help button home button
AJRCCM
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Online Data Supplement
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Cohen, E. S.
Right arrow Articles by Hollenberg, S. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Cohen, E. S.
Right arrow Articles by Hollenberg, S. M.
American Journal of Respiratory and Critical Care Medicine Vol 166. pp. 16-20, (2002)
© 2002 American Thoracic Society

Original Article

Adenosine Deaminase Inhibition Attenuates Microvascular Dysfunction and Improves Survival in Sepsis

Elliott S. Cohen, William R. Law, Cordus R. Easington, Kenneth Q. Cruz, Beth A. Nardulli, Robert A. Balk, Joseph E. Parrillo and Steven M. Hollenberg

Section of Pulmonary and Critical Care Medicine and Section of Critical Care Medicine, Rush-Presbyterian-St. Lukes Medical Center; Department of Physiology and Biophysics, University of Illinois, Chicago, Illinois

Correspondence and requests for reprints should be addressed to Elliott S. Cohen, M.D., Section of Pulmonary and Critical Care Medicine, Suite 054, 1725 W. Harrison Street, Chicago, IL 60612. E-mail: ecohenus{at}yahoo.com


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
The ability of increased endogenous adenosine to mitigate microvascular derangements in sepsis was studied. Pentostatin (2'-deoxycoformycin), an inhibitor of adenosine deaminase, was administered to mice immediately after induction of sepsis by cecal ligation and puncture. Intravital video microscopy of cremasteric postcapillary venules was performed. Leukocyte rolling and adhesion were significantly increased in septic mice compared with control mice. Treatment of septic mice with pentostatin significantly decreased leukocyte rolling and adhesion (6.02 ± 0.09 versus 1.72 ± 0.12 rolling cells/min, 2.07 ± 0.04 versus 0.62 ± 0.05 adherent cells/100 µm per minute; p < 0.001). Albumin leakage (ratio) was significantly attenuated in septic animals treated with pentostatin (0.42 ± 0.05 versus 0.21 ± 0.04; p < 0.01). Circulating levels of interleukin-6, tumor necrosis factor-{alpha}, and soluble tumor necrosis factor type II receptor were decreased in septic mice treated with pentostatin. Survival was significantly improved at 48 hours in mice treated with pentostatin. These results suggest an important role for adenosine in modulating both leukocyte-dependent and -independent mechanisms of endothelial injury in sepsis. Exploiting the advantageous action of endogenous adenosine represents a potentially useful and novel therapeutic approach for the treatment of sepsis.

Key Words: sepsis • adenosine • microvasculature • leukocyte • endothelium


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
A central feature of the innate immune response to infection is endothelial cell-directed recruitment and activation of neutrophils at the site of infection to eradicate pathogens. This is mediated by the upregulation of complementary adhesion molecules and ligands on leukocytes and endothelial cells, induced by bacterial products and proinflammatory mediators (1). Leukocyte infiltration from blood to tissue is a multistep process that includes initial contact between leukocyte and endothelium, followed by a weak transient adhesive interaction manifested as leukocyte rolling, followed by firm leukocyte adhesion to the vessel wall. Firm adhesion then allows leukocytes to transmigrate across the vessel wall to target sites (2). During this process of adherence and migration, activated neutrophils can damage the endothelium (3). The upregulation of adhesion molecules by proinflammatory mediators becomes widespread in severe sepsis, occurring not only at the site of infection but throughout the vasculature. As such, neutrophils can adhere to and damage endothelium in noninfected tissues (4). This process contributes to the multiorgan failure characteristic of severe sepsis.

Adenosine is an endogenous regulator of leukocyte–endothelial interactions and inhibits neutrophil-mediated injury to endothelial cells (5). These immunomodulatory effects are mediated through receptors on neutrophils (6). To investigate the effects of endogenous adenosine on leukocyte–endothelial interactions and endothelial injury in an experimental model of severe sepsis, we pharmacologically inhibited the degradation of adenosine with pentostatin (2'-deoxycoformycin, Nipent; SuperGen, Dublin, CA). Pentostatin is a potent inhibitor of adenosine deaminase, the purine salvage enzyme involved in the irreversible deamination of adenosine. The compound avidly binds to the enzyme (Kd ~ 10-12) and causes prolonged inhibition of activity. Pentostatin has been used safely and effectively in the clinical arena for treatment of hairy cell leukemia (7).

The microvascular postcapillary venule is the site of leukocyte adhesion and emigration. We used intravital microscopy in an open cremaster model (8), a site distant from the initial infection, to investigate the effects of adenosine deaminase inhibition on leukocyte rolling, adhesion, and microvascular permeability in postcapillary venules of septic mice. We also determined the effects on selected circulating inflammatory cytokine responses. Finally, we determined whether these effects were associated with a reduction in mortality from septic shock.


   METHODS
TOP
 ABSTRACT
 INTRODUCTION
 METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
The study was performed in accordance with National Institutes of Health (NIH, Bethesda, MD) guidelines for use of experimental animals. Male BALB/c mice (18–20 g) were used in all experiments. Supplementary details regarding the methods may be found in the online data supplement.

Cecal Ligation and Puncture
Mice were made septic by cecal ligation and puncture (CLP), using previously published methods (9, 10). Animals were resuscitated with normal saline (50 ml/kg, subcutaneous) immediately after and 12 hours after CLP. Septic mice in this model become bacteremic with gram-negative enteric organisms (11).

Drug Administration
Pentostatin (SuperGen) was administered (1 mg/kg, subcutaneous) once, immediately after CLP.

Intravital Video Microscopy
Experiments were performed 15–18 hours after CLP. The mice were anesthetized intramuscularly with ketamine and acepromazine. The carotid artery was cannulated for measurement of systemic blood pressure. The cremaster muscle was dissected and exteriorized onto a clear viewing platform with blood and nerve supplies preserved and suffused with Krebs solution. The preparation was placed on the stage of an upright microscope and the microcirculation was viewed through a x50 objective. The image was captured by video camera and recorded by video cassette recorder. The numbers of rolling and adherent leukocytes were determined offline; leukocytes were considered to be rolling if they were moving slower than erythrocytes (2, 12–14).

Center line erythrocyte (red blood cell [RBC]) velocity, mean RBC velocity, and wall shear were measured with an optical Doppler velocimeter and the shear rate was calculated as [(mean RBC velocity/diameter) x 8 (s-1)] (15, 16).

To quantify albumin leakage across cremasteric postcapillary venules, fluorescein isothiocyanate (FITC)-labeled albumin (50 mg/kg; Sigma, St. Louis, MO) was administered intra-arterially, and fluorescence intensity was detected with a signal intensified (SIT) camera. The fluorescence intensity of FITC-labeled albumin within three segments of the venule under study (Vi) and in three contiguous areas of perivenular interstitium (Vo) was measured at 2 minutes and leakage was indexed as Vo/Vi (17).

Experimental Protocol
After 20 minutes of stabilization, baseline blood pressure, RBC velocity, and vessel diameter were recorded. Leukocyte rolling and adhesion were recorded continuously for 20 minutes in four groups of animals: control, control–pentostatin, septic, and septic–pentostatin. FITC-labeled albumin was then infused intra-arterially. Images were captured at 2 minutes postinfusion for determination of the permeability index. Background fluorescence was subtracted from images. Blood was collected, centrifuged, and stored at -80° C until analysis for circulating interleukin-6 (IL-6), tumor necrosis factor-{alpha} (TNF-{alpha}), and soluble TNF receptors using commercially available enzyme-linked immunosorbent assays (R&D Systems, Minneapolis, MN).

Survival Studies
Survival was tested in a separate cohort of animals. Mice were made septic by CLP; control animals underwent sham ligation. Separate groups of septic and control animals were administered pentostatin (1 mg/kg) immediately postsurgery. All groups were resuscitated with fluids (saline at 50 ml/kg) and treated subcutaneously with antibiotics (ceftriaxone at 30 mg/kg and clindamycin at 25 mg/kg) every 6 hours. Mice were observed continually for 48 hours.

Data Analysis
Data are reported as means ± SEM, with "n" indicating the number of animals. Differences between means were analyzed by one-way analysis of variance. A p value of <= 0.05 was accepted as significantly different, and power > 0.80 was used to accept adequate sensitivity of the test to detect differences (SigmaStat version 2.03; SPSS Science, Chicago, IL). The Kaplan–Meier product limit method was used for survival studies.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
The administration of pentostatin did not significantly affect systemic arterial blood pressure, white blood cell counts, or wall shear rate in either control or septic mice. The mean arterial pressure (under anesthesia) in the septic animals was significantly lower than in sham-operated animals (p < 0.01). The blood pressure in septic animals treated with pentostatin was slightly but not significantly higher than in septic animals without pentostatin (p = 0.126). The blood pressure in sham-operated animals treated with pentostatin was not different from sham-operated animals without pentostatin (Table 1). Total circulating leukocytes were significantly different between the septic animals and the sham-operated animals (p < 0.01). White blood cell counts in both septic and control animals treated with pentostatin were not significantly different from those of their respective untreated groups. Venular shear did not differ significantly among all four groups (Table 1).


View this table:
[in this window]
[in a new window]
  		TABLE 1. Vascular data for four animal groups studied

 
Leukocyte rolling and adhesion was increased significantly in septic mice compared with control mice (control, 0.74 ± 0.05 rolling cells/min, 0.63 ± 0.07 adherent cells/100 µm per minute; septic, 6.02 ± 0.09 rolling cells/min, 2.07 ± 0.04 adherent cells/100 µm per minute; n = 6 and 8, respectively; both p < 0.001). Treatment of septic mice with pentostatin significantly decreased leukocyte rolling and adhesion (1.72 ± 0.12 rolling cells/min, 0.62 ± 0.05 adherent cells/100 µm per minute; n = 8; p < 0.001 compared with untreated septic). Treatment of control mice with pentostatin had no significant effect on leukocyte rolling and adhesion (0.68 ± 0.04 rolling cells/min, 0.51 ± 0.04 adherent cells/100 µm per minute; n = 4; p > 0.05 compared with untreated control) (Figure 1) .



View larger version (22K):
[in this window]
[in a new window]
  		Figure 1. Rolling flux and adhesion of leukocytes to endothelium. *Significant difference from untreated control; {dagger}significant difference from untreated septic (p < 0.001 in both cases).

 
Albumin leakage (reported as a leakage ratio; see above) from cremasteric microvascular venules was significantly increased in septic animals as compared with sham-operated control animals (control, 0.13 ± 0.02; septic, 0.42 ± 0.05; n = 6 and 6, respectively; p < 0.01). Treatment of septic mice with pentostatin significantly attenuated this leakage (0.21 ± 0.04; n = 6; p < 0.01 compared with untreated septic). Treatment of sham-operated control animals with pentostatin had no significant effect on leakage compared with untreated counterparts (0.17 ± 0.04) (Figure 2) .



View larger version (11K):
[in this window]
[in a new window]
  		Figure 2. Fluorescein isothiocyanate (FITC)-labeled albumin leakage from postcapillary venules. Leakage was measured as the ratio of fluorescence intensity outside the vessel to fluorescence intensity inside the vessel. *Significant difference from untreated control; {dagger}significant difference from untreated septic (p < 0.01 in both cases).

 
Serum IL-6 and TNF-{alpha} were significantly elevated in septic animals compared with control animals (11.97 ± 3.85 ng/ml, n = 8 versus 0.57 ± 0.09 ng/ml, n = 15, p < 0.001 for IL-6; and 127.7 ± 26.5 pg/ml, n = 10 versus 35.8 ± 16.7 pg/ml, n = 15, p < 0.001 for TNF-{alpha}). Treatment of septic mice with pentostatin significantly attenuated this rise in both IL-6 and TNF-{alpha} (5.53 ± 1.44 ng/ml, n = 11, p = 0.035 and 20.3 ± 14.8 pg/ml, n = 11, p = 0.002, respectively) (Figures 3A and 3B) . Circulating levels of soluble TNF receptors I and II (sTNFRI or p55 and sTNFRII or p75) were significantly increased in septic mice compared with control animals (4.63 ± 0.77 ng/ml, n = 11 versus 1.29 ± 0.223 ng/ml, n = 16 for p55 and 23.76 ± 3.28 ng/ml, n = 9 versus 4.75 ± 0.596 ng/ml, n = 12 for p75; p < 0.001 for both). Pentostatin-treated septic mice had significantly decreased levels of sTNFRII, but no significant change in sTNFRI (16.53 ± 1.23 ng/ml, n = 12, p = 0.05 and 4.62 ± 0.40 ng/ml, n = 18, p = 0.723, respectively) (Figure 3C). Control mice administered pentostatin demonstrated no significant alterations in serum TNF-{alpha}, IL-6, or sTNFRII. Serum sTNFRI was significantly reduced by pentostatin in control mice.





View larger version (50K):
[in this window]
[in a new window]
  		Figure 3. (A) Serum IL-6 measured 18 hours after CLP. (B) Serum TNF measured 18 hours after CLP. (C) Soluble TNF receptors I (p55) and II (p75) measured 18 hours after CLP. For all: *significant difference from untreated control (p < 0.001 for all); {dagger}significant difference from untreated septic (p = 0.035 for IL-6, p = 0.002 for TNF, and p = 0.05 for p75); {ddagger}significant difference from sham-untreated animals (p = 0.046 for p55).

 
Survival of pentostatin-treated septic animals was significantly improved at 48 hours compared with septic animals not given pentostatin (56% survival versus 38% survival; n = 73 and 75; p < 0.01). Survival of sham-operated control animals both with and without pentostatin treatment was 100% at 48 hours (Figure 4) .



View larger version (14K):
[in this window]
[in a new window]
  		Figure 4. Survival study over 48 hours. All groups received fluid and antibiotics every 6 hours (see text). *Survival of septic mice treated with pentostatin (n = 73) was significantly improved compared with septic mice not given pentostatin (n = 75) (p < 0.01).

 

   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
The present study demonstrates the therapeutic potential of inhibiting adenosine deaminase in sepsis, using the compound pentostatin. Using intravital video microscopy, we have shown that pentostatin decreases leukocyte rolling, adhesion, and microvascular permeability in a clinically relevant animal model of sepsis. The treated animals also had attenuation but not ablation of cytokine responses. In addition, treatment of septic mice with pentostatin was associated with a significantly decreased mortality from septic shock.

Leukocyte rolling is a prerequisite for adhesion, as a leukocyte cannot adhere unless it initially rolls along the endothelium. In our study, septic mice had markedly increased numbers of rolling and adherent leukocytes compared with sham-operated control animals, at a site distant from the initial infection. These results corroborate previous findings from our laboratory in a similar model of CLP-induced sepsis in rats (2).

Our finding of increased microvascular permeability in septic animals is consistent with previous video microscopy studies using endotoxin infusion (18, 19). Leukocyte adhesion in the microvasculature is a key event in the initiation and maintenance of acute inflammatory responses (20–22). The fact that the increased permeability correlated with increased leukocyte adhesion, and that decreasing leukocyte adhesion with pentostatin also correlated with decreased permeability, suggests a direct role for leukocytes in damaging the endothelium. However, the current experiments do not preclude involvement of neutrophil-independent mechanisms in causing at least some of the increased microvascular permeability observed.

The role of endogenous adenosine in the pathophysiology and treatment of sepsis has not been extensively explored. Because of the rapid metabolism of adenosine in vivo, a single administration of the nucleoside would not be expected to have significant effects on the outcome of sepsis. A single infusion of adenosine before the administration of endotoxin in mice has been shown to have no effect on mortality, whereas a single infusion of a synthetic adenosine receptor agonist did increase survival (23). An adenosine A2A receptor agonist has also been shown to markedly attenuate TNF-{alpha} release in rats during endotoxin shock (24). In addition, these investigators presented evidence suggesting alterations in TNF-{alpha} and IL-1ß, using a short-acting adenosine deaminase inhibitor, but the differences did not achieve statistical significance. Selective inhibition of adenosine kinase in a rat CLP model, leading to increased endogenous adenosine, has been shown to improve survival (25). To increase endogenous adenosine in vivo, and to avoid the problems associated with exogenous adenosine administration, we used a potent, long-lasting inhibitor of the enzyme adenosine deaminase, preventing the conversion of adenosine to inosine.

Adenosine has been shown to have multiple effects on the function of neutrophils. Cronstein and coworkers have repeatedly shown the ability of adenosine to decrease neutrophil adhesion and endothelial injury, an effect likely mediated through decreased superoxide generation and the regulation of adhesion molecule expression (5, 26–28). In addition, adenosine has been shown to decrease the expression of E-selectin and vascular cell adhesion molecule-1 by activated endothelial cells, an effect significantly enhanced by the addition of 2'-deoxycoformycin (pentostatin) (29). Our data demonstrating decreased leukocyte rolling and adhesion are consistent with the proposition that endogenous adenosine plays such a role in sepsis, and that this role can be enhanced by inhibition of adenosine deaminase. We have shown that venular shear was not significantly different between groups of animals. This suggests that the effect of pentostatin in decreasing leukocyte rolling and adhesion was not mediated through changes in local blood flow, but instead by changes in the adhesiveness of the cells to endothelium, effects mediated via adhesion molecules on both the inflammatory cells and the endothelial cells.

It is increasingly apparent that feedback between pro and antiinflammatory processes is critically important to outcome from sepsis. The balance between pro and antiinflammatory cytokines is influenced not only by levels of cytokines themselves but by levels of cytokine receptors. Bemelmans and coworkers demonstrated that blockade of TNF-{alpha} with any one of three anti-TNF antibodies resulted in increased serum concentrations of TNF receptors after lipopolysaccharide challenge in mice (30). In addition, complete ablation of the effects of a given cytokine may not be beneficial in infectious processes. A randomized trial with humans, using an sTNFR fusion protein, actually worsened the outcome of sepsis in a dose-dependent fashion (31). In considering our data from such a vantage point, it is interesting to note that the effects of pentostatin on both TNF-{alpha} and its receptors suggest potentially beneficial effects on the balance between pro and antiinflammatory molecules. Not only was there an attenuation of the proinflammatory cytokine TNF-{alpha}, there was also a diminution of circulating sTNFRII. Even the lack of change in sTNFRI after pentostatin treatment suggests an influence, because simple attenuation of TNF-{alpha} would be expected to cause an increase in sTNFRI (30). These data suggest that pentostatin influenced both arms of the inflammatory response.

The decreases in leukocyte rolling and adhesion, microvascular permeability, and the modulation of inflammatory cytokine activity described in this investigation of mice treated with pentostatin were associated with improved survival in the face of severe sepsis. Pentostatin has multiple effects on cellular function and it is possible that factors other than effects on rolling, adhesion, and leakage contribute to improved survival. The slightly different resuscitation regimens used in the video microscopy experiments and the survival studies complicate direct correlations, but pentostatin decreased leukocyte adhesion even in the more severe, less resuscitated model.

Our survival study design used fluids and antibiotics in all experimental groups to replicate more closely the supportive therapy performed in the clinical arena. This supportive therapy alone significantly improved survival from 0% to nearly 30% (9). In concordance with this earlier report, we found 38% survival of CLP mice that received fluid and antibiotic supportive therapy alone. The additional significant improvement in survival achieved by adding pentostatin to the treatment regimen suggests that this novel approach has significant therapeutic potential.

Clinical Implications
Vascular injury in sepsis, whether related directly or indirectly to neutrophil activation, contributes significantly to the characteristic multiorgan failure. Interventions aimed at reducing this injury have the potential to improve outcomes not only of patients with sepsis, but other acute inflammatory states as well. We have shown in the current study that pharmacologic inhibition of adenosine deaminase with pentostatin led to favorable alterations in leukocyte–endothelial interactions, as well as decreases in circulating levels of systemic mediators of inflammation. Pentostatin administration also led to improved survival in a fluid-resuscitated and antibiotic-treated animal model of sepsis.

Pentostatin is currently used clinically in the treatment of hairy cell leukemia. Myelosuppression, which occurs less frequently with the currently used regimens (lower dose given every 2 weeks), is thought to be related to the underlying malignancy rather than to the treatment (7). Other potential toxicities when used in humans for hematologic malignancies may include increased risk of infection, the degree of which depends on the underlying malignancy (increased risk in chronic lymphocytic leukemia versus hairy cell leukemia). The most commonly reported side effects include nausea and/or vomiting. Renal and hepatic dysfunction is usually mild and transient (7). CNS side effects with currently used dosages are usually confined to headache, malaise, and depression. Skin rash and other hypersensitivity reactions have also been reported (7). It should also be noted that we are suggesting short-term use of adenosine deaminase inhibition to treat sepsis. The potential for toxicity at the dose we used has been reported to occur only with protracted treatment. Although we did not specifically look at these side effects in our animal model (other than myelosuppression), the fact that all the control animals administered pentostatin had the same survival (100%) as sham-treated animals not given the drug suggests that significantly severe adverse effects did not occur. Further studies will clearly be needed to characterize adverse effects in septic mice.

The available data suggest that adenosine deaminase inhibition leads to a balanced modulation of inflammation, rather than complete abolition of factors that contribute to host defenses against infection. The current studies have confirmed these findings in a clinically relevant model of sepsis, and have shown that this balanced modulation is associated with improved outcome. Further studies investigating the manipulation of endogenous adenosine for therapy of sepsis are warranted. These studies would include administration of the compound at a later time when sepsis is further advanced.


   Acknowledgments
 
The authors thank Mrs. Francine Rampick for secretarial assistance.

Supported in part by National Institutes of Health grant RO1-GM5088 and SuperGen Corporation (Dublin, CA).


   FOOTNOTES
 
This article has an online data supplement, which is accessible from this issue's table of contents online at www.atsjournals.org

Received in original form September 17, 2001; accepted in final form January 11, 2002


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Witko-Sarsat V, Rieu P, Descamps-Latscha B, Lesavre P, Halbwachs-Mecarelli L. Neutrophils: molecules, functions and pathophysiological aspects. Lab Invest 2000;80:617–653.[Medline]
  2. Sundrani R, Easington CR, Mattoo A, Parrillo JE, Hollenberg SM. Nitric oxide synthase inhibition increases venular leukocyte rolling and adhesion in septic rats. Crit Care Med 2000;28:2898–2903.[CrossRef][Medline]
  3. Murphy HS, Bakopoulos N, Dame MK, Varani J, Ward PA. Heterogeneity of vascular endothelial cells: differences in susceptibility to neutrophil-mediated injury. Microvasc Res 1998;56:203–211.[CrossRef][Medline]
  4. Parent C, Eichacker PQ. Neutrophil and endothelial cell interactions in sepsis: the role of adhesion molecules. Infect Dis Clin North Am 1999; 13:427–447.[CrossRef][Medline]
  5. Cronstein BN, Levin RI, Belanoff J, Weissmann G, Hirschhorn R. Adenosine: an endogenous inhibitor of neutrophil-mediated injury to endothelial cells. J Clin Invest 1986;78:760–770.[Medline]
  6. Collis MG, Hourani SM. Adenosine receptor subtypes. Trends Pharmacol Sci 1993;14:360–366.[Medline]
  7. Brogden RN, Sorkin EM. Pentostatin: a review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in lymphoproliferative disorders. Drugs 1993;46:652–677.[Medline]
  8. Baez S. An open cremaster muscle preparation for the study of blood vessels by in vivo microscopy. Microvasc Res 1973;5:384–394.[CrossRef][Medline]
  9. Hollenberg SM, Broussard M, Osman J, Parrillo JE. Increased microvascular reactivity and improved mortality in septic mice lacking inducible nitric oxide synthase. Circ Res 2000;86:774–778.[Abstract/Free Full Text]
  10. Hollenberg SM, Easington CR, Osman J, Broussard M, Parrillo JE. Effects of nitric oxide synthase inhibition on microvascular reactivity in septic mice. Shock 1999;12:262–267.[Medline]
  11. Hollenberg SM, Dumasius A, Easington C, Colilla SA, Neumann A, Parrillo JE. Characterization of a hyperdynamic murine model of resuscitated sepsis using echocardiography. Am J Respir Crit Care Med 2001;164:891–895.[Abstract/Free Full Text]
  12. Kubes P, Suzuki M, Granger DN. Nitric oxide: an endogenous modulator of leukocyte adhesion. Proc Natl Acad Sci USA 1991;88:4651–4655.[Abstract/Free Full Text]
  13. Kubes P, Kanwar S, Niu XF, Gaboury JP. Nitric oxide synthesis inhibition induces leukocyte adhesion via superoxide and mast cells. FASEB J 1993;7:1293–1299.[Abstract]
  14. Kubes P, Kanwar S. Histamine induces leukocyte rolling in post-capillary venules. A P-selectin-mediated event. J Immunol 1994;152:3570–3577.[Abstract]
  15. Davis MJ. Determination of volumetric flow in capillary tubes using an optical Doppler velocimeter. Microvasc Res 1987;34:223–230.[CrossRef][Medline]
  16. Damiano ER, Westheider J, Tozeren A, Ley K. Variation in the velocity, deformation, and adhesion energy density of leukocytes rolling within venules. Circ Res 1996;79:1122–1130.[Abstract/Free Full Text]
  17. Kurose I, Kubes P, Wolf R, Anderson DC, Paulson J, Miyasaka M, Granger DN. Inhibition of nitric oxide production: mechanisms of vascular albumin leakage. Circ Res 1993;73:164–171.[Abstract]
  18. Yi ES, Ulich TR. Endotoxin, interleukin-1, and tumor necrosis factor cause neutrophil-dependent microvascular leakage in postcapillary venules. Am J Pathol 1992;140:659–663.[Abstract]
  19. Kurose I, Suematsu M, Miura S, Fukumura D, Sekizuka E, Nagata H, Oshio C, Tsuchiya M. Oxyradical generation from leukocytes during endotoxin-induced microcirculatory disturbance in rat mesentery: attenuating effect of cetraxate. Toxicol Appl Pharmacol 1993;120:37–44.[CrossRef][Medline]
  20. Granger DN, Kubes P. The microcirculation and inflammation: modulation of leukocyte–endothelial cell adhesion. J Leukoc Biol 1994;55:662–675.[Abstract]
  21. Korthuis RJ, Anderson DC, Granger DN. Role of neutrophil–endothelial cell adhesion in inflammatory disorders. J Crit Care 1994;9:47–71.[CrossRef][Medline]
  22. Schmid-Schonbein GW. The damaging potential of leukocyte activation in the microcirculation. Angiology 1993;44:45–56.[Medline]
  23. Parmely MJ, Zhou WW, Edwards CK III, Borcherding DR, Silverstein R, Morrison DC. Adenosine and a related carbocyclic nucleoside analogue selectively inhibit tumor necrosis factor-{alpha} production and protect mice against endotoxin challenge. J Immunol 1993;151:389–396.[Abstract]
  24. Tofovic SP, Zacharia L, Carcillo JA, Jackson EK. Inhibition of adenosine deaminase attenuates endotoxin-induced release of cytokines in vivo in rats. Shock 2001;16:196–202.[Medline]
  25. Firestein GS, Boyle D, Bullough DA, Gruber HE, Sajjadi FG, Montag A, Sambol B, Mullane KM. Protective effect of an adenosine kinase inhibitor in septic shock. J Immunol 1994;152:5853–5859.[Abstract]
  26. Cronstein BN, Kramer SB, Weissmann G, Hirschhorn R. Adenosine: a physiological modulator of superoxide anion generation by human neutrophils. J Exp Med 1983;158:1160–1177.[Abstract/Free Full Text]
  27. Cronstein BN, Daguma L, Nichols D, Hutchison AJ, Williams M. The adenosine/neutrophil paradox resolved: human neutrophils possess both A1 and A2 receptors that promote chemotaxis and inhibit O2 generation, respectively. J Clin Invest 1990;85:1150–1157.[Medline]
  28. Cronstein BN, Levin RI, Philips M, Hirschhorn R, Abramson SB, Weissmann G. Neutrophil adherence to endothelium is enhanced via adenosine A1 receptors and inhibited via adenosine A2 receptors. J Immunol 1992;148:2201–2206.[Abstract]
  29. Bouma MG, van den Wildenberg FA, Buurman WA. Adenosine inhibits cytokine release and expression of adhesion molecules by activated human endothelial cells. Am J Physiol 1996;270:C522–C529.[Medline]
  30. Bemelmans MH, Gouma DJ, Buurman WA. LPS-induced sTNF-receptor release in vivo in a murine model: investigation of the role of tumor necrosis factor, IL-1, leukemia inhibiting factor, and IFN-{gamma}. J Immunol 1993;151:5554–5562.[Abstract]
  31. Fisher CJ Jr, Agosti JM, Opal SM, Lowry SF, Balk RA, Sadoff JC, Abraham E, Schein RM, Benjamin E. Treatment of septic shock with the tumor necrosis factor receptor Fc fusion protein: the Soluble TNF Receptor Sepsis Study Group. N Engl J Med 1996;334:1697–1702.[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
H. T. Lee, M. Kim, J. D. Joo, G. Gallos, J.-F. Chen, and C. W. Emala
A3 adenosine receptor activation decreases mortality and renal and hepatic injury in murine septic peritonitis
Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2006; 291(4): R959 - R969.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
W. R. Law
Adenosine receptors in the response to sepsis: what do receptor-specific knockouts tell us?
Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2006; 291(4): R957 - R958.
[Full Text] [PDF]

Home page
 BloodHome page
H. K. Eltzschig, M. Faigle, S. Knapp, J. Karhausen, J. Ibla, P. Rosenberger, K. C. Odegard, P. C. Laussen, L. F. Thompson, and S. P. Colgan
Endothelial catabolism of extracellular adenosine during hypoxia: the role of surface adenosine deaminase and CD26
Blood, September 1, 2006; 108(5): 1602 - 1610.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
M. Eisenhut
Comment on "Pretreatment Intracerebral and Peripheral Blood Immune Responses in Vietnamese Adults with Tuberculous Meningitis: Diagnostic Value and Relationship to Disease Severity and Outcome"
J. Immunol., May 1, 2006; 176(9): 5137 - 5137.
[Full Text] [PDF]

Home page
 J. Leukoc. Biol.Home page
G. W. Sullivan, D. D. Lee, W. G. Ross, J. A. DiVietro, C. M. Lappas, M. B. Lawrence, and J. Linden
Activation of A2A adenosine receptors inhibits expression of {alpha}4/{beta}1 integrin (very late antigen-4) on stimulated human neutrophils
J. Leukoc. Biol., January 1, 2004; 75(1): 127 - 134.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Crit. Care Med.Home page
M. J. Tobin
Critical Care Medicine in AJRCCM 2002
Am. J. Respir. Crit. Care Med., February 1, 2003; 167(3): 294 - 305.
[Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Online Data Supplement
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Cohen, E. S.
Right arrow Articles by Hollenberg, S. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Cohen, E. S.
Right arrow Articles by Hollenberg, S. M.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Proc. Am. Thorac. Soc. Am. J. Respir. Cell Mol. Biol.
Copyright © 2002 American Thoracic Society