Inhibition of tumor necrosis factor production and ICAM-1 expression by pentoxifylline: beneficial effects in sepsis syndrome

Intercellular Adhesion Molecule 1: More than a Leukocyte Adhesion Molecule

Intercellular adhesion molecule 1 (ICAM-1) is a transmembrane protein in the immunoglobulin superfamily expressed on the surface of multiple cell populations and upregulated by inflammatory stimuli. It mediates cellular adhesive interactions by binding to the β2 integrins macrophage antigen 1 and leukocyte function-associated antigen 1, as well as other ligands. It has important roles in the immune system, including in leukocyte adhesion to the endothelium and transendothelial migration, and at the immunological synapse formed between lymphocytes and antigen-presenting cells. ICAM-1 has also been implicated in the pathophysiology of diverse diseases from cardiovascular diseases to autoimmune disorders, certain infections, and cancer. In this review, we summarize the current understanding of the structure and regulation of the ICAM1 gene and the ICAM-1 protein. We discuss the roles of ICAM-1 in the normal immune system and a selection of diseases to highlight the breadth and often double-edged nature of its functions. Finally, we discuss current therapeutics and opportunities for advancements.

Apoptosis and Bcl-2 Expression in Irradiated Lungs and the Effect of Pentoxifylline

We measured number of bcl-2, apoptotic, neutrophil, and surfactant apoprotein D (SP-D) positive cells in irradiated rat lungs during different time points after the sublethal whole-thorax irradiation of rats. We also investigated the influence of pentoxifylline (PTX) therapy on these markers. Wistar rats were given 15 Gy thoracic irradiation and PTX (35 mg/kg) twice a week. Animals were examined histologically and imunohistochemically at intervals from 1-12 weeks. In non-treated rats compared with treated rats, bcl-2 expression was significantly inhibited from 4 weeks after irradiation. A higher apoptosis presence in non-treated rats from 4 weeks was found and apoptosis development in PTX-treated animals was delayed and started 8 weeks after irradiation. Similar differences were measured during neutrophil granulocytes examination. Neutrophil penetration in non-treated rats was found 5 weeks after irradiation in contrast to the RP onset of PTX-treated animals 8 weeks after irradiation. The number of SP-D positive cells in non-treated rats observed until 5 weeks after irradiation was higher than in the control group. PTX-treated animals expressed higher number of SP-D positive cells during the whole experiment than the control group. We suggest that apoptosis is linked to neutrophil granulocyte actions during the RP onset and that PTX-therapy causes diminished inflammation development.

Effects of pentoxifylline on immediate and late-phase cutaneous reactions in response to anti-immunoglobulin E antibodies in clinically normal dogs

OBJECTIVE

To characterize the effects of pentoxifylline on the gross and microscopic variables associated with immediate and late-phase inflammation following injection of IgE-specific antibodies in the skin of clinically normal dogs.

ANIMALS

6 healthy adult mixed-breed dogs.

PROCEDURES

Intradermal injections (0.1 mL each) of PBS solution, histamine phosphate, and cross-linking rabbit-origin anti-canine IgE antibodies (3 injections/dog) were administered at 0 hours on day 0; wheal sizes were evaluated at 20 minutes, 6 hours, and 24 hours. Biopsy specimens of injected and noninjected skin were collected 24 hours after injection. On day 2, treatment with pentoxifylline (20 mg/kg, PO, q 8 h) was initiated and continued until day 30. For each dog, injection, measurement, and biopsy procedures were repeated on days 30 to 31 and on days 37 to 38 (ie, after discontinuation of pentoxifylline administration).

RESULTS

Pentoxifylline administration was associated with a significant decrease in wheal size at 6 and 24 hours (but not at 20 minutes) after injection of anti-canine IgE. Repeated injections performed 1 week after drug discontinuation revealed partial recovery of the 6-hour cutaneous reaction and complete recovery of the 24-hour cutaneous reaction. Pentoxifylline administration was also associated with inhibition of mast cell degranulation and significant decreases in the total numbers of cutaneous inflammatory cells and eosinophils, compared with pretreatment findings.

CONCLUSIONS AND CLINICAL RELEVANCE

In clinically normal dogs, pentoxifylline effectively impaired late-phase reactions but not immediate reactions at sites of intradermal injection of IgE-specific antibodies by inhibiting mast cell degranulation and recruitment of cutaneous inflammatory cells, especially eosinophils.

Biventricular pacing in heart failure: a review

Biventricular pacing has been an exciting recent advance in the management of drug-refractory heart failure. This new therapy has evolved as much from necessity as scientific observation, since benefits derived from pharmacotherapy currently appear to have reached their peak. Clinical trials of biventricular pacing are establishing morbidity and mortality benefits in heart failure. New challenges in the use of these pacemakers are now arising. These include the accurate diagnosis of ventricular dyssynchrony and, hence, potential responders to the refinement of implantation of the left ventricular lead to the appropriate dyssynchronous ventricular area and optimization of pacemaker programming. This review gives a general overview of the principles and the current evidence for the use of biventricular pacemakers in the treatment of heart failure. In addition, a discussion of current research and future projects is included.

[Changes in diagnostic and therapeutic standards of acute pancreatitis in clinical practice. Epidemiologic analysis of data from a regional center of internal medicine and surgery]

Epidemiological data analysis of a tertiary (regional) medical and surgical center. Diagnostic and therapeutic standards of patients with acute pancreatitis have changed significantly in the last few decades. Progress in laboratory and imaging diagnostics and achievements in experimental research resulted in a significant modification of the guidelines related to the care of pancreatitic patients. The aim was to analyse and compare the data of patients with acute pancreatitis treated in 1996 (period I) and 2004 (period II) at the Departments of Internal Medicine and Surgery, University of Szeged, to evaluate the concordance with international guidelines during medical and surgical treatment.

RESULTS

The authors analysed the clinical data of 126 and 124 patients, respectively, with acute pancreatitis observed during the two periods. An increase in the incidence of biliary acute pancreatitis, more frequent use of antibiotics, a higher frequency of therapeutic endoscopies (papillotomy and biliary stone extraction), the general application of ultrasonography-guided fine needle aspiration and bacterial culturing in cases of suspected infected necrosis, and higher effectiveness in complex surgical and supportive management of infected necrosis cases were detected in period II.

CONCLUSION

Although most of the achievements suggested in international guidelines on medical/endoscopic and surgical treatment of acute pancreatitis have been implemented during the observation period, no significant changes in the morbidity and mortality data of patients were found.

Clinical treatment regimens for chronic heart failure: a review

Chronic heart failure (CHF) is increasing in prevalence worldwide, particularly in the elderly. Accordingly, this epidemic is likely to translate into a major increase in healthcare costs. Systolic heart failure is the most common cause of CHF presentations. Although the causes vary, the most common single aetiological factor is ischaemic heart disease, which accounts for approximately 50% of heart failure presentations. Research into CHF pharmacotherapy has been copious, with the focus principally centred on systolic heart failure. The evidence base for pharmacotherapy in CHF is amongst the largest currently in clinical medicine. There have been multiple trials establishing the mortality and morbidity benefits of pharmacotherapy. Amongst these, large scale trials of angiotensin-converting enzyme inhibitors, beta-blockers and spironolactone have provided a sound basis for evidence-based treatment approaches to the CHF patient. Recently research interest has increased in biomedical engineering with studies being performed in biventricular pacing and mechanical hearts. Early data with biventricular pacing or cardiac resynchronisation therapy is encouraging. Diastolic heart failure alone accounts for at least 20 - 40% of CHF presentations and whilst it may occur in isolation, is most commonly seen in association with systolic heart failure. In this study, we present a broad overview of the current therapeutic modalities for the management of CHF, with particular emphasis on pharmacotherapy.

The ACVD task force on canine atopic dermatitis (XXII): nonsteroidal anti-inflammatory pharmacotherapy

The pharmacotherapy of canine atopic dermatitis has relied primarily on the use of glucocorticoids and anti-histamines. During the last decade, other anti-inflammatory drugs have been investigated in clinical trials. This paper will review the studies using misoprostol, cyclosporine, tacrolimus, phosphodiesterase inhibitors, capsaicin, leukotriene inhibitors and serotonin-reuptake inhibitors for treatment of dogs with atopic dermatitis. For each drug the mechanism of action, the rationale for use in atopic dermatitis, the clinical efficacy, reported adverse effects and strength of recommendation for treatment of canine atopic dermatitis are described. At the time of this writing, there is fair evidence to support the recommendation for using cyclosporine, misoprostol and pentoxifylline for treatment of canine atopic dermatitis. This recommendation can be strengthened by the performance of additional blinded randomized controlled trials with larger number of dogs. In contrast, there is insufficient evidence to recommend for or against treatment with tacrolimus, leukotriene inhibitors, serotonin-reuptake antagonists and capsaicin.

Pentoxifylline inhibits the synthesis and IFN-gamma-inducing activity of IL-18

The effect of phosphodiesterase-inhibiting anti-inflammatory drug pentoxifylline (PTX) on LPS-induced IL-18 synthesis and IL-18-mediated IFN-gamma-induction were investigated. In a dose-dependent manner PTX inhibited production of IL-18 in LPS-treated cultures of murine spleen cells and bone marrow-derived macrophages. Similarly, PTX treatment significantly reduced blood IL-18 levels and expression of spleen IL-18 mRNA in LPS-challenged mice. The inhibitory effect of PTX was specific for IL-18, since LPS-induced IL-12 p40 release was not suppressed either in splenocyte cultures or blood of LPS-injected animals. Synergistic induction of IFN-gamma by combined IL-12/IL-18 treatment was also inhibited by PTX in vitro and in vivo. Experiments with IL-12 pretreatment of splenocytes, followed by IL-18 stimulation, revealed that PTX suppressed both IL-12 and IL-18 signals responsible for IFN-gamma induction. These results suggest that interference with IL-18 synthesis and IFN-gamma-inducing activity might contribute to anti-inflammatory actions of PTX.

Cloricromene, a semi-synthetic coumarin derivative, inhibits tumor necrosis factor-alpha production at a pre-transcriptional level

Cloricromene decreases myocardial infarct size after ischemic-reperfusion injury in vivo, and it has been suggested that this is due to inhibition of tumor necrosis factor-alpha (TNF-alpha). The purpose of this work was to characterize the mechanism of cloricromene-induced inhibition of TNF-alpha in rat macrophages. Cloricromene inhibited lipopolysaccharide-induced TNF-alpha release in a dose-dependent manner (IC(50)=5.9 +/- 0.8 microM). This was not due to cytotoxicity, as cloricromene was well tolerated up to 500 microM. Cloricromene inhibited lipopolysaccharide-induced expression of TNF-alpha mRNA, which suggests a pre-transcriptional effect. We then investigated the early signal transduction pathway triggered by lipopolysaccharide. The binding of lipopolysaccharide to its receptor CD14 activates protein kinase C and nuclear factor-kappaB (NF-kappaB). Cloricromene inhibited NF-kappaB activation in a dose-dependent manner, but affected protein kinase C translocation only slightly. We then established that cloricromene inhibited lipopolysaccharide-induced cellular oxidative activity, which is important for NF-kappaB activation. Our results show that cloricromene interferes with the early signal transduction pathway triggered by lipopolysaccharide.

Diagnostic relevance of procalcitonin, IL-6, and sICAM-1 in the prediction of infected necrosis in acute pancreatitis

BACKGROUND

Infected pancreatic necrosis (IPN) is an absolute indication for surgical intervention, therefore an early and accurate laboratory diagnosis is necessary to confirm the infection. The aim of the study was to analyze the clinical value of procalcitonin (PCT) for the prediction of infected necrosis, in comparison with interleukin-6 (IL-6) and sICAM 1.

PATIENTS AND METHODS

A total of 30 patients were investigated; 10 patients with sterile pancreatic necrosis (SPN), 10 with IPN, and 10 with sepsis of different origin. The concentrations of PCT in the patients' sera were measured by immunoluminometric assay (BRAHMS Diagnostica, Berlin, Germany, PCT Lumitest), the IL-6 concentrations by bioassay, applying the B-9 cell line, and the sICAM-1 levels by enzyme-linked immunosorbent assay (ELISA) (R&D). PCT was determined in cell lysates by ECL Western blot.

RESULTS

PCT was found in relatively high concentrations (8.5 +/- 4.8 ng/mL) only in patients with infected pancreatic necrosis, and in patients with sepsis of different origin ( 15 +/- 5.4 ng/mL). Positive values (> 1 ng/mL) preceded positive bacterial results from either blood or surgical samples. None of the serum samples of patients with SPN exhibited PCT concentrations higher than 1.2 ng/mL. In contrast, IL-6 and sICAM-1 were overproduced in both types (infected and sterile) of pancreatic necrosis, and their levels remained elevated for several days even after surgical elimination of the infected focus (widespread necrosectomy and continuous lavage). Sensitivity, specificity, and positive predictive values for discriminating IPN from SPN was 90, 100, and 100% for PCT (p < 0.0001); 100, 20, and 55% for IL-6 (p 0.474 n.s.) and 90, 10, and 50% for sICAM-1 (p 1.000 n.s.). Immunoblotting revealed no PCT in patients' leukocytes, or in human endothelial cell lines.

CONCLUSION

Elevated serum IL-6 and sICAM-1 levels are characteristic in systemic inflammatory response syndrome (SIRS) of either infectious or noninfectious origin. In contrast, the PCT level is an accurate, readily available parameter that allows the discrimination of IPN, and is a helpful marker facilitating a decision concerning surgical intervention.

Diagnostic relevance of procalcitonin, IL-6, and sICAM-1 in the prediction of infected necrosis in acute pancreatitis

BACKGROUND

Infected pancreatic necrosis (IPN) is an absolute indication for surgical intervention, therefore an early and accurate laboratory diagnosis is necessary to confirm the infection. The aim of the study was to analyze the clinical value of procalcitonin (PCT) for the prediction of infected necrosis, in comparison with interleukin-6 (IL-6) and sICAM 1.

PATIENTS AND METHODS

A total of 30 patients were investigated; 10 patients with sterile pancreatic necrosis (SPN), 10 with IPN, and 10 with sepsis of different origin. The concentrations of PCT in the patients' sera were measured by immunoluminometric assay (BRAHMS Diagnostica, Berlin, Germany, PCT Lumitest), the IL-6 concentrations by bioassay, applying the B-9 cell line, and the sICAM-1 levels by enzyme-linked immunosorbent assay (ELISA) (R&D). PCT was determined in cell lysates by ECL Western blot.

RESULTS

PCT was found in relatively high concentrations (8.5 +/- 4.8 ng/mL) only in patients with infected pancreatic necrosis, and in patients with sepsis of different origin ( 15 +/- 5.4 ng/mL). Positive values (> 1 ng/mL) preceded positive bacterial results from either blood or surgical samples. None of the serum samples of patients with SPN exhibited PCT concentrations higher than 1.2 ng/mL. In contrast, IL-6 and sICAM-1 were overproduced in both types (infected and sterile) of pancreatic necrosis, and their levels remained elevated for several days even after surgical elimination of the infected focus (widespread necrosectomy and continuous lavage). Sensitivity, specificity, and positive predictive values for discriminating IPN from SPN was 90, 100, and 100% for PCT (p < 0.0001); 100, 20, and 55% for IL-6 (p 0.474 n.s.) and 90, 10, and 50% for sICAM-1 (p 1.000 n.s.). Immunoblotting revealed no PCT in patients' leukocytes, or in human endothelial cell lines.

CONCLUSION

Elevated serum IL-6 and sICAM-1 levels are characteristic in systemic inflammatory response syndrome (SIRS) of either infectious or noninfectious origin. In contrast, the PCT level is an accurate, readily available parameter that allows the discrimination of IPN, and is a helpful marker facilitating a decision concerning surgical intervention.

Antioxidants in the prevention of renal disease

In view of the role of oxidative processes in inflicting damage that leads to glomerulosclerosis and renal medullary interstitial fibrosis, more attention could be paid to the use of antioxidant food constituents and the usage of drugs with recognized antioxidant potential. In any case atherosclerosis is an important component of chronic renal diseases. There is a wide choice of foods and drugs that could confer benefit. Supplementation with vitamins E and C, use of soy protein diets and drinking green tea could be sufficient to confer remarkable improvements.

Antimalarial drugs modulate the expression of monocyte receptors

The cytoadherence of four Plasmodium falciparum malaria isolates (FCR-3, RSA-14, 15 and 17) to monocytes was used as a measure of the expression of monocyte receptors after the monocytes had been exposed to seven antimalarial drugs. Quinine, chloroquine, primaquine, pyrimethamine, artemesinin, mefloquine and proguanil all down-regulated the expression of monocyte receptors by 40% or greater at the therapeutic concentrations of each drug. Each malaria isolate had a unique adherence profile for drug induced changes in monocytes. Each drug appeared to alter the expression of more than one monocyte receptor. The most effective drugs were quinine, pyrimethamine and palludrin and the least effective were artemether and mefloquine. The results suggest a previously undetected immunomodulatory action of antimalarial drugs.

Effect of the immunomodulating agent, pentoxifylline, in the treatment of sepsis in prematurely delivered infants: a placebo-controlled, double-blind trial

OBJECTIVE

To evaluate the influence of the methylxanthine derivative, pentoxifylline, on plasma levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, and IL-6 in prematurely delivered infants with generalized bacterial infections and to assess the effect of this immunomodulating drug on the clinical outcome in newborns with sepsis.

DESIGN

A prospective, randomized, double-blind trial.

SETTING

The neonatal intensive therapy units in university teaching hospitals.

PATIENTS

One hundred patients with sepsis admitted during a 1.5-yr period.

INTERVENTIONS

Patients were randomly assigned to receive pentoxifylline (pentoxifylline group) in a dose of 5 mg/kg/hr for 6 hrs on 6 successive days or an identically presented placebo (placebo group).

MEASUREMENTS AND MAIN RESULTS

Only infants with sepsis confirmed by positive blood culture were recruited into the study. There were no significant differences at randomization between the pentoxifylline and placebo groups with regard to the birth weight, gestational age, gender, Apgar score, hypotension, neutropenia, thrombocytopenia, metabolic acidosis, plasma levels of cytokines, and occurrence of shock. Plasma levels of TNF, IL-1, and IL-6 were evaluated before and after the drug or placebo administration on the first, third, and sixth days of therapy. Cytokines were determined by immunoenzymetric test EASIA (TNF) and Endogen Interleukin-Elisa (IL-1, IL-6). The frequency of gram-negative sepsis was similar in both groups (37.5% and 36.8%). Pentoxifylline significantly diminished plasma TNF levels (p = .009) but had no effect on plasma IL-1 levels. Mean plasma IL-6 levels, which were measured in the pentoxifylline group on the 6th day of the study, were significantly lower compared with respective data obtained in the placebo group. Only 1 of 40 infants with sepsis in the pentoxifylline group died, whereas 6 of 38 infants in the placebo group did not survive (p = .046). An increased incidence of disordered peripheral circulation and metabolic acidosis (p = .048), anuria or oliguria (p = .03), disseminated intravascular coagulation (p = .043), and the occurrence of clinical symptoms of necrotizing enterocolitis (p = .025) was observed in the course of sepsis in infants in the placebo group.

CONCLUSION

Pentoxifylline significantly affects the synthesis of TNF and IL-6 as well as reduces the mortality rate in premature infants with sepsis. The dosage and schedule of drug administration in this study attenuated the severity of the clinical course of sepsis in this group of patients.

Progress in the management and treatment of infected pancreatic necrosis

Infected pancreatic necrosis and sepsis are the leading causes of mortality in necrotizing pancreatitis. A review has been undertaken of the results of the past two decades relating to different surgical treatments of infected pancreatic necrosis. During the period 1978-85, the surgical treatment of necrotizing pancreatitis and its complications in our department consisted of the 'conventional' therapy (resection of the involved pancreatic tissue, or necrosectomy and drainage) in 61 patients, with a mortality rate of 36% (22 patients died). Since 1986, we have performed necrosectomy and other surgical interventions combined with continuous widespread lavage in 142 patients with infected pancreatic necrosis. The overall mortality decreased significantly to 6.3% (9 patients died). This result was achieved by means of aggressive surgical treatment, continuous, prolonged washing and suction drainage and supportive therapy, including immunonutrition, modifying the cytokine production and adequate antibiotic and antifungal medication. This surgical strategy provides the possibility for recovery in cases of necrotizing pancreatitis with septic complications.

Soluble ICAM-1 in CSF coincides with the extent of cerebral damage in patients with severe traumatic brain injury

The intercellular adhesion molecule-1 (ICAM-1) expressed by endothelial cells is crucial in promoting adhesion and transmigration of circulating leukocytes across the blood-brain barrier (BBB). Migrated immunocompetent cells, in turn, release mediators that stimulate glial and endothelial cells to express ICAM-1 and release cytokines, possibly sustaining cerebral damage. Following activation, proteolytic cleavage of membrane-anchored ICAM-1 results in measurable levels of a soluble form, sICAM-1. The aims of this study were to investigate the changes of sICAM-1 levels in ventricular CSF and serum and to elucidate the influence of structural brain damage as estimated by computerized tomography (CT) as well as the extent of BBB dysfunction as calculated by the CSF/serum albumin ratio (QA) in patients with severe traumatic brain injury (TBI). All investigated parameters revealed two subgroups. Patients belonging to group A had sICAM-1 levels in CSF above normal range, presented marked cerebral damage and a disturbance of the BBB (range 0.6-24.7 ng/ml, n = 8). In contrast, patients belonging to group B had no elevation of sICAM-1 values in CSF (range 0.3-3.9 ng/ml, n = 5; p < 0.017) and showed minor cerebral damage with an intact BBB in most cases. In addition, overall analysis showed that sICAM-1 in CSF correlated with the extent of BBB damage as indicated by the QA (r = 0.76; p < 0.001). These results suggest that increased sICAM-1 levels in CSF might depict ongoing immunologic activation and that sICAM-1 correlates with the extent of tissue and BBB damage. The origin of soluble ICAM-1 in CSF and its pathophysiologic role after TBI remains to be clarified.

Experimental acute pancreatitis results in increased blood-brain barrier permeability in the rat: a potential role for tumor necrosis factor and interleukin 6

Pancreatic encephalopathy is a severe complication of acute pancreatitis. Proinflammatory cytokines may play a role in the development of multi-organ failure during pancreatitis. In the present study, we measured the changes in the blood-brain barrier (BBB) permeability concomitantly with the determination of serum tumor necrosis factor (TNF) and interleukin-6 (IL-6) levels in rats before, as well as 6, 24 and 48 h after the beginning of intraductal taurocholic acid-induced acute pancreatitis. Cytokine concentrations were measured in bioassays with specific cell lines (WEHI-164 for TNF and B-9 for IL-6), while the BBB permeability was determined for a small (sodium fluorescein, molecular weight (MW) 376 Da), and a large (Evans' blue-albumin, MW 67000 Da) tracer by spectrophotometry in the parietal cortex, hippocampus, striatum, cerebellum and medulla of rats. The serum TNF level was significantly (P < 0.05) increased 6 and 24 h after the induction of pancreatitis, while the IL-6 level increased after 24 and 48 h. A significant (P < 0.05) increase in BBB permeability for both tracers developed at 6 and 24 h in different brain regions of animals with acute pancreatitis. We conclude that cytokines, such as TNF and IL-6, may contribute to the vasogenic brain edema formation during acute pancreatitis.

Pentoxifylline reduces venular leukocyte adherence ("reflow paradox") but not microvascular "no reflow" in hepatic ischemia/reperfusion

Postischemic reperfusion injury is caused by microcirculatory disturbances, including both nutritive perfusion failure (no reflow) and leukocyte activation (reflow paradox). Recent studies brought evidence that pentoxifylline (PTX) reduces tissue injury, decreases enzyme release, and improves survival after normothermic liver ischemia/reperfusion. The mechanisms of action, however, by which PTX protects postischemic tissue from injury have not been elucidated yet. With the use of fluorescence microscopy in a rat hepatic ischemia/reperfusion model, we studied in vivo the action of PTX on the manifestation of postischemic sinusoidal perfusion failure and microvascular leukocyte adherence. Microvascular reperfusion after 20 min portal triad cross-clamping was characterized by the cessation of blood flow within individual sinusoids (no reflow) and accumulation of leukocytes within the hepatic microvasculature, with stasis in sinusoids and rolling and firm adherence in postsinusoidal venules. PTX (20 mg/kg x hr i.v.) significantly (P < 0.05) attenuated microvascular leukocyte accumulation (44,600 +/- 1833 mm(-3) vs 67,684 +/- 2620 mm(-3) in saline-treated controls) and firm adherence of leukocytes in postsinusoidal venules (316.9 +/- 40.9 mm(-2) vs 522.9 +/- 95.0 mm(-2)); however, PTX did not influence manifestation of individual sinusoidal perfusion failure. Since reperfusion-induced parenchymal cell damage was found reduced in treated animals, we conclude that PTX attenuates postischemic injury in rat liver by reduction of leukocytic/inflammatory response but not by prevention of nutritive perfusion failure.