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PubMed1991

[Alveolo-capillary permeability following multiple trauma--monitoring by bronchoalveolar lavage].

In trauma patients (ISS greater than 40 points) bronchoalveolar lavage (BAL) as well as the first clinical measurements was performed within the first 6 hours after admission to hospital. Thereafter BAL was carried out once per day, using 100 ml NaCl 0.9% (10 x 10 ml). BAL-protein-concentrations (i.e. albumin) were converted to epithelial lining fluid (ELF) according to Rennard, using urea as an internal standard. The limitations of this method were taken into account. The alveolo-capillary permeability (ACP) was described by the quotient of the protein concentrations in ELF and plasma. Progressive lung failure (ARDS) was defined using the criteria given by Murray. Lung contusion was an exclusion criteria. The study period was 14 days. This study evaluated data from 12 patients (m: 10, f: 2; age 30.4 (17-52); ISS 63.4). Five patients developed a progressive lung failure ("+ARDS"--age 32.2; ISS 71.5), 7 patient suffered no pulmonary failure during intensive care ("-ARDS")--age 29.5; ISS 59.2). No patient died in the course of the study. An increased ACP for albumin (combined endothelial-epithelial disturbance) was detectable for both +ARDS- und -ARDS-patients after the 6th hour, reaching a maximum around the 24th hour. +ARDS-patients showed a significant higher ACP. Further, beginning from the 48th hour to the 4th day, the ACP value for -ARDS-patients again dropped to a physiologic range. The degree of the increased ACP depends on the size of the marker protein, but it is independent of pulmonary hemodynamics. It is of value for the prediction of ARDS within 24 hours and for monitoring of pulmonary damage in posttraumatic course.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1977

Effects of glucocorticoids on ventricular performance and capillary permeability during hemorrhagic shock.

The effects of glucocorticoids on fluid uptake and myocardial performance was investigated in 14 dogs and two baboons. The animals were placed into stimulated hemorrhagic shock using a servocontrolled pump to maintain arterial pressure at desired levels. Ventricular function curves were generated by stepwise changes in afterload or by venous infusion and the resultant data were grouped by digital computer into similar preload, heart rate, and afterload groupings. Fluid uptake was monitored from the pump reservoir. Methylprednisolone was given intravenously, 30 mg/kg, approximately 3 hr after the postinfusion period. Fluid loss decreased and ventricular performance improved, as measured by maximal dp/dt, (maximal dp/dt)/developed pressure, and time to peak ventricular pressure. The improvements with steroid infusion were relatively small, however, and were not maintained for more than about 3 hr. Heart rate decreased markedly in response to the steroid, despite a general vasodilator response. The glucocorticoids appear to have mild beneficial effects on the myocardium and on capillary permeability in the presence of high circulating levels of catecholamines in the postinfusion phase of hemorrhagic shock.

Animals↗
PubMed1981

Regional blood flow, capillary permeability, and glucose utilization in two brain tumor models: preliminary observations and pharmacokinetic implications.

Regional quantitative autoradiographic measurements of blood flow, capillary permeability, and glucose utilization were made in rats harboring an intracerebral Walker 256 metastatic tumor or a well-differentiated oligodendroglioma. Distinct differences were observed between the two brain tumor models; regional differences within the metastatic tumor appeared to be partly related to tumor size. The pharmacokinetic implications of these physiological measurements with respect to drug delivery to tumor tissue are discussed. The interrelationship of commonly used parameters to quantitate transport across the blood-brain barrier--permeability coefficient, permeability-surface area product, transfer constant, extraction fraction, equilibrium half-time, and blood flow--and their relevance to effective brain tumor chemotherapy are demonstrated.

Animals↗
PubMed1992

Increased capillary permeability for plasma proteins in oral contraceptive users.

The transcapillary fluid balance was examined in eleven women before administration of a monophasic oral contraceptive (desogestrel 0.15 mg, ethinylestradiol 0.03 mg), and after three and six months of use. The interstitial colloid osmotic pressure was measured by the "wick" method, and the interstitial hydrostatic pressure by the "wick-in-needle" method in subcutaneous tissue on thorax and leg. During the six-month observation period, the following changes were observed: Plasma colloid osmotic pressure decreased (mean 1.8 mmHg, p = 0.047), as well as serum albumin (mean 5.1 g/l, p = 0.0006), total protein concentration (mean 2.8 g/l, p = 0.0006), hemoglobin (mean 0.5 g/dl, p = 0.014) and hematocrit (mean 1.8%, p = 0.047). Blood pressure and body weight remained unchanged, but foot volume showed a significant increase. The colloid osmotic pressure gradient (plasma-interstitium) was significantly reduced. The results indicate an increase in plasma volume in addition to an increased capillary permeability to plasma proteins during oral contraceptive use. We suggest that the observed changes in transcapillary fluid balance is caused by the estrogen component of the oral contraceptive pill.

Adolescent↗
PubMed1975

[Hemodynamic study of pulmonary edemas due to the increase of alveolo-capillary permeability].

Hemodynamic data were collected in 42 patients with pulmonary edema (P.E.) due to altered permeability of various causes. Pulmonary artery wedge pressure (PWP) was normal, whatever the time of the study and the severity of the P.E. Pulmonary artery hypertension was present in the cases with severe hypoxemia, but disappeared with hypoxemia correction. In some cases, a hyperkinetic or a hypovolemic syndrome was found, being induced by the cause of P.E. Although within normal limits, PWP was significantly higher at the first hours of P.E. than after the 6th hour. Perfusion of colloid solutes worsened P.E., although increasing PWP by only a few mmHg. Dehydration using diuretics markedly improved the venous admixture, although PWP was previously normal. These data document the production of P.E. in many causes-such as severe sepsis, drowning, fat embolism, barbiturate overdose-by impaired alveolo-capillary permeability, PWP and blood protein content remaining within normal limits. They also demonstrate the noxious effects of overperfusion and the efficiency of dehydration in such pulmonary edemas.

Adult↗
PubMed2004

Effect of re-expansion after short-period lung collapse on pulmonary capillary permeability and pro-inflammatory cytokine gene expression in isolated rabbit lungs.

BACKGROUND: Re-expansion pulmonary oedema is a rare complication caused by rapid re-expansion of a chronically collapsed lung. Several cases of pulmonary oedema associated with one-lung ventilation (OLV) have been reported recently. Elevated levels of pro-inflammatory cytokines in pulmonary oedema fluid are suggested to play important roles in its development. Activation of cytokines after re-expansion of collapsed lung during OLV has not been thoroughly investigated. Here we investigated the effects of re-expansion of the collapsed lung on pulmonary oedema formation and pro-inflammatory cytokine expression. METHODS: Lungs isolated from female white Japanese rabbits were perfused and divided into a basal (BAS) group (n=7, baseline measurement alone), a control (CONT) group (n=9, ventilated without lung collapse for 120 min) and an atelectasis (ATEL) group (n=9, lung collapsed for 55 min followed by re-expansion and ventilation for 65 min). Pulmonary vascular resistance (PVR) and the coefficient of filtration (Kfc) were measured at baseline and 60 and 120 min. At the end of perfusion, bronchoalveolar lavage fluid/plasma protein ratio (B/P), wet/dry lung weight ratio (W/D) and mRNA expressions of tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta and myeloperoxidase (MPO) were determined. RESULTS: TNF-alpha and IL-1beta mRNA were significantly up-regulated in lungs of the ATEL group compared with BAS and CONT, though no significant differences were noted in PVR, Kfc, B/P and W/D within and between groups. MPO increased at 120 min in CONT and ATEL groups. CONCLUSION: Pro-inflammatory cytokines were up-regulated upon re-expansion and ventilation after short-period lung collapse, though no changes were noted in pulmonary capillary permeability.

Animals↗
PubMed1969

Heart capillary permeability to lipid-insoluble molecules.

1. A study has been made, in the isolated, beating dog heart perfused with blood, of the transcapillary exchange of the following substances: [(3)H]water, (22)Na, (86)Rb, (36)Cl, [(14)C]urea, [(3)H]glycerol, [(3)H]glucose, [(14)C]sucrose and [(3)H]inulin.2. The method used to study the exchange was the ;indicator diffusion' technique. It consists in a rapid arterial injection of a mixture containing a diffusible and a non-diffusible molecule, followed by a rapid split collection of the venous outflow, up to 30 sec. The fractional extraction, E, of the diffusible substance was obtained by comparing the relative concentrations of both tracers in injected medium and in each venous sample.3. E for [(3)H]water was the highest (0.90 +/- 0.3), and it did not vary with flow. All other molecules had values for E that decreased as flow increased.4. Capillary permeability constant, P, was estimated from PS = - F ln (1 - E), in which S is the surface area of exchange and F is the blood perfusion rate. To test the validity of the equation, E was measured at different blood perfusion rates. It was found that the equation did not apply at relatively low flows for the more diffusible substances.5. The average values of P estimated for inulin, sucrose, glucose, glycerol and urea were 0.27, 0.8, 1.0, 1.5 and 3.1 x 10(5) (cm/sec), respectively. The ratio P/D (in which D is the free diffusion in water constant) was the same for all these substances. This can be interpreted as showing that if pores exist in the capillary endothelium, they must be larger than 80-100 A diameter. It is concluded that the pores could actually be the intercellular slits as previously suggested by electron microscope studies. Endothelial cell participation in the exchange appears to be small except for [(3)H]water.

Animals↗
PubMed1994

Albuminuria and overall capillary permeability of albumin in acute altitude hypoxia.

The mechanism of proteinuria at high altitude is unclear. Renal function and urinary excretion rate of albumin (Ualb) at rest and during submaximal exercise and transcapillary escape rate of 125I-labeled albumin (TERalb) were investigated in 12 normal volunteers at sea level and after rapid and passive ascent to 4,350 m. The calcium antagonist isradipine (5 mg/day; n = 6) or placebo (n = 6) was administered to abolish hypoxia-induced rises in blood pressure. Lithium clearance and urinary excretion of beta 2-microglobulin were used to evaluate renal tubular function. High altitude increased Ualb from 2.8 to > 5.0 micrograms/min in both groups (P < 0.05). In the placebo group, high altitude significantly increased filtration fraction (P < 0.05), but this response was abolished by isradipine. Lithium clearance and urinary excretion of beta 2-microglobulin remained unchanged by hypoxia in both groups. Exercise did not reveal any further renal dysfunction. In both groups, high altitude increased TERalb from 4.8 to > 6.7%/h (P < 0.05). In conclusion, acute altitude hypoxia increases Ualb despite unchanged tubular function and independent of effects of isradipine on filtration fraction. The elevated TERalb suggests an overall increase in capillary permeability, including the glomerular endothelium, as the critical factor in high-altitude induced albuminuria.

Adult↗
PubMed1995

NEM inhibits transcytosis, endocytosis, and capillary permeability: implication of caveolae fusion in endothelia.

Various vesicular carriers transport select molecular cargo between intracellular compartments utilizing a budding mechanism with docking and fusion of individual vesicles with their target membranes. This fusion requires key intracellular component(s) that are sensitive to alkylation with N-ethylmaleimide (NEM). In endothelium, caveolae may mediate endocytosis and transcytosis of select macromolecules. If caveolae utilize a mechanism similar to other vesicular carriers, then their transport should also be sensitive to NEM. The following tracers were chosen based on their pathway specificity: 1) albumin-gold complexes (A-Au) that bind gp30 and gp18 for endocytosis by caveolae, 2) native albumin that binds albondin and is transported by caveolae, 3) ferritin as a fluid-phase probe transcytosed by caveolae, and 4) inulin as a paracellular probe. In culture, NEM significantly inhibited A-Au uptake and delivery to endosomes but not endothelial cell surface binding. In rat lung, NEM reduced capillary permeability to albumin and the tissue uptake of ferritin and A-Au, but not inulin, indicating inhibition of caveolae-mediated but not paracellular transport. Neutral but not charged alkylating agents inhibited A-Au uptake, consistent with their relative abilities to cross membranes and modify intracellular factors. Like other vesicular pathways, endothelial caveolae transport their select ligands utilizing a NEM-sensitive mechanism, apparently requiring vesicle-membrane fusion.

Animals↗
PubMed2006

Increased pulmonary capillary permeability and extravascular lung water after major vascular surgery: effect on radiography and ventilatory variables.

INTRODUCTION: We decided to investigate the pathogenesis of pulmonary ventilatory and radiographic abnormalities in patients after major vascular surgery. PATIENTS AND METHODS: Sixteen mechanically ventilated patients without heart failure were studied, within 3 h after major abdominal surgery. We measured extravascular lung water, intrathoracic, global end-diastolic and pulmonary blood volumes, (67)Ga-transferrin pulmonary leak index and ventilatory and radiographic variables. The latter allowed computation of the lung injury score as a measure of lung injury. RESULTS: The extravascular lung water was elevated (>7 mL kg(-1)) in 5 of 16 patients, while the pulmonary leak index was elevated in 11 patients and a supranormal extravascular lung water was associated with a high pulmonary leak index and higher extravascular lung water relative to intrathoracic blood volume or pulmonary blood volume. Patients were arbitrarily divided into those with a lung injury score >1 and < or =1, and only differed in the factors composing the score as well as in extravascular lung water divided by pulmonary blood volume. A lung injury score >1 was associated with a longer duration of mechanical ventilation. CONCLUSION: Our data suggest that mild, subclinical, pulmonary oedema is relatively common after major vascular surgery, mainly caused by increased pulmonary capillary permeability in the absence of overt heart failure. However, permeability oedema only partially contributes to postoperative lung injury score and need for mechanical ventilation, suggesting a major contribution by atelectasis.

Aged↗