Ileal microvascular permeability: a comparison of PS and sigma d using lymphatic and isotopic protein clearances

1992 ◽  
Vol 262 (3) ◽  
pp. G572-G580 ◽  
Author(s):  
M. I. Townsley ◽  
S. M. Smith ◽  
R. K. Reed ◽  
V. H. Pitts ◽  
A. E. Taylor
Keyword(s):  
Blood Flow ◽  
Venous Pressure ◽  
Lymph Flow ◽  
Control Group ◽  
Reflection Coefficients ◽  
Additional Group ◽  
Permeability Surface ◽  
Albumin Clearance ◽  
D Values ◽  
Ig G

Lymphatic clearances of total protein, albumin, immunoglobulin (Ig) G, and IgM obtained in autoperfused cat ileum as venous pressure (Pv) was elevated were analyzed using traditional methods as well as the newer maximal diffusion (max,diff) method of Reed et al. [Am. J. Physiol. 261 (Heart Circ. Physiol. 30): H728-H740, 1991; Am. J. Physiol. 257 (Heart Circ. Physiol. 26): H1037-H1041, 1989] to determine capillary osmotic reflection coefficients (sigma d) and unique permeability surface area products (PS). In a control group (n = 6), sigma d max,diff and PSmax,diff for albumin, IgG, and IgM could not be determined due to their transiently high clearance patterns. These patterns were not altered by treatment with vasodilators (n = 6) to prevent redistribution of blood flow from the mucosal-submucosal to muscularis layer of the ileum, which accompanies elevation of ileal Pv. Furthermore, sigma d values for IgG in both groups were lower than those for both albumin and IgM, a finding inconsistent with predictions based on pore theory, together suggesting that lymphatic protein clearances were influenced by washout of interstitial proteins, a conclusion supported by the decrease in tissue content of albumin and IgG after elevation of Pv. Clearances of radiolabeled albumin (n = 10) and IgG (n = 6), measured after an initial 2-h steady-state period at a constant Pv, were markedly reduced at low lymph flow compared with those obtained in the shorter term experiments. In an additional group (n = 5), albumin clearance peaked at 10 times baseline within 15 min after a step increase in Pv to 30 mmHg but fell to only 3 times baseline within 1 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyaluronan flux from cat intestine: changes with lymph flow

1992 ◽  
Vol 262 (2) ◽  
pp. H457-H462 ◽  
Author(s):  
R. K. Reed ◽  
M. I. Townsley ◽  
T. C. Laurent ◽  
A. E. Taylor
Keyword(s):  
Blood Flow ◽  
Major Part ◽  
Interstitial Fluid ◽  
Venous Pressure ◽  
Lymph Flow ◽  
Fluid Flux ◽  
Control Value ◽  
One Step ◽  
Experimental Group

Isolated and autoperfused ileal segments from pentobarbital-anesthetized cats were used to study turnover of hyaluronan in the intestine. A postnodal lymphatic was cannulated, and transcapillary and interstitial fluid fluxes were increased by raising venous pressure. Lymph hyaluronan concentration in control averaged 20.2 +/- 18.8 (SD) micrograms/ml (range 4.6-50) and increased with increasing lymph flow in all experiments to peak at concentrations two to three times above control values (at 15-20 mmHg increase in venous pressure). At higher lymph flows, hyaluronan concentration fell to below 5 micrograms/ml to an average of 21.3 +/- 19.5% of control value at the highest venous pressures used (30-40 mmHg). Tissue hyaluronan content fell from 349 +/- 191 micrograms/g dry wt in control to 148 +/- 78 micrograms/g dry wt (P less than 0.05) at the end of the experiment. In a second group, vasodilators were administered before elevation of venous pressure to prevent redistribution of blood flow between mucosal and muscular layers. The results were similar to those obtained above. In a third experimental group, venous pressure was elevated in one step to 30 mmHg and maintained at this level. Again, hyaluronan concentration initially increased and later fell well below control values. We conclude that a major part of the intestinal hyaluronan is easily mobilized by increased interstitial fluid flux.

Enzyme-linked immunosorbent assay of colostral IgG transported into lymph and plasma in neonatal pigs

1992 ◽  
Vol 263 (4) ◽  
pp. R976-R980
Author(s):  
H. Kiriyama
Keyword(s):  
Blood Flow ◽  
Small Intestine ◽  
Immunosorbent Assay ◽  
Lymph Flow ◽  
Enzyme Linked Immunosorbent Assay ◽  
Maximal Level ◽  
Neonatal Pigs ◽  
Duodenal Lumen ◽  
Ig G ◽  
Plateau Level

Amounts of colostral proteins in lymph and plasma were estimated by an enzyme-linked immunosorbent assay (ELISA) after infusion of bovine colostrum into the duodenal lumen in nonsuckling neonatal pigs. The rate of immunoglobulin (Ig) G transport in lymph of the thoracic duct reached the maximal level (4.7 +/- 1.3 mg.15 min-1.kg body wt-1) within 3 h after the duodenal infusion. The rate of small protein (SP) transport more slowly increased than that of IgG. On the contrary, casein remained in the much lower level in lymph. IgG concentration in plasma increased gradually and reached a plateau level (2.5 +/- 0.9 g/l) 5 h after the infusion, but the levels of SP and casein were slowly and slightly increased in plasma. The IgG-to-casein and SP-to-casein ratios in lymph and plasma were 161:15:1 and 128:12:1 4 h after the infusion, respectively, and much higher than the value in the colostrum (IgG/SP/casein = 15:4:1). These results indicate 1) that IgG transported via lymph flow after absorption through the small intestine is faster than that via blood flow, 2) that the concentration of absorbed IgG is higher than that of absorbed SP and much higher than the concentration of absorbed casein both in the lymph and plasma, and 3) that total amount of colostral protein transported via blood flow is larger than that transported via lymph flow.

Intestinal capillary filtration in acute and chronic portal hypertension

1988 ◽  
Vol 254 (3) ◽  
pp. G339-G345 ◽  
Author(s):  
R. J. Korthuis ◽  
D. A. Kinden ◽  
G. E. Brimer ◽  
K. A. Slattery ◽  
P. Stogsdill ◽  
...  
Keyword(s):  
Blood Flow ◽  
Portal Hypertension ◽  
Capillary Pressure ◽  
Vascular Resistance ◽  
Interstitial Fluid ◽  
Venous Pressure ◽  
Fluid Pressure ◽  
Lymph Flow ◽  
Interstitial Fluid Pressure ◽  
Capillary Filtration

The impact of acute and chronic portal hypertension on the dynamics of intestinal microvascular fluid exchange was examined in anesthetized, fasted, sham-operated control rats with normal portal pressures (CON), during acute elevations in portal pressure (APH) in control rats, and in rats in which chronic portal hypertension (CPH) was produced by calibrated stenosis of the portal vein 10 days prior to the experiments. Although intestinal blood flow and vascular resistance were not altered by APH in control rats, CPH was associated with an increased intestinal blood flow and reduced intestinal vascular resistance when compared with CON and APH. Intestinal capillary pressure and lymph flow were elevated in APH and CPH relative to control values. However, the increase in both variables was greater in CPH. The capillary filtration coefficient was elevated only in CPH. The transcapillary oncotic pressure gradient was not altered by APH or CPH. Interstitial fluid pressure was increased from -1.1 mmHg in CON to 3.9 mmHg during APH and to 5.0 mmHg in CPH. The results of this study indicate that chronic elevations in portal venous pressure produce larger increments in intestinal capillary pressure and filtration rate than do acute elevations in portal venous pressure of the same magnitude. However, the potential edemagenic effects of elevated capillary pressure in both acute and chronic portal hypertension are opposed by increases in lymph flow and interstitial fluid pressure.

Effect of luminal distension on intestinal transcapillary fluid exchange

1980 ◽  
Vol 239 (6) ◽  
pp. G516-G523
Author(s):  
D. N. Granger ◽  
P. R. Kvietys ◽  
N. A. Mortillaro ◽  
A. E. Taylor
Keyword(s):  
Blood Flow ◽  
Protein Concentration ◽  
Venous Pressure ◽  
Lymph Flow ◽  
Direct Effects ◽  
Fluid Exchange ◽  
Venous Outflow ◽  
Plasma Protein Concentration ◽  
Pressure Elevation ◽  
The Relationship

The direct effects of luminal distension pressure on intestinal transcapillary fluid exchange were studied in isolated autoperfused cat ileum preparations. Intestinal lymph flow, lymphatic pressure, lymph-to-plasma protein concentration ratio (L/P), blood flow, and perfusion pressures were allowed to reach a steady state at different luminal distension pressures (0–40 mmHg). Luminal distension was induced using a nonabsorbable silicone solution, thereby eliminating an influence of net water absorption. At a venous outflow pressure of 0 mmHg, lymph flow and lymphatic pressure increased, whereas blood flow and L/P decreased as luminal pressure was increased. The relationship between lymph flow, blood flow, and venous pressure was acquired at luminal pressures of 0 and 20 mmHg. When luminal pressure was 0, lymph flow increased and blood flow decreased progressively with venous pressure elevation; however, when luminal pressure was 20 mmHg, lymph flow and blood flow were unaffected until pressure exceeded 20 mmHg. The results of this study indicate that luminal pressure elevation enhances transcapillary fluid exchange and imposes a “waterfall” effect on the intestinal vasculature.

Effect of Change in Renal Venous Pressure Upon Renal Vascular Resistance, Urine and Lymph Flow Rates

1958 ◽  
Vol 195 (1) ◽  
pp. 97-110 ◽  
Author(s):  
F. J. Haddy ◽  
J. Scott ◽  
M. Fleishman ◽  
D. Emanuel
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Flow Rate ◽  
Venous Pressure ◽  
Blood Flow Rate ◽  
Lymph Flow ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Constant Resistance ◽  
Renal Vascular

The usual increase in intrarenal resistance as a function of flow rate was augmented by elevation of venous pressure. The augmentation was more apparent in innervated than denervated kidneys. With blood flow rate held constant, resistance increased as a function of venous pressure in innervated kidneys but decreased slightly in denervated kidneys. The latter response was not different during administration of phentolamine, phentolamine and eserine or during perfusion of live innervated and dead kidneys with dextran. Resistance changes induced by elevation of only arterial pressure were the same in innervated and denervated kidneys. For a given arterial pressure in dead kidneys perfused with dextran, resistance was higher with venous pressure elevated than it was with pressure normal. Lymph flow rate increased as a function of venous pressure. Urine flow rate decreased as a function of venous pressure with blood flow rate uncontrolled but did not change when flow rate was held constant. Therefore, high renal vein pressures increase resistance by reflex active vasoconstriction as well as by passive vasoconstriction. The reduction in urine flow rate is in part related to these resistance controlling mechanisms.

Estimation of capillary reflection coefficients and unique PS products in dog paw

1989 ◽  
Vol 257 (3) ◽  
pp. H1037-H1041 ◽  
Author(s):  
R. K. Reed ◽  
M. I. Townsley ◽  
A. E. Taylor
Keyword(s):  
Total Protein ◽  
Peclet Number ◽  
Reflection Coefficients ◽  
Plasma Protein Concentration ◽  
Linear Portion ◽  
Péclet Number ◽  
Capillary Membrane ◽  
Permeability Surface ◽  
The Relationship ◽  
Ig G

Lymphatic protein flux (Js) obtained in canine hindpaws at low lymph flows were used to determine the capillary osmotic reflection coefficients (sigma d) and unique permeability surface area (PS) products for total proteins, albumin, immunoglobulin (Ig)G, and IgM. This new analysis is based on the phenomenon that when maximal diffusion occurs across the capillary membrane, the Peclet number [x = Jv(1 - sigma d)/PS] attains a unique value defined only by sigma d. The diffusive flux is maximal when the relationship between protein flux and transcapillary fluid flux (Jv) changes from a curvilinear to a linear relationship. The slope of the linear portion of this protein flux relationship was used to determine sigma d as (1 - sigma d) = delta Js/(delta JvCp), where Cp is the plasma protein concentration. With the use of sigma d, the Jv at which the maximal diffusion occurred, and the corresponding Peclet number, a unique value is obtained for the PS product. Experiments performed using lymph from canine hindpaws (n = 6) yielded sigma d's (mean +/- SD) of 0.91 +/- 0.03, 0.83 +/- 0.11, 0.96 +/- 0.03, and virtually 1 for total protein, albumin, IgG, and IgM, respectively. The corresponding PS products for total protein, albumin, and IgG were 25.0 +/- 13.2, 28.4 +/- 6.6, and 14.0 +/- 7.9 microliters.min-1.100 g-1, respectively; PS for IgM was almost zero.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of methysergide administration on edema formation at the site of scald

1995 ◽  
Vol 78 (1) ◽  
pp. 191-197 ◽  
Author(s):  
J. J. Ferrara ◽  
E. W. Franklin ◽  
E. U. Choe ◽  
H. L. Lippton ◽  
A. L. Hyman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Concentration Ratio ◽  
Protein Concentration ◽  
Venous Pressure ◽  
Lymph Flow ◽  
Plasma Protein Concentration ◽  
Edema Formation ◽  
Femoral Blood Flow ◽  
S 100 ◽  
Femoral Blood

Femoral blood flow (Qa), hind paw lymph flow (Qlym), and lymph-to-plasma protein concentration ratio (Clym/Cp) were monitored before and 4 h after 1) 5-s 100 degrees C paw scald, 2) methysergide (1 mg/kg iv) 20 min before scald, 3) methysergide 30 min after scald, and 4) methysergide only. Before experimentation, hind paw venous pressure was elevated and maintained until steady-state Qa, Qlym, and minimal Clym/Cp levels were reached. The reflection coefficient (sigma d) was determined as 1 - minimal Clym/Cp; the filtration coefficient (Kf) was calculated. Methysergide alone caused no changes. Increases in Qa, Qlym, Clym/Cp, and Kf were identified in all scald groups. Compared with scald only animals, pre- and postscald methysergide blunted the increases in Qa, Qlym, Kf, and paw weight gain without an effect on sigma d. These data demonstrate that methysergide reduces edema formation at the site of scald, perhaps by modulating the burn-induced vasodilator response and/or by limiting the burn-induced increase in microvascular surface area.

Comparison of protein lymph flux and extravascular uptake in skin during increased venous pressure

1992 ◽  
Vol 263 (3) ◽  
pp. H895-H902 ◽  
Author(s):  
J. R. Wallace ◽  
D. R. Bell
Keyword(s):  
Reflection Coefficient ◽  
Immunoglobulin G ◽  
Venous Pressure ◽  
Lymph Flow ◽  
Reflection Coefficients ◽  
The Relationship

The hypothesis that the albumin reflection coefficient is underestimated from measurements of lymph protein flux because of a prolonged interstitial washout was tested in the hindleg of anesthetized rabbits. In heel skin, the initial extravascular uptake for labeled albumin and immunoglobulin G (IgG) was compared with prenodal lymph flux for native albumin and IgG. Venous pressure was increased in one leg for 4 h, while the contralateral leg was the control. The extravascular uptake for labeled albumin was 67% greater than control during the fourth hour of increased venous pressure. Lymph albumin flux was 2.3 times control, indicating a small but significant washout of interstitial albumin. The magnitude of the interstitial washout for IgG was less than that for albumin. Using the relationship between the change in extravascular uptake and the change in lymph flow, the reflection coefficients for albumin and IgG were both 0.91. The reflection coefficient for albumin using lymph protein flux was lower because of a continued interstitial washout.

Permeability of intestinal capillaries to endogenous macromolecules

1980 ◽  
Vol 238 (4) ◽  
pp. H457-H464 ◽  
Author(s):  
D. N. Granger ◽  
A. E. Taylor
Keyword(s):  
Surface Area ◽  
Venous Pressure ◽  
Protein Fractions ◽  
Plasma Protein Concentration ◽  
Continuous Type ◽  
Endogenous Protein ◽  
Permeability Surface ◽  
Gradient Gel Electrophoresis ◽  
Osmotic Reflection Coefficient ◽  
D Values

Steady-state lymphatic and plasma protein concentration (CL and CP) and lymph flows were analyzed in an autoperfused cat ileum preparation at venous outflow pressures of 0, 10, 20, and 30 mmHg. Albumin and nine endogenous protein fractions were analyzed in lymph and plasma by polyacrylamide gradient gel electrophoresis. The osmotic reflection coefficient (sigma d = 1--CL/CP when CL/CP is no longer influenced by capillary filtration rate. The sigma d values acquired increased as the molecular radius of the protein fraction increased. Permeability-surface area products were estimated for the various protein fractions by applying the acquired data to the Kedem-Katchalsky protein flux equation. A comparison of the permeability-surface area products at various venous pressures suggests a reduction in capillary surface area as venous pressure is increased to 20 and 30 mmHg. The results suggest that intestinal capillaries selectively restrict macromolecules to a greater degree than the continuous type of capillaries of many other organs.

Efficacy of Near-Infrared Spectrometry for Monitoring the Cerebral Effects of Severe Dilutional Anemia

2014 ◽  
Vol 17 (3) ◽  
pp. 154 ◽  
Author(s):  
Arıtürk Cem ◽  
Ustalar Serpil ◽  
Toraman Fevzi ◽  
Ökten Murat ◽  
Güllü Ümit ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Surgery ◽  
Blood Lactate ◽  
Near Infrared ◽  
Bypass Graft ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Infrared Spectrometry ◽  
Control Group ◽  
Near Infrared Spectrometry

<p><strong>Introduction:</strong> Clear guidelines for red cell transfusion during cardiac surgery have not yet been established. The current focus on blood conservation during cardiac surgery has increased the urgency to determine the minimum safe hematocrit for these patients. The aim of this study was to determine whether monitoring of cerebral regional oxygen saturation (rSO<sub>2</sub>) via near-infrared spectrometry (NIRS) is effective for assessing the cerebral effects of severe dilutional anemia during elective coronary arterial bypass graft surgery (CABG).</p><p><strong>Methods:</strong> The prospective observational study involved patients who underwent cerebral rSO<sub>2</sub> monitoring by NIRS during elective isolated first-time CABG: an anemic group (<em>N</em>=15) (minimum Hemoglobin (Hb) N=15) (Hb &gt;8 g/dL during CPB). Mean arterial pressure (MAP), pump blood flow, blood lactate level, pCO<sub>2</sub>, pO<sub>2</sub> at five time points and cross-clamp time, extracorporeal circulation time were recorded for each patient. Group results statistically were compared.</p><p><strong>Results:</strong> The anemic group had significantly lower mean preoperative Hb than the control group (10.3 mg/dL versus 14.2 mg/dL; <em>P</em> = .001). The lowest Hb levels were observed in the hypothermic period of CPB in the anemic group. None of the controls exhibited a &gt;20% decrease in cerebral rSO<sub>2</sub>. Eleven (73.3%) of the anemic patients required an increase in pump blood flow to raise their cerebral rSO<sub>2</sub>.</p><p><strong>Conclusions:</strong> In this study, the changes in cerebral rSO<sub>2</sub> in the patients with low Hb were within acceptable limits, and this was in concordance with the blood lactate levels and blood-gas analysis. It can be suggested that NIRS monitoring of cerebral rSO<sub>2</sub> can assist in decision making related to blood transfusion and dilutional anemia during CPB.</p>

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