Reperfusion after limb ischemia leads to sequestration of polymorphonuclear leukocytes (PMN) in the lungs and to leukocyte- (WBC) and thromboxane- (Tx) dependent respiratory dysfunction. This study examines the intermediary role of the chemoattractants leukotriene (LT)B4 and complement (C) fragments. Anesthetized sheep with chronic lung lymph fistulae underwent 2 hours of ...

The changes in vascular albumin permeation induced by systemic anaphylaxis were studied simultaneously in 21 different tissues of the same animal. Before Ag challenge sensitized rats were injected i.v. with 125I-albumin (test tracer), 51Cr-RBC (vascular space marker) and 57Co-EDTA (extravascular space marker). The index of vascular permeation used was the ...

We prepared nine sheep with acute tracheobronchial afferent (TBN) and caudal mediastinal efferent (CMN) lymph fistulas. After a baseline period (B) in 3 sheep, we administered histamine (H) continuously for 4 h. In six sheep, we elevated left atrial pressure (PLA) and reestablished steady-state conditions prior to H administration. The ...

The purpose of this project was to study the effects of increased plasma concentrations of arginine vasopressin (AVP) on hemodynamics and lung fluid balance in lambs. We studied 16 unanesthetized newborn lambs during a base-line period and while infusing AVP into a hindlimb vein at 1.65 +/- 0.12 and 2.98 ...

The purpose of this study was to determine to what extent fetal thoracic duct lymph flow may be reduced by increases in fetal venous pressure. In pregnant sheep the fetal left thoracic lymph duct was catheterized at the base of the neck and this catheter was connected to a jugular-vein ...

We compared the cardiopulmonary responses to a single bolus (1.5 microgram/kg) vs. continuous infusion of endotoxin (LPS) (24 ng/kg/hr) in unanesthetized sheep. A single bolus produced an initial marked increase in pulmonary arterial pressure and plasma thromboxane levels and an elevated flow rate of lung lymph low in protein. Concomitantly, ...

It has been previously reported that enprofylline (3-propyl xanthine) prevents histamine-mediated edema formation in the guinea pig lung. To further assess the potential anti-inflammatory effects of enprofylline, we infused it intra-arterially into the canine forelimb before and during a local intra-arterial infusion of histamine (4 micrograms/min) while monitoring forelimb skin ...

Lower torso ischemia leads during reperfusion to leukocyte (white blood cell)-dependent lung injury. This study tests the intermediary role of oxygen free radicals (OFRs) in mediating this event. Chronically instrumented anesthetized sheep underwent 2 hours of bilateral hindlimb ischemia. In untreated control animals (n = 7), 1 minute after tourniquet ...

The pathogenesis of reexpansion pulmonary edema has not been well studied. We tested the hypothesis that both long term collapse and subsequent reexpansion of the lungs cause reexpansion pulmonary edema by increasing pulmonary microvascular permeability. We investigated lymph dynamics in 15 experiments on collapsed lung and 10 experiments after lung ...

We have studied 9 patients with burns (20%-75%) who had inhalation injuries and compared their actual fluid requirements with their requirements calculated from the Muir and Barclay formula. All patients were resuscitated with plasma protein fraction at a rate sufficient to keep their physiological variables within the following range: heart ...

Pulmonary insufficiency is a major cause for mortality and morbidity following shock and sepsis. We studied the effect of hemorrhagic shock and retransfusion on endotoxin-induced lung dysfunction. Eighteen unanesthetized sheep with chronic lung lymph fistulae were divided into 3 groups. In Group I (n = 5) hemorrhagic shock of 50 ...

In urethan-anesthetized rats the appearance rates of urea (U), antipyrine (A), and alpha-methyl-D-glucoside (MG) in the venous blood of perfused jejunal segment were measured in the undistended state and after elevation of the intraluminal pressure up to 10 cmH2O. Serosal and inner cylindrical surface area of the jejunal segment were ...

The effects of hypoxia and zymosan-activated plasma (ZAP) on lung hemodynamics and fluid exchange were studied in unanesthetized goats. Hypoxia produced a sustained increase in pulmonary arterial pressure (PPA), but had no effect on lung lymph flow and protein content. Following ZAP infusion there was an early phase of leukopenia ...

The clinical use of interleukin-2 (IL-2) is limited by severe cardiopulmonary dysfunction. This study examines the mechanism of respiratory failure related to IL-2, using sheep with chronic lung lymph fistulae. Awake animals were infused with an intravenous (I.V.) bolus of IL-2 10(5) U/kg (n = 5) or its excipient (EXC) ...

Hydrostatic and oncotic pressures are the primary determinants of fluid movement across the pulmonary vascular membrane. The precise role of oncotic pressure in regulating transvascular fluid exchange especially when hydrostatic pressure is high is not known. Awake, adult sheep were instrumented for pressure monitoring and the collection of pulmonary lymph. ...

To study the effect of pulmonary perfusion on fluid filtration in the newborn lung, we measured pulmonary vascular pressures, cardiac output, lung lymph flow, and concentrations of protein in lymph and plasma of nine healthy, awake lambs, 2-3 wk old, before and during sustained alterations in pulmonary blood flow. A ...

Lower torso ischemia leads on reperfusion to sequestration of polymorphonuclear leukocytes (PMN) in the lungs and increased permeability. This study tests the role of circulating leukocytes (WBC) in mediating this lung injury. Anesthetized sheep prepared with chronic lung lymph fistulae underwent 2 hours of bilateral hind limb tourniquet ischemia. In ...

We investigated whether platelet-activating factor (PAF) mediates endotoxin-induced systemic and pulmonary vascular derangements by studying the effects of a selective PAF receptor antagonist, SRI 63-441, during endotoxemia in sheep. Endotoxin infusion (1.3 micrograms/kg over 0.5 h) caused a rapid, transient rise in pulmonary arterial pressure (Ppa) from 16 +/- 3 ...

The effect of the leukotriene D4, leukotriene E4 (LTD4/E4) receptor antagonist LY-171883 was studied in endotoxemia. Eighteen awake sheep were divided into three groups. In Group (n = 4) 4 mg/kg LY-171883 was twice injected intravenously. In Group II (n = 9) 1 microgram/kg E. coli endotoxin was administered intravenously. ...

A yearling Hanoverian filly had intermittent colic for 6 weeks, chylous peritoneal effusion, and a firm mass palpable per rectum. Exploratory laparotomy revealed mesenteric lymphadenopathy, adhesion of the mesenteric root to the duodenum and jejunum, distention of the mesenteric veins and lymphatic vessels, and increased jejunal venous pressure. Lesions in ...

1. Lymph flow was measured by cannulating metatarsal lymphatics in the sheep hindlimb. The region was perfused with warmed, heparinized, oxygenated blood via the tibio-cranial artery cannulated just distal to the hock. Constant and pulsatile perfusion pressures were compared. A cuff was inflated over the metatarsals to maintain venous pressure ...

We studied the effects of an increase in pulmonary blood flow (PBF) on steady-state lung lymph flow (QL) and protein transport in anesthetized dogs (n = 7) to estimate the effect of vascular recruitment in zone 3 on transvascular filtration. At the end of each experiment, we increased left atrial ...

The effect of glass-bead microemboli (diameter 100 micron, range 77-125 micron) in the absence of fibrinolysis inhibition on pulmonary hemodynamics and microvascular permeability was determined in anesthetized, microfilaria-free dogs acutely prepared for the collection of lung lymph. Pulmonary vascular resistance, pulmonary capillary pressure (Pc), lymph flow (QL), and the ratio ...

Experiments were conducted on five chronically instrumented unanesthetized sheep to determine the effects of verapamil, a calcium channel inhibitor, on the pulmonary hemodynamic and microvascular permeability responses to endotoxemia. Paired control endotoxemia experiments (E) and endotoxemia with verapamil treatment (30-60 micrograms.kg-1.min-1) experiments (V + E) were conducted on each sheep ...

The forces and membrane coefficients governing transcapillary and lymphatic fluid fluxes were measured in the cat jejunum before and during perfusion of the gut lumen with oleic acid (5 mM) solubilized with taurocholic acid (10 mM). Net transmucosal fluid flux, lymph flow, capillary pressure (Pc), blood flow, capillary filtration coefficient ...

We sought to determine the effect of corticosteroid therapy in a new acute model of oxidant lung injury, thoracic irradiation in awake sheep. Sheep were irradiated with 1,500 rads to the whole chest except for blocking the heart and adjacent ventral lung. Seven experimental sheep were given methylprednisolone (1 g ...

We examined the effects of serotonin (5-HT) infusion on hemodynamics, vascular compliance (Cvasc), and the filtration coefficient (Kf) in the isolated canine lower left lung lobe (LLL) perfused at constant flow. In one group (5-HT; n = 8), 5-HT was infused at 55 micrograms/min for 35 min and then at ...

The ability of the purified stereoisomers of the beta 2-receptor agonist terbutaline to block bradykinin-mediated increases in lymph flow and protein concentration was assessed in the canine forelimb perfused at constant arterial flow. Intra-arterial infusion of bradykinin (2 micrograms/min, n = 8) decreased forelimb arterial pressures but did not affect ...

The thoracic duct and right lymphatic duct of the dogs in the experimental group were ligated at the neck. Saline labelled with Evans blue was injected (10 ml.kg-1) into the pleural cavity. The colloid osmotic pressure of the saline was adjusted to be exactly equal to that of normal pleural ...

The mechanisms underlying the vascular responses of superficial fibular nerve stimulation (SFNS) have not been defined. Right hindpaws of anesthetized heparinized dogs were vascularly and neurally isolated, enclosed in a volume recorder, and perfused with controlled pressure. Vascular volume (VV) (131I-labeled albumin) and rate of tissue volume changes (VT) (plethysmography) ...

A thoracic duct lymph fistula in combination with a lung lymph fistula in the awake sheep was used to evaluate effects of thoracic lymph diversion during a septic insult and to monitor systemic and local changes in the lung and gastrointestinal tract. Live Escherichia coli 10(9) kg-1 b.w. were infused ...

Changes in pulmonary capillary filtration induced by hyperoxia were investigated in 15 dogs. After 12 h of normobaric hyperoxic exposure, animals were anesthetized and artificially ventilated with 100% O2. A pulmonary lymphatic vessel was cannulated, and lymph flow and protein content were measured together with pulmonary and systemic hemodynamics. An ...

Regulation of lymphatics by sympathetic nerves or hormones seems probable. To elucidate this, we perfused a lymphatic vessel in the paw of the anesthetized dog while measuring lymphatic perfusion pressure. We studied the effects of norepinephrine, epinephrine, hemorrhage, and carotid occlusion on lymphatic pressure. Blood was pumped to the forelimb ...

Respiratory decompression sickness (RDCS, "the chokes") is a potentially lethal consequence of ambient pressure reduction. Lack of a clearly suitable animal model has impeded understanding of this condition. RDCS, unaccompanied by central nervous system signs, occurred in 17 of 18 unanesthetized sheep exposed to compressed air at 230 kPa (2.27 ...

The effect of superior vena caval pressure (SVCP) elevation on the formation of pleural effusions (PE) was studied in sheep. Through a right thoracotomy, a Silastic cuff was placed around the superior vena cava. Catheters for monitoring SVCP and pulmonary artery pressure (PAP) were also placed. After a 1- to ...

We determined the effect of H2O2 on both the physiological and biochemical lung changes seen in the adult sheep after endotoxin. Fourteen unanesthetized adult sheep with chronic lung lymph fistula were given Escherichia coli endotoxin (1 microgram/kg) over 30 min. Seven sheep were given catalase (32,500 U/kg body wt) as ...

It has been suggested that coronary ischemia increases extravascular lung water. To determine whether pulmonary microvascular permeability is increased by coronary ischemia, we measured pulmonary hemodynamics, lung lymph flow (QL), and lymph-to-plasma protein concentration ratio (L/P) in 12 sheep with chronic lung lymph fistulas. Studies were done in 3 groups: ...

Inhalation injury was produced in sheep that were chronically prepared for study. The injury was induced by insufflating them with smoke from burning cotton cloth. One group of animals was treated with the oxygen-free radical scavenger dimethylsulfoxide (DMSO) and heparin. Another group received heparin treatment alone, and a third was ...

The cardiopulmonary effects of a third-degree scald burn involving the anterolateral chest wall was compared with a burn of equal size (30% of total body surface) to the flanks in anesthetized sheep with lung lymph fistulas. The chest-burn group was characterized by immediate decreases in cardiac output (6.5 to 3.0 ...

Manipulation of arachidonic acid metabolism may be important in the prevention and treatment of the adult respiratory distress syndrome. This study evaluated a thromboxane receptor blocker, BM 13.177, in a sheep endotoxin model. Sheep with chronic lung lymph fistulas were pretreated with the blocker before being given endotoxin. The blocker ...

Neutralization of heparin by protamine is a common procedure following extracorporeal circulation (cardiopulmonary bypass) of blood. Protamine administration has been shown to cause serious hemodynamic derangement in some patients. Obstruction of the pulmonary vascular bed following protamine administration has been suggested to be the primary cause of hemodynamic changes. The ...

This study tests whether activated complement leads to a selective entrapment of polymorphonuclear leukocytes (PMN's) in the lungs. Awake sheep were infused for 5 min with zymosan-activated plasma (ZAP, 2.5 mg/ml) at a rate of 5 ml/min into the superior vena cava (IV, n = 4) or intra-arterially into the ...

Pancreatic secretion during pancreatic duct obstruction results in increased duct pressure. The normally impermeable pancreatic duct becomes permeable to macromolecules the size of pancreatic enzymes after secretion against obstruction. Permeability and morphologic changes may be related to increased secretory pressure during obstruction. We obstructed the main pancreatic duct of cats ...

We analyzed the effects of Escherichia coli endotoxin infusion on pulmonary microvessels in sheep by using a two-pore mathematical model of the microvascular barrier. Five sheep were prepared with lung lymph fistulas and instrumented to measure pulmonary arterial and left atrial pressures. Multiple indicator-dilution curves (with 125I-labeled albumin, 51Cr-labeled erythrocytes, ...

Chronic sepsis was induced by administering endotoxin (lipopolysaccharide--LPS) at 12-hr intervals to sheep. The animals (n = 7) responded to the first dose of LPS with increased pulmonary arterial pressure (PAP), systemic vascular resistance, plasma and lymph thromboxane B2 (TxB2) concentrations, and lung lymph flow rate concurrent with a reduction ...

Antithrombin III (AT III) is a major modulator of the clotting cascade and is decreased in disseminated intravascular coagulation (DIC). AT III was given as a pretreatment to dogs with endotoxin-induced DIC. Significant improvement in clotting parameters (prothrombin time, fibrinogen, fibrin degradation products) was noted. There was no effect on ...

Xanthines have been employed clinically to treat asthma and related pulmonary conditions because of their bronchodilator properties. In addition, xanthines have been reported to block and/or attenuate the increase in microvascular permeability to macromolecules produced by some putative inflammatory mediators. In order to more completely assess the anti-inflammatory capabilities of ...

Leukotrienes, lypoxygenase metabolites of arachadonic acid, have been reported to be potent vasoconstrictors in some organs. This study was undertaken to delineate the actions of leukotrienes on both vascular and lymphatic vessels in the canine forelimb. Bolus intra-arterial injections of 1 microgram and 10 micrograms of leukotriene B4, C4, and ...

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 ...

Lower torso ischemia and reperfusion has been shown to stimulate the generation of thromboxane (Tx)A2, leading to transient pulmonary hypertension and later to polymorphonuclear leukocyte accumulations in the lungs. This study investigated whether hind limb ischemia leads to increased pulmonary microvascular permeability. Anesthetized sheep (n = 6) previously prepared with ...