plasma protein concentration was 5.7 +/- 0.3 g/100 ml, lung lymph 4.1 +/- 0.4, and interstitial fluid 4.6 +/- 0.4. Base-line lymph flow was 11.0 ml/h and increased to 27.8 ml/h during edema. Average albumin fractions in lymph and interstitial fluid were 0.53 +/- 0.01 and 0.50 +/- 0.02, respectively, compared with 0.43 +/- 0.01 for plasma. We conclude in both high-pressure and altered-permeability edema, the protein composition of lung lymph collected from the major lung efferent lymphatic is representative of the free interstitial edema fluid.

Effect of complement activation with cobra venom factor on pulmonary vascular permeability

1986 ◽  
Vol 61 (6) ◽  
pp. 2202-2209 ◽  
Author(s):  
A. Johnson ◽  
J. A. Cooper ◽  
A. B. Malik
Keyword(s):  
Vascular Permeability ◽  
Plasma Protein ◽  
Complement Activation ◽  
Concentration Ratio ◽  
Protein Concentration ◽  
Cobra Venom ◽  
Plasma Protein Concentration ◽  
Cobra Venom Factor ◽  
Pulmonary Vascular Permeability ◽  
Protein Clearance

We examined the effect of acute complement activation on lung vascular permeability to proteins in awake sheep prepared with lung lymph fistulas. Complement was activated by cobra venom factor (CVF) infusion (400 U/kg for 1 h iv). Studies were made in two groups of sheep: 1) infusion of CVF containing the endogenous phospholipase A2 (PLA2) (n = 6); and 2) infusion of CVF pretreated with bromophenacyl bromide to inhibit PLA2 activity (n = 5). Intravascular complement activation transiently increased mean pulmonary arterial pressure (Ppa) and pulmonary vascular resistance (PVR) in both groups. Pulmonary lymph flow (Qlym) and lymph protein clearance (Qlym X lymph-to-plasma protein concentration ratio) were also transiently increased in both groups. Pulmonary vascular permeability to proteins was assessed by raising left atrial pressure and determining the lymph-to-plasma protein concentration ratio (L/P) at maximal Qlym. In both groups the L/P at maximal Qlym was not different from normal. In a separate group (n = 4), CVF-induced complement activation was associated with 111In-oxine granulocyte sequestration in the lungs. In vitro plasma from CVF-treated animals aggregated neutrophils but did not stimulate neutrophils to produce superoxide anion generation. Therefore, CVF-induced complement activation results in pulmonary neutrophil sequestration and in increases in PVR and lymph protein clearance. The increase in lymph protein clearance is due to increased pulmonary microvascular pressure and not increased vascular permeability to proteins.

Isoproterenol and aminophylline reduce lung capillary filtration during high permeability

1979 ◽  
Vol 46 (1) ◽  
pp. 146-151 ◽  
Author(s):  
T. Foy ◽  
J. Marion ◽  
K. L. Brigham ◽  
T. R. Harris
Keyword(s):  
Plasma Protein ◽  
Protein Concentration ◽  
Lymph Flow ◽  
High Permeability ◽  
Plasma Protein Concentration ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Lung Lymph ◽  
Lung Vascular Permeability ◽  
Lung Lymph Flow

Pseudomonas bacteremia in sheep causes a prolonged increase in lung vascular permeability to protein. Isoproterenol and aminophylline could effect lung fluid balance after Pseudomonas by reducing vascular pressures or by blocking release of permeability mediators. We measured vascular pressures, lung lymph flow, and lymph and plasma protein concentrations in unanesthetized sheep under baseline conditions and during steady-state increased permeability after Pseudomonas. Pseudomonas caused pulmonary vascular pressures to rise and lung lymph flow to increase fivefold, but lymph/plasma protein concentration did not change. Pulmonary vascular pressures and lung lymph flow decreased during intravenous infusion of isoproterenol and aminophylline. The decrease in lymph flow after isoproterenol and isoproterenol plus aminophylline was linearly related to the decrease in microvascular pressure (r = 0.71). Lymph/plasma total protein concentration ratios and lymph clearance of proteins with molecular radii 36--96 A remained high during isoproterenol and aminophylline. These drugs can substantially reduce transvascular filtration primarily because they reduce lung vascular pressures.

Effect of increased hydrostatic pressure on lymphatic elimination of hyaluronan from sheep lung

1988 ◽  
Vol 64 (4) ◽  
pp. 1327-1332 ◽  
Author(s):  
L. Lebel ◽  
L. Smith ◽  
B. Risberg ◽  
B. Gerdin ◽  
T. C. Laurent
Keyword(s):  
Hydrostatic Pressure ◽  
Mediastinal Lymph Node ◽  
Elimination Rate ◽  
Base Line ◽  
Time Period ◽  
Plasma Concentration Ratio ◽  
Level 1 ◽  
Level 2 ◽  
Lung Lymph ◽  
Lung Lymph Flow

The effects of increased hydrostatic pressure on the concentrations of hyaluronan (hyaluronic acid) in lung lymph and serum were investigated in awake sheep with a cannula in the efferent vessel from the caudal mediastinal lymph node. Lung lymph was sampled at base line [left atrial pressure (LAP) 6.5 ± 1.7 mmHg] and after two increases of LAP to 25.7 ± 2.2 mmHg (level 1) and 37.0 ± 5.1 mmHg (level 2). The lung lymph flow increased from 1.9 ± 0.5 at base line to 9.3 ± 2.2 and 15.9 ± 0.7 ml/30 min, and the lymph-to-plasma concentration ratio of total protein decreased from 0.63 ± 0.02 to 0.32 ± 0.04 and 0.32 ± 0.05 at the two elevated levels of LAP, respectively. The hyaluronan concentration in lung lymph was unchanged, and there was a flow-dependent elimination of hyaluronan from the lung that increased from 23 ± 8 to 87 ± 19 and 137 ± 37 micrograms/30 min, respectively. The lung concentration of hyaluronan was 167 ± 28 micrograms/g fresh lung, and at base line it was calculated that slightly less than 2% of the lung hyaluronan was eliminated by the lymphatic route in 24 h. If extrapolated to 24 h, the elimination rate of hyaluronan seen during elevated LAP would result in lymphatic elimination of 18% of the lung hyaluronan over this time period. Since hyaluronan is responsible for part of the protein exclusion in the extracellular matrix, it is plausible that washout of interstitial hyaluronan contributes to the decrease in albumin exclusion from the interstitium that occurs after an elevation of LAP.

Effects of hypoproteinemia and increased vascular pressure on lung fluid balance in sheep

1983 ◽  
Vol 55 (5) ◽  
pp. 1514-1522 ◽  
Author(s):  
G. C. Kramer ◽  
B. A. Harms ◽  
B. I. Bodai ◽  
E. M. Renkin ◽  
R. H. Demling
Keyword(s):  
Plasma Protein ◽  
Fluid Balance ◽  
Protein Concentration ◽  
Lymph Flow ◽  
Base Line ◽  
Oncotic Pressure ◽  
Plasma Protein Concentration ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Normal Plasma

We compared the effects of a sustained decrease in plasma oncotic pressure on lung fluid balance with those of an increase in vascular pressure in six unanesthetized sheep. Initial plasma protein concentration of 58.0 +/- 2.2 (SE) mg/ml was quickly reduced to 34.0 +/- 1.4 mg/ml via plasmapheresis and held at this value for 24 h. Red cells were returned with lactated Ringer solution infused at a rate adjusted to maintain central venous pressure; cardiac output and pulmonary vascular pressures also remained at base line. Steady-state lymph flows increased from a base-line value of 8.8 +/- 3.2 to 20.1 +/- 5.6 ml/h, while the lymph-to-plasma protein concentration ratio ( [L/P] ) decreased from 0.65 +/- 0.03 to 0.44 +/- 0.04. Decreased lymph protein resulted in reestablishment of base-line plasma-to-lymph oncotic gradient. The increased lymph flow was not the result of increased filtration forces, since all vascular pressures and the oncotic gradient were unchanged; nor was it due entirely to increased surface area since [L/P] was decreased. The decrease in plasma oncotic pressure, delta pi P, was twice as effective at increasing lymph flow (1.66 ml X h-1 X mmHg-1, delta pi P) as an equivalent increase in microvascular pressure, delta PC, at normal plasma protein concentration (0.82 ml X h-1 X mmHg-1, delta PC). Elevation of microvascular pressure during hypoproteinemia had a greater effect on lymph flow (1.44 ml X h-1 X mmHg-1, delta PC) than at normal plasma protein concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hypoproteinemia on lung fluid balance in awake newborn lambs

1986 ◽  
Vol 61 (3) ◽  
pp. 1139-1148 ◽  
Author(s):  
T. A. Hazinski ◽  
R. D. Bland ◽  
T. N. Hansen ◽  
E. G. Sedin ◽  
R. B. Goldberg
Keyword(s):  
Plasma Protein ◽  
Fluid Balance ◽  
Left Atrial ◽  
Protein Concentration ◽  
Lymph Flow ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Plasma Protein Concentration ◽  
Lung Fluid ◽  
Lung Lymph

To study the influence of plasma protein concentration on fluid balance in the newborn lung, we measured pulmonary arterial and left atrial pressures, lung lymph flow, and concentrations of protein in lymph and plasma of eight lambs, 2–3 wk old, before and after we reduced their plasma protein concentration from 5.8 +/- 0.3 to 3.6 +/- 0.6 g/dl. Each lamb underwent two studies, interrupted by a 3-day period in which we drained protein-rich systemic lymph through a thoracic duct fistula and replaced fluid losses with feedings of a protein-free solution of electrolytes and glucose. Each study consisted of a 2-h control period followed by 4 h of increased lung microvascular pressure produced by inflation of a balloon in the left atrium. Body weight and vascular pressures did not differ significantly during the two studies, but lung lymph flow increased from 2.6 +/- 0.1 ml/h during normoproteinemia to 4.1 +/- 0.1 ml/h during hypoproteinemia. During development of hypoproteinemia, the average difference in protein osmotic pressure between plasma and lymph decreased by 1.6 +/- 2 Torr at normal left atrial pressure and by 4.9 +/- 2.2 Torr at elevated left atrial pressure. When applied to the Starling equation governing microvascular fluid balance, these changes in liquid driving pressure were sufficient to account for the observed increases in lung fluid filtration; reduction of plasma protein concentration did not cause a statistically significant change in calculated filtration coefficient. Protein loss did not influence net protein clearance from the lungs nor did it accentuate the increase in lymph flow associated with left atrial pressure elevation.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of pulmonary arterial occlusion on lung fluid and protein exchange

1982 ◽  
Vol 53 (3) ◽  
pp. 543-548 ◽  
Author(s):  
P. S. Barie ◽  
A. B. Malik
Keyword(s):  
Protein Concentration ◽  
Arterial Occlusion ◽  
Base Line ◽  
Plasma Protein Concentration ◽  
Lung Fluid ◽  
Mean Pulmonary Arterial Pressure ◽  
Protein Clearance ◽  
Pulmonary Arterial ◽  
Lung Lymph ◽  
Protein Exchange

We examined the effects of left pulmonary arterial occlusion and reperfusion on pulmonary transvascular fluid and protein exchange in the sheep lung lymph fistula preparation. Pulmonary lymph flow (Qlym) increased from the base-line value of 5.0 +/- 0.8 to 10.0 +/- 2.1 ml/h after occlusion (P less than 0.05); the steady-state value of 11.9 +/- 2.2 ml/h during reperfusion was not significantly different from the value during occlusion. The lymph-to-plasma protein concentration ratio (L/P) did not change significantly during either occlusion or reperfusion. Transvascular protein clearance (Qlym X L/P) increased from 3.7 +/- 0.6 to 8.4 +/- 2.1 ml/h during occlusion (P less than 0.05) and remained elevated at 8.6 +/- 1.7 ml/h during reperfusion. The sustained increases in Qlym and protein clearance could not be explained by the 3-Torr increase in mean pulmonary arterial pressure during the occlusion period or by an increase in the interstitial protein concentration caused by a period of decreased filtration during occlusion. The increases in protein clearance that occurred with increased Qlym during occlusion and reperfusion were greater than the increases in protein clearance with comparably increased Qlym during left atrial hypertension. The results suggest that occlusion of a pulmonary artery increases vascular permeability to plasma proteins in the lung.

Hypoproteinemia slows lung liquid clearance in young lambs

1993 ◽  
Vol 74 (1) ◽  
pp. 153-160 ◽  
Author(s):  
J. J. Cummings ◽  
D. P. Carlton ◽  
F. R. Poulain ◽  
J. U. Raj ◽  
R. D. Bland
Keyword(s):  
Osmotic Pressure ◽  
Plasma Protein ◽  
Protein Concentration ◽  
Initial Rate ◽  
Isotonic Saline ◽  
Intratracheal Instillation ◽  
Lung Water ◽  
Plasma Protein Concentration ◽  
Lung Liquid ◽  
Lung Lymph

To determine whether hypoproteinemia slows the rate at which liquid is cleared from the lung lumen, we studied 36 lambs, 18 of which underwent repeated plasmapheresis, reducing plasma protein concentration by 37% and plasma protein osmotic pressure by 39%. We killed 29 lambs (14 hypoproteinemic and 15 normoproteinemic) and removed their lungs 1, 2, or 6 h after intratracheal instillation of isotonic saline (6 ml/kg body wt). We measured extravascular lung water and determined the percentage of tracheally instilled liquid that was cleared from the lungs by comparison with control lambs that did not receive saline into their airways. The percent liquid cleared from the lungs after 1 and 2 h was significantly less in hypoproteinemic than in normoproteinemic lambs (37 vs. 65% at 1 h, 58 vs. 75% at 2 h, respectively). By 6 h nearly all the liquid (> 92%) was cleared from the lungs of all lambs. Thus hypoproteinemia slows the initial rate of clearance of liquid from the lungs of lambs. To determine whether reduced plasma protein osmotic pressure might redirect this liquid into lung lymphatics, we measured lung lymph flow (Q1) in five lambs (7.7 +/- 1.4 kg, 19 +/- 4 days old) for > or = 2 h before and 6 h after tracheal instillation of saline. In each lamb, paired studies were done 3–6 days apart; between studies the lambs underwent plasmapheresis.(ABSTRACT TRUNCATED AT 250 WORDS)

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