Phalloidin prevents leukocyte emigration induced by proinflammatory stimuli in rat mesentery

1992 ◽  
Vol 263 (6) ◽  
pp. H1637-H1642 ◽  
Author(s):  
H. Asako ◽  
R. E. Wolf ◽  
D. N. Granger ◽  
R. J. Korthuis
Keyword(s):  
Inflammatory Mediators ◽  
Inflammatory Mediator ◽  
Control Period ◽  
Leukotriene B4 ◽  
Leukocyte Rolling ◽  
Leukocyte Adherence ◽  
Initial Exposure ◽  
Rolling Velocity ◽  
Rat Mesentery

The objective of this study was to determine whether phalloidin, a potent microfilament stabilizer, can modify inflammatory mediator-induced leukocyte adhesion and extravasation in postcapillary venules of the rat mesentery. To address this issue, the rat mesentery was prepared for in vivo microscopic observation. Venules with initial diameters ranging between 25 and 35 microns were selected for study. Erythrocyte velocity, vessel diameter, leukocyte rolling velocity, and the number of adherent (stationary for 30 s) and emigrated leukocytes were initially determined during superfusion of the mesentery with phosphate-buffered saline. After these variables were recorded during the control period, either 100 nM platelet-activating factor (PAF), 20 nM leukotriene B4 (LTB4), or 1 microM N-formyl-methionyl-leucyl-phenylalanine (FMLP) was added to the superfusate. Repeat measurements were obtained between 50 and 60 min after initial exposure to the inflammatory mediator. In some experiments, rats were given phalloidin (25 or 500 micrograms/kg iv) 30 min before superfusion with the inflammatory mediators. Superfusion of the mesentery with either PAF, LTB4, or FMLP enhanced leukocyte adherence and emigration and reduced leukocyte rolling velocity. Pretreatment with the low dose of phalloidin effectively prevented leukocyte emigration but had no effect on the increased leukocyte adherence elicited by the three inflammatory mediators. However, when administered at the higher dose, phalloidin prevented both leukocyte adherence and emigration. Neither dose of phalloidin altered the upregulation of neutrophil membrane CD11/CD18 glycoprotein adherence complex induced by PAF or LTB4. These results are consistent with the concept that PAF, LTB4, and FMLP increase leukocyte extravasation by a process that may involve alterations in the endothelial cell cytoskeleton.

Molecular determinants of lipid mediator-induced leukocyte adherence and emigration in rat mesenteric venules

1994 ◽  
Vol 266 (3) ◽  
pp. H847-H853 ◽  
Author(s):  
B. J. Zimmerman ◽  
J. W. Holt ◽  
J. C. Paulson ◽  
D. C. Anderson ◽  
M. Miyasaka ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Platelet Activating Factor ◽  
Leukotriene B4 ◽  
Intercellular Adhesion Molecule ◽  
Lipid Mediator ◽  
Leukocyte Rolling ◽  
Leukocyte Adherence ◽  
Intercellular Adhesion Molecule 1 ◽  
Rolling Velocity ◽  
Molecular Determinants

The objective of this study was to identify the molecular determinants of leukocyte rolling, adherence, and emigration elicited in postcapillary venules by the lipid mediators leukotriene B4 (LTB4) or platelet-activating factor (PAF). Leukocyte-endothelial cell adhesion and shear rate were monitored in rat mesenteric venules during superfusion with either LTB4 or PAF in the presence or absence of monoclonal antibodies (MAbs) directed against either leukocyte (CD18, CD11b) or endothelial cell [intercellular adhesion molecule 1 (ICAM-1), E-selectin, P-selectin] adhesion glycoproteins. In untreated animals and in animals receiving a nonbinding control MAb, LTB4 and PAF increased the number of both adherent (8- and 4-fold, respectively) and emigrated (14- and 8-fold, respectively) leukocytes, while reducing leukocyte rolling velocity (36 and 33%, respectively). The LTB4- and PAF-induced leukocyte adherence and emigration were significantly attenuated by pretreatment with MAbs directed against CD18, CD11b, ICAM-1, and E-selectin, but not P-selectin. The reduction in leukocyte rolling velocity induced by LTB4 was not affected by any of the MAbs; however, both P- and E-selectin MAbs significantly attenuated the reduction in leukocyte rolling velocity elicited by PAF. The results of this study indicate that the leukocyte adherence and emigration induced by both LTB4 and PAF are mediated by CD11b/CD18 on leukocytes and by ICAM-1 and E-selectin on endothelial cells. The molecular determinant of leukocyte rolling appears to be mediator specific, with the selectins mediating the rolling elicited by PAF.

Dimethylsulfoxide prevents chemoattractant-induced leukocyte adherence

1989 ◽  
Vol 256 (2) ◽  
pp. H594-H597
Author(s):  
E. Sekizuka ◽  
J. N. Benoit ◽  
M. B. Grisham ◽  
D. N. Granger
Keyword(s):  
Control Period ◽  
Radical Scavenging ◽  
Distal Colon ◽  
Leukotriene B4 ◽  
Leukocyte Adherence ◽  
Sprague Dawley ◽  
Rolling Velocity ◽  
Intestinal Microcirculation ◽  
Endothelial Surface ◽  
Radical Scavenging Properties

The objective of this study was to determine whether dimethylsulfoxide (DMSO) influences chemoattractant-induced leukocyte adherence in the intestinal microcirculation. The distal colon of Sprague-Dawley rats was prepared for intravital microscopic observation of 25-35 microns diameter venules located in the muscularis externa. The number and average velocity of rolling leukocytes and the number of leukocytes adherent to the venular endothelial surface were determined from recorded video images. After a control period of observation, either N-formyl-methionyl-leucyl-phenylalanine (FMLP) or leukotriene B4 (LTB4) was added to the serosal superfusion solution. Both FMLP (1 microM) and LTB4 (1 microM) consistently caused leukocytes to adhere to venular endothelium. DMSO, at concentrations ranging between 2.5 and 140 mM, inhibited FMLP-induced leukocyte adherence in a dose-related manner. LTB4-induced leukocyte adherence was also significantly attenuated by DMSO. Leukocyte rolling velocity and leukocyte flux were not affected by DMSO. These results indicate that DMSO significantly inhibits leukocyte adherence at concentrations commonly used for its hydroxyl radical scavenging properties.

Factors Influencing Leukocyte Adherence in Microvessels

1977 ◽  
Vol 38 (04) ◽  
pp. 0823-0830 ◽  
Author(s):  
Mayrovttz N. Harvey ◽  
Wiedeman P. Mary ◽  
Ronald F. Tuma
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Tissue Injury ◽  
Threshold Value ◽  
In Vivo Studies ◽  
Leukocyte Adherence ◽  
Rolling Velocity ◽  
Subsequent Behavior ◽  
Flow Stasis

SummaryIn vivo studies of the microcirculation of an untraumatized and unanesthetized animal preparation has shown that leukocyte adherence to vascular endothelium is an extremely rare occurrence. Induction of leukocyte adherence can be produced in a variety of ways including direct trauma to the vessels, remote tissue injury via laser irradiation, and denuding the epithelium overlying the observed vessels. The role of blood flow and local hemodynamics on the leukocyte adherence process is quite complex and still not fully understood. From the results reported it may be concluded that blood flow stasis will not produce leukocyte adherence but will augment pre-existing adherence. Studies using 2 quantitative measures of adherence, leukocyte flux and leukocyte velocity have shown these parameters to be affected differently by local hemodynamics. Initial adherence appears to be critically dependent on the magnitude of the blood shear stress at the vessel wall as evidenced by the lack of observable leukocyte flux above some threshold value. Subsequent behavior of the leukocytes as characterized by their average rolling velocity shows no apparent relationship to shear stress but, for low velocities, may be related to the linear blood velocity.

Leukotriene B4: An inflammatory mediator In vivo

1981 ◽  
Vol 22 (2) ◽  
pp. 213-222 ◽  
Author(s):  
M.A. Bray ◽  
A.W. Ford-Hutchinson ◽  
M.J.H. Smith
Keyword(s):  
Inflammatory Mediator ◽  
Leukotriene B4

Leukocyte adhesion in local versus hemorrhage-induced ischemia

1992 ◽  
Vol 263 (3) ◽  
pp. H810-H815 ◽  
Author(s):  
M. A. Perry ◽  
D. N. Granger
Keyword(s):  
Endothelial Cell ◽  
Leukocyte Adhesion ◽  
Ischemia Reperfusion ◽  
Leukocyte Rolling ◽  
Leukocyte Adherence ◽  
Rolling Velocity ◽  
Local Ischemia ◽  
Cell Adhesive ◽  
Local Restriction ◽  
Adhesive Interactions

The objective of this study was to compare the leukocyte-endothelial cell adhesive interactions elicited in postcapillary venules by either local ischemia-reperfusion or hemorrhage-reperfusion. Leukocyte rolling, adherence, and emigration were monitored in cat mesenteric venules exposed to an 85% reduction in blood flow (induced by either hemorrhage or local restriction of arterial inflow) for 1 h, followed by 1 h reperfusion. Leukocyte-endothelial cell interactions, venular diameter, and red blood cell velocity were measured during baseline, ischemia, and reperfusion periods. Both local and hemorrhage-induced ischemia reperfusion caused a reduction in leukocyte rolling velocity and increases in leukocyte adherence and emigration. Quantitatively, the adherence and emigration responses in both ischemia models were nearly identical. However, the two models differed in their response to immunoneutralization of the leukocyte adhesion glycoprotein CD11/CD18 with monoclonal antibody (MAb) IB4. The MAb had a more profound effect in attenuating leukocyte adherence and emigration in the local ischemia model. These results indicate that different factors may contribute to leukocyte-endothelial cell adhesive interactions observed in local vs. systemic models of ischemia-reperfusion.

scholarly journals Sialyl Lewisx (sLex) and an sLexMimetic, CGP69669A, Disrupt E-Selectin–Dependent Leukocyte Rolling In Vivo

Blood ◽  
1998 ◽  
Vol 91 (2) ◽  
pp. 475-483 ◽  
Author(s):  
Keith E. Norman ◽  
Gary P. Anderson ◽  
Hartmut C. Kolb ◽  
Klaus Ley ◽  
Beat Ernst
Keyword(s):  
Leukocyte Rolling ◽  
Sialyl Lewisx ◽  
Necrosis Factor Alpha ◽  
Rolling Velocity ◽  
Beneficial Effects ◽  
Selectin Family ◽  
Factor Alpha ◽  
Observable Event

Abstract Leukocyte rolling is the earliest observable event in their recruitment from the circulation to inflamed tissue. This rolling is mediated largely by interaction between the selectin family of adhesion molecules and their glycosylated ligands. Although the nature of these ligands and their interaction with the selectins is not fully understood, it is accepted that expression of fucosylated sialylated glycans such as sialyl Lewisx (sLex) is required for function. Despite findings that sLex inhibits binding of leukocytes to E-selectin in vitro, and has beneficial effects in inflammatory disease models, inhibition of E-selectin–dependent leukocyte rolling in vivo has not been described. Functional overlap between the selectins has been noted and reduction of rolling by E-selectin antibodies only occurs if P-selectin is absent or blocked. We demonstrate that leukocyte rolling velocity in tumor necrosis factor alpha (TNFα)-stimulated mouse cremaster is increased following treatment with either sLex or the sLex-mimetic CGP69669A and that rolling is dramatically reduced if CGP69669A is applied in the presence of anti–P-selectin antibody. These effects are characteristic of E-selectin antagonism. In contrast, surgically stimulated (L- or P-selectin–dependent) rolling is unaffected by either sLex or CGP69669A. Our data demonstrate that CGP69669A is an effective and selective antagonist of E-selectin in vivo.

Spontaneous leukocyte rolling in venules in untraumatized skin of conscious and anesthetized animals

1994 ◽  
Vol 267 (3) ◽  
pp. H1199-H1204 ◽  
Author(s):  
G. H. Janssen ◽  
G. J. Tangelder ◽  
M. G. Oude Egbrink ◽  
R. S. Reneman
Keyword(s):  
Defense Mechanisms ◽  
Fluorescent Labeling ◽  
Leukocyte Rolling ◽  
Rolling Velocity ◽  
Conscious Rats ◽  
Swiss Mice ◽  
Anesthetized Rats ◽  
Mouse Ear ◽  
Rats And Mice

Intravital bright-field videomicroscopy was used to investigate whether leukocyte rolling can be observed under normal physiological conditions. We studied skin venules in trained conscious rats and anesthetized rats and mice without touching the skin itself. Leukocyte rolling was spontaneously present in all hindpaw venules of Lewis rats (diam 8-27 microns) and also in all mouse ear venules (Swiss, 13-38 microns; BALB/c, 12-56 microns). Rolling levels (in leukocytes/min, median and range) were 8 (3-15) in conscious rats, 9 (3-19) in anesthetized rats, 30 (5-160) in anesthetized Swiss mice, and 10 (3-22) in anesthetized BALB/c mice. These levels appeared to be independent of time. Noninvasive mechanical stimulation induced an average increase of 32%. Fluorescent labeling of leukocytes in vivo with acridine orange had no influence. In Swiss mice, the rolling velocity was < 50 microns/s for > 75% of the leukocytes (median 31 microns/s); this parameter did not correlate with reduced velocity (17-68 s-1) and hence wall shear rate. Our finding that leukocyte rolling is spontaneously present in skin venules of anesthetized and conscious animals suggests a constant vigilance of the host defense mechanisms in the skin.

Ethanol enhances leukocyte-endothelial cell interactions in mesenteric venules

1990 ◽  
Vol 259 (4) ◽  
pp. G578-G583 ◽  
Author(s):  
P. R. Kvietys ◽  
M. A. Perry ◽  
T. S. Gaginella ◽  
D. N. Granger
Keyword(s):  
Endothelial Cell ◽  
Receptor Antagonist ◽  
Alcohol Intoxication ◽  
Leukotriene B4 ◽  
Cell Interactions ◽  
In Vivo Studies ◽  
Rolling Velocity ◽  
Neutrophil Adherence

In vivo studies have implicated neutrophils in the gastric mucosal injury produced by intraluminal administration of ethanol. However, in vitro studies indicate that ethanol inhibits various neutrophil functions such as adherence, chemotaxis, and degranulation. The aim of the present study was to assess whether ethanol, at clinically relevant concentrations, is proinflammatory in vivo. Ethanol (0.2, 1.0, 2.0, and 4.0%) was applied to the surface of the cat mesentery, and neutrophil adherence to venules (30 microns diam) and extravasation into the interstitium were quantitated using intravital microscopy. Hemodynamic parameters were also measured (venular diameter, red blood cell velocity, and leukocyte rolling velocity) or calculated (venular blood flow and wall shear stress). In this model ethanol produced a dose-dependent increase in neutrophil adherence and extravasation. The increase in leukocyte-endothelial cell interactions could not be attributed to alterations in hemodynamic factors. Pretreatment of animals with a monoclonal antibody (MoAb IB4) directed to the neutrophil CD11/CD18 adherence complex completely prevented the ethanol-induced neutrophil adherence and extravasation. Pretreatment with a leukotriene B4 (LTB4)-receptor antagonist (SC 41930) or a platelet-activating factor (PAF)-receptor antagonist (WEB 2170) did not alter the ethanol-induced neutrophil-endothelial interactions. We conclude that ethanol is proinflammatory at concentrations which may be achieved in the mucosal interstitium during acute alcohol intoxication. The ethanol-induced leukocyte adherence and extravasation is dependent on the expression of adhesive glycoproteins. The inflammatory mediators, PAF and LTB4, do not appear to play an important role in the leukocyte-endothelial cell interactions initiated by ethanol.

scholarly journals Leukocyte recruitment in the airways: an intravital microscopic study of rat tracheal microcirculation

2002 ◽  
Vol 282 (5) ◽  
pp. L959-L967 ◽  
Author(s):  
Lina H. K. Lim ◽  
Bruce S. Bochner ◽  
Elizabeth M. Wagner
Keyword(s):  
Real Time ◽  
Leukocyte Recruitment ◽  
New Method ◽  
Histological Evaluation ◽  
Leukocyte Rolling ◽  
Adherent Cells ◽  
Rolling Velocity ◽  
Leukocyte Extravasation ◽  
Local Superfusion

Because of its relative inaccessibility, inflammatory cell extravasation within the airway circulation in vivo has been difficult to investigate in real time. A new method has been established using intravital microscopy in the anesthetized rat to visualize leukocytes in superficial postcapillary venules of the trachea. This technique has been validated using local superfusion of lipopolysaccharide (LPS) and N-formyl-methionyl-leucyl-phenylalanine (FMLP). Basal leukocyte rolling velocity (55.4 ± 9.3 μm/s) and adhesion (1.4 ± 0.3 cells/100 μm) were monitored in postcapillary venules (33.9 ± 1.3 μm diameter). At all time points up to 90 min, these parameters were unaltered in control rats ( n= 7). In contrast, vessels exposed to 1 μg/ml of LPS ( n = 6) exhibited a 57% reduction in leukocyte rolling velocity and an increase in the number of adherent cells (4.7 ± 1 cells/100 μm, P < 0.05). Superfusion with 0.1 μM of FMLP ( n = 6) also resulted in a 45% reduction in rolling velocity and an increase in adherent cells (4 ± 0.7 cells/100 μm, P < 0.05). Histological evaluation confirmed local stimulus-induced leukocyte extravasation. These results demonstrate leukocyte recruitment in the airway microvasculature and provide an important new method to study airway inflammation in real time.

Molecular mechanisms involved in superoxide-induced leukocyte-endothelial cell interactions in vivo

1994 ◽  
Vol 266 (2) ◽  
pp. H637-H642 ◽  
Author(s):  
J. P. Gaboury ◽  
D. C. Anderson ◽  
P. Kubes
Keyword(s):  
Molecular Mechanisms ◽  
Leukocyte Adhesion ◽  
Platelet Activating Factor ◽  
Leukocyte Rolling ◽  
Rolling Velocity ◽  
Paf Receptor ◽  
Rolling Leukocytes ◽  
Adherent Leukocytes ◽  
Web 2086

Intravital microscopy was used to monitor leukocyte adherence, flux, rolling velocity, and number of rolling leukocytes (flux/velocity) in venules 25–40 microns in diameter. The superoxide-generating system, hypoxanthine and xanthine oxidase (HX/XO), was infused into the mesenteric circulation in untreated animals or in animals pretreated with either catalase (a hydrogen peroxide scavenger), WEB-2086 [a platelet-activating factor (PAF) receptor antagonist], or monoclonal antibodies directed against adhesion molecules CD18 (CL26) or P-selectin (PB1.3). HX/XO infusion caused a decrease in leukocyte rolling velocity and an increase in the number of rolling and adherent leukocytes. WEB-2086 prevented the increase in leukocyte adhesion and markedly increased leukocyte rolling velocity. PB1.3 abolished the HX/XO-associated rise in the flux of rolling leukocytes and proportionally decreased the number of adherent leukocytes. CL26 abolished HX/XO-induced leukocyte adhesion and also reduced the number of rolling leukocytes. In conclusion, P-selectin mediates the increased leukocyte flux induced by superoxide, whereas PAF and CD18 modulate leukocyte adhesion. PAF also reduces leukocyte rolling velocity, possibly as a result of CD18, but not P-selectin.

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