[Lymph-blood microcirculatory shifts in the intestines during histamine action]

The infusion of histamine increased the lymph flow in the cat innervated intestine due to squeezing off of the lymph from lymphatic vessels under motor activation of the intestine, followed by an increase in the lymph production because of accelerated transcapillary transfer of fluid from the blood into interstitium. The increase in the water hemato-lymphatic transition was maintained by an augmentation of the capillary filtration coefficient against the background of both a decrease and an increase tin capillary hydrostatic pressure occurring simultaneously with a drop of the perfusion pressure under the effect of histamine. After decentralization of the intestine histamine led to a drop of capillary hydrostatic pressure, leaving the shifts of other parameters the same.

[Effect of opioid peptides on the lymphatic drainage of the pancreas in the rat and dog]

The effect of dalargin and some other ligands of the opioid receptors on drainage function of the pancreatic lymphatic system was studied in rats and dogs. In rats, dalargin (30-1000 micrograms/kg, subcutaneously) accelerated the elimination of Evans blue from beneath the pancreatic capsule in a dose-related manner. The effect of dalargin was attenuated by naloxone. Specific agonists of mu-, delta- and sigma-opioid receptors had no dalargin-like activity. In dogs, dalargin (60-80 micrograms/kg, subcutaneously) after the administration of Evans blue into the pancreas increased its concentration in the truncus lymphaticus and slowed down its penetration into the blood. Thus, dalargin accelerates the elimination of Evans blue from the pancreas due to the intensification of lymphatic drainage. The effect of dalargin was mediated by subpopulation of opioid receptors with which their certain selective ligands have but slight interaction.

Ibuprofen reduces the lung lymph flow changes associated with inhalation injury

Inhalation injury was produced in sheep which 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 cyclooxygenase inhibitor ibuprofen and another group was untreated. Eight hr following the administration of smoke, there was an elevation of lung lymph flow in both groups. These changes were not as severe in the animals which were treated with ibuprofen. The pulmonary changes which occur following smoke inhalation injury are associated with elevations of the metabolites of arachidonic acid, especially those generated by the cyclooxygenase pathway. These metabolites in some way contribute to the pathophysiological changes induced by the inhalation of smoke, since they are reduced by the administration of a cyclooxygenase inhibitor.

Effects of fenoldopam on feline intestinal microcirculation

Experiments were performed to evaluate the effects of the specific dopamine-1-receptor agonist, fenoldopam, on the feline intestinal microcirculation. Cranial mesenteric arterial pressure, cranial mesenteric vein pressure, cranial mesenteric vein blood flow, venous occlusion capillary pressure, pre- and postcapillary resistances, total mesenteric vascular resistance, lymph flow, lymph and plasma protein concentrations, the capillary osmotic reflection coefficient, and the capillary filtration coefficient were determined in an isolated autoperfused jejunal segment in anesthetized fasted cats during intra-arterial administration of saline or fenoldopam mesylate in saline. Fenoldopam significantly increased mean cranial mesenteric vein blood flow from 26.8 +/- 3.4 to 33.7 +/- 2.8 ml.min-1.100 g-1. This increase in blood flow was due primarily to a significant decrease in mean intestinal vascular resistance from 3.14 +/- 0.32 to 2.54 +/- 0.2 mm Hg.ml-1.min-1.100 g-1, since cranial mesenteric arterial pressure during fenoldopam infusion was not different from the value obtained during control studies. Mean capillary pressure during fenoldopam infusion (17.2 +/- 0.5 mm Hg) was significantly greater than mean capillary pressure during control studies (15.6 +/- 0.3 mm Hg). The mean lymph flow during fenoldopam infusion (0.186 +/- 0.083 g/dl) was significantly greater than the value obtained during saline infusion (0.08 +/- 0.009 g/dl). Fenoldopam infusion significantly increased the mean capillary filtration coefficient from 0.135 +/- 0.021 to 0.275 +/- 0.035 ml.min-1.100 g-1.mm Hg-1 without altering the capillary osmotic reflection coefficient. These results suggest that specific dopamine-1-receptor stimulation in the small intestine increases the perfused capillary density without altering capillary permeability.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of dalargin on blood and lymph microcirculation]

Dalargin (a synthetic analog of leu-enkephalin), when applied to the microvessel surface or administered intramuscularly at doses 0.004-40.0 micrograms/kg increased the permeability of the rat mesenteric microvascular wall and activated the lymph flow due to enhanced contraction of lymphatic microvascular wall and valves. Moreover, Dalargin evoked leukocyte migration from venules and activated the intestinal muscular contractions.

Pulmonary microvascular changes following fluid resuscitation in an ovine model of endotoxemia

Fluid resuscitation is complicated in hypotensive septic patients by their susceptibility to pulmonary edema. This problem was evaluated in the ovine model of endotoxemia with a chronic lung lymph fistula. Escherichia coli endotoxin (lipopolysaccharide, 1.5 micrograms/kg) was given intravenously over 30 minutes. Group M (n = 9) continued to receive baseline fluids (2 mL/kg/h), while group R (n = 6) received 7 mL/kg/h of Ringer's lactate. After an initial drop in cardiac index, animals in both groups developed a hyperdynamic state. The fall in mean arterial pressure seen in group M was absent from group R. The higher fluid volume resulted in a rise in left atrial pressure and pulmonary microvascular pressure. The lung lymph flow and permeability index were elevated in both groups but were higher in group R. The calculated filtration coefficient showed a threefold increase in both groups. Augmented fluid resuscitation during endotoxemia resulted in an elevated interstitial fluid flux and permeability index secondary to an increase in pulmonary microvascular pressure and greater surface area of the injured microvascular beds being perfused.

Effect of catalase on endotoxin-induced acute lung injury in unanesthetized sheep

Administration of endotoxin intravenously to unanesthetized sheep causes an acute lung injury characterized by increased microvascular barrier permeability and subsequent pulmonary edema. Endotoxin-induced sheep lung injury can be attenuated by leukocyte depletion, and may be mediated by toxic metabolites of oxygen. We studied effects of administering catalase, which catalyzes conversion of hydrogen peroxide to oxygen and water, to sheep subsequently infused with endotoxin to test the hypothesis that hydrogen peroxide plays a role in the pathogenesis of lung injury. We found that infusions of endotoxin (1 microgram/kg) into untreated sheep caused the expected biphasic response, a transient, early, marked pulmonary arterial hypertension followed by a prolonged increase in protein-rich lung lymph flow characteristic of increased microvascular permeability filtration in the lungs. Intraperitoneal injections of catalase (50 mg/kg) prior to infusing endotoxin in these same sheep resulted in substantial catalase activity in plasma and in lung lymph, and attenuated the expected changes in pulmonary arterial pressure, lung lymph flow, and arterial leukocyte counts and oxygen tension after endotoxin infusions. Furthermore, mechanical elevation of hydrostatic pressure in the lungs of a catalase-treated sheep infused with endotoxin resulted in increased lung lymph flow with a decreased protein concentration, indicating that the microvascular barrier to fluid and protein was functionally intact. Administration of catalase that was inactivated by reaction with hydrogen peroxide in the presence of aminotriazole or administration of the catalase vehicle, thymol, had no effects on the sheep responses to endotoxin. We conclude that hydrogen peroxide plays a role in the pathogenesis of endotoxin-induced acute lung injury in sheep.

[Morphocytochemical reaction of the lymph nodes in dogs to the administration of lysozyme]

By means of morphological, morphometrical and histochemical methods pelvic and tracheobronchial lymph nodes have been studied in dogs and concentration of lysozyme has been estimated in blood serum, in lymph and the lymph nodes after a single intramuscular injection of lysozyme (2 mg/kg of body mass). In the material investigated total concentration of lysozyme reaches its maximal values in 6 h after injection, then it gradually decreases and in 48 h reaches its control level. Morphometrically changes in cell composition are revealed predominantly of immune-competent cells in T- and B-dependent zones of the lymph nodes. Thus, the volumetric part of lymphoblasts in the germinative centers of the lymphoid nodules reaches its maximal indices by 48 h after lysozyme injection, while plasmatization of the paracortical zone and of medullary cords increases up to the 7th day. By the 14th day the volumetric part of lymphoblasts, immunoblasts and plasmocytes decreases gradually, and in 21 days after injection of the drug contents of the blast forms of the cells in the structural-functional zones of the lymph nodes does not differ from that in the control. The data obtained demonstrate the immunomorphological rearrangement of the lymph nodes in response to the exogenic lysozyme administration.

Effects of methylprednisolone on acute lung paraquat toxicity in sheep

Infused into sheep, paraquat causes increased flow of protein-rich lung lymph, increased prostanoid production, and neutrophil accumulation in the lung. The effects of high-dose methylprednisolone on the response to paraquat infusion were studied in awake sheep with chronic lung lymph fistulas. Seven sheep were infused with paraquat (30 mg/kg) alone. Six sheep received methylprednisolone (1.0 g plus 0.5 g/h intravenously), beginning 30 min before paraquat (pretreatment), and 5 received methylprednisolone, beginning 4 h after paraquat (post-treatment). Neutrophil accumulation in the lung was measured in biopsy tissue taken at baseline and at postmortem. Methylprednisolone pretreatment significantly prevented the increase in lung lymph flow (paraquat, from 4.4 +/- 0.3 to 11.1 +/- 0.8 ml/h, p less than 0.05; pretreatment, from 4.8 +/- 0.9 to 3.7 +/- 0.3, NS), and the increase in lymph-to-plasma protein concentration ratio (paraquat, from 0.69 +/- 0.02 to 0.80 +/- 0.02, p less than 0.05; pretreatment, from 0.66 +/- 0.06 to 0.60 +/- 0.02, NS) during 8 h after paraquat infusion. Treatment with methylprednisolone after paraquat also reduced the changes in lung lymph flow and protein clearance. Methylprednisolone prior to paraquat significantly inhibited accumulation of 6-keto-PGF1 alpha in lymph and plasma, but did not significantly inhibit accumulation of TxB2 in lymph or plasma. The number of neutrophils in the paraquat lungs was 3 to 4 times that in the control lungs, with or without methylprednisolone. Methylprednisolone pretreatment prolonged the survival time, but did not prevent death within 48 h after paraquat infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased outputs of lymphocytes in lymph efferent from the lymph nodes of sheep during systemic arterial hypertension induced by phenylephrine or dopamine

Induced systemic arterial hypotension by intravenous nitroprusside administration and by acute arterial occlusion in sheep have been found to reduce lymphocyte traffic as mirrored in the output of lymphocytes into the efferent lymph of peripheral lymph nodes. In the present series of experiments in sheep with chronically cannulated efferent lymphatics of peripheral lymph nodes, induced and monitored systemic arterial hypertension with intravenous pump infusions of phenylephrine or dopamine both produced sharp increases in the output of lymphocytes into efferent lymph in all of 27 studies. The increases in lymphocyte output with dopamine were more sustained and less associated with evidence of lymphoid tissue damage than with phenylephrine. Phenylephrine infusions were attended by a high incidence of gross bleeding into the efferent lymph, of increased coagulability of efferent lymph in the absence of gross bleeding and of prolonged depression of lymphocyte outputs after the cessation of intravenous infusion.

Perilla ketone: a model of increased pulmonary microvascular permeability pulmonary edema in sheep

A model of increased microvascular permeability pulmonary edema was developed in chronically instrumented unanesthetized sheep using perilla ketone (PK). PK did not cause changes in pulmonary hemodynamics but did cause marked increases in the flow of protein-rich lung lymph. The changes in lung lymph flow were accompanied by radiographic evidence of both interstitial and alveolar pulmonary edema as well as hypoxemia. PK did not cause acute changes in lung mechanics. Dynamic compliance of the lungs and FRC decreased later, concomitant with the changes in lung lymph flow, radiographic evidence for pulmonary edema, and hypoxemia. Resistance to air flow across the lungs and specific conductance did not change significantly after PK infusion. The severity of the radiographic evidence for pulmonary edema observed after PK correlated with the severity of the concomitant hypoxemia and changes in dynamic compliance of the lungs. PK did not cause increases in the concentrations of cyclooxygenase products of arachidonic acid in lung lymph or plasma or changes in blood leukocyte counts. We conclude that PK causes increased lung microvascular permeability pulmonary edema without acute changes in pulmonary hemodynamics. This model permits study of the pathophysiologic aspects of increased lung microvascular permeability without the concomitant functional alterations that complicate most other experimental models of diffuse lung injury.

Lung vascular effects of lipid infusion in awake lambs

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, lymph and plasma protein concentrations, and partial pressures of oxygen and carbon dioxide in arterial blood of 11 awake chronically catheterized lambs that received a 2-3 h control infusion of glucose-saline solution followed by Intralipid at a dose of 67.5, 125, or 250 (mg/h)/kg body weight for 6 h. Intralipid caused an acute dose-dependent increase in pulmonary arterial pressure, with no significant change in cardiac output or left atrial pressure. The pulmonary hypertension, which lasted for at least 2 h, was accompanied by a greater than 50% increase in lung lymph flow and a significant decrease in lymph protein concentration relative to plasma protein concentration. Pulmonary artery pressure gradually decreased to control values during the final 2 h of lipid infusion, but lymph flow remained 35% above control and lymph protein concentration remained low. Lipid infusion also was associated with a modest decrease in PaO2. Both arterial and venous administration of lipid gave similar results. In separate studies, lipid infusion caused a significant increase in plasma concentrations of thromboxane B2, the stable metabolite of thromboxane A2, without affecting plasma concentrations of 6-keto prostaglandin F1 alpha, the stable metabolite of prostacyclin. Pretreatment with imidazole, which attenuated the lipid-induced increase in thromboxane B2 concentration, completely blocked the pulmonary hemodynamic response to lipid.(ABSTRACT TRUNCATED AT 250 WORDS)

[Relation of lymph and microcirculation dynamics in the extremities of cats as affected by bradykinin and histamine]

In perfused with constant flow isolated cat hindlimbs, i.a. infusion of 0.1-1.0 micrograms.min-1.kg-1 histamine and bradykinin caused a dilatation of arteries and veins and an increase of the capillary filtration coefficient. Histamine elevated capillary hydrostatic pressure and dilated lymphatic ducts with no alteration in the lymph formation process in the hindlimb. Bradykinin decreased capillary hydrostatic pressure and activated formation of lymph. The elevation of transcapillary fluid movement under the effect of bradykinin seems to be the result of a disturbance in colloid osmotic (oncotic) pressures on both sides of the capillary wall.

Hypertonic saline resuscitates dogs in endotoxin shock

In this experiment we determined if infusions of hypertonic saline (HS, 1080 Na meq/liter) could resuscitate dogs in endotoxin shock as effectively as Ringer's lactate (RL, 130 Na meq/liter). Anesthetized dogs received iv 0.5 mg/kg of Escherichia coli endotoxin, and mean arterial pressure (MAP, mm Hg) decreased from 148 +/- 5 to 58 +/- 14 within 30 min. To resuscitate the dogs 13 meq/kg of sodium was intravenously infused over 90 min as either a 10% body weight load of RL (n = 5) or a 1.2% body weight load of HS (n = 5). Both solutions produced an equivalent hemodynamic resuscitation 3 to 4 hr postinfusion with an increase in MAP (RL, 119 +/- 4; HS, 108 +/- 7), the restoration of cardiac outputs to baseline (RL, 2.0 +/- 0.2; HS, 1.9 +/- 0.3 liter/min), and similar renal inulin clearances (RL, 48 +/- 16; HS, 44 +/- 7 ml/min). The net fluid gain (resuscitation fluid volume infused minus urine output as percentage of body weight) was much greater in the RL group (7.2 +/- 1.0%) than in the HS group (0.48 +/- 0.2%). Plasma volume (PV, percentage of body weight) was measured with Evans blue dye in these splenectomized dogs. The increase in PV in the RL dogs (1.25 +/- 0.04%) was slightly greater than the increase in the HS group (0.94 +/- 0.13). Prenodal skin lymph was collected from both hindpaws, and the fractional increase in skin lymph flow after RL (4.5 +/- 2.9) was greater than the increase in the HS group (1.7 +/- 0.3).(ABSTRACT TRUNCATED AT 250 WORDS)

[Pancreatic enzyme increase under elevated pressure in the organ's ductal system]

Experiments performed in dogs revealed that, at an increased resistance against outflow of juice from pancreatic duct system, both the increment of deviation of pancreatic hydrolases into the blood and lymph and an obvious inhibition of pancreatic secretion activated with secretin and octapeptide cholecystokinin, occur.

Effect of heparin on increased pulmonary microvascular permeability after bone marrow embolism in awake sheep

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 min caused rapid, but transient, increases (p less than 0.05) in mean pulmonary artery pressure and pulmonary vascular resistance. These increases were accompanied by significant increases in the lymph concentrations of thromboxane B2 and 6-keto-PGF1 alpha. Pulmonary lymph flow increased by 3.9-fold (+/- 0.8) over baseline by 120 min after BMS with no change in the lymph-to-plasma protein concentration ratio (L/P ratio). Heparin pretreatment (700 U/kg) enhanced the BMS-induced increases in pulmonary artery pressure and pulmonary vascular resistance. Thromboxane B2 concentrations in the lymph increased, whereas there was no change in the concentration of 6-keto-PGF1 alpha. Lung lymph flow increased 4-fold (+/- 1.0) over baseline by 120 min after BMS without a change in L/P ratio. Changes in lung vascular permeability were evaluated by elevating pulmonary microvascular pressure (left atrial balloon catheter inflation) at 120 min after BMS. Lung lymph flow increased 7-fold (+/- 1.1) from baseline, whereas the L/P ratio decreased to a mean value of 0.48 +/- 0.03. The protein reflection coefficient (sigma = 1 - L/P ratio) decreased from a control mean of 0.69 +/- 0.02 to 0.52 +/- 0.03 after the BMS challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II infusion increases thoracic duct lymph flow in chronically catheterized sheep

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 X min-1 for a 5-min period at each dose. At the lowest dose the mean arterial pressure increased from 10 to 20% over base line. At the highest dose, the left thoracic duct flow rate peaked at 361% 10 min after the infusion was started, whereas arterial pressure peaked at 183% of the control value. Peak lymph flow occurred 4-6 min after the maximal increase in mean systemic arterial pressure. Neither hematocrit nor venous pressure were altered at any of the doses administered. This suggests that the interstitial fluid space pressure remained unchanged and that the increase in lymph flow was not secondary to fluid transfer from the intravascular system. We postulate, therefore, that the effect of angiotensin II in the increase of lymph flow rate is by direct action on the lymphatic vessels themselves.

The effect of dextran solution on pulmonary plasma-lymph barrier in awake sheep

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 pressure (Pla), aortic pressure (Psa), cardiac output (CO), oncotic pressures of both plasma (IImv) and lung lymph (IIpmv), lung lymph flow rate (Qlym), and lymph-to-plasma ratio of total protein (L/P). Infusion of dextran solution caused significant increases in Ppa, Pla and CO and decrease in plasma-lung lymph oncotic pressure gradient (IImv-IIpmv), without changes in L/P. Infusion of normal saline caused significant increases in Ppa and Pla and no changes in IImv-IIpmv and CO, and slight decrease in L/P. The calculated filtration coefficients increased by 2.2 fold after dextran infusion and 1.7 fold after normal saline infusion. Moreover, an apparent increase in protein transport across microvessels as evidenced by the normal L/P despite increases in hydrostatic pressure occurred after dextran solution infusion. These results suggest that dextran solution may increase permeability of microvascular wall, as well as effective net pressure gradient across microvessels, both of which result in a large net fluid filtration from microvessels to perimicrovascular compartment.

Characteristic features concerning the action of prostaglandin F2 alpha (PGF2 alpha) on the microvascular territories drained by truncus jugularis

In dogs, PGF2 alpha injected into the Arteria facialis increases the local blood flow and microvascular permeability accompanied by an important increase of lymph and salivary flow. The results of our investigations allowed us to speculate that PGF2 alpha may be an important component of the regulatory mechanism underlying salivary secretion.

CVF-induced decomplementation: effect on lung transvascular protein flux after thrombin

We examined the effects of cobra venom factor (CVF) on the changes in pulmonary hemodynamics and transvascular fluid and protein exchange following thrombin-induced pulmonary microembolism. Studies were made in unanesthetized sheep prepared with lung lymph fistulas. The animals received tranexamic acid (100 mg) to suppress fibrinolysis and were then challenged with an intravenous infusion of alpha-thrombin (80 U/kg). Control-thrombin challenged sheep were compared with the CVF-treated sheep challenged with the same thrombin dosage. CVF treatment (187 U X kg-1 X day-1 for 4 days) decreased the total hemolytic complement activity by 45% of control. Thrombin infusion in control sheep increased the mean pulmonary arterial pressure (Ppa), pulmonary vascular resistance (PVR), and lymph protein clearance (pulmonary lymph flow X lymph-to-plasma protein concentration ratio, Clym). Thrombin infusion in CVF-treated sheep produced smaller increments in Ppa, PVR, and Clym. Pulmonary lymph obtained from control-thrombin and CVF-thrombin sheep induced migration of granulocytes obtained from normal unchallenged sheep. The granulocytes obtained from CVF-treated sheep responded relatively less to the migratory and O-2-generating stimuli (i.e., zymosan-treated serum, pulmonary lymph from sheep after thrombin challenge, and plasma from sheep after CVF treatment) compared with normal granulocytes. The attenuation of the thrombin-induced increases in Ppa, PVR, and lung transvascular fluid and protein exchange by CVF treatment may be the result of impaired function of granulocytes.

Beta-adrenergic agonists increase lung liquid clearance in anesthetized sheep

We did experiments to determine whether beta-adrenergic agonists increase lung liquid clearance in anesthetized ventilated adult sheep and, if so, whether the increase is mediated by beta receptors and what mechanism is involved. We instilled 100 ml of autologous serum either alone or with a beta-adrenergic agonist (terbutaline, 10(-5) M, or epinephrine, 5.5 X 10(-6) M) into one lower lobe. After 4 h both terbutaline and epinephrine increased lung liquid clearance. The increase in lung liquid clearance was inhibited when propranolol (a beta blocker) or amiloride (a sodium channel blocker) was added to the terbutaline. Increased clearance was not explained by changes in pulmonary hemodynamics, pulmonary blood flow, or lung lymph flow. We conclude that beta-adrenergic agonists increase lung liquid clearance in anesthetized intact adult sheep. This increase is mediated through beta receptors and probably depends on increased active transport of sodium across the alveolar barrier.

Lung lymph flow after bone marrow injection into goats was reduced by indomethacin

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 from a base line of 18.5 cmH2O but had returned to base line by 6 h. Lymph flow increased in the control group from a base line of 7.3 ml/h to a peak of 22.4 ml/h and remained near that level. It increased from a base line of 6.4 ml/h to a peak of 9.8 ml/h in the treated group and remained close to that value. The lymph-to-plasma protein ratio was little changed throughout the experiment. Cardiac output decreased by 1.2 l/min in the control group but was unchanged from base line in the treated group. Systemic arterial pressure was similar in both groups of animals. We conclude that indomethacin prevents the pulmonary hypertension seen after bone marrow infusion and protects against some of the increased permeability.

Effect of dietary and infused lactose on rat intestinal lymph lipids

Twenty-four male, 6- to 8-week-old Sprague-Dawley rats were fed one of two skim-milk-based diets or stock laboratory diet for 100-120 days to assess the effect of dietary and infused lactose on intestinal lymph lipids. One skim-milk-based diet had its lactose enzymatically hydrolyzed by commercial beta-galactosidase to its constituent monosaccharides galactose and glucose, while the second skim milk diet was unaltered. Serum triglycerides, but not serum cholesterol, were higher in the lactose- versus the glucose-/galactose-adapted rats at 90 days. There was no diet-associated qualitative difference in serum lipoproteins as analyzed by agarose gel electrophoresis. After the rats had consumed the diets for 100-120 days, 0.9% saline and 20% solutions of lactose, and equimolar mixtures of glucose/galactose, glucose and maltose were infused sequentially via a duodenal cannula, then intestinal lymph was collected via a mesenteric lymph duct cannula, the only significant difference was a 134% increase in lymph cholesterol, but not lymph triglyceride output, when lactose was infused into lactose-adapted rats.

Acute effect of paraquat on lung fluid balance and prostanoid production in awake sheep

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 protein and fluid fluxes, histologic features, and prostanoid production, using awake sheep with chronic lung lymph fistulas (n = 6). Lung lymph flow increased significantly 3.5 h after intravenous infusion of paraquat and rose to 2.6 times baseline within 8 h (from 4.4 +/- 0.4 to 11.4 +/- 1.5 ml/h, p less than 0.05). Lymph-plasma protein concentration ratio increased during the same time period (from 0.64 +/- 0.05 to 0.75 +/- 0.04, p less than 0.05). Lung lymph protein clearance also increased at 3.5 h and remained elevated throughout the duration of the experiment. Pulmonary arterial and left atrial pressure were only slightly altered. Plasma and lung lymph thromboxane A2 (as TXB2) concentrations were significantly increased at 30 min and continued so thereafter. Plasma and lung lymph prostacyclin (6-keto-PGF1 alpha) concentrations increased significantly at 3 h and were more than 5 times baseline by 7 h. The time course of the increase in 6-keto-PGF1 alpha concentrations seemed similar to that of lung lymph flow. The high flow of protein-rich lymph strongly suggested an increase in pulmonary vascular permeability, which may indicate pulmonary endothelial damage. Histologic studies of the lungs revealed only minor changes in perivascular cuffing, minimal alveolar hemorrhage, and slight neutrophilic alveolar wall infiltration.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of ganglionic blockade and subsequent i.v. infusion of catecholamines and angiotensin II on the formation and transport of lymph. Studies in anesthesized dogs and a review of the literature]

The effect of ganglionic blockade (GB) and subsequent i.v. infusion of adrenaline (AD), noradrenaline (NA), isoproterenol (IP), and angiotensin II (AII) on thoracic duct lymph flow (LF) and transcapillary escape rate of plasma proteins (FER) was studied in anaesthetized (Nembutal), paralyzed (pancuronium), and artificially ventilated dogs. The carotid artery, the external jugular vein, and the thoracic duct were cannulated. Following a control period, GB was performed by pentolinium tartrate and thereafter the other drugs were infused in a random sequence for 30-60 min with 1 h intervals. Mean arterial blood pressure was decreased from 125 to 90 mmHg by GB, it was increased by 36 mmHg by AD, 41 mmHg by NA, and 44 mmHg by AII, and was decreased by 27 mmHg by IP. LF was about 38 microliter/min/kg before GB and was not changed systematically by GB, because either the sympathetic tone was rather weak or the intrinsic contractions and the tone of lymphatics were reduced by GB. FER was not affected by GB. LF increased by 9 microliter/min/kg (control 36 microliter/min/kg) during AII infusion, probably due to increased lymph formation; the latter can be concluded from the 68% increase in FER. NA raised LF by 15 microliter/min/kg (control 44 microliter/min/kg) probably due to alpha-adrenergic stimulation of the intrinsic contractions of lymphatics; lymph formation seemed not to be affected because FER was not changed systematically. AD enhanced LF by 29 microliters/min/kg (control 39 microliters/min/kg).(ABSTRACT TRUNCATED AT 250 WORDS)