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)

Poly (ADP-ribose) synthetase (PARS) is a DNA protective enzyme activated by single-strand breakage. It is suspected that exaggerated PARS activation related to biochemical stress by reactive oxygen and nitrogen species contributes to cellular injury in sepsis. The main hypothesis is that PARS activation leads to massive ATP and NAD consumption and consequent cellular energy depletion. The PARS inhibitor 3-amino-benzamide (3AB) is protective in rodents challenged with either endotoxin or intraperitoneal zymozan. The present experiment was designed to test the effect of 3AB in a more clinically relevant model of sepsis, namely polymicrobial sepsis induced by cecal ligature and puncture (CLP). Adult male Wistar rats were anesthetized, instrumented with catheters in the jugular vein and in the carotid artery, and then randomized into three groups: Sham (no laparotomy, n = 13), CLP (n = 15), and CLP/3AB (n = 18). All animals were allowed to recover and they received a continuous intravenous infusion of saline (20 mL/kg/h) and fentanyl (20 microg/kg/h). 3AB was administered to the CLP/3AB group as an intravenous bolus (10 mg/kg) followed by a continuous intravenous infusion (10 mg/kg/h). After 24 h, blood was drawn for the determination of biological indicators of organ injury. Rats were then anesthetized and biopsies of the liver were quickly frozen into liquid nitrogen for the subsequent determination of NAD and ATP levels. Further organ samples were collected for the assay of myeloperoxidase (MPO) to indicate tissue infiltration by leukocytes, and nitrotyrosine to indicate the level of biochemical stress by reactive nitrogen species. Twenty-four-hour mortality was 0/13 (Sham), 1/15 (CLP), and 5/18 (CLP/3AB; p = NS). In the surviving rats, CLP induced a clear elevation of liver enzymes, bilirubin, and pancreatic lipase, but not creatinine in the plasma, as well as a marked increase of MPO activity in liver, jejunum, and lung, but not kidney or heart. None of these variables was affected by treatment with 3AB. Furthermore, CLP did not cause depletion of NAD or ATP in the liver, nor any change in the nitrotyrosine content of any organ. These data argue against a general role of PARS activation in the pathogenesis of sepsis-induced tissue injury.
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PMID:Does the activation of poly (ADP-ribose) synthetase mediate tissue injury in the sepsis induced by cecal ligation and puncture? 1202 68

Inflammation in asthma, sepsis, transplant rejection, and many neurodegenerative diseases associates an up-regulation of NO synthesis with increased protein nitration at tyrosine. Nitration can cause protein dysfunction and is implicated in pathogenesis, but few proteins that appear nitrated in vivo have been identified. To understand how this modification impacts physiology and disease, we used a proteomic approach toward targets of protein nitration in both in vivo and cell culture inflammatory disease models. This approach identified more than 40 nitrotyrosine-immunopositive proteins, including 30 not previously identified, that became modified as a consequence of the inflammatory response. These targets include proteins involved in oxidative stress, apoptosis, ATP production, and other metabolic functions. Our approach provides a means toward obtaining a comprehensive view of the nitroproteome and promises to broaden understanding of how NO regulates cellular processes.
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PMID:Proteomic method identifies proteins nitrated in vivo during inflammatory challenge. 1159 16

The pore-forming cytolysin of Vibrio vulnificus (VVC) causes severe hypotension and vasodilatation in vivo. Under the condition of bacterial sepsis, large amounts of nitric oxide (NO) produced by inducible NO synthase (iNOS) can contribute to host-induced tissue damage causing hypotension and septic shock. In this study, we investigated the effect of purified VVC on NO production in mouse peritoneal macrophages. VVC induced NO production in the presence of interferon-gamma. Increased NO production was not affected by polymyxin B, and heat inactivation of cytolysin abolished the NO-inducing capability. NO production was induced at the same concentration range of cytolysin for pore formation, as evidenced by the release of preloaded 2-deoxy-d-[(3)H]glucose. At the higher concentrations of cytolysin causing the depletion of cellular ATP, no NO production was observed. Increased expression of iNOS and activation of NFkappaB by VVC were confirmed by Western blotting and gel shift assay, respectively. These results suggest the role of cytolysin as an inducer of iNOS and NO production in macrophage and as a possible virulence determinant in V. vulnificus infection.
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PMID:Induction of nitric oxide synthase expression by Vibrio vulnificus cytolysin. 1179 87

Glutamine has beneficial effects on enterocytes and the immune system in sepsis, but its effects on hepatic metabolism remain unknown. The aim of the present study was to determine the effects of glutamine on hepatocyte energy metabolism under conditions of neonatal endotoxaemia. Suckling Wistar rats were injected intraperitoneally with 200 microg/kg lipopolysaccharide. Oxygen consumption was measured polarographically in hepatocytes respiring on either palmitate (0.5 mM) or palmitate plus glutamine (10 mM). Total hepatocyte oxygen consumption was similar in hepatocytes from control and endotoxic rats, but this was due to a decrease in intramitochondrial and an increase in extramitochondrial oxygen consumption in the cells from endotoxic animals. The addition of glutamine to hepatocytes from endotoxic rats restored intramitochondrial oxygen consumption to control levels. Although glutamine did not reverse the inhibition of the thermogenic proton leak observed in endotoxaemia, it significantly increased oxygen consumption due to mitochondrial ATP synthesis (P=0.03). Glutamine significantly increased the hepatocyte ATP/ADP ratio (P=0.02 compared with hepatocytes from endotoxic rats). Electron microscopy revealed morphological damage to the mitochondria of hepatocytes from endotoxic rats, and a return to a normal appearance with the addition of glutamine. We conclude that glutamine reverses the inhibition of mitochondrial metabolism that is observed in endotoxaemia. The effect is primarily at the level of ATP synthesis.
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PMID:Hepatocyte mitochondrial metabolism is inhibited in neonatal rat endotoxaemia: effects of glutamine. 1186 75

Hepatocyte injury and necrosis from many causes may result in pediatric liver disease. Influenced by other cell types in the liver, by its unique vascular arrangements, by lobular zonation, and by contributory effects of sepsis, reactive oxygen species and disordered hepatic architecture, the hepatocyte is prone to injury from exogenous toxins, from inborn errors of metabolism, from hepatotrophic viruses, and from immune mechanisms. Experimental studies on cultured hepatocytes or animal models must be interpreted with caution. Having discussed general concepts, this review describes immune mechanisms of liver injury, as seen in autoimmune hepatitis, hepatitis B and C infection, the anticonvulsant hypersensitivity syndrome, and autoimmune polyendocrinopathy. Of the monogenic disorders causing significant liver injury in childhood, alpha-1 antitrypsin deficiency and Niemann-Pick C disease demonstrate the effect of endoplasmic or endosomal retention of macromolecules. Tyrosinemia illustrates how understanding the biochemical defect leads to understanding cell injury, extrahepatic porphyric effects, oncogenesis, pharmacological intervention, and possible stem cell therapy. Pathogenesis of cirrhosis in galactosemia remains incompletely understood. In hereditary fructose intolerance, phosphate sequestration causes ATP depletion. Recent information about mitochondrial disease, NASH, disorders of glycosylation, Wilson's disease, and the progressive familial intrahepatic cholestases is discussed.
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PMID:Mechanisms of liver injury relevant to pediatric hepatology. 1189 Feb 7

The present study was designed to test the hypothesis that induction of chronic peritoneal sepsis in rats would produce a more severe calcium paradox-mediated myocardial injury in isolated heart preparation than is seen in normal hearts, and that this would be inhibited by sucrose as in normal hearts. Male Sprague-Dawley rats were made septic using 200 mg of cecal material (obtained from a donor rat) suspended in 5 mL of 5% dextrose in sterile water D5 W/kg. In septic animals, the cecal material was injected in the peritoneum, while sham-septic animals received only D5 W/kg (5 mL/kg). A third group consisting of normal rats (no surgery) group was also included. Hearts were harvested from all three groups and were subjected to a calcium paradox-mediated injury in an isolated heart preparation. Hearts were perfused with Krebs-Henseleit (KH) medium and were allowed to stabilize, followed by a perfusion with Ca2+-free KH for 10 min. After this 10-min Ca2+-free KH perfusion, rats were reperfused with KH medium for 60 min. Ca2+-free KH medium was used in control experiments, while sucrose experiments were conducted with the same medium except that 150 mM sucrose replaced 75 mM NaCl. A marked decrease in ATP and phosphocreatine occurred during Ca2+ reperfusion in all hearts in absence of sucrose. In the presence of the disaccharide, no change in high-energy phosphate (HEP) levels was observed in normal hearts, while lower ATP concentrations were seen in sham and septic hearts. Thus, sucrose did not inhibit cellular injury in sham and septic hearts as it did in normal hearts, and this might be due to a smaller HEP availability. Control studies with normal, sham, and septic hearts exhibited cessation of contractions in the absence of Ca2+, and appearance of large amounts of cytosolic protein in the effluent perfusate during Ca2+ reperfusion. With normal hearts, perfusion with sucrose caused a 96% inhibition of the total creatine kinase (CK) release observed in control experiments. With sham hearts, 32% of CK release was inhibited by sucrose, while 68% of the CK release was attributed to stress associated with surgery performed in the sham-septic group. In septic hearts, only 8% of the CK release was inhibited by sucrose, suggesting that more severe myocardial injury occurs when septic hearts are subjected to a calcium paradox as compared to other groups. It is evident that sucrose can inhibit a small fraction of the CK release from septic hearts during the calcium paradox as compared to the large CK loss associated with sham sepsis. We have concluded that induction of sepsis made the heart more susceptible to a calcium paradox-mediated myocardial injury.
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PMID:Induction of peritoneal sepsis increases the susceptibility of isolated hearts to a calcium paradox-mediated injury. 1190 Mar 37

The main causes for acute renal failure (ARF) in the newborn include endogenous factors (such as hypotension, hypovolemia, hypoxemia, perinatal asphyxia, and neonatal septicemia) and exogenous factors such as mechanical ventilation, nephrotoxic agents (antibiotics, indomethacin, ibuprofen, angiotensin converting enzyme inhibitors, and tolazoline). These conditions determinate vasoactive disturbances interfering with the delicate balance of intrarenal vasoconstrictor and vasodilator forces, which regulates the glomerular filtration rate (GFR) in the healthy term, and particularly in the premature infant. Factors influencing renal prognosis are the severity of the underlying disorder, the rapidity of an accurate diagnosis, prompt treatment, and avoidance of severe iatrogenic complications. Plasma creatinine concentrations should be used with some caution for ARF diagnosis in the first days of life. General measures of kidney protection include correcting abnormalities in fluid homeostasis, adequate ventilation and rational choice of drugs. Moreover, in order to protect the kidney, different compounds have been proposed such as diuretics (furosemide and torasemide), and dopaminergic agents (dopamine, dopexamine). With the increasing knowledge of the mechanisms governing the development of ARF, progress has been made in the development of new treatment modalities. For example theophylline, calcium antagonists, ATP-MgCl2, thyroxine, and antibodies against endothelin may in the near future be used to prevent or ameliorate the prognosis of the neonatal stressed kidney. The main renal replacement therapies are possible in the newborn. However preventive measures are easily available in the neonatal period and they often represent the most efficacious procedures.
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PMID:[Aggression to the immature kidney]. 1198 7

Bacterial sepsis is frequently accompanied by increased blood concentration of lactic acid, which traditionally is attributed to poor tissue perfusion, hypoxia and anaerobic glycolysis. Therapy aimed at improving oxygen delivery to tissues often does not correct the hyperlactatemia, suggesting that high blood lactate in sepsis is not due to hypoxia. Various tissues, including skeletal muscle, demonstrate increased lactate production under well-oxygenated conditions when the activity of the Na+-K+ ATPase is stimulated. Although both muscle Na+-K+ ATPase activity and muscle plasma membrane content of Na+, K+-ATPase subunits are increased in sepsis, no studies in vivo have demonstrated correlation between lactate production and changes in intracellular Na+ and K+ resulting from increased Na+-K+ pump activity in sepsis. Plasma concentrations of lactate and epinephrine, a known stimulator of the Na+-K+ pump, were increased in rats made septic by E. coli injection. Muscle lactate content was significantly increased in septic rats, although muscle ATP and phosphocreatine remained normal, suggesting oxygen delivery remained adequate for mitochondrial energy metabolism. In septic rats, muscle intracellular ratio of Na+:K+ was significantly reduced, indicating increased Na+-K+ pump activity. These data thus demonstrate that increased muscle lactate during sepsis correlates with evidence of elevated muscle Na+-K+ ATPase activity, but not with evidence of impaired oxidative metabolism. This study also further supports a role for epinephrine in this process.
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PMID:Role of skeletal muscle Na+-K+ ATPase activity in increased lactate production in sub-acute sepsis. 1200 73

Vibrio vulnificus is an estuarian bacterium that causes septicemia and serious wound infection. The cytolysin, one of the important virulence determinants in V. vulnificus infection, has been reported to have lethal activity primarily by increasing pulmonary vascular permeability. In the present study, we investigated the cytotoxic mechanism of V. vulnificus cytolysin in cultured pulmonary artery endothelial (CPAE) cells, which are possible target cells of cytolysin in vivo. V. vulnificus cytolysin caused the CPAE cell damages with elevation of the cytosolic free Ca2+, DNA fragmentation, and decrease of the cellular NAD+ and ATP level. These cytotoxic effects of V. vulnificus cytolysin were prevented by EGTA and aminobenzamide, but were not affected by verapamil or catalase. These results indicate that the elevation of cytosolic free Ca2+ induced by V. vulnificus cytolysin causes the increase of DNA fragmentation and the damaged DNA activates nuclear poly(ADP-ribose) synthetase, which depletes the cellular NAD+ and ATP, resulting in cell death.
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PMID:Cytotoxic mechanism of Vibrio vulnificus cytolysin in CPAE cells. 1200 77

The purpose of this study was to investigate alterations of phospholamban phosphorylation and its interaction with Ca2+ transport(Ca2+-ATPase activity and Ca2+ uptake) in sarcoplasmic reticulum (SR) during the progression of sepsis. Sepsis was induced by cecal ligation and puncture (CLP). Phospholamban phosphorylation was studied by the labeling of the myocardial ATP pool by perfusing isolated rat hearts with [32P]H3PO4 followed by identification of the phosphorylated phospholamban. Results show that phospholamban phosphorylation was increased by 153% during the early hyperdynamic phase (9 h after CLP), while it was decreased by 51% during the late hypodynamic phase (18 h after CLP) of sepsis. The increase in phospholamban phosphorylation during early sepsis was associated with increases in +dP/dt(max) and tissue cAMP content, while Ca2+ transport, left ventricular developed pressure (LVDP), and -dP/dt(max) remained unchanged. The decrease in phospholamban phosphorylation during late sepsis was accompanied by decreases in Ca2+ transport, LVDP, +/-dP/dt(max), and tissue cAMP content. When isoproterenol was present in the perfusion medium, all parameters measured were stimulated in all three experimental groups (control, early sepsis, and late sepsis) except that Ca2+-ATPase activity and SR Ca2+ uptake were unresponsive in the early and the late septic groups. These findings demonstrate that during the late hypodynamic phase of sepsis, the observed decrease in myocardial contractility was due to the decrease in phospholamban phosphorylation, which resulted in decreased Ca2+ transport across the SR. In contrast, during the early hyperdynamic phase of sepsis, the increase in phospholamban phosphorylation did not correlate with increases in Ca2+ uptake and Ca2+-ATPase activity. Thus, the interaction between phospholamban phosphorylation and Ca2+ transport across the SR was disrupted during the early phase of sepsis.
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PMID:Altered phospholamban-calcium ATPase interaction in cardiac sarcoplasmic reticulum during the progression of sepsis. 1202 59


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