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

Modification in the enzymatic complement and lipogenic functions of rat liver endoplasmic reticulum (ER) were shown to occur during pneumococcal sepsis. Glucose-6-phosphatase, 5'nucleotidase, esterase, and NADPH cytochrome C reductase decreased in activity by as much as 50% with respect to controls. Hydroxymethylglutaryl-CoA and NADH cytochrome C reductases were increased 6-and 2-fold, respectively. Alkaline phosphatase and inosine-5'-diphosphatase did not differ with respect to fasted controls. The lipogenic capacity of the ER was shown to be enhanced. In vitro [14C]acetate incorporation into cholesterol and other lipids by hepatocytes isolated from infected rats was increased 2-to 10-fold. It is concluded that the flow of acetyl-CoA in liver cell of Streptococcus pneumoniae-infected rats is toward lipogenesis rather than ketogenesis.
 ...
PMID:Effects of pneumococcal infection on rat liver microsomal enzymes and lipogenesis by isolated hepatocytes. 1 31

Irreversible sepsis, in spite of advancements in topical therapy and antimicrobial agents, remains the leading cause of death in major thermal injury. A defect in intracellular bactericidal capacity in leukocytes from severely burned patients appears to correspond with increases in bacterial wound colonization and ultimate sepsis. This leukocyte defect has been demonstrated by abnormally low nitroblue tetrazolium reduction (NBT) and oxygen consumption of white cells in patients with major thermal injury. The subcellular mechanisms responsible for decreased bactericidal capacity were therefore investigated. Nicotinamide-adenine dinucleotide (NADH) and nicotinamide-adenine phosphodinucleotide (NADPH) oxidase activity was measured in patients with major burns, controls (normals), and in patients with nonburn stress or infection. NADH and NADPH oxidase levels in leukocytes from burn patients were not significantly different from those of normal nonchallenged controls but were significantly lower than the leukocyte values found in the patients with nonburn infections or stress. This NADH and NADPH defect in the subcellular leukocyte fraction suggests that it may be a significant factor in the reduced bactericidal function of the intact leukocyte in thermally injured patients.
 ...
PMID:The role of NADH-NADPH oxidase activity in the leukocyte function of burned patients. 76 16

A 52 yr old Caucasian female (F. E.) had hemolytic anemia, a leukemoid reaction, and fatal sepsis due to Escherichia coli. Her leukocytes ingested bacteria normally but did not kill catalase positive Staphylococcus aureus, Escherichia coli, and Serratia marcescens. An H(2)O(2)-producing bacterium, Streptococcus faecalis, was killed normally. Granule myeloperoxidase, acid and alkaline phosphatase, and beta glucuronidase activities were normal, and these enzymes shifted normally to the phagocyte vacuole (light and electron microscopy). Intravacuolar reduction of nitroblue tetrazolium did not occur. Moreover, only minimal quantities of H(2)O(2) were generated, and the hexose monophosphate shunt (HMPS) was not stimulated during phagocytosis. These observations suggested the diagnosis of chronic granulomatous disease. However, in contrast to control and chronic granulomatous disease leukocytes, glucose-6-phosphate dehydrogenase activity was completely absent in F. E. leukocytes whereas NADH oxidase and NADPH oxidase activities were both normal. Unlike chronic granulomatous disease, methylene blue did not stimulate the hexose monophosphate shunt in F. E. cells. Thus, F. E. and chronic granulomatous disease leukocytes appear to share certain metabolic and bactericidal defects, but the metabolic basis of the abnormality differs. Chronic granulomatous disease cells lack oxidase activity which produces H(2)O(2); F. E. cells had normal levels of oxidase activity but failed to produce NADPH due to complete glucose-6-phosphate dehydrogenase deficiency. These data indicate that a complete absence of leukocyte glucose-6-phosphate dehydrogenase with defective hexose monophosphate shunt activity is associated with low H(2)O(2) production and inadequate bactericidal activity, and further suggest an important role for NADPH in the production of H(2)O(2) in human granulocytes.
 ...
PMID:Complete deficiency of leukocyte glucose-6-phosphate dehydrogenase with defective bactericidal activity. 440 Dec 71

Inhibitors of nitric oxide (NO) synthesis have been used in the treatment of septic and endotoxic shock. However, several studies question the beneficial effect of inhibiting NO production in sepsis and endotoxemia. We have investigated the effect of inhibition of NO synthesis after endotoxemia in the isolated perfused rat heart. In hearts from endotoxin-treated animals, coronary flow was elevated 64% and oxygen consumption was elevated 20% compared with control hearts. NADH fluorescence imaging was used as an indicator of regional hypoperfusion. A homogeneous low-surface NADH fluorescence, indicative of adequate tissue perfusion, was observed in both control and endotoxin-treated hearts. The increase in coronary flow and oxygen consumption could only partially be prevented by pretreatment of the animals with dexamethasone. Addition of N omega-nitro-L-arginine (NNLA), an inhibitor of NO synthesis, to the perfusion medium eliminated differences in coronary flow and oxygen consumption between normal and endotoxin-treated hearts. However, NADH surface fluorescence images of endotoxin-treated hearts after NNLA revealed areas of high fluorescence, indicating local ischemia, whereas the control hearts remained without signs of ischemia. The ischemic areas were present at various perfusion pressures and disappeared after the infusion of L-arginine, the natural precursor of NO, or the exogenous NO donor sodium nitroprusside. Methylene blue (MB), an inhibitor of soluble guanylate cyclase, the effector enzyme of NO, also eliminated differences in coronary flow and produced similar areas of local myocardial ischemia in endotoxin-treated hearts but not in control hearts.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Inhibition of nitric oxide synthesis causes myocardial ischemia in endotoxemic rats. 753 18

Defective oxygen consumption and a pathological dependence of oxygen uptake on O2 supply have been considered important events in sepsis. To relate these features with tissue and mitochondrial metabolism, we studied oxygen uptake in whole isolated and perfused rat liver at two O2 supply levels, in the same liver slices, and in isolated liver mitochondria. Experimental sepsis in rats was induced by cecal ligation and double-gauge puncture. The results showed that liver and tissue slices from septic animals had a 60% greater O2 uptake than that of controls and that, during sepsis, liver O2 uptake was markedly dependent on O2 supply. Concomitantly, mitochondrial O2 uptake was nearly 30% greater with malate-glutamate as substrate, but not with succinate; lowering O2 concentration in the medium did not alter the enhanced function. In submitochondrial, only NADH-dehydrogenase activity was 100% higher in septic samples. At least, in some tissues, O2 dependence is a function of O2 availability, sensitized by increased mitochondrial O2 uptake related to changes in respiratory enzymes.
 ...
PMID:Liver oxygen uptake dependence and mitochondrial function in septic rats. 762 58

The effects of intravenous bolus injection of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) on hepatic mitochondrial energy metabolism were investigated in rats. The rats were injected with 15 micrograms/kg body wt of human recombinant TNF-alpha and IL-1 beta. The hepatic energy charge decreased to 0.794 +/- 0.005 and 0.789 +/- 0.006 in comparison with the sham control value of 0.838 +/- 0.007 and 0.835 +/- 0.011 at 12 and 24 hr after the treatment. The mitochondrial redox state (NAD+/NADH) increased from 17.4 +/- 1.9, 16.6 +/- 1.4, and 19.2 +/- 2.1 to 33.5 +/- 3.5, 27.8 +/- 2.8, and 30.9 +/- 2.6 concomitant with an increase in arterial blood ketone body ratio (acetoacetate/beta-hydroxybutyrate) from 0.49 +/- 0.04, 0.34 +/- 0.04, and 0.44 +/- 0.09 to 1.00 +/- 0.16, 0.69 +/- 0.13, and 0.86 +/- 0.15 at 3, 12, and 24 hr after the treatment. Total ketone body concentration in liver tissue and arterial blood was significantly lower at 24 hr after the treatment. State 3 respiration rate of isolated mitochondria increased by 29.2, 30.3, and 19.2% concomitant with an increase in oxidative phosphorylation rate by 26, 33.7, and 24.3% at 3, 12, and 24 hr after the treatment. These results showed that the administration of TNF-alpha and IL-1 beta in rats induced a hypermetabolic state in hepatic mitochondrial energy metabolism, which is a pattern similar to sepsis and presumably a compensatory reaction to the increased energy consumption.
 ...
PMID:The effect of a bolus injection of TNF-alpha and IL-1 beta on hepatic energy metabolism in rats. 774 63

Our previous studies have shown that rat pulmonary microvascular smooth muscle cells (RPMSMC) upregulate inducible nitric oxide synthase (iNOS) and produce nitric oxide (NO) when treated with interleukin-1 beta (IL-1 beta). We now report that an additional effect of IL-1 beta stimulation in RPMSMC is an increase in production of superoxide (O2-) that results in the formation of peroxynitrite (ONOO-). IL-1 beta produced a rapid (within 1 h) concentration-dependent increase in O2-, as detected by ferricytochrome c reduction and lucigenin-enhanced chemiluminescence. O2- production was sensitive to quinacrine and diphenyliodinium, suggesting that NADH and NADPH oxidoreductases were responsible. After induction of iNOS and production of iNOS-derived NO, ONOO- was detected by luminol-enhanced chemiluminescence and was found to cause lipid peroxidation and to form nitrotyrosine in the cytoskeleton, detected by immunostaining. Cell viability, however, appeared to be unaffected. IL-1 beta-mediated induction of RPMSMC-derived ONOO- may have significant effects on pulmonary vascular function in sepsis and inflammatory states.
 ...
PMID:IL-1 beta stimulates superoxide and delayed peroxynitrite production by pulmonary vascular smooth muscle cells. 899 63

Diminished availability of oxygen at the cellular level might account for organ dysfunction in sepsis. Although the classical forms of tissue hypoxia due to hypoxemia, anemia, or inadequate perfusion all might be important under some conditions, it seems increasingly likely that a fourth mechanism, namely cytopathic hypoxia, might play a role as well. The term cytopathic hypoxia is used to denote diminished production of adenosine triphosphate (ATP) despite normal (or even supranormal) PO2 values in the vicinity of mitochondria within cells. At least in theory, cytopathic hypoxia could be a consequence of several different (but mutually compatible) pathogenic mechanisms, including diminished delivery of a key substrate (e.g., pyruvate) into the mitochondrial tricarboxylic acid (TCA) cycle, inhibition of key mitochondrial enzymes involved in either the TCA cycle or the electron transport chain, activation of the enzyme, poly-(ADP)-ribosylpolymerase (PARP), or collapse of the protonic gradient across the inner mitochondrial membrane leading to uncoupling of oxidation (of NADH and FADH) from phosphorylation of ADP to form ATP. Tantalizing, but limited, data support the view that cytopathic hypoxia occurs in both animals and patients with sepsis or endotoxemia.
 ...
PMID:Cytopathic hypoxia in sepsis. 924 46

Severe muscle wasting is a characteristic feature of sepsis. We have previously established that the rate of protein synthesis in muscles composed of fast-twitch fibers is severely diminished in response to sepsis. The present studies investigate the biochemical reactions responsible for the decreased rate of protein synthesis using gastrocnemius from control and septic rats perfused in situ. Analysis of free ribosomal subunits indicated peptide-chain initiation was impaired by infection. To characterize biochemical reactions in the pathway of peptide-chain initiation affected, the effect of sepsis on the incorporation of initiator [35S]methionyl-tRNA (met-tRNA(imet)) into the 40S initiation complex was examined. Sepsis caused a 65% decrease in the binding of radiolabelled met-tRNA(imet) to the 40S initiation complex compared with controls. The binding of met-tRNA(met) to the 40S ribosome is regulated by eukaryotic initiation factor eIF-2B, whose activity can be modulated in part by the redox state of pyridine dinucleotides. The mean cytoplasmic NADH/NAD+ ratio was increased 2 fold in sepsis, while the NADPH/NADP+ ratio was unchanged. These findings identify the formation of the 40S initiation complex as a defect in the protein synthesis machinery during sepsis. The decreased formation of the 40S initiation complex in muscle could not be explained by changes in the cytoplasmic redox state.
 ...
PMID:Reduced 40S initiation complex formation in skeletal muscle during sepsis. 954 85

Mitochondrial complexes I, II, and III were studied in isolated brain mitochondrial preparations with the goal of determining their relative abilities to reduce O2 to hydrogen peroxide (H2O2) or to reduce the alternative electron acceptors nitroblue tetrazolium (NBT) and diphenyliodonium (DPI). Complex I and II stimulation caused H2O2 formation and reduced NBT and DPI as indicated by dichlorodihydrofluorescein oxidation, nitroformazan precipitation, and DPI-mediated enzyme inactivation. The O2 consumption rate was more rapid under complex II (succinate) stimulation than under complex I (NADH) stimulation. In contrast, H2O2 generation and NBT and DPI reduction kinetics were favored by NADH addition but were virtually unobservable during succinate-linked respiration. NADH oxidation was strongly suppressed by rotenone, but NADH-coupled H2O2 flux was accelerated by rotenone. Alpha-phenyl-N-tert-butyl nitrone (PBN), a compound documented to inhibit oxidative stress in models of stroke, sepsis, and parkinsonism, partially inhibited complex I-stimulated H2O2 flux and NBT reduction and also protected complex I from DPI-mediated inactivation while trapping the phenyl radical product of DPI reduction. The results suggest that complex I may be the principal source of brain mitochondrial H2O2 synthesis, possessing an "electron leak" site upstream from the rotenone binding site (i.e., on the NADH side of the enzyme). The inhibition of H2O2 production by PBN suggests a novel explanation for the broad-spectrum antioxidant and antiinflammatory activity of this nitrone spin trap.
 ...
PMID:Interaction of alpha-phenyl-N-tert-butyl nitrone and alternative electron acceptors with complex I indicates a substrate reduction site upstream from the rotenone binding site. 983 55


1 2 3 4 Next >>