Inhibition of nitric oxide synthesis improves detoxication in inflammatory liver dysfunction in vivo

1997 ◽  
Vol 273 (2) ◽  
pp. G530-G536 ◽  
Author(s):  
A. Veihelmann ◽  
T. Brill ◽  
M. Blobner ◽  
I. Scheller ◽  
B. Mayer ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
In Vitro Assays ◽  
Serum Concentrations ◽  
Aminopyrine Breath Test ◽  
Vitro Assay ◽  
Synthase Inhibitor ◽  
Cytochrome P 450 ◽  
Stimulation Of

Inflammatory stimulation of the liver induces nitric oxide (NO) biosynthesis and suppression of detoxication. In this study the effect of NO biosynthesis on cytochrome P-450 (CYP) enzyme activity was investigated by comparing in vivo and in vitro assays. To establish liver inflammation, CD rats were injected with Corynebacterium parvum (C. parvum) suspension. After 5 days NO biosynthesis was highly induced as indicated by increased NO2- plus NO3- serum concentrations. At the same time the aminopyrine breath test (ABT), measuring CYP activity in vivo, was reduced to 42% and the in vitro assay of aminopyrine turnover was suppressed to 12% of NaCl- injected controls. When C. parvum-injected animals were treated with the NO synthase inhibitor NG-monomethyl-L-arginine (L-NMMA), CYP activities significantly improved with an ABT of 76% and an in vitro aminopyrine turnover of 47% of controls. Neither C. parvum injections nor L-NMMA treatment resulted in a significant change of CYP protein concentrations. These data indicate that suppression of xenobiotic metabolism can be attenuated by inhibition of NO biosynthesis during an ongoing process of inflammation.

Abstract 18060: TRAIL Promotes Angiogenesis and Ischemia-Induced Neovascularisation via NOX4, H2O2 and Nitric Oxide-Dependent Mechanisms

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Belinda A Di Bartolo ◽  
Sian P Cartland ◽  
Leonel Prado-Lourenco ◽  
Nor Saadah M Azahri ◽  
Thuan Thai ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Angiogenic Factor ◽  
Tubule Formation ◽  
Nitric Oxide Synthase Inhibitor ◽  
Therapeutic Implications ◽  
Synthase Inhibitor ◽  
Oxide Synthase ◽  
First Time

Background: Angiogenesis and neovascularization are essential processes that follow ischemia insults. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) not only induces endothelial cell (EC) death and inhibits angiogenesis, but also promotes EC migration, invasion and proliferation in vitro . These seemingly opposite effects make its role in angiogenesis in vivo unclear. Using TRAIL -/- and wild-type mice, we sought to determine the role of TRAIL in angiogenesis and neovascularisation. We also sought mechanisms in vitro . Methods and Results: Reduced vascularisation assessed by real-time in vivo 3D Vevo ultrasound imaging and CD31 staining was observed in TRAIL -/- mice 28 d after hindlimb ischemia. Moreover, reduced capillary formation and increased apoptosis was evident in TRAIL -/- muscles even at 3 d after ischemic surgery. We have previously shown that fibroblast growth factor-2 (FGF-2), a potent angiogenic factor, regulates TRAIL gene expression in vascular smooth muscle cells. Indeed, FGF-2 also regulates TRAIL expression in ECs, and FGF-2-inducible proliferation, migration and tubule formation was inhibited with siRNA targeting TRAIL. Notably, both FGF-2 and TRAIL significantly increased NOX4 expression. TRAIL-inducible angiogenic activity in ECs was inhibited with siRNAs targeting NOX4, and consistent with these, NOX4 mRNA was reduced in 3 d ischemic hindlimbs of TRAIL -/- mice. TRAIL stimulated intracellular H 2 O 2 levels in ECs, and TRAIL-inducible proliferation, migration and tubule formation was inhibited with not only PEG-catalase, a H 2 O 2 scavenger, but also blocked with L-NAME, a nitric oxide synthase inhibitor. Conclusions: This is the first demonstration showing that TRAIL promotes angiogenesis in vivo . We show for the first time that the TRAIL stimulates NOX4 expression to mediate nitric oxide-dependent angiogenic effects. This has significant therapeutic implications such that TRAIL may improve the angiogenic response to ischemia and increase perfusion recovery in patients with CVD and diabetes.

scholarly journals Leucine-Rich Diet Modulates the Metabolomic and Proteomic Profile of Skeletal Muscle during Cancer Cachexia

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1880 ◽  
Author(s):  
Bread Cruz ◽  
André Oliveira ◽  
Lais Rosa Viana ◽  
Leisa Lopes-Aguiar ◽  
Rafael Canevarolo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cancer Cachexia ◽  
Energy Generation ◽  
In Vitro Assays ◽  
Proteomic Profile ◽  
Adult Rats ◽  
Vitro Assay ◽  
Tumour Bearing

Background: Cancer-cachexia induces a variety of metabolic disorders, including skeletal muscle imbalance. Alternative therapy, as nutritional supplementation with leucine, shows a modulatory effect over tumour damage in vivo and in vitro. Method: Adult rats distributed into Control (C), Walker tumour-bearing (W), control fed a leucine-rich diet (L), and tumour-bearing fed a leucine-rich diet (WL) groups had the gastrocnemius muscle metabolomic and proteomic assays performed in parallel to in vitro assays. Results: W group presented an affected muscle metabolomic and proteomic profile mainly related to energy generation and carbohydrates catabolic processes, but leucine-supplemented group (WL) recovered the energy production. In vitro assay showed that cell proliferation, mitochondria number and oxygen consumption were higher under leucine effect than the tumour influence. Muscle proteomics results showed that the main affected cell component was mitochondria, leading to an impacted energy generation, including impairment in proteins of the tricarboxylic cycle and carbohydrates catabolic processes, which were modulated and improved by leucine treatment. Conclusion: In summary, we showed a beneficial effect of leucine upon mitochondria, providing information about the muscle glycolytic pathways used by this amino acid, where it can be associated with the preservation of morphometric parameters and consequent protection against the effects of cachexia.

The nitric oxide synthase inhibitor, N-monomethyl-L-arginine blocks induction of a long-term potentiation-like phenomenon in rat medial frontal cortical neurons in vitro

1993 ◽  
Vol 70 (3) ◽  
pp. 1255-1259 ◽  
Author(s):  
A. V. Nowicky ◽  
L. J. Bindman
Keyword(s):  
Nitric Oxide ◽  
Cortical Neurons ◽  
Long Term Potentiation ◽  
Control Group ◽  
Term Potentiation ◽  
The Mean ◽  
Synthase Inhibitor ◽  
Stimulation Of

1. Nitric oxide has been implicated in the production of long-term depression (LTD) in the cerebellum and in the production of long-term potentiation (LTP) and LTD in the hippocampus. We now provide evidence of its involvement in the induction of long-term synaptic potentiation in in vitro slices in the cerebral cortex of the rat. 2. Intracellular recordings were made from layer V neurons in the medial frontal cortex, and excitatory synaptic potentials (EPSPs) were evoked by electrical stimulation of layers II/III. Tetanic stimulation of this pathway may induce LTD or LTP or no change at these synapses. First we established experimental conditions under which a long lasting potentiation could be induced with a high incidence (> 60%), namely perfusion of slices with 1 microM bicuculline methiodide, second the use of increased shock duration in the tetanic conditioning stimuli, third and most important the addition of QX-314 to the microelectrode to reduce potassium conductances. Because the potentiation of the mean EPSP slope was significantly greater than the control at 40-min postconditioning, but was declining throughout this period, we refer to it for brevity as LTP, but strictly class it as an LTP-like phenomenon. 3. The nitric oxide (NO) synthase inhibitor interfered with the production of LTP. In the control group of neurons (n = 13) the mean depolarizing slope of the EPSP at 30-min post-conditioning was 142.7 +/- 2% (mean +/- SE) of the prestimulation control.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of Inhibition of Bovine Hepatic Cytochrome P450 by 43 Commercial Bovine Medicines Using a Combination of In Vitro Assays and Pharmacokinetic Data from the Literature

2020 ◽  
Vol 13 (2) ◽  
pp. 123-131
Author(s):  
Steven X. Hu ◽  
Chase A. Mazur ◽  
Kenneth L. Feenstra
Keyword(s):  
Liver Microsomes ◽  
In Vitro Assay ◽  
In Vitro Assays ◽  
Pharmacokinetic Studies ◽  
Pharmacokinetic Data ◽  
Vitro Assay ◽  
Administration Routes ◽  
Ic50 Values

Background: There has been a lack of information about the inhibition of bovine medicines on bovine hepatic CYP450 at their commercial doses and dosing routes. Objective: The aim of this work was to assess the inhibition of 43 bovine medicines on bovine hepatic CYP450 using a combination of in vitro assay and Cmax values from pharmacokinetic studies with their commercial doses and dosing routes in the literature. Methods: Those drugs were first evaluated through a single point inhibitory assay at 3 μM in bovine liver microsomes for six specific CYP450 metabolisms, phenacetin o-deethylation, coumarin 7- hydroxylation, tolbutamide 4-hydroxylation, bufuralol 1-hydroxylation, chlorzoxazone 6-hydroxylation and midazolam 1’-hydroxylation. When the inhibition was greater than 20% in the assay, IC50 values were then determined. The potential in vivo bovine hepatic CYP450 inhibition by those drugs was assessed using a combination of the IC50 values and in vivo Cmax values from pharmacokinetic studies at their commercial doses and administration routes in the literature. Results: Fifteen bovine medicines or metabolites showed in vitro inhibition on one or more bovine hepatic CYP450 metabolisms with different IC50 values. Desfuroylceftiour (active metabolite of ceftiofur), nitroxinil and flunixin have the potential to inhibit one of the bovine hepatic CYP450 isoforms in vivo at their commercial doses and administration routes. The rest of the bovine medicines had low risks of in vivo bovine hepatic CYP450 inhibition. Conclusion: This combination of in vitro assay and in vivo Cmax data provides a good approach to assess the inhibition of bovine medicines on bovine hepatic CYP450.

Effect of Chronically Administered Ketoconazole on the Elimination of Theophylline in Man

1987 ◽  
Vol 21 (6) ◽  
pp. 514-517 ◽  
Author(s):  
James J. Heusner ◽  
George E. Dukes ◽  
Douglas E. Rollins ◽  
Keith G. Tolman ◽  
Raymond E. Galinsky
Keyword(s):  
Multiple Dose ◽  
Statistical Difference ◽  
Dosage Adjustment ◽  
Serum Concentrations ◽  
Fluorescence Polarization Immunoassay ◽  
Metabolic Processes ◽  
Time Points ◽  
Cytochrome P 450

Ketoconazole, a nitrogen-substituted imidazole, has been shown to be a potent in vitro inhibitor of cytochrome P-450-mediated metabolic processes. Conflicting reports exist concerning the in vivo effect of ketoconazole on concomitantly administered drugs that require these metabolic processes for clearance. Therefore, the effect of multiple-dose ketoconazole on the elimination of theophylline, a drug metabolized by cytochrome P-450, in ten healthy, nonsmoking males (aged 18–40 years) was evaluated. Each subject received aminophylline 6 mg/kg iv before and at the end of seven days of ketoconazole 200 mg/d po. Theophylline serum concentrations were determined by fluorescence polarization immunoassay (TDx) at 12 time points over the 24-hour period following each infusion. No statistical difference (two-tailed t-test) in half-life (mean ± SD 7.8 ± 1.8 vs. 8.2 ± 1.9 h) or clearance (0.797 ± 0.201 vs. 0.722 ± 0.133 ml/min/kg) could be demonstrated for theophylline before or after ketoconazole administration. Theophylline dosage adjustment is probably not necessary for concomitant theophylline and ketoconazole drug therapy.

scholarly journals In Vitro Assays for Phototoxicity

1998 ◽  
Vol 17 (5) ◽  
pp. 567-570
Author(s):  
A. Kornhauser ◽  
R. R. Wei ◽  
W. G. Warner
Keyword(s):  
In Vitro Assay ◽  
In Vitro Assays ◽  
Vitro Assay ◽  
Cellular Targets ◽  
Photooxidative Damage ◽  
Us Government ◽  
Promising Area ◽  
Rna And Dna

This paper summarizes a few in vitro methods to assess photodamage in cells irradiated with UV of various wavelengths in the presence of a number of photo-sensitizers. A single in vitro assay for phototoxicity (photoirritation) is not likely to be predictive because of different mechanisms of phototoxicity and diverse cellular targets for injury. A number of methods have to be combined to provide a better prediction of these phenomena. Measurement of mechanistically relevant biomarkers also represents a promising area of in vitro testing for phototoxicity, and it is also briefly reviewed in this paper. Photodynamic sensitizers, representing a large class of phototoxic agents, can now be identified by sensitive measurement of photooxidative damage to cellular RNA and DNA. Currently, US government agencies have not identified a single in vitro assay for phototoxicity which would be acceptable for replacing an in vivo assay for regulatory purposes.

In vivo production of nitric oxide correlates with NMDA-induced cerebral hyperemia in newborn sheep

1995 ◽  
Vol 269 (1) ◽  
pp. H215-H221 ◽  
Author(s):  
F. J. Northington ◽  
J. R. Tobin ◽  
R. C. Koehler ◽  
R. J. Traystman
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Production ◽  
Nitric Oxide Synthase Inhibitor ◽  
Oxide Production ◽  
Adenosine Receptor Agonist ◽  
Synthase Inhibitor ◽  
Oxide Synthase ◽  
Hydrogen Clearance

Stimulation of N-methyl-D-aspartate (NMDA) receptors in brain increases nitric oxide production in vitro. We tested the hypothesis that nitric oxide participates in the increase in local cerebral blood flow (CBF) caused by infusion of NMDA in anesthetized newborn sheep. We used the combined hydrogen clearance and microdialysis technique for simultaneous measurement of local CBF, infusion of drugs, and measurement of interstitial levels of L-[14C]citrulline in the parietal cortex. Release of L-[14C]citrulline into the dialysate during continuous infusion of L-[14C]arginine was used as a marker of nitric oxide production in vivo. Citrulline recovery and CBF were measured hourly during a 4-h infusion of cerebrospinal fluid containing either 1) no additional drugs, 2) 1 mM NMDA, 3) 1 mM NG-nitro-L-arginine methyl ester (L-NAME, a nitric oxide synthase inhibitor), 4) 1 mM NMDA + 1 mM L-NAME, 5) 0.1 mM 2-chloroadenosine (adenosine receptor agonist), or 6) 0.1 mM 2-chloroadenosine + 1 mM L-NAME. At 240 min of perfusion, CBF (ml.min-1.100 g-1; means +/- SE) was as follows: control 52 +/- 3, NMDA 116 +/- 11, L-NAME 32 +/- 5, NMDA+L-NAME 40 +/- 4,2-chloroadenosine 201 +/- 63, and 2-chloroadenosine+L-NAME 129 +/- 18. Citrulline recovery (fmol/min) at 240 min of perfusion was as follows: control 38 +/- 12, NMDA 149 +/- 21, L-NAME 9 +/- 1, NMDA+L-NAME 39 +/- 5, 2-chloroadenosine 13 +/- 5, and 2-chloroadenosine+L-NAME 17 +/- 1.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals 1341. Development of a Series of High-Throughput Screens to Identify Leads for Nontuberculous Mycobacteria Drug Design

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S485-S485
Author(s):  
Sarah McGuffin ◽  
Steven Mullen ◽  
Julie Early ◽  
Tanya Parish
Keyword(s):  
Drug Discovery ◽  
Drug Development ◽  
High Throughput ◽  
Nontuberculous Mycobacteria ◽  
Human Infection ◽  
Attrition Rate ◽  
In Vitro Assays ◽  
Vitro Assay

Abstract Background Nontuberculous mycobacteria (NTM), particularly Mycobacterium avium complex and Mycobacterium abscessus complex, cause significant morbidity and mortality in patients with impaired host immunity or pre-existing structural lung conditions. NTM infections are increasing at an alarming rate worldwide and there is a dearth of progress in regard to the development of efficacious and tolerable drugs to treat such infections. Traditional drug discovery screens do not account for the diverse physiological conditions, microenvironments, and compartments that the bacilli encounter during human infection. In order to help populate the NTM drug pipeline, and explore the disconnect between in vitro activity, in vivo activity, and clinical outcomes, we are developing a high throughput in vitro assay platform that will more closely model the unique infection-relevant conditions encountered by NTM. Methods We are developing and validating a suite of in vitro assays that screen compounds for activity against extracellular planktonic bacteria, extracellular bacteria within biofilms, intracellular bacteria, and nutrient-starved non-replicating bacteria. Results We are using both the smooth and rough morphotypes of M. abscessus and M. avium. We have validated high throughput assays to pharmaceutical standards for replicating and non-replicating M. abscessus. We have also tested a panel of 18 known anti-mycobacterial compounds. Assay development is currently underway to test compounds for activity against NTM in biofilm and inside macrophages as well. Conclusion To enhance hit identification for scaffolds to use as starting points for NTM drug development, focused libraries of compounds that have undergone significant preclinical profiling and/or compounds with known activity against M. tuberculosis (TB) will be screened. Such a “piggyback” approach usurps advances made in TB drug development and leverages them for NTM drug discovery. This will help expedite novel drug development, reduce attrition rate, and offer a shorter route to clinical use as it exploits the prior investment in medicinal chemistry, pharmacology, and toxicology. Disclosures All authors: No reported disclosures.

scholarly journals Immune modulation by fish kinetoplastid parasites: a role for nitric oxide

Parasitology ◽  
2002 ◽  
Vol 124 (1) ◽  
pp. 77-86 ◽  
Author(s):  
J. P. J. SAEIJ ◽  
W. B. VAN MUISWINKEL ◽  
A. GROENEVELD ◽  
G. F. WIEGERTJES
Keyword(s):  
Nitric Oxide ◽  
Immune Modulation ◽  
Head Kidney ◽  
Fish Host ◽  
No Production ◽  
Phagocytic Cells ◽  
Term Survival ◽  
Synthase Inhibitor

Trypanoplasma borreli and Trypanosoma carassii are kinetoplastid parasites infecting cyprinid fish. We investigated the role of nitric oxide (NO) in immune modulation during T. borreli and T. carassii infection of carp. Phagocytic cells from different organs produced NO and serum nitrate levels increased, demonstrating that T. borreli activates NO production in vivo. In contrast, T. carassii did not induce NO production in vivo and inhibited LPS-induced NO production in vitro. Production of NO was detrimental to the host as T. borreli-infected carp treated with the inducible NO synthase inhibitor aminoguanidine had a higher survival than infected control carp. This detrimental effect can be explained (in part) by the toxicity of NO to cells in vitro as NO inhibited the proliferative response of blood and spleen leukocytes. Head-kidney phagocytes were resistant to the immunosuppressive effects of NO in vitro. The NO-inducing activity of T. borreli may be an adaptation developed to ensure survival and immune evasion in the fish host. Apparently, T. carassii has adopted another strategy by deactivating specific functions of phagocytes. Both strategies may ensure long-term survival of the parasite.

scholarly journals Evaluation of Antagonism Activity and Control of Vibrio alginolyticus in Artemia Culture Using Mixed Probiotic

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Mei Yun Beryl Chean ◽  
Puvaneswari Puvanasundram ◽  
Jasmin Yaminudin ◽  
Murni Karim
Keyword(s):  
Vibrio Alginolyticus ◽  
In Vitro Assays ◽  
High Concentration ◽  
Immersion Method ◽  
Vitro Assay ◽  
Single Strain ◽  
Artemia Nauplii ◽  
And Control

Supplementation with mixed probiotic in aquaculture has been proven to benefit the hosts as disease resistance tool. In this study, a mixed probiotic which consisted of three isolated strains (Lysinibacillus fusiformis strain SPS11, A2, and Bacillus megaterium strain I24) was formulated for the in vitro assays against Vibrio alginolyticus and in vivo preliminary study towards Artemia nauplii. These strains showed antagonism activities against V. alginolyticus in in vitro assay. An increase in biofilm formation of this mixed probiotic was observed which indicated that the strains could work synergistically with each other to confer benefits to the hosts. Enrichment of Artemia nauplii with the formulated mixed probiotic was done to investigate its role in enhancing resistance against the V. alginolyticus. Artemia nauplii were cultured in two different concentrations of mixed probiotic (106 and 108 CFU mL-1) and challenged via immersion method. The mixed probiotic at both concentrations resulted in significantly higher survival of Artemia compared to the challenged group with no probiont added (106 CFU mL-1, 65.00 ± 0.00 % and 108 CFU mL-1, 77.50 ± 3.53 %). Significant reduction of Vibrio loads was observed in Artemia and its culture water supplemented with mixed probiotic at 108 CFU mL-1 whereas there was no reduction of Vibrio at 106 CFU mL-1. This study suggests that the usage of formulated mixed probiotic at high concentration (108 CFU mL-1) as opposed to single-strain probiotic can confer protection against V. alginolyticus infection towards Artemia.

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