Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043167 (pertussis)
19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nitric oxide (NO) induction was studied in the peritoneal macrophages and spleen cells of female NIH mice immunised with whole cell Bordetella pertussis vaccines of moderate and high potency, respectively. Compared with controls receiving diluent only, the macrophages and spleen cells of the vaccinated mice developed high levels of reactive nitrogen intermediates from the third day after injection. The nitrite concentrations achieved maximum values at the 10th day, but significant levels persisted until the 25th day. Heat-killed B. pertussis cells were the most effective inducer of NO synthesis, followed by lipopolysaccharide and agglutinogens Fim 2 and 3. Pertussis toxoid, filamentous haemagglutinin and pertactin were poor inducers of NO synthesis. The specific nitric oxide synthase inhibitor, aminoguanidine, and anti-IFN-gamma antibody blocked formation of nitrite by the macrophages and spleen cells. The production of NO in response to in vitro culture with bacterial antigen was clearly associated with protective immunity in vivo as determined by i.c. challenge. These results suggest that reactive nitrogen intermediates play a role in the immune response induced by whole cell pertussis vaccines.
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PMID:Nitric oxide induction in murine macrophages and spleen cells by whole-cell Bordetella pertussis vaccine. 960 4

The addition of nitric oxide (NO), in the form of either donor compounds or nitric oxide gas, inhibits hormone-stimulated cAMP accumulation in N18TG2 cells. Hormone receptors and Gs are not targets of NO because forskolin-stimulated cAMP accumulation is also inhibited. The inhibitory effect of NO is not altered by pretreatment of cells with pertussis toxin, indicating that Gi is not mediating the effect of NO. cAMP accumulation in these cells is not altered by cell incubation with Ca++ ionophore or calmidazolium, indicating that calmodulin is not the target for NO. Experiments also rule out changes in phosphodiesterase or cGMP as mediators of the effect of NO. Cell incubation with superoxide dismutase in the presence or absence of catalase indicate that nitric oxide is the reactive species. The inhibitory action of nitric oxide is readily reversed, allowing full recovery of hormone and forskolin stimulation within 20 min of incubation in the absence of nitric oxide. The sum of the data indicate that NO targets either the adenylyl cyclase itself, or a regulatory component distinct from G proteins or calmodulin, to inhibit activation of the enzyme.
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PMID:Effects of nitric oxide on adenylyl cyclase stimulation in N18TG2 neuroblastoma cells. 965 72

The production of nitric oxide (NO) may play an important role in functional responses of the human polymorphonuclear neutrophil granulocytes (PMNs). Others have described the presence of both an inducible, Ca2+-independent and a constitutionally expressed, Ca2+-dependent nitric oxide synthase (NOS) in human PMNs. However, the conditions for production and release of NO in human PMNs are still largely unknown. We assessed mechanisms for activation of NO release from human PMNs and particularly the dependence on extracellular and intracellular Ca2+. We addressed this question by applying a variety of agonists with known and differing mechanisms of activation in PMNs and measuring the released NO by two highly sensitive and specific real-time methods for detection of NO, the oxidation of oxyhemoglobin to methemoglobin and an electrochemical method. We found that human PMNs activated with the surface receptor-dependent agonist, N-formyl-methionyl-leucyl-phenylalanine (fMLP); the calcium ionophore, A23187; or the direct stimulator of protein kinase C, phorbol myristate acetate (PMA), produced NO which was inhibited by a specific NOS inhibitor, NG-monomethyl-L-arginine. The NO production induced by fMLP or A23187 was dependent on the presence of extracellular Ca2+, but this was not the case for PMA. The stimulatory effect of fMLP was almost completely inhibited by Bordetella pertussis toxin. These results indicate an NOS activity in purified human PMNs in vitro, and the transduction mechanisms for the agonists used show strong similarity with previously known pathways for other neutrophil functions.
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PMID:Stimulus-dependent transduction mechanisms for nitric oxide release in human polymorphonuclear neutrophil leukocytes. 966 72

An intact chemotactic response is vital for leukocyte trafficking and host defense. Opiates are known to exert a number of immunomodulating effects in vitro and in vivo, and we sought to determine whether they were capable of inhibiting chemokine-induced directional migration of human leukocytes, and if so, to ascertain the mechanism involved. The endogenous opioid met-enkephalin induced monocyte chemotaxis in a pertussis toxin-sensitive manner. Met-enkephalin, as well as morphine, inhibited IL-8-induced chemotaxis of human neutrophils and macrophage inflammatory protein (MIP)-1alpha, regulated upon activation, normal T expressed and secreted (RANTES), and monocyte chemoattractant protein 1, but not MIP-1beta-induced chemotaxis of human monocytes. This inhibition of chemotaxis was mediated by delta and micro but not kappa G protein-coupled opiate receptors. Calcium flux induced by chemokines was unaffected by met-enkephalin pretreatment. Unlike other opiate-induced changes in leukocyte function, the inhibition of chemotaxis was not mediated by nitric oxide. Opiates induced phosphorylation of the chemokine receptors CXCR1 and CXCR2, but neither induced internalization of chemokine receptors nor perturbed chemokine binding. Thus, inhibition of chemokine-induced chemotaxis by opiates is due to heterologous desensitization through phosphorylation of chemokine receptors. This may contribute to the defects in host defense seen with opiate abuse and has important implications for immunomodulation induced by several endogenous neuropeptides which act through G protein-coupled receptors.
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PMID:Opiates transdeactivate chemokine receptors: delta and mu opiate receptor-mediated heterologous desensitization. 967 44

Nitric oxide (NO) synthesized within mammalian sinoatrial cells has been shown to participate in cholinergic control of heart rate (HR). However, it is not known whether NO synthesized within neurons plays a role in HR regulation. HR dynamics were measured in 24 wild-type (WT) mice and 24 mice in which the gene for neuronal NO synthase (nNOS) was absent (nNOS-/- mice). Mean HR and HR variability were compared in subsets of these animals at baseline, after parasympathetic blockade with atropine (0.5 mg/kg i.p.), after beta-adrenergic blockade with propranolol (1 mg/kg i.p.), and after combined autonomic blockade. Other animals underwent pressor challenge with phenylephrine (3 mg/kg i.p.) after beta-adrenergic blockade to test for a baroreflex-mediated cardioinhibitory response. The latter experiments were then repeated after inactivation of inhibitory G proteins with pertussis toxin (PTX) (30 microgram/kg i.p.). At baseline, nNOS-/- mice had higher mean HR (711+/-8 vs. 650+/-8 bpm, P = 0.0004) and lower HR variance (424+/-70 vs. 1,112+/-174 bpm2, P = 0.001) compared with WT mice. In nNOS-/- mice, atropine administration led to a much smaller change in mean HR (-2+/-9 vs. 49+/-5 bpm, P = 0.0008) and in HR variance (64+/-24 vs. -903+/-295 bpm2, P = 0.02) than in WT mice. In contrast, propranolol administration and combined autonomic blockade led to similar changes in mean HR between the two groups. After beta-adrenergic blockade, phenylephrine injection elicited a fall in mean HR and rise in HR variance in WT mice that was partially attenuated after treatment with PTX. The response to pressor challenge in nNOS-/- mice before PTX administration was similar to that in WT mice. However, PTX-treated nNOS-/- mice had a dramatically attenuated response to phenylephrine. These findings suggest that the absence of nNOS activity leads to reduced baseline parasympathetic tone, but does not prevent baroreflex-mediated cardioinhibition unless inhibitory G proteins are also inactivated. Thus, neuronally derived NO and cardiac inhibitory G protein activity serve as parallel pathways to mediate autonomic slowing of heart rate in the mouse.
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PMID:Interaction between neuronal nitric oxide synthase and inhibitory G protein activity in heart rate regulation in conscious mice. 976 19

The endothelium plays an obligatory role in a number of relaxations of isolated arteries. These endothelium-dependent relaxations are due to the release by the endothelial cells of potent vasodilator substances [endothelium-derived relaxing factors (EDRF)]. The best characterized EDRF is nitric oxide (NO). Nitric oxide is formed by the metabolism of L-arginine by the constitutive NO synthase of endothelial cells. In arterial smooth muscle, the relaxations evoked by EDRF are explained best by the stimulation by NO of soluble guanylate cyclase that leads to the accumulation of cyclic GMP. The endothelial cells also release an unidentified substance that causes hyperpolarization of the cell membrane (endothelium-derived hyperpolarizing factor, EDHF). The release of EDRF from the endothelium can be mediated by both pertussis toxin-sensitive (alpha2-adrenergic activation, serotonin, thrombin, aggregating platelets) and insensitive (adenosine diphosphate, bradykinin) G-proteins. In blood vessels from animals with regenerated endothelium, and/or atherosclerosis, there is a selective loss of the pertussis-toxin sensitive mechanism of EDRF-release which favors the occurrence of vasospasm, thrombosis and cellular growth.
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PMID:Endothelial dysfunction and vascular disease. 980 82

Interactions between two classes of receptors have been observed in several cell lines and preparations. The aim of this work was to assess the impact of simultaneous stimulation of endothelial muscarinic and alpha2-adrenergic receptors (alpha2-AR) on vascular reactivity. Rabbit middle cerebral arteries were isolated and changes in isometric tension were recorded in the presence of indomethacin. Inhibition of nitric oxide (NO) synthase with Nomega-nitro-L-arginine (L-NOARG, 100 micromol l(-1)) revealed alpha-AR-dependent contractions. Pre-addition of acetylcholine (ACH, 1 micromol l(-1)) augmented oxymetazoline (OXY, 10 micromol l(-1), alpha2-AR agonist)-, but decreased phenylephrine (PE, 10 micromol(-1), alpha1-AR agonist)-induced contraction (P<0.05). The effects of ACH were endothelium-dependent. Vessels were precontracted with 40 mmol l(-1) KCl-physiological salt solution (PSS) in the absence of L-NOARG, or PE or OXY in the presence of L-NOARG. In the presence of high external K+ or PE, ACH induced a potent relaxation (P<0.05). In the presence of OXY, however, ACH mediated contraction (P<0.05). After pertussis toxin (PTX, inactivator of Galpha(i/o) proteins) pre-treatment, alpha2-AR-dependent contractions were abolished. Forty mmol l(-1) KCl-PSS induced contraction was not altered by PTX whereas ACH-induced relaxation was augmented (P<0.05). To investigate if endothelin-1 (ET-1) intervened in the endothelium-dependent contractile response to ACH in the presence of OXY-dependent tone, vessels were incubated in the presence of BQ123 (1 micromol l(-1)), an ETA receptor antagonist. OXY-mediated tone was not affected by BQ123; however, ACH-induced contraction was reversed to a relaxation (P<0.05). These data indicate that activation of endothelial alpha2-AR triggers an endothelium-dependent, ET-1 mediated, contraction to ACH. This suggests that activation of alpha2-AR affects muscarinic receptor/G protein coupling leading to an opposite biological effect.
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PMID:Functional cross-talk between endothelial muscarinic and alpha2-adrenergic receptors in rabbit cerebral arteries. 986 46

Nitric oxide (NO) is a major transmitter in mediating cerebral neurogenic vasodilation in several species. Recent findings have suggested that acetylcholine, which is costored with NO in cerebral perivascular nerves, plays a role in modulating NO release, presumably by acting on muscarinic (M) receptors on nitric oxidergic nerve terminals. The present study was designed using an in vitro tissue bath technique to pharmacologically characterize the presynaptic muscarinic-receptor subtype(s) that mediate modulation of NO release and therefore neurogenic vasodilation and to investigate further the possible mechanisms involved in this presynaptic modulation in porcine basilar arteries. Transmural nerve stimulation (TNS) elicited a frequency-dependent, tetrodotoxin-sensitive relaxation. The relaxation was abolished by nitro-L-arginine (30 microM) and was completely reversed by L-arginine and L-citrulline, but not by their D-enantiomers. Atropine (0.01-1 microM), pirenzepine (an M1-receptor antagonist, 0. 01-1 microM), and methoctramine (an M2-receptor antagonist, 0.01-1 microM), but not 4-DAMP (an M3-receptor antagonist) or tropicamide (an M4-receptor antagonist) at concentrations as high as 10 mM, significantly increased the TNS-elicited relaxation. This relaxation, on the other hand, was significantly attenuated by arecaidine but-2-ynyl ester tosylate (an M2-receptor agonist, 0.1 microM) but was not affected by McN-A-343 (an M1-receptor agonist, 1 microM). Double-labeling immunohistochemical study demonstrated that perivascular M2 receptor-immunoreactive fibers were completely coincident with NADPH diaphorase fibers. Furthermore, the muscarinic receptor-mediated modulation of TNS-elicited relaxation was completely prevented by omega-conotoxin GVIA (0.1 microM), a specific N-type Ca2+ channel inhibitor, but was still observed in the presence of tetraethylammonium (1 mM), 8-bromo-cAMP (0.5 mM), and pertussis toxin. It is concluded that the presynaptic M2 receptors on porcine cerebral perivascular nitric oxidergic nerves mediate inhibition of NO release. The inhibition is due primarily to a decreased Ca2+ influx through N-type Ca2+ channels.
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PMID:Mechanism of prejunctional muscarinic receptor-mediated inhibition of neurogenic vasodilation in cerebral arteries. 988 33

Because arachidonate metabolites are potent mediators of inflammation, we have studied the effects of leukotriene B4 (LTB4) and the cysteinyl leukotrienes C4 and D4 (LTC4 and LTD4) on the release of nitric oxide (NO), in vitro, by human polymorphonuclear granulocytes (PMN). Two independent and highly sensitive real-time methods were used for these studies, ie, the NO-dependent oxidation of oxyhemoglobin (HbO2) to methemoglobin and a NO-sensitive microelectrode. When activated with LTB4, LTC4, or LTD4, but not with other lipoxygenase products such as 5S-HETE, 5-oxo-ETE or 5S, 12S-diHETE, PMN produced NO in a stimulus- and concentration-dependent manner. The rank order of potency was LTB4 = LTC4 > LTD4, corresponding to 232 +/- 50 pmol of NO/10(6) PMN for 100 nmol/L LTB4 after 30 minutes. The kinetic properties of the responses were similar for all three leukotrienes with a maximum response at 13 +/- 3 minutes. Cysteinyl leukotriene and LTB4 antagonists inhibited the agonist-induced NO production by 70%, and treatment with Bordetella pertussis toxin, or chelation of cytosolic Ca2+, [Ca2+]i, also efficiently inhibited this response. In contrast, treatment of PMN with cytochalasin B (5 microg/mL) enhanced the LTB4-induced NO formation by 86%. Thus, this is the first demonstration that the cysteinyl leukotrienes LTC4 and LTD4, as well as LTB4, activate NO release from human PMN by surface receptor, G-protein and [Ca2+]i-dependent mechanisms. This effect differs from activation of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, for which only LTB4 is an activator.
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PMID:Activation of nitric oxide release and oxidative metabolism by leukotrienes B4, C4, and D4 in human polymorphonuclear leukocytes. 994 84

Heparin, which is widely used clinically, has recently been shown to have specific properties affecting the vascular endothelium. We hypothesized that heparin stimulates endothelial nitric oxide synthase (eNOS) activity by a mechanism independent of its anticoagulant properties and dependent on an inhibitory guanine nucleotide regulatory protein (Gi). We determined the effect of both heparin and N-acetyl heparin (Non-Hep), a heparin derivative without anticoagulant properties, on eNOS activity in cultured bovine aortic endothelial cells and on endothelium-dependent relaxation in isolated vascular rings. The eNOS activity was determined by measuring both citrulline and nitric oxide (NO) metabolite formation. Heparin and Non-Hep dose-dependently increased basal eNOS activity (ED50 1.0 microgram/ml or 0.15 U/ml), an effect that was significantly inhibited by pertussis toxin (100 ng/ml), a Gi-protein inhibitor. Agonist-stimulated (acetylcholine, 10 microM) eNOS activity was potentiated following pre-treatment with both heparin and Non-Hep and reversed by pertussis toxin. Heparin and Non-Hep induced a dose-dependent relaxation in preconstricted thoracic aortic rings, an effect that was significantly inhibited by pertussis toxin, endothelial inactivation (following treatment with sodium deoxycholate) and NG-nitro-L-arginine-methyl ester (L-NAME). We conclude that heparin and non-anticoagulant heparin induce endothelium-dependent relaxation following activation of eNOS by a mechanism involving a Gi-protein. Administration of heparin derivatives without anticoagulant properties may have therapeutic implications for the preservation of eNOS in conditions characterized by endothelial dysfunction.
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PMID:Non-anticoagulant heparin increases endothelial nitric oxide synthase activity: role of inhibitory guanine nucleotide proteins. 999 May 38


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