Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.2 (focal adhesion kinase)
44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a recognized inhibitor of nitric oxide (NO) synthesis, Nw-nitro L-arginine methyl ester (L-NAME), we tested the hypothesis of the existence of a nonendothelial source of NO in vascular tissue using rings of rat thoracic aorta in which endothelial cells have been removed by mechanical abrasion and have totally lost their endothelium-dependent relaxation. Contractility of the muscle was tested by recording the concentration-dependent contraction of the preparations induced by an alpha-adrenergic agonist, phenylephrine. Contractility in aortas from Wistar-Kyoto normotensive rats (WKY) and spontaneous hypertensive rats (SHR) was not significantly affected by a 30-min to 2-hour incubation with L-NAME prior to agonist stimulation. However, preparations incubated for 30 min with 1 mM L-arginine (L-ARG) and then washed for 1 h in standard Krebs solution had a significantly reduced contraction to phenylephrine in both WKY and SHR. In these preparations pretreated with L-ARG, L-NAME significantly increased contractility in both WKY and SHR; this effect was prevented by L-ARG but not by D-arginine. Responses to phenylephrine were not inhibited by L-ARG when preparations were incubated from the beginning of the experiment with 1 mM cycloheximide, thus suggesting a dependence on protein synthesis of the attenuation of contraction seen with L-ARG. Intact aortic rings processed for NADPH diaphorase histochemistry, a putative marker for NO synthase, showed NADPH diaphorase reactivity only in the endothelial layer and in the adventitia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Nonendothelial aortic source of nitric oxide in Wistar-Kyoto normotensive and spontaneous hypertensive rats. 130 32

Conversion of L-arginine to L-citrulline and nitric oxide (NO) by NO synthase induced in the murine EMT-6 cells resulted in the release of a large amount of the stable reactional intermediate N omega-hydroxy-L-arginine into the extracellular medium. We have prepared [3H]N omega-hydroxy-L-arginine biosynthetically, and shown that, after its uptake, this molecule can induce cytostasis in NO synthase-deficient P-815 and U-937 tumor cells. This long-lived intermediate could behave as a supplier of NO or other toxic molecules in cell-cell interactions.
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PMID:N omega-hydroxy-L-arginine, a reactional intermediate in nitric oxide biosynthesis, induces cytostasis in human and murine tumor cells. 750 81

Nitric oxide (NO) is an important mediator of the hemodynamic effects of sepsis; however, its microcirculatory effects are unknown. To determine the role of NO in the small intestinal (SI) microcirculation, an intact SI loop was exteriorized from decerebrate rats into a controlled Krebs' bath. Bacteremic rats received 10(9) Escherichia coli intravenously. Videomicroscopy was used to measure arteriolar diameters (A1, A3) and optical Doppler velocimetry to quantitate flow. In controls, topical NO synthase (NO-S) substrate L-arginine (L-ARG; 10(-4) M) did not affect diameters or flow. Inhibition of NO-S by N omega-nitro-L-arginine methyl ester (L-NAME; 10(-4) M) caused constriction (A1 = -18%; A3 = -24% from baseline diameter) and reduced A1 flow by 62%. These alterations were similar to bacteremic controls (A1 = -20%; A3 = -18%; A1 flow = -42%), despite the increased cardiac output (+21%). L-NAME treatment of bacteremic rats resulted in further constriction (A1 = -31%; A3 = -32%) and decreased A1 flow (-75%). Topical L-ARG (10(-4) M) ameliorated constriction (A1 = -6%; A3 = +7%) and improved blood flow (-5%) during bacteremia. We conclude that: 1) NO is important for basal SI microvascular tone; 2) bacteremia causes SI arteriolar constriction and hypoperfusion; 3) NO-S inhibition during sepsis may exacerbate SI vasoconstriction and hypoperfusion.
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PMID:Role of nitric oxide in the small intestinal microcirculation during bacteremia. 753 19

Coronal slices of rat brain were incubated for 40 min in 300 microM kainate (KA) or 500 microM N-methyl-D-aspartate (NMDA). Histological examination showed neuronal degeneration accompanied by significant losses in the activity of neuron-specific enolase (NSE; EC 4.2.1.11) (-23% KA; -26% NMDA). The activity of the glial enzyme glutamine synthetase (GS; EC 6.3.1.2) was also reduced (-32% KA; -27% NMDA). Pre-incubation with 100 microM L-NG-nitroarginine (L-N-ARG), an inhibitor of nitric oxide (NO) synthase (EC 1.14.23.-), for 20 min attenuated the toxicity of toxicity of NMDA, but not KA. NSE levels after successive incubation in L-N-ARG and NMDA were 95% of controls incubated in Krebs bicarbonate medium only (GS activity 89% of controls). In contrast, pre-incubation with L-N-ARG prior to the addition of KA resulted in neuronal degeneration and significant reductions in NSE levels and GS activities. These observations suggest that the unrestricted function of NO synthase is significant in mediating NMDA neurotoxicity whereas KA toxicity is associated with alternative mechanisms not linked to NO production.
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PMID:Reduction of striatal N-methyl-D-aspartate toxicity by inhibition of nitric oxide synthase. 767 41

Previous work has suggested that the antinociceptive effect of nitrous oxide (N2O) in rats is mediated, at least in part, by beta-endorphin (beta-EP) and that centrally administered beta-EP stimulates release of methionine-enkephalin (ME) in the rat spinal cord. Since inhibition of central nitric oxide (NO) production has been found to suppress N2O antinociception, we examined the possible involvement of NO in the release of spinal cord ME by i.c.v. beta-EP. Urethane-anesthetized, male Sprague-Dawley rats were intrathecally (i.t.) perfused with artificial cerebrospinal fluid (aCSF) and fractions of perfusate were assayed for immunoreactive (i.r.) ME. The beta-EP-induced increase in ME concentration in the i.t. perfusate was significantly suppressed by perfusing the animal with aCSF containing 100 microM L-NG-nitro arginine (L-NOARG), an inhibitor of NO synthase (NOS). The further addition of 50 microM L-arginine (L-ARG), but not D-arginine (D-ARG), to the aCSF reversed the suppression of the ME change by L-NOARG. However, the potency of L-ARG decreased with increasing concentrations of L-ARG. On the other hand, increasing the concentration of L-NOARG in the aCSF to 250 microM failed to produce a greater suppression of the beta-EP-induced increase in ME. These findings suggest that NO may mediate the beta-EP-induced release of ME in the spinal cord and that interference with this mechanism might be an explanation for the antagonism of N2O antinociception in rats by NOS inhibitors.
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PMID:Involvement of nitric oxide in intracerebroventricular beta-endorphin-induced neuronal release of methionine-enkephalin. 779 28

Inflammatory mediators stimulate arginine-derived nitric oxide (NO) production in a variety of cells. The purpose of this study was to determine if the inflammatory mediators, endotoxin (LPS) and interferon gamma (IFN), stimulate arginine transport and nitric oxide production in a murine breast cancer cell line. We also investigated the effect of the nitric oxide synthase (NOS) inhibitors, omega-nitro-L-arginine methyl ester (LNAME) and aminoguanidine (AG), as well as the effect of varying the concentration of L-arginine in the cellular media, on arginine transport and NO production in these tumors cells. Confluent EMT-6 murine breast cancer cells were incubated with LPS (10 microgram/ml) and IFN (50 units/ml) in the presence or absence of the NOS inhibitors, L-NAME (2 mM) or AG (1 mM), and arginine transport (using L-[3H]arginine) and NO production (the stable end-product nitrite was assayed using the Greiss reagent) were measured at various time points. In addition, the effect of varying the concentration of L-arginine (0, 10, 100, 1000, 10,000 mM) in the cellular media on stimulated L-arginine transport and nitrite accumulation was assessed. Incubation of EMT-6 with LPS and IFN stimulated arginine transport approximately 70% over control levels at 12 hr and transport returned to basal levels at 24 hr. LPS/IFN-stimulated EMT-6 cells produced 25 microM nitrite at 24 hr and reached a plateau of 55 microM nitrite at 48 hr. The NO synthase inhibitors, L-NAME and AG, failed to inhibit basal and stimulated levels of arginine transport, but significantly inhibited nitrite accumulation, which was restored by 10 mM L-arginine. Finally, L-arginine was necessary in the media for nitrite accumulation by LPS/IFN-stimulated cells, with maximal accumulation at 1 mM L-arginine. In summary, LPS/IFN stimulate arginine transport and NO production in the EMT-6 breast cancer cell line. L-NAME and AG do not inhibit basal or stimulated arginine transport in this tumor cell line and extracellular L-arginine is required for NO synthesis in these cells. LPS/IFN stimulation of arginine transport may represent an adaptive response to provide increased substrate for enhanced tumor cell NO production.
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PMID:Inflammatory mediators stimulate arginine transport and arginine-derived nitric oxide production in a murine breast cancer cell line. 859 55

Arginine-derived nitric oxide (NO) has been identified in some tumor cell lines and solid human tumors. The effect of tumor cell NO on tumor biology is poorly understood. The purpose of this study was to investigate the effect of NO production by EMT-6 murine breast cancer cells on tumor cell growth in vitro and subcutaneous tumor growth and experimental pulmonary metastasis in vivo. EMT-6 cells were incubated with endotoxin (LPS, 10 microgram/ml) and interferon-gamma (IFN, 50 U/ml), in the presence or absence of the NO synthase inhibitor, omega-nitro-L-arginine methyl ester (L-NAME, 2 mM), and NO production and cell number were assessed 24 hr later. EMT-6 cells were also treated overnight with LPS/IFN, in the presence or absence of L-NAME, washed and injected either subcutaneously in the dorsal flank (n = 40) or via the tail vein (n = 40) of syngeneic BALB/c mice. Two weeks following tumor cell injection, tumor size and number of pulmonary metastases were assessed. LPS/IFN stimulated NO production in EMT-6 cells and inhibited cell growth in vitro by 50%. L-NAME blocked LPS/IFN stimulation of NO production and restored cell growth to near control levels. When injected into BALB/c mice, LPS/IFN-stimulated tumor cells demonstrated a two-fold increase in subcutaneous tumor growth and experimental pulmonary metastases over control cells. L-NAME reduced tumor size and number of lung metastases to control levels, suggesting that tumor cell NO production was responsible for this effect. In summary, LPS/IFN-stimulated NO production in EMT-6 tumor cells inhibits tumor cell growth in vitro, yet paradoxically augments tumor growth and metastasis in vivo.
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PMID:Tumor cell nitric oxide inhibits cell growth in vitro, but stimulates tumorigenesis and experimental lung metastasis in vivo. 866 Nov 71

In whole-cell recordings from CA1 neurons, net outward currents (at ca. -20 mV, from VH ca. -50 mV) were 40-50% depressed by sodium nitroprusside (100-500 microM) or L-arginine (L-ARG; 50-200 microM), but not by D-arginine (100 microM). The NO synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME; 200 microM) restored the L-ARG-depressed current to ca. 80% of control. In naive cells, L-NAME increased outward currents by 45 +/- 12.6%; the enhanced currents were then reduced by adding L-ARG (200-400 microM). The NO-sensitive current is Ca-dependent, because L-NAME and L-ARG were ineffective in Mn/low Ca medium or when electrodes contained 2.2 mM EGTA. Since high voltage-activated Ca-currents were unaltered by L-NAME, we conclude that NO tonically enhances excitability in slices by depressing a voltage- and calcium-dependent (IK(Ca)-type) outward current.
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PMID:Nitric oxide tonically depresses a voltage- and Ca-dependent outward current in hippocampal slices. 883 Mar 13

The effects of N-methyl-D-aspartate (NMDA), kainate, S-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and KCl on striatal nitric oxide (NO), acetylcholine (ACh), dopamine (DA), serotonin (5-HT), aspartate (ASP), glutamate (GLU) and gamma-aminobutyric acid (GABA) release were measured in anaesthetized rats in vivo by microdialysis and in vitro in organotypic slice cultures. Local NMDA (1-100 microM) infusion by retrodialysis dose-dependently increased levels of classical transmitters, NO2-, NO3-, citrulline and arginine at similar thresholds (10 microM). Similar patterns of NMDA-evoked (50 microM) release were seen in striatal cultures. NMDA-evoked changes were all calcium-dependent and blocked by NMDA (APV or MK-801) but not AMPA/kainate (DNQX) receptor antagonists, excepting DA which could be prevented by both. In vivo, kainate increased NO2-, NO3-, CIT and ARG levels at 50 and 100 microM but was less potent than NMDA. Kainate also evoked significant ACh, DA and GLU release dose-dependently starting at 1-10 microM whereas 5-HT, ASP and GABA required 50 or 100 microM doses. Kainate effects were inhibited by DNQX, but not by APV, and were calcium-dependent, AMPA failed to alter NO2-, NO3-, CIT or ARG levels at 50 or 100 microM doses but dose-dependently increased ACh and DA. Similar results were seen with kainate (50 microM) and AMPA (50 microM) in vitro. KCl evoked NO2-, NO3-, CIT and ARG release as well as that of the classical transmitters in vivo and in vitro. In vivo administration of the NO synthase inhibitor L-nitroarginine (L-NARG; 100 microM) significantly reduced NO2-, NO3- and CIT levels and prevented NMDA, kainate or KCl-evoked increases. It also potentiated ACh, ASP, GLU and GABA release and reduced that of DA in response to 50 microM NMDA whereas treatment with an NO-donor (SNAP; 10 microM) significantly reduced evoked ACh, ASP and GLU release. The NO synthase inhibitor L-NARG potentiated kainate-evoked ACh release and reduced that of DA, although less potently than NMDA, but it had no effect on KCl-evoked transmitter release. Overall, these results show that both NMDA and kainate increase striatal NO release at similar dose-thresholds as for classical transmitter release suggesting that NO is dynamically released under physiological and not just pathological conditions. Reductions of striatal NO levels also potentiates calcium-dependent transmitter release in response to NMDA and, to a lesser extent, kainate, whereas increasing them reduces it. This is consistent with a role for NO as a neuroprotective agent in this region acting to desensitize NMDA receptors.
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PMID:NMDA and kainate-evoked release of nitric oxide and classical transmitters in the rat striatum: in vivo evidence that nitric oxide may play a neuroprotective role. 899 12

Nitric oxide (NO) may play an important regulatory role in airway function. We have, thus, investigated in vitro whether epithelium derived NO may modulate cholinergic neurotransmission, via release of NO in guinea pig trachea, by using L-arginine (L-ARG), a precursor of NO synthesis, and L-N(G)-nitro-arginine-methyl-ester (L-NAME), an inhibitor of NO synthase. Results show that L-ARG and L-NAME modify acetylcholine sensitivity in epithelium-intact smooth muscle preparations, suggesting a probable NO synthesis by tracheal guinea pig epithelium.
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PMID:Functional role of nitric oxide in guinea pig tracheal epithelium. 900 50


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