Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pentoxifylline, a methylxanthine derivative, has been widely used to improve erythrocyte deformability and capillary blood circulation in patients with claudication and cerebrovascular disorders as well as in animals with sepsis. Here, we investigate the effects of pentoxifylline on the hypotension, vascular hyporeactivity to noradrenaline, release of tumour necrosis factor-alpha (TNF-alpha) and nitric oxide (NO), and inducible NO synthase protein expression in a rat model of circulatory shock induced by bacterial endotoxin (Escherichia coli lipopolysaccharide). In addition, we have evaluated the effect of pentoxifylline on the 36-h survival rate in a murine model of endotoxaemia. Male Wistar-Kyoto rats were anaesthetised and instrumented for the measurement of mean arterial pressure and heart rate. Injection of lipopolysaccharide (10 mg/kg, i.v.) resulted in a significant fall in mean arterial pressure and an increase of heart rate. In contrast, animals pretreated with pentoxifylline (3 mg/kg, i.v., at 30 min prior to lipopolysaccharide) maintained a significantly higher mean arterial pressure but showed no effect on the tachycardia when compared to rats given only lipopolysaccharide (lipopolysaccharide-rats). The pressor effect of noradrenaline (1 microg/kg, i.v.) was also significantly reduced after the treatment of rats with lipopolysaccharide. Similarly, rings of thoracic aorta obtained from lipopolysaccharide-rats showed a significant reduction in the contractile responses elicited by noradrenaline (1 microM). Pretreatment of lipopolysaccharide-rats with pentoxifylline partially, but significantly, prevented this lipopolysaccharide-induced hyporeactivity to noradrenaline in vivo and ex vivo. The injection of lipopolysaccharide resulted in bell-shape changes in plasma TNF-alpha level which reached a peak at 60 min, whereas the effect of lipopolysaccharide on the plasma level of nitrate (an indicator of NO formation) was increased in a time-dependent manner. This increase of both TNF-alpha and nitrate levels induced by lipopolysaccharide was significantly reduced in lipopolysaccharide-rats pretreated with pentoxifylline. Endotoxaemia for 240 min caused a significantly increased protein expression of inducible NO synthase in the lung. In lipopolysaccharide-rats pretreated with pentoxifylline, inducible NO synthase protein expression in lung homogenates was attenuated by 48 +/- 5%. Treatment of conscious mice with a high dose of endotoxin (60 mg/kg, i.p.) resulted in a survival rate of only 10% at 36 h (n = 20). However, therapeutic application of pentoxifylline (3 mg/kg, i.p. at 0, 6, 15 and 24 h after lipopolysaccharide) increased the 36-h survival to 35% (n = 20). Thus, pentoxifylline protects against circulatory failure and improves survival in rodents with severe endotoxaemia. These effects may be due to inhibition of the release of TNF-alpha and of the induction of inducible NO synthase.
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PMID:Pentoxifylline improves circulatory failure and survival in murine models of endotoxaemia. 1040 50

Pentoxifylline is a phosphodiesterase inhibitor, known to suppress tumour necrosis factor-alpha production and improve cardiopulmonary parameters and survival in animal models of sepsis. Using a porcine model of abdominal trauma resulting from the combined insults of haemorrhage and infection, a randomised placebo-controlled trial was conducted of pentoxifylline (20 mg/kg bolus followed by 20 mg/kg infusion over 1 h) administered in addition to a colloid resuscitation regimen. Female Large White pigs (45-60 kg) were bled 40% of their blood volume and peritonitis was induced using E. coli (O18: K1: H7) in an autoclaved faecal suspension. Animals were resuscitated with either colloid alone (n=5) or colloid plus pentoxifylline (n=5). Pentoxifylline attenuated increases in mean arterial and pulmonary artery pressures and reduced both systemic and pulmonary vascular resistance. It worsened the lactic acidosis associated with 'septic shock' and failed to reduce serum TNF-alpha levels. Pentoxifylline, in the high doses used in this study, does not have a role as an adjunct to resuscitation in this clinically relevant model of trauma.
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PMID:Pentoxifylline fails to improve organ dysfunction and survival when used in the resuscitation of a porcine model of haemorrhage and abdominal sepsis. 1069 1

Cytokines are proteins that are produced by immune and non-immune cells, and they function as mediators to facilitate cellular communication. Their production is regulated by a complex network of co-stimulatory and feedback loops that responds to a variety of stimuli. Several pharmacological agents have been found to alter systemic concentrations and/or the activity of different cytokines via a variety of mechanisms, including changes in biosynthesis, secretion, and/or stability. Many of the agents that modulate cytokine levels commonly are used in the management of critically ill patients. Catecholamines for example, have been found to promote the secretion of anti-inflammatory cytokines, and, therefore, may alter acute inflammatory processes such as sepsis. Antimicrobials have multiple effects on cytokine production, either secondary to the release of endotoxins from gram-negative bacteria or via direct activity on cytokine expression at the transcriptional and/or post-transcriptional level. Pentoxifylline has multiple effects on the immune system, but inhibition of pro-inflammatory cytokine release predominates. The reminder of the known drug-cytokine interactions and their effect on the inflammatory process are discussed. Information on the pharmacodynamic effect of drugs is limited, and our understanding of the clinical significance of these observations awaits further investigation. This review was designed to provide intensivists and other clinicians with useful information regarding the effect of medications on cytokine activity. It is also intended to help researchers and clinicians to optimize the design of studies of pharmacotherapeutic modulation of cytokines and to avoid the use of some agents in clinical circumstances in which cytokine manipulation is undesirable.
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PMID:Unintended immunomodulation: part II. Effects of pharmacological agents on cytokine activity. 1080 9

Early sepsis leads to renal hypoperfusion, despite a hyperdynamic systemic circulation. It is thought that failure of local control of the renal microcirculation leads to hypoperfusion and organ dysfunction. Of the many mediators implicated in the pathogenesis of microvascular vasoconstriction, arachidonic acid metabolites are thought to be important. Vasoconstriction may be due to excess production of vasoconstrictors or loss of vasodilators. Using the isolated perfused kidney model, we describe a sepsis-induced rise in renal vascular resistance and increased production of key arachidonic acid metabolites, both vasoconstrictors and vasodilators, suggesting excessive production of vasoconstrictors as a cause for microcirculatory hypoperfusion. There is evidence of increased enzymatic production of arachidonic acid metabolites as well as nonenzymatic, free radical, catalyzed conversion of arachidonic acid. Pentoxifylline (a phosphodiesterase inhibitor) and U74389G (an antioxidant) both have a protective effect on the renal microcirculation during sepsis. Both drugs appear to alter the renal microvascular response to sepsis by altering renal arachidonic acid metabolism. This study demonstrates that sepsis leads to increased renal vascular resistance. This response is in part mediated by metabolites produced by metabolism of arachidonic acid within the kidney. The ability of drugs to modulate arachidonic acid metabolism and so alter the renal response to sepsis suggests a possible role for these agents in protecting the renal microcirculation during sepsis.
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PMID:Lazaroid and pentoxifylline suppress sepsis-induced increases in renal vascular resistance via altered arachidonic acid metabolism. 1094 46

Pentoxifylline interrupts early gene activation for tumor necrosis factor, interleukin-1, and interleukin-6 production and improves survival from experimental sepsis. These effects can alter nitrogen loss during critical illness. To determine the dose-dependent influence of pentoxifylline on nitrogen loss, 44 male Sprague-Dawley rats (220 to 265 g) were randomized to receive parenteral nutrition only (PN), PN plus continuous infusion of Escherichia coli 026:B6 lipopolysaccharide (LPS) at 9 mg x kg(-1) x d(-1), or PN plus LPS plus a continuous infusion of pentoxifylline at either 25 (PEN25) or 100 mg x kg(-1) x d(-1) (PEN100) for 48 h. Before randomization, all animals underwent intravenous cannulation and 40 h of PN adaptation. All animals received isocaloric, isonitrogenous PN (160 kcal x kg(-1) x d(-1) and 1.0 gN x kg(-1) x d(-1)) and were kept nil per os except for water ad libitum. Administration of LPS significantly worsened nitrogen balance for all three groups compared with PN control; however, pentoxifylline only modestly improved nitrogen balance compared with LPS (206 +/- 255, -497 +/- 331, -332 +/- 329, and -310 +/- 383 mg/48hr for the PN, LPS, PEN25, and PEN100 groups, respectively; P < 0.001). Pentoxifylline did not significantly change 3-methylhistidine urinary excretion compared with LPS (573 +/- 180, 705 +/- 156, 780 +/- 326, and 683 +/- 266 microg/48 h for the PN, LPS, PEN25, and PEN100 groups, respectively, P not significant). Pentoxifylline, given in therapeutic doses after an endotoxin challenge, modestly, but not significantly, improved nitrogen balance. Urinary 3-methylhistidine excretion was not influenced by pentoxifylline. A dose-dependent effect by pentoxifylline on these markers was not evident.
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PMID:Effect of pentoxifylline on nitrogen balance and 3-methylhistidine excretion in parenterally fed endotoxemic rats. 1144 84

Pentoxifylline, a methylxanthine derivative and nonspecific type 4 phosphodiesterase inhibitor, has been used to improve survival of animals with sepsis and to attenuate lung injury in acute lung inflammation. The purpose of this study was to examine whether pentoxifylline would inhibit the expression of inflammatory cytokines, particularly tumor necrosis factor alpha (TNF), and thereby decrease the pathophysiology of acute porcine pleuropneumonia. E. coli lipopolysaccharide (LPS) and bacterial extracts of A. pleuropneumoniae--induced elevations in TNF mRNA which were fully abrogated by addition of pentoxifylline in both alveolar macrophage and neutrophil cultures. A 30% reduction in the level of LPS-induced interleukin (IL)-1beta mRNA levels also was achieved in macrophages. Pentoxifylline did not affect either IL-1alpha or IL-8 expression in vitro. Pentoxifylline therapy in vivo significantly reduced the number of band neutrophils in swine but did not reduce the pathology associated with pleuropneumonia, including changes in serum zinc, iron, or haptoglobin. Neither did it alter TNF, IL-1, IL-6, or IL-8 expression. Measurement of pentoxifylline and its metabolites in pig sera suggested that efficacious doses of pentoxifylline were probably not achieved in vivo. However, subcutaneous doses of pentoxifylline higher than 25 mg/kg produced transient diarrhea, vomiting, and tremors. These results suggest that pentoxifylline is an effective pharmacological tool for the dissection of cytokine regulation in vitro, but inhibitory concentrations may not be achievable for in vivo pharmacological use in swine.
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PMID:Effects of pentoxifylline on inflammatory cytokine expression and acute pleuropneumonia in swine. 1199 42

Bacterial translocation (BT) occurs mainly in preseptic conditions such as intestinal obstruction, trauma, and burn, and the underlying mechanisms are still unclear. Pentoxifylline (PTX) is a derivative of methyl xanthine and has several beneficial effects in sepsis. We investigated the effects of PTX on a rat BT model. Simple intestinal obstruction (IO) was choosen to create high BT rates. Rats were divided in to five groups of 10 rats. Either 50 mg/kg PTX or placebo (3 mg/100 g saline) was administered subcutaneously following IO, either by single injection or twice with a 12-h interval. All rats were sacrificed 12 or 24 h after the procedure, and mesenteric lymph nodes (MLN), liver, and blood samples were obtained under aseptic conditions for bacterial cultures. The samples were obtained 12 h following IO in the first two groups, and the same samples were obtained 24 h after IO in last three groups. Groups IV and V were the PTX treatment groups. PTX was re-injected 12 h after IO only in group IV. As a result, BT rates in MLNs and liver were found to be significantly low, blood specimens remained sterile in PTX-pretreated and -treated rats, and BT rates were high in control groups and group V (once treatment late specimen group). We conclude that simple intestinal obstruction causes BT, and PTX reduces BT in rats with IO during the first 12-h period if PTX is given once immediately following IO. PTX reduces BT during the first 24-h after IO provided that is injected twice with a 12-h interval. More experimental studies are need to explain the exact mechanism of this beneficial effect.
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PMID:The effects of pentoxifylline on bacterial translocation after intestinal obstruction. 1216 78

Sepsis and endotoxin (LPS or lipopolysaccharide) injection induce a state of growth hormone (GH) resistance leading to decreased circulating insulin-like growth factor (IGF)-I. Because the proinflammatory cytokines tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta inhibit the GH-stimulated IGF-I expression in vitro, it was tempting to speculate that these two cytokines might play an important role in the reduction of circulating IGF-I levels caused by LPS. Pentoxifylline, a methylxanthine usually used in the treatment of peripheral arterial circulatory disorders, has been reported to inhibit TNF-alpha synthesis. The goal of our study was to investigate whether inhibition of TNF-alpha production by pentoxifylline could prevent the decrease in IGF-I and the GH resistance caused by LPS injection. Because previous studies demonstrated that pentoxifylline can reduce muscle catabolism induced by sepsis, we also assessed whether pentoxifylline could exert its anticatabolic effect by preventing the decrease in circulating IGF-I. LPS injection in rats decreased serum IGF-I (-45% at 12 h; P<0.01 vs time 0) and its liver mRNA (-67% at 12 h; P<0.01 vs time 0) while it induced circulating TNF-alpha and IL-1beta and their hepatic expression (P<0.01). Pretreatment of LPS-treated animals by pentoxifylline abolished the LPS-induced rise in serum TNF-alpha (-98% at 90 min; P<0.001 vs LPS alone) and to a lesser extent in serum IL-1beta (-44% at 3 h; not significant vs LPS alone). Despite its dramatic inhibitory effect on TNF-alpha induction, however, pentoxifylline failed to suppress both the decrease in IGF-I and the GH resistance induced by LPS in rats. These results suggest that mediators other than TNF-alpha, in particular IL-1beta or IL-6, could contribute to the GH resistance induced by LPS. They also suggest that the anticatabolic effect of pentoxifylline is not due to prevention of the decline of circulating IGF-I.
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PMID:Inhibition of TNF-alpha production by pentoxifylline does not prevent endotoxin-induced decrease in serum IGF-I. 1284 41

The methanol extract of Anacardium occidentale stem bark was evaluated for activities against the lipopolysaccharide (LPS)-induced septic shock, as well as LPS-induced microvascular permeability in mice. Pre-treatment with Anacardium occidentale extract (25-200 mg/kg) caused a dose-dependent and significant (p < 0.05) reduction in the elevated levels of alanine and aspartate aminotransferases in the sera of D-galactosamine-primed mice injected with LPS. The highest dose of the extract studied (200 mg/kg) produced a 100% protection against death from sepsis. Pentoxifylline (100 mg/kg) and L-NAME (5 mg/kg) offered 100% protection against LPS-induced septic shock, and produced marked reduction in elevated levels of transferases. A dose-related inhibition of LPS-induced microvascular permability in mice was also produced by pentoxifylline, L-NAME and the extract.
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PMID:Effects of Anacardium occidentale stem bark extract on in vivo inflammatory models. 1550 26

Several pharmacological agents have been found to alter systemic concentrations and/or the activity of different cytokines via a variety of mechanisms, including changes in biosynthesis, secretion, and/or stability. Pentoxifylline (PTX), which is a methylxanthine derivative for example, has multiple effects on the immune system, but inhibition of pro-inflammatory cytokine release predominates. In this study we aimed to evaluate the influence of PTX on plasma levels of tumor necrosis factor (TNF) alpha and interleukin (IL)-6 in newborn infants with sepsis. The study included 20 infants with neonatal sepsis. In all subjects blood samples for serum C-reactive protein, TNF alpha and IL-6 determinations were received before giving PTX and at the 12th and 24th hours following PTX. In addition, white blood cell was counted before giving PTX and on the 3rd and 7th day following PTX. The infants were randomly divided into two groups. Firstly, PTX was used in infants who were successively admitted to the clinic and the subsequent infants were accepted as a control group. Of 20 infants, 13 infants received PTX and seven infants did not. We did not find any difference in the leukocyte count, serum C-reactive protein level, TNF alpha and IL-6 levels between the two groups of patients (P>0.05). While three infants died in the group of receiving PTX, death was not recorded in the group of non-receiving PTX (P>0.05). Our findings showed that PTX treatment did not affect leukocyte counts, serum CRP levels, TNF alpha and IL-6 levels and death ratio in newborn infants with sepsis. The last result may be due to the fact that the number of patients in the study was very small. We think that more extensive and controlled studies should be performed about this subject.
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PMID:Effect of pentoxifylline on tumor necrosis factor-alpha and interleukin-6 levels in neonatal sepsis. 1572 86


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