Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0406810 (NAME)
13,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Laboratory data indicate that morphine decreases the numbier of peritoneal and alveolar macrophages (Mphi) and compromises their phagocytic capability for immune complexes and bacteria. We hypothesize that morphine decreases the number of, as well as compromises the phagocytic capability of, Mphi by programming their death. We studied the effect of morphine on Mphi apoptosis in vivo as well as in vitro. Peritoneal Mphi harvested from morphine-treated rats showed DNA fragmentation. Morphine enhanced murine Mphi (J 774.16) apoptosis in a dose-dependent manner. Human monocytes treated with morphine showed a classic ladder pattern in gel electrophoretic and end-labeling studies. Morphine promoted nitric oxide (NO) production both under basal and LPS-activated states. N(G)-nitro-L-arginine methyl ester (L-NAME) and N(G)-monomethyl-L-arginine monoacetate (L-NMMA), inhibitors of NO synthase, attenuated the morphine-induced generation of NO by Mphi. Morphine also enhanced Mphi mRNA expression of inducible NO synthase (iNOS). Since morphine-induced Mphi apoptosis was inhibited by L-NAME and L-NMMA, it appears that morphine-induced Mphi apoptosis may be mediated through the generation of NO. Morphine promoted the synthesis of Bax and p53 proteins by Mphi. Moreover, IL-converting enzyme (ICE)-1 inhibitor attenuated morphine-induced Mphi apoptosis. These studies suggest that morphine activates the induction phase of the apoptotic pathway through accumulation of p53. The effector phase of morphine-induced apoptosis appears to proceed through the accumulation of Bax and activation of ICE-1. The present study provides a basis for a hypothesis that morphine may be directly compromising immune function by promoting Mphi apoptosis in patients with opiate addiction.
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PMID:Morphine enhances macrophage apoptosis. 946 50

1 The characterization of the B1 kinin receptor, and some mediators involved in the inflammatory response elicited by intrathoracic (i.t.) administration of des-Arg9-bradykinin (BK) in the mouse model of pleurisy, was investigated. 2 An i.t. injection of des-Arg9-BK (10-100 nmol per site), a selective B1 agonist, caused a significant and dose-related increase in the vascular permeability observed after 5 min, which peaked at 1 h, associated with an increase in cell influx, mainly neutrophils, and, to a lesser extent, mononuclear cell influx, peaking at 4 h and lasting for up to 48 h. The increase in fluid leakage caused by des-Arg9-BK was completely resolved 4 h after peptide injection. I.t. injection of Lys-des-Arg9-BK (30 nmol per site) caused a similar inflammatory response. 3 Both the exudation and the neutrophil influx elicited by i.t. injection of des-Arg9-BK were significantly antagonized (P<0.01) by an i.t. injection of the selective B1 antagonists des-Arg9-[Leu8]-BK (60 and 100 nmol per site) or des-Arg9-NPC 17731 (5 nmol per site), administered in association with des-Arg9-BK (P<0.01), or 30 and 60 min before the cellular peak, respectively. In contrast, an i.t. injection of the B2 bradykinin selective receptor antagonist Hoe 140 (30 nmol per site), at a dose which consistently antagonized bradykinin (10 nmol per site)-induced pleurisy, had no significant effect on des-Arg9-BK-induced pleurisy. 4 An i.t. injection of the selective tachykinin receptor antagonists (NK1) FK 888 (1 nmol per site), (NK2) SR 48968 (20 nmol per site) or (NK3) SR 142801 (10 nmol per site), administered 5 min before pleurisy induction, significantly antagonized neutrophil migration caused by i.t. injection of des-Arg9-BK. In addition, FK 888 and SR 142801, but not SR 48968, also prevented the influx of mononuclear cells in response to i.t. injection of des-Arg9-BK (P<0.01). However, the NK3 receptor antagonist SR 142801 (10 nmol per site) also significantly inhibited des-Arg9-BK-induced plasma extravasation. An i.t. injection of the calcitonin gene-related peptide (CGRP) receptor antagonist CGRP8-37 (1 nmol per site), administered 5 min before pleurisy induction, inhibited des-Arg9-BK-induced plasma extravasation (P<0.01), without significantly affecting the total and differential cell migration. 5 The nitric oxide synthase inhibitors L-NOARG and L-NAME (1 pmol per site), administered 30 min beforehand, almost completely prevented des-Arg9-BK (i.t.)-induced neutrophil cell migration (P<0.01), and, to a lesser extent, mononuclear cell migration (P<0.01). The D-enantiomer D-NAME had no effect on des-Arg9-BK-induced pleurisy. At the same dose range, L-NOARG and L-NAME inhibited the total cell migration (P<0.01). L-NAME, but not L-NOARG caused significant inhibition of des-Arg9-BK-induced fluid leakage. Indomethacin (1 mg kg(-1), i.p.), administered 1 h before des-Arg9-BK (30 nmol per site), inhibited the mononuclear cell migration (P<0.05), but, surprisingly, increased the neutrophil migration at 4 h without interfering with plasma extravasation. The administration of terfenadine (50 mg kg(-1), i.p.), 30 min before des-Arg9-BK (30 nmol per site), did not interfere significantly with the total cell migration or with the plasma extravasation in the mouse pleurisy caused by i.t. injection of des-Arg9-BK. 6 Pretreatment of animals with the lipopolysaccharide of E. coli (LPS; 10 microg per animal, i.v.) for 24 h did not result in any significant change of the inflammatory response induced by i.t. injection of des-Arg9-BK compared with the saline treated group. However, the identical treatment of mice with LPS resulted in a marked enhancement of des-Arg9-BK induced paw oedema (P<0.01). 7 In conclusion, we have demonstrated that the inflammatory response induced by i.t. injection of desArg9-BK, in a murine model of pleurisy, is mediated by stimulation of constitutive B1 receptors. (These responses are largely mediated by release of neuropeptides such as substanceP or CGRP and also by NO, but products derived from cyclo-oxygenase pathway and histamine seem not to be involved. Therefore, these results further support the notion that the B1 kinin receptor has an important role in modulating inflammatory responses, and it is suggested that selective B1 antagonists may provide therapeutic benefit in the treatment of inflammatory and allergic conditions.
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PMID:Characterization of the receptor and the mechanisms underlying the inflammatory response induced by des-Arg9-BK in mouse pleurisy. 948 17

From undetectable basal levels, TNFalpha is produced in the hypothalamus of rats challenged with a systemic low profile endotoxin (LPS) at least 30 min before its release may be detected in the plasma. The cytotoxic activity of this hypothalamic TNFalpha correlates with its immunoreactivity. Injection of BB-1101, a matrix metalloprotease inhibitor, immediately after the LPS totally inhibits the plasma LPS-induced TNFalpha release without affecting the hypothalamic TNFalpha response. Likewise, L-NAME pretreatment, a nitric oxide inhibitor which reportedly crosses the blood-brain barrier, blunts the plasma TNFalpha response by almost 66%, but leaves the hypothalamic TNFalpha response unchanged. The present study thus describes the early occurrence of hypothalamic TNFalpha in response to systemic LPS injection, which is not subjected to the same regulations as plasma TNFalpha.
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PMID:Differential regulation of brain and plasma TNFalpha produced after endotoxin shock. 950 74

We examined the effects of IL-10 on tumour necrosis factor-alpha (TNF-alpha) and NO production by LPS-activated macrophages and on the ability of these cells to control Trypanosoma cruzi infection. We first observed that the addition of rIL-10 to macrophages of the J774 cell line decreased their synthesis of TNF-alpha but increased their release of NO in a dose-dependent manner. In parallel, treatment of J774 cells with rIL-10 resulted in a better control of T. cruzi infection involving up-regulation of NO synthesis, as it was not observed in presence of N-nitro-L-arginine methyl ester (L-NAME), a competitive inhibitor of NO synthase. The enhancing effect of rIL-10 on NO production was not observed on peritoneal macrophages from wild-type C57Bl/6 mice, but well on macrophages from IL-10 knock-out mice. The control of NO production by endogenous IL-10 was confirmed by the demonstration that neutralization of IL-10 secreted by LPS-activated macrophages from wild-type mice inhibited their production of NO and, in parallel, their ability to control T. cruzi infection. Taken together, these data demonstrate that both exogenous and endogenous IL-10 up-regulate the production of NO by LPS-activated macrophages and improve thereby their ability to clear T. cruzi infection.
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PMID:IL-10 up-regulates nitric oxide (NO) synthesis by lipopolysaccharide (LPS)-activated macrophages: improved control of Trypanosoma cruzi infection. 969 84

We investigated whether a complete inhibition of nitric oxide (NO) formation caused by bacterial endotoxin (lipopolysaccharide, LPS) in vivo prevents the hypotension and restores the vascular hyporeactivity to normal in vivo and ex vivo. The combination of dexamethasone (Dex; 3 mg/kg at 30 min before LPS) plus aminoguanidine (AG; 15 mg/kg at 2 h after LPS) inhibited the overproduction of nitrate (an indicator of NO) in the plasma and aortic smooth muscle and also prevented the development of the delayed hypotension in rats treated with LPS for 6 h. However, the vascular hyporeactivity to norepinephrine (NE) was only partially improved either in vivo or ex vivo in endotoxemic rats treated with Dex plus AG. Pretreatment of aortic rings with Nomega-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2, 4]oxidazolo[4,3-a]quinoxalin-1-one (ODQ) enhanced the contraction to NE in rings obtained from LPS-treated rats, but not in those from Dex plus AG-treated endotoxemic rats. Methylene blue, an inhibitor of soluble guanylyl cyclase (GC), completely restored contractions to NE and aortic cGMP levels to normal either in LPS-treated rats or in Dex plus AG-treated endotoxemic rats, whereas the cGMP level was partially inhibited by ODQ in LPS-treated rats only. These results suggest that non-NO mediator(s) also activates soluble GC during endotoxemia. Interestingly, we found that in the presence of tetraethylammonium (an inhibitor of K+ channels) plus L-NAME or charybdotoxin [a specific inhibitor of large-conductance Ca2+-activated K+ (KCa) channels] plus ODQ, the vascular hyporeactivity to NE in the LPS-treated group was also completely restored to normal. In addition, in the presence of L-NAME or ODQ, the vascular hyporeactivity to high K+ was abolished in rings from the LPS-treated group. These results suggest that LPS causes the production of other mediator(s), in addition to NO, which also stimulates soluble GC (i.e., increases the formation of cGMP) and then activates the large-conductance KCa channels in the vascular smooth muscle causing vascular hyporeactivity.
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PMID:Nitric oxide-independent activation of soluble guanylyl cyclase contributes to endotoxin shock in rats. 974 61

It was recently demonstrated that the diffusible messenger molecule nitric oxide (NO) is involved in the febrile response of rats and rabbits to exogenous or endogenous pyrogens. In this study we have investigated the effects of systemic administration of the NO-synthase inhibitor N-nitro-l-arginine-methylester (l-NAME) on abdominal temperature and on lipopolysaccharide- (LPS-) induced fever in guinea-pigs. We further studied the effects of l-NAME on the LPS-induced circulating cytokine network by measurement of tumor necrosis factor alpha (TNF) and interleukin-6 (IL-6) in blood plasma during the time course of fever. At a dose of 10 mg/kg, intra-arterial injection of l-NAME per se had no influence on the abdominal temperature of guinea-pigs, while administration of 50 mg/kg l-NAME evoked a pronounced fall of body temperature which lasted about 12 h. When injected simultaneously with 10 microgram/kg LPS into the arterial circulation, the lower dose of l-NAME that did not decrease abdominal temperature per se caused a significant attenuation of LPS-induced fever due to suppression of the second phase of the biphasic febrile response. The LPS-induced cytokine network remained unimpaired by the treatment with l-NAME. Peak activity of TNF in plasma (measured 60 min after LPS injection) was 20,596+/-2368 pg/ml in control animals and 18,900+/-4778 pg/ml in guinea-pigs treated with l-NAME. In addition, circulating levels of IL-6 were not statistically different between both groups of animals 60 min or 180 min after administration of LPS along with l-NAME or vehicle. The results confirm that endogenous NO formation has a role in the generation of LPS-induced fever and demonstrate that the attenuation of fever by inhibition of NO-synthase is independent of the circulating LPS-induced cytokine network.
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PMID:Inhibition of nitric oxide synthase attenuates lipopolysaccharide-induced fever without reduction of circulating cytokines in guinea-pigs. 979 99

The interaction between constitutive nitric oxide and oxygen may depend on the degree of tissue oxygenation and may play a critical role in the pathophysiological response to endotoxaemia. We investigated if hyperoxia (100% O2) attenuated the systemic and pulmonary vasoconstriction and increased biosynthesis of thromboxane B2 (TXB2) and 6-keto-prostaglandin (PG) F1alpha induced by inhibition of nitric oxide synthase with NG-nitro-L-arginine-methyl-ester (L-NAME) in a porcine model of endotoxaemia. Twenty-two domestic, random source pigs, weighing 15.4 +/- 2.7 kg (mean +/- standard deviation) were the subjects of this study. Pigs were anaesthetized with isoflurane in 100% O2, orotracheally intubated and ventilated to maintain normocapnia, and then instrumented for haemodynamic monitoring. Following instrumentation, pigs were maintained at an end-tidal isoflurane concentration of 2%. Pigs were randomly assigned to treatment groups: saline + 30% O2 (Control, n = 6); Escherichia coli lipopolysaccharide (5 microg/kg/h from 1 to 2 h followed by 2 microg/kg/h from 2 to 5 h) + 30% O2 (LPS, n = 4); L-NAME (0.5 mg/kg/h, from 0 to 5 h) + LPS + 100% O2 (n = 6); and L-NAME + LPS + 30% O2 (n = 6). L-NAME and endotoxin significantly (P < 0.05) increased mean arterial pressure, mean pulmonary arterial pressure, and systemic and pulmonary vascular resistance index beginning at 90 min. When results were pooled across all time periods, mean arterial pressure and mean pulmonary arterial pressure were significantly higher in the L-NAME + LPS + 30% O2 group than all other groups, reflecting pulmonary and systemic vasoconstriction. Hyperoxia attenuated the L-NAME + LPS-induced increases in TXB2 and 6-keto-PGF1alpha concentrations at 90 and 120 min and 120 min, respectively, although the differences were not statistically significant. These results support the observation that nitric oxide synthase inhibition with L-NAME has deleterious haemodynamic effects in this model of endotoxaemia. The temporal attenuation of L-NAME-induced pulmonary and systemic vasoconstriction by hyperoxia suggested that the haemodynamic effects of acute endotoxaemia were in part influenced by the relative amounts of nitric oxide and oxygen present.
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PMID:The effects of hyperoxia on the biosynthesis of cyclooxygenase products and haemodynamic response to nitric oxide synthase inhibition with L-NAME in endotoxaemic pigs. 981 34

Recent evidence indicates that free oxygen radicals, in particular hydroxyl radicals, may act as intracellular second messengers for the induction of IL-8, a potent chemoattractant and activator of neutrophil granulocytes. Here we report that peroxynitrite (ONOO-), formed by a reaction of nitric oxide (NO) with superoxide, mediates IL-8 gene expression and IL-8 production in LPS-stimulated human whole blood. The NO synthase inhibitors aminoguanidine and NG-nitro-L-arginine methyl ester (L-NAME) blocked IL-8 release by approximately 90% in response to LPS (1 microg/ml), but did not affect the production of IL-1beta or TNF-alpha. Both aminoguanidine and L-NAME blocked the induction of IL-8 mRNA by LPS. Authentic ONOO- (2.5-80 microM) augmented IL-8 mRNA expression and stimulated IL-8 release in a concentration-dependent manner, whereas the NO-releasing compounds, S-nitroso-N-acetyl-DL-penicillamine and sodium nitroprusside failed to induce cytokine production. Combination of the NO-generating chemicals with a superoxide-generating system (xanthine/xanthine oxidase) markedly increased IL-8 release. Enhanced ONOO- formation was detected in granulocytes, monocytes, lymphocytes, and plasma after challenge with LPS. Furthermore, pyrrolidine dithiocarbamate, an inhibitor of activation of nuclear factor-gammaB, markedly attenuated the induction of IL-8 mRNA expression and IL-8 release by either LPS or ONOO-. Our study identifies ONOO- as a novel signaling mechanism for IL-8 gene expression and suggests that inhibition of ONOO- formation or scavenging ONOO- may represent a novel therapeutic approach to inhibit IL-8 production that could lead to reduction of neutrophil accumulation and activation.
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PMID:Peroxynitrite mediates IL-8 gene expression and production in lipopolysaccharide-stimulated human whole blood. 982 May 46

The role of endotoxin (lipopolysaccharide, LPS) and nitric oxide in hepatic oxygen metabolism was investigated in 36 pigs receiving 1) LPS (1.7 microgram. kg-1. h-1) for 7 h and NG-nitro-L-arginine methyl ester (L-NAME; 25 mg/kg) after 3 h, 2) LPS, 3) NaCl and L-NAME, and 4) NaCl. Infusion of LPS reduced hepatic oxygen delivery (DO2H) from 60 +/- 4 to 30 +/- 5 ml/min (P < 0.05) and increased the oxygen extraction ratio from 0.29 +/- 0.07 to 0.68 +/- 0.04 after 3 h (P < 0.05). Hepatic oxygen consumption (VO2H) was maintained (18 +/- 4 and 21 +/- 4 ml/min, change not significant), but acidosis developed. Administration of L-NAME during endotoxemia caused further reduction of DO2H from 30 +/- 3 to 13 +/- 2 ml/min (P < 0.05) and increased hepatic oxygen extraction ratio from 0.46 +/- 0.04 to 0.80 +/- 0.03 (P < 0.05). There was a decrease in VO2H from 13 +/- 2 to 9 +/- 2 ml/min that did not reach statistical significance, probably representing a type II error. Acidosis was aggravated. Administration of L-NAME in the absence of endotoxin also increased the hepatic oxygen extraction ratio, but no acidosis developed. In a different experiment, liver blood flow was mechanically reduced in the presence and absence of endotoxin, comparable to the flow reductions caused by L-NAME. The increase in hepatic oxygen extraction ratio (0.34) and maximum hepatic oxygen extraction ratio (approximately 0.90) was similar whether DO2H was reduced by occlusion or by L-NAME. We concluded that L-NAME has detrimental circulatory effects in this model. However, neither endotoxin nor L-NAME seemed to prevent the ability of the still circulated parts of the liver to increase hepatic oxygen extraction ratio to almost maximum when oxygen delivery was reduced. The effect of L-NAME on oxygen transport thus seems to be caused by a reduction in DO2H rather than by alterations in oxygen extraction capabilities.
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PMID:Hepatic oxygen metabolism in porcine endotoxemia: the effect of nitric oxide synthase inhibition. 984 75

Transient pulmonary hypertension after inhibition of nitric oxide synthase (NOS) does not alter pulmonary reflection coefficients or lymph flows in endotoxemic sheep. To test the effects of persistent pulmonary hypertension induced by N omega-nitro-L-arginine methylester (L-NAME) and of inhaled NO on pulmonary edema, 18 sheep (three groups) were chronically instrumented with pulmonary artery catheters, femoral arterial fiberoptic thermistor catheters, and tracheostomy. The awake, spontaneously breathing animals received Salmonella typhi endotoxin (lipopolysaccharide; LPS) (10 ng/kg/ min) for 28 h. After 24 h, an airflow of 6 L/min was delivered through the tracheostomy. One group of animals (L-NAME/air) received L-NAME intravenously (25 mg/kg + 5 mg/kg/h) and breathed air. The second group (L-NAME/NO) was given L-NAME and NO (40 ppm) was added to the airflow. The third group was given NaCl 0.9% and breathed air (NaCl/air). Extravascular lung water was measured through the double-indicator dilution technique. Endotoxemia caused pulmonary edema, which was aggravated by L-NAME. Breathing of NO normalized pulmonary artery pressure (Ppa) and ameliorated pulmonary edema. Inhalation of NO may therefore be a therapeutic option for pulmonary edema associated with pulmonary hypertension.
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PMID:Role of nitric oxide in sepsis-associated pulmonary edema. 987 46


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