We studied the vertical movement of 2 mg technetium-labeled albumin injected intrapleurally in 0.5 ml saline (15% of pleural liquid volume) in eight spontaneously breathing anesthetized dogs subject to a sudden change in posture (prone to supine or vice versa). The albumin movements were evaluated through a large field gamma ...

The role of thromboxane A2 in sheep endotoxemia, an animal model of the adult respiratory distress syndrome, was investigated by a combined biochemical and pharmacological approach. Endogenous thromboxane biosynthesis was assessed by gas chromatographic-mass spectrometric analysis of urinary (thromboxane B2, 2,3-dinor-thromboxane B2) and plasma (11-dehydrothromboxane B2) metabolites that demonstrated a ...

The spontaneous contractions of the initial lymphatics of the bat's wing were observed to be modulated by changes in local blood flow. Lymphatic pressure and frequency of contraction were measured with the servo-null technique during the occlusion of the ulnar artery or vein. Lymphatic contractile activity was decreased during arterial ...

Based on a prospective study of 92 patients with DVT initiated in 1979, including a follow-up every year, the following investigations were performed: phlebography, Doppler-ultrasound, plethysmography (strain gauge and PPG) and foot-volumetry. In ulcer-patients skin blood flow was measured by Laser-Doppler and local oxygen supply by measurement of transcutaneous oxygen. ...

Effects of hypobaria on lung fluid balance were studied in five awake sheep with chronic lung lymph fistulas using a decompression chamber. Each sheep was exposed to three conditions of 6,600-m-simulated high altitude in random order as follows: 1) 6,600-m-simulated hypoxic hypobaria (barometric pressure 326 Torr, 21% inspired O2 fraction), ...

In the anesthetized sheep, pressure pulses generated in the feet are transmitted downstream in the veins but not in the lymphatics at normal intralymphatic pressure. When the sheep is tilted on a tilt table, gravitational changes occur in venous pressure but not in the pressure in adjacent lymphatics. These results ...

We hypothesized that toxic O2 radicals might be important mediators of endotoxin-induced acute respiratory failure in pigs. As a relatively specific scavenger of .OH, we infused dimethylthiourea (DMTU, 1 g/kg) before endotoxemia. Escherichia coli endotoxin (055-B5) was infused intravenously into anesthetized 10- to 14-wk-old pigs at 5 micrograms/kg the 1st ...

An important functional property of lymphatic vessels is their ability to pump fluid. To quantitate this activity in vivo, sheep mesenteric lymphatic segments were isolated from all lymph input and provided with lymph plasma or saline from a reservoir. Lymphatic pumping was controlled by transmural pressure with increases in pressure ...

Numerous reports have shown that intravascular lipid infusion may cause pulmonary dysfunction in a variety of species, including humans. To determine the effects of parenteral lipid on neonatal pulmonary hemodynamics, lung fluid filtration, and respiratory gas exchange, we measured pulmonary arterial and left atrial pressures, cardiac output, lung lymph flow, ...

The effects of endotoxin on the ability of lymphatic vessels to pump fluid in vivo have been assessed with the use of a sheep model system that permits analysis of lymph pumping in sheep without the complication of variable lymph inputs. This involved the isolation of intestinal lymphatic vessels from ...

We hypothesized that superoxide anion (O2-.) and hydrogen peroxide (H2O2) might be important mediators of endotoxin-induced acute respiratory failure (ARF) in pigs. As specific scavengers of O2-. and H2O2, we infused polyethylene glycol-superoxide dismutase (PEG-SOD; 2,000 IU/kg) and PEG-catalase (CAT; 15,000 IU/kg), respectively. Escherichia coli endotoxin (055-B5) was infused intravenously ...

OKY 046, a specific thromboxane synthase inhibitor, was used to investigate whether large pulmonary emboli, like microemboli, cause an increase in thromboxane A2 and an associated increase in vascular permeability in sheep. Nineteen sheep were anaesthetised and had cannulas inserted into the afferent lymphatic of the caudal mediastinal lymph node ...

We tested the early effects of endotoxin on both the permeability of capillary membranes and microvascular pressure. One group of dogs (n = 8) were fluid loaded (30 ml/kg dextran-40) after having been subjected to a 2-h Escherichia coli endotoxin infusion (0.25 micrograms/kg X min). A second control group of ...

Escherichia coli endotoxin causes increased capillary membrane permeability and increased pulmonary arterial pressure (PAP) in sheep. If the pulmonary hypertension extends to the level of the microvasculature, then the increased microvascular pressure may contribute to the pulmonary edema caused by endotoxin. We tested the hypothesis that reducing the pulmonary hypertension ...

The luminal and outer wall morphology of the initial lymphatics in the rat tongue were demonstrated using scanning electron microscopy (SEM) after tissue perfusion with pressures up to 300 torr, topical heat and histamine administration. The findings emphasize the structural and functional importance of the reticular fiber network of the ...

Microvascular permeability is presumed to increase during cardiopulmonary bypass, but this has not been directly demonstrated. Method: Therefore, a controlled experimental study was performed in dogs in which the permeability ratio of the small intestinal microvasculature was determined. Shortly after 120 minutes of cardiopulmonary bypass (experimental group, n = 7) ...

Our model of the pulmonary interstitial-lymphatic system is based on the assumption that the lung interstitial space can be divided into two compartments. The first compartment (C1) contains the terminal lymph vessels. Increases in the fluid pressure within this compartment, along with increased pressure generated by lymph vessel pumping, cause ...

1. In previous studies, exogenous serotonin (5-HT), administered intravenously, caused dose-related increases in mean arterial pressure and heart rate in conscious sheep. The 5-HT2 antagonist ketanserin (0.1 mg/kg per h, i.v.) was shown to lower blood pressure in the conscious sheep primarily through antagonism of alpha-adrenoceptors. 2. A newer 5-HT2 ...

We examined the alterations in pulmonary transvascular fluid and protein exchange after intravenous infusion of fat emboli, i.e., bone marrow suspension (BMS) in awake sheep prepared with chronic lung lymph fistulas and compared these changes with those observed in sheep pretreated with heparin. The BMS injection (0.2 ml/kg) over 15 ...

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 ...

In order to investigate the effects of thermal injury on microvascular hemodynamics and permeability, hindpaw arterial (PA), venous (PV), and capillary (PC) pressures, blood (QB) and lymph (QL) flows, and lymph (CL) and plasma (CP) total protein concentrations were measured before and for 3 hr after a 10-sec 100 degrees ...

Both pregnancy and estrogen administration are associated with a decrease in the systemic vasculature pressor response to angiotensin II infusion; however, the lymphatic vessel system response is not clear. In the present study we infused angiotensin II to nine nonpregnant splenectomized ewes with 0.1, 10, or 1,000 ng X kg-1 ...

The canine lung lobe was embolized with 100-micron glass beads before lobectomy and blood anticoagulation. The lobe was isolated, ventilated, and pump-perfused with blood at an arterial pressure (Pa) of about 50 (high pressure, HP, n = 9) or 25 Torr (low pressure, LP, n = 9). Rus/PVR, the ratio ...

We investigated the effect of dextran solution on lung lymph flow in awake sheep with chronic lung lymph fistulas. Ten percent of dextran (molecular weight 40,000) solution or normal saline were infused at 1000 ml/h for 2 h through left atrial catheter. We measured pulmonary arterial pressure (Ppa), left atrial ...

The effect of indomethacin (INDO), an inhibitor of prostaglandin (PG) cyclooxygenase, on pulmonary vascular permeability is unclear. We measured angiotensin converting enzyme (ACE) activity in plasma and lung lymph in order to evaluate pulmonary endothelial integrity. Eighteen sheep, anesthetized and acutely prepared for the collection lung lymph, were used in ...

An increase in aortic pressure from 60 to 120 mmHg accelerated ribosomal protein synthesis in rat hearts during 1 or 2 h of labeling with 0.4 mM [3H]phenylalanine. When hearts were perfused with buffer that contained 20 mM glucose and normal plasma concentrations of 19 other amino acids without added ...

In many sheep Escherichia coli endotoxin results in pulmonary hypertension, increased microvascular permeability, pulmonary edema, and increased central venous pressure. Since lung lymph drains into the systemic veins, increases in venous pressure may impair lymph flow sufficiently to enhance the accumulation of extravascular fluid. We tested the hypothesis that, following ...

The return of fluid and protein to the bloodstream by the lymphatic circulation may play an important role in reconstituting intravascular volume following hemorrhage. In this study, we have defined the lymph-flow changes that occur in cannulated mesenteric lymphatics following a 25% blood loss in anesthetized sheep and investigated the ...

The effects of external pressure on the relative terminal lymphatic flow rate following occlusion of the lymph system were studied. Sulfur colloid tagged with 99mTc was injected into the hind thigh of dogs prior to compressive loading. Initially, the lymphatic clearance of the tracer was measured for approximately forty minutes ...

The effect of preparative trauma on lung microvascular permeability during lung lymph fistula preparation in sheep was investigated. Two groups of anesthetized sheep were used. In group I (controls: n = 3) the lymph fistula was prepared 3 to 4 days before the experiment. In group II (experimental group: n ...

We examined the pulmonary response to bone marrow embolism in untreated and indomethacin-treated goats. Pulmonary arterial pressure increased by 15 cmH2O after bone marrow infusion, reaching a peak of 37.2 then stabilizing at greater than 30 cmH2O in the control group. In the treated group it increased by 4.3 cmH2O ...

1. Lymph flow and pressure fluctuations were measured by cannulating popliteal efferent and distal hind-limb afferent lymphatic vessels in anaesthetized sheep. The cannula outflow height was raised above the vessels to increase lymphatic outflow pressure. 2. Lymph flow decreased non-linearly as the outflow was raised. The rate of decrease increased ...

Marked leukopenia and sequestration of granulocytes in the lung are consistently seen in severe early onset group B streptococcal (GBS) disease in human infants. To investigate the role of granulocytes as potential mediators in the pulmonary pathophysiology of this disease, the effects of intravenously administered GBS type III toxin were ...

The effect of vasoactive agents on the spontaneous contractions of the initial lymphatics of the bat's wing was investigated. Initial lymphatic contractile frequency and pulsatile pressure were measured with the servo-null micropressure system. Norepinephrine, phenylepinephrine, isoproterenol, acetylcholine, histamine, serotonin, bradykinin, prostaglandin F2a, prostaglandin E2, indomethacin and ibuprofen were delivered to ...

The direct and indirect actions of two active components of slow-reacting substance of anaphylaxis, leukotrienes C4 (LTC4) and D4 (LTD4), were studied in chronically instrumented unanesthetized sheep. Intravenous injection of 3 micrograms of LTD4 caused immediate marked pulmonary arterial hypertension which returned to baseline in 6.5 +/- 1.0 min. Dynamic ...

We studied the effects of a selective leukotriene (LT) antagonist (FPL 57231, 2 mg kg-1 min-1) on the acute cardiopulmonary changes observed in feline endotoxin shock. LTC4 and LTD4 (0.1-3.0 micrograms kg-1) given intravenously had little or no activity on pulmonary arterial pressure (PAP), dynamic lung compliance (Cdyn), and airways ...

We used quantitative reflectance autoradiography to compare the concentration of albumin in visceral pleural lymphatics at the cranial and caudal ends of the sheep's lung in the vertical (60 degrees head-up) and horizontal (supine) positions. Twelve to fourteen hours after injecting 125I-albumin intravenously we placed four anesthetized sheep in the ...

Pulmonary dysfunction is a well-recognized complication of burn wound excision. It remains unclear whether this is caused by bacteria or inflammatory mediators released during excision of the wound. We produced a 15% full-thickness burn in 18 sheep, and between days 5 and 7 completely excised the wound under general anesthesia. ...

Skin microvascular membrane permeability was assessed in anesthetized dogs after resuscitation from endotoxin shock. Infusion of Ringer's lactate solution, in a volume equal to 7 per cent of the body weight, reversed hypotension produced by an intravenous injection of Escherichia coli endotoxin (0.5 milligrams per kilogram). The shock group was ...

Rapid cardiac growth in adult rats and neonatal pigs involves more efficient use of existing components of the protein synthesis pathway and synthesis of new ribosomes and mRNA to increase the capacity for protein synthesis. Greater efficiency of synthesis can be induced by mechanical perturbations that stretch the ventricular wall, ...

We previously reported that the very act of cannulating a lung lymph vessel could alter the unique flow characteristics that existed within the lymphatic before cannulation. We postulated that this phenomenon could hold true for lymphatics draining any organ within the body. Since it is frequently important to know the ...

To test the hypothesis that the broad spectrum protease inhibitor, aprotinin, can prevent early pathophysiology of sepsis, we administered endotoxin (0.1-0.75 microgram/kg) by a 30-min infusion to awake goats. Animals were used as their own controls receiving endotoxin with no treatment on one day and treatment with a bolus injection ...

Paraquat, a widely used herbicide, causes severe lung damage in humans and laboratory animals. Pulmonary edema is a common initial feature of paraquat toxicity, but its pathophysiology is not well understood. The purpose of this investigation was to determine the acute toxic effect of paraquat (30 mg/kg) on pulmonary transvascular ...

An experimental model for sialography, involving retrograde infusion of contrast medium into the rat submandibular gland under continuous pressure monitoring, was developed. Morphologic alterations induced during infusion of water- and lipid-soluble radiographic contrast media and the distribution of the media were examined with light and electron microscopy. An uneven distribution ...

To study the relationship between lung weight and lymph flow, we used an in situ, isolated sheep lung preparation that allowed these two variables to be measured simultaneously. All lungs were perfused for 4.5 h at a constant rate of 100 ml X min-1 X kg-1. In control lungs, the ...

The technique of vascular labeling was developed to mark sites of increased microvascular permeability. We used the vascular labeling technique in anesthetized sheep and found that hemodynamics and airway pressure were adversely affected by intraarterial infusions of two vascular tracers. Monastral blue (nine sheep) immediately caused systemic arterial hypotension, pulmonary ...

Pulmonary lymph drains into the thoracic duct and then into the systemic venous circulation. Since systemic venous pressure (SVP) must be overcome before pulmonary lymph can flow, variations in SVP may affect lymph flow rate and therefore the rate of fluid accumulation within the lung. The importance of this issue ...

Lymph pressure (Pl) in the subserosal lymphatics and mesenteric lymphatics was determined in the jejunum at various intraluminal distension pressures (DP). Pl in the subserosal lymphatics was approximately equal to DP, in the range of 3-100 mmHg, whether the intestine was in the basal state or during water absorption. At ...

The influence of lysophosphatidylcholine (lysoPC), taurodeoxycholate (TDC), and taurochenodeoxycholate (TCDC) on the permeability properties of the ischaemic small-intestinal mucosa was investigated. We first studied the effect of ischaemia alone, then of lysoPC, TDC, or TCDC alone, and finally of ischaemia together with lysoPC, TDC, or TCDC on the permeability to ...

Gabexate mesilate (GM), a proteolytic enzyme inhibitor, was given to 31 chronically instrumented sheep either as a pretreatment or treatment to determine its effects on the cardiopulmonary response to endotoxin (ET). Twelve sheep received GM prior to endotoxin (0.75 microgram/kg), 10 after ET and 9 received GM without ET. A ...