Lymph flow from edematous dog lungs

We measured the flow rate (QLV) from cannulated lung lymph vessels in anesthetized dogs. Low-resistance lymph cannulas were used and the vessels were cannulated at the lung hilus. When we increased left atrial pressure to 42.9 +/- 5.7 (SD) cmH2O (base line = 6.6 +/- 4.6 cmH2O), the lungs became edematous and QLV increased from a base line of 20.4 +/- 21.5 microliters/min to 388 +/- 185 microliters/min. QLV plateaued at the higher level. We also measured the relationship between lymph flow rate and the height of the outflow end of the lymph cannula. From this relationship, determined at the end of the period of elevated left atrial pressure, we calculated the effective resistance and pressure driving lymph from the lungs. We also cannulated lymph vessels in the downstream direction and estimated the effective resistance and pressure opposing flow into the part of the lymphatic system between the lung hilus and the veins (extrapulmonary lymph vessels). We found that the effective resistance of the extrapulmonary part of the lymph system (0.042 +/- 0.030 (SD) cmH2O X min X microliter-1) was large compared with the resistance of the lymph vessels from the lungs (0.026 +/- 0.027). These data indicate that the resistance of the extrapulmonary part of the lung lymph system limits the maximum flow of lymph from edematous lungs.

Download Full-text

Furosemide reduces lung fluid filtration in lambs with lung microvascular injury from air emboli

Journal of Applied Physiology ◽

10.1152/jappl.1989.67.5.1990 ◽

1989 ◽

Vol 67 (5) ◽

pp. 1990-1996 ◽

Cited By ~ 10

Author(s):

M. E. Berner ◽

W. G. Teague ◽

R. G. Scheerer ◽

R. D. Bland

Keyword(s):

Cardiac Output ◽

Left Atrial ◽

Balloon Catheter ◽

Lymph Flow ◽

Atrial Pressure ◽

Left Atrial Pressure ◽

Protein Ratio ◽

Fluid Filtration ◽

Lung Lymph ◽

Lung Lymph Flow

To study the effects of furosemide on the neonatal pulmonary circulation in the presence of lung injury, we measured pulmonary arterial and left atrial pressures, cardiac output, lung lymph flow, and concentrations of protein in lymph and plasma of nine lambs that received furosemide, 2 mg/kg iv, during a continuous 8-h intravenous infusion of air. Air embolism increased pulmonary vascular resistance by 71% and nearly tripled steady-state lung lymph flow, with no change in lymph-to-plasma protein ratio. These findings reflect an increase in lung vascular protein permeability. During sustained lung endothelial injury, diuresis from furosemide led to a rapid reduction in cardiac output (average 29%) and a 2-Torr decrease in left atrial pressure. Diuresis also led to hemoconcentration, with a 15% increase in both plasma and lymph protein concentrations. These changes were associated with a 27% reduction in lung lymph flow. In a second set of studies, we prevented the reduction in left atrial pressure after furosemide by inflating a balloon catheter in the left atrium. Nevertheless, lymph flow decreased by 25%, commensurate with the reduction in cardiac output that occurred after furosemide. In a third series of experiments, we minimized the furosemide-related decrease in cardiac output by opening an external fistula between the carotid artery and jugular vein immediately after injection of furosemide. In these studies, the reduction in lung lymph flow (average 17%) paralleled the smaller (17%) decrease in cardiac output. These results suggest that changes in lung vascular filtration pressure probably do not account for the reduction in lung lymph flow after furosemide in the presence of lung vascular injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Download Full-text

Left atrial pressure elevation recreates the altered lung lymph flow of seizures

Journal of Applied Physiology ◽

10.1152/jappl.1982.53.2.432 ◽

1982 ◽

Vol 53 (2) ◽

pp. 432-435 ◽

Cited By ~ 14

Author(s):

R. P. Simon ◽

L. L. Bayne ◽

M. P. Naughton

Keyword(s):

Left Atrial ◽

Pressor Response ◽

Lymph Flow ◽

Atrial Pressure ◽

Left Atrial Pressure ◽

Pressure Elevation ◽

Generalized Seizures ◽

Neural Interactions ◽

Lung Lymph ◽

Lung Lymph Flow

We compared the effects of elevated left atrial pressure of central nervous system origin (bicuculline-induced seizures) with an identical pulmonary vascular pressure elevation induced in six sheep by inflation of a balloon in the left atrium. The degree and duration of the consequent elevation in pulmonary lymph flow and the alteration in protein movement in the two groups was identical. Alterations in pulmonary fluid and protein flux resulting from generalized seizures can be explained by the pressor response alone; specific brain-lung neural interactions need not be postulated.

Download Full-text

Effect of hypoproteinemia on lung fluid balance in awake newborn lambs

Journal of Applied Physiology ◽

10.1152/jappl.1986.61.3.1139 ◽

1986 ◽

Vol 61 (3) ◽

pp. 1139-1148 ◽

Cited By ~ 14

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)

Download Full-text

Effects of coronary flow reduction on lung vascular tissue transport in sheep

Journal of Applied Physiology ◽

10.1152/jappl.1983.55.6.1906 ◽

1983 ◽

Vol 55 (6) ◽

pp. 1906-1915 ◽

Cited By ~ 3

Author(s):

T. R. Harris ◽

J. C. Collins ◽

R. J. Roselli

Keyword(s):

Left Atrial ◽

Coronary Flow ◽

Vascular Tissue ◽

Lymph Flow ◽

Atrial Pressure ◽

Left Atrial Pressure ◽

Base Line ◽

Flow Reduction ◽

Second Period ◽

Increased Pressure

This study was performed to measure the effects of a sustained reduction in coronary flow on lung lymph flow and protein content. Ten halothane-anesthetized sheep with cannulated lymphatic vessels were provided with a carotid-to-left anterior descending coronary artery cannula containing an electromagnetic flowmeter. One group of five animals was observed at base line and after coronary flow was reduced to 38% of base line. A second group of five animals acted as controls and was observed at base line, for 111 min of increased left atrial pressure, and a second period of normal pressures. Sustained coronary flow reduction led to significant increases in pulmonary arterial pressure, left atrial pressure, lymph flow, total protein lymph-to-plasma concentration ratio (L/P), and protein lymph clearance (L/P X lymph flow). Analysis of the pressure, lymph, protein, and indicator data with a two-pore model of the microvascular barrier showed that the observations were consistent with the concept that coronary flow reduction decreased functioning lung capillary surface but increased the size of the large pore and the number of small pores relative to the number of larger pores. Control studies showed increases in lymph flow and decreases in L/P with increased pressure but no significant changes in any variable between the first and second period of normal pressures. We conclude that coronary flow reduction increases lung vascular-tissue transport by decreasing the resistance of the microvascular barrier to protein and fluid movement. However, increased pressure secondary to left ventricular dysfunction plays a role in the magnitude of this response.

Download Full-text

Effect of hypoxia on lung lymph flow in newborn lambs with left atrial hypertension

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1988.254.3.h487 ◽

1988 ◽

Vol 254 (3) ◽

pp. H487-H493

Author(s):

J. U. Raj ◽

T. A. Hazinski ◽

R. D. Bland

Keyword(s):

Blood Flow ◽

Left Atrial ◽

Control Period ◽

Lymph Flow ◽

Atrial Pressure ◽

Left Atrial Pressure ◽

Fluid Filtration ◽

Alveolar Hypoxia ◽

Lung Lymph ◽

Lung Lymph Flow

To determine the effect of left atrial hypertension on the vascular response to hypoxia in the newborn lung, we measured pulmonary artery and left atrial pressures, lung blood flow and lymph flow, and concentrations of protein in lymph and plasma of 13 lambs that spontaneously breathed air for 2-6 h (control period), followed by 8-11% O2 mixed with 3-5% CO2 and N2 for 2-4 h (experimental period). In eight studies, the lambs were made hypoxic first, after which we elevated their left atrial pressure by 10-12 Torr for 2-3 h. In 10 additional studies, we reversed the sequence by raising left atrial pressure first followed by addition of hypoxia. In lambs with normal left atrial pressure, alveolar hypoxia increased both pulmonary blood flow and lymph flow, with an associated reduction in lymph-to-plasma protein ratio (L/P). When left atrial pressure was increased in the presence of hypoxia, lymph flow increased by a small amount and L/P decreased further. In lambs with preexisting left atrial pressure elevation, addition of alveolar hypoxia increased both blood flow and lymph flow with no significant change in L/P. These results suggest that in newborn lambs with normal left atrial pressure, alveolar hypoxia increases lung lymph flow mainly by increasing microvascular filtration pressure, whereas in lambs with elevated left atrial pressure, hypoxia increases lymph flow by another mechanism, perhaps by increasing the perfused surface area for fluid filtration.

Download Full-text

A theoretical model of protein, fluid, and small molecule transport in the lung

Journal of Applied Physiology ◽

10.1152/jappl.1981.50.1.1 ◽

1981 ◽

Vol 50 (1) ◽

pp. 1-14 ◽

Cited By ~ 24

Author(s):

T. R. Harris ◽

R. J. Roselli

Keyword(s):

Left Atrial ◽

Fluid Pressure ◽

Intestinal Transport ◽

Lymph Flow ◽

Atrial Pressure ◽

Left Atrial Pressure ◽

Base Line ◽

Small Pore ◽

Endogenous Proteins ◽

Resistance Decrease

The purposes of this research were to derive a mathematical model of blood-intestinal transport for the lung and to study the ability of this model to describe the results of previous lymph-collection and multiple-indicator experiments on the lungs of unanesthetized sheep. We used a three-pore model of the microvascular barrier to describe lymph flow, lymph-to-plasma ratios (L/P) of eight endogenous proteins, and the microvascular permeability-surface area (PST) of the lungs to [14C]urea in sheep experiments under base-line conditions and after acute elevation of the left atrial pressure. The results indicate that endothelial pathways consisting of a small pore (28 A), intermediate pore (180 A), and a large pore (1,000 A) can describe experimental L/P values and PST. The description of lymph flow required either than interstitial fluid pressure increase with left atrial pressure or that postcapillary venous resistance decrease relative to precapillary values. We concluded that multiple-pore theory is a useful approach to the description of lung blood-interstitial transport.

Download Full-text

Effects of left atrial pressure elevation and histamine infusion on lung lymph in awake sheep

Journal of Applied Physiology ◽

10.1152/jappl.1984.56.4.1083 ◽

1984 ◽

Vol 56 (4) ◽

pp. 1083-1089 ◽

Cited By ~ 10

Author(s):

G. R. Bernard ◽

J. R. Snapper ◽

A. A. Hutchison ◽

K. L. Brigham

Keyword(s):

Left Atrial ◽

Foley Catheter ◽

Lymph Flow ◽

Microvascular Permeability ◽

Transient Increase ◽

Atrial Pressure ◽

Left Atrial Pressure ◽

Pressure Elevation ◽

Lung Lymph ◽

Lung Lymph Flow

To study the mechanism by which infused histamine increases lung fluid and solute exchange, the effects of left atrial pressure elevation (using a Foley catheter positioned at the mitral valve orifice) on lung lymph flow and protein content were studied in the presence and absence of histamine infusion in nine chronically instrumented unanesthetized sheep. In six sheep, histamine infusion (1–3 micrograms X kg-1 X min-1) was begun 2 h before increasing left atrial pressure by 10 and 20 cmH2O for 3 h each. Control experiments were performed on the same sheep to study the effects of left atrial pressure elevation alone and histamine infusion alone. Left atrial pressure elevation in the presence of histamine infusion did not cause a disproportionate increase in lung lymph flow nor was the lymph-to-plasma protein concentration ratio (L/P) different from left atrial pressure elevation alone. This argues against the presence of increased microvascular permeability at the time of these elevations. In three sheep, left atrial pressure was elevated by 20 cmH2O, and then histamine was infused at 2 micrograms X kg-1 X min-1. Histamine infusion caused a transient increase in L/P and a large increase in lymph flow, findings like those we have previously taken to represent an increase in microvascular permeability. However, L/P decreased to values comparable to those seen with elevated left atrial pressure alone. These observations suggest that histamine infusion may have a biphasic effect on lung lymph. There is an early (1–3 h) transient increase in lymph protein clearance that could result from a transient increase in permeability followed by a sustained increase in microvascular surface area. The early response is difficult to interpret because the changes are transient and could be affected by alterations outside the lung.

Download Full-text

Contamination of caudal mediastinal node efferent lymph in sheep

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1981.241.3.h354 ◽

1981 ◽

Vol 241 (3) ◽

pp. H354-H357 ◽

Cited By ~ 2

Author(s):

R. Drake ◽

T. Adair ◽

D. Traber ◽

J. Gabel

Keyword(s):

Flow Rate ◽

Lymph Flow ◽

Lymph Vessels ◽

Mediastinal Node ◽

Lung Lymph

Many investigators have used the chronic sheep lung lymph preparation to collect caudal mediastinal node (CMN) efferent lymph. These investigators have assumed that the lymph collected with the preparation is almost pure lung lymph. We examined 17 sheep for possible systemic contamination to the lymph, and in each sheep we found one to five lymph vessels that ran from the diaphragm to the CMN. Contamination from these vessels would not be eliminated in the chronic sheep preparation. We estimated the flow rate from these vessels to be 3.0 +/- 2.6 (SD) ml/h in anesthetized sheep. This represents 25-60% of the lymph flow rate in the chronic lymph preparation. In five sheep, we also located 1-4 esophageal lymph vessels that entered th CMN. These results show that lymph collected with the chronic sheep lung lymph preparation contains a significant nonpulmonary contamination.

Download Full-text

Effect of lymphatic cannula outflow height on lung microvascular permeability estimations

Journal of Applied Physiology ◽

10.1152/jappl.1984.57.5.1412 ◽

1984 ◽

Vol 57 (5) ◽

pp. 1412-1416 ◽

Cited By ~ 17

Author(s):

G. A. Laine ◽

R. E. Drake ◽

F. G. Zavisca ◽

J. C. Gabel

Keyword(s):

Left Atrial ◽

Atrial Pressure ◽

Left Atrial Pressure ◽

Lymph Vessel ◽

Percent Change ◽

Permeability Surface ◽

Percent Increase ◽

Anesthetized Dogs ◽

Area Product ◽

Lung Lymph

Estimates of the pulmonary microvascular membrane reflection coefficient (sigma) and permeability-surface area product (PS) are frequently made with the assumption that a percent change in transmicrovascular fluid flux (Jv) will be represented by an equal percent change in the lymph flow rate (QL) from a single cannulated lung lymph vessel. To test this, we measured QL in seven anesthetized dogs with the outflow end of the lymph cannula set at several heights (H) above and below the lung hilus. The left atrial pressure was then elevated to increase Jv, and QL was again measured at several H's. The percent increase in QL at elevated left atrial pressure depended on H. We used the QL data and lymph and plasma protein concentrations to estimate sigma and PS with a modified form of the Kedem and Katchalsky equations. The calculated values varied considerably with H. Our results indicate that changes in Jv are not represented by equal changes in QL. Therefore, techniques for estimating permeability that depend upon QL as an estimate of Jv may lead to erroneous estimates of sigma and PS.

Download Full-text