scholarly journals Dual effects of nitric oxide on cat carotid body chemoreception

2000 ◽  
Vol 89 (3) ◽  
pp. 1005-1012 ◽  
Author(s):  
Rodrigo Iturriaga ◽  
Sandra Villanueva ◽  
Matias Mosqueira
Keyword(s):  
Nitric Oxide ◽  
Carotid Body ◽  
Carotid Sinus ◽  
Dependent Manner ◽  
Carotid Sinus Nerve ◽  
Dual Effect ◽  
No Donors ◽  
Pentobarbital Sodium ◽  
Carbon Fiber Microelectrodes ◽  
Dose Dependent

We studied the effects of nitric oxide (NO) released by NO donors on cat carotid body (CB) chemosensory activity during normoxia and hypoxia. CBs excised from pentobarbital sodium-anaesthetized cats were perfused with Tyrode at 38°C and pH 7.40. The frequency of chemosensory discharges (ƒx) was recorded from the carotid sinus nerve, and changes of NO concentration were measured by a chronoamperometric technique, with NO-selective carbon-fiber microelectrodes inserted in the CB. During steady chemosensory excitation induced by hypoxia, bolus injections of NO (ΔNO = 0.5–12 μM), released by S-nitroso- N-acetylpenicillamine (SNAP) and 6-(2-hydroxy-1-methyl-nitrosohydrazino)- N-methyl-1-hexanamine (NOC-9), transiently reduced ƒx in a dose-dependent manner. However, during normoxia, the same concentration of NO (ΔNO = 0.5–13 μM) released by the NO donors increased ƒx in a dose-dependent manner. The present results show a dual effect of NO on CB chemoreception that is dependent on the Po 2 levels. During hypoxia, NO is predominantly an inhibitor of chemoreception, whereas, in normoxia, NO increased ƒx. The mechanisms by which NO produces chemosensory excitation during normoxia remain to be determined.

scholarly journals Glyoxalase I is a novel nitric-oxide-responsive protein

1999 ◽  
Vol 344 (3) ◽  
pp. 837-844 ◽  
Author(s):  
Atsushi MITSUMOTO ◽  
Kwi-Ryeon KIM ◽  
Genichiro OSHIMA ◽  
Manabu KUNIMOTO ◽  
Katsuya OKAWA ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Culture Medium ◽  
Molecular Mechanisms ◽  
Peptide Mapping ◽  
Glyoxalase I ◽  
Dependent Manner ◽  
Human Endothelial Cells ◽  
Native Form ◽  
No Donors ◽  
Dose Dependent

To clarify the molecular mechanisms of nitric oxide (NO) signalling, we examined the NO-responsive proteins in cultured human endothelial cells by two-dimensional (2D) PAGE. Levels of two proteins [NO-responsive proteins (NORPs)] with different pI values responded to NO donors. One NORP (pI 5.2) appeared in response to NO, whereas another (pI 5.0) disappeared. These proteins were identified as a native form and a modified form of human glyoxalase I (Glox I; EC 4.4.1.5) by peptide mapping, microsequencing and correlation between the activity and the isoelectric shift. Glox I lost activity in response to NO, and all NO donors tested inhibited its activity in a dose-dependent manner. Activity and normal electrophoretic mobility were restored by dithiothreitol and by the removal of sources of NO from the culture medium. Glox I was selectively inactivated by NO; compounds that induce oxidative stress (H2O2, paraquat and arsenite) failed to inhibit this enzyme. Our results suggest that NO oxidatively modifies Glox I and reversibly inhibits the enzyme's activity. The inactivation of Glox I by NO was more effective than that of glyceraldehyde-3-phosphate dehydrogenase (G3PDH), another NO-sensitive enzyme. Thus Glox I seems to be a novel NO-responsive protein that is more sensitive to NO than G3PDH.

Ecological and physiological as well as biochemical properties of representatives of the Genus sedum L.

2014 ◽  
Vol 25 (3-4) ◽  
pp. 24-33
Author(s):  
O. I. Dzjuba ◽  
M. V. Yatsenko
Keyword(s):  
Nitric Oxide ◽  
Cell Line ◽  
Methanol Extract ◽  
Hepatoma Cell ◽  
Ethanol Extract ◽  
Biochemical Properties ◽  
Biologically Active ◽  
Hepatoma Cell Line ◽  
Dependent Manner ◽  
Dose Dependent

The article deals with the history of the study and the current state of research of physiological and biochemical properties of the plant genus Sedum that are useful for human and has been used in folk medicine for many years. It was noticed that antioxidant properties of extracts from plants S. sarmentosum, S. sempervivoides, S. takesimense were caused by the presence of phenolic compounds. Methanol extract of plants S. takesimense exhibited strong scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals as well as significant inhibitory effects on lipid peroxidation and low density lipoprotein (LDL) oxidation induced by a metal ion Cu2+. Various immunomodulatory activities of various fractions of plants extracts (S. dendroideum, S. kamtschaticum, S. sarmentosum, S. telephium) are observed. It was shown that the ethanol extract of S. sarmentosum and it’s fractions suppressed specific antibody and cellular responses to ovalbumin in mice. The methanol extract of plants S. sarmentosum reduced the levels of anti-inflammatory markers, such as volume of exudates, number of polymorphonuclear leukocytes, suppressed nitric oxide synthesis in activated macrophages via suppressed induction of inducible nitric oxide synthase (iNOS). Polysaccharides fractions from plants S. telephium inducing productions of tumor necrosis factor alpha (TNF-α), increasing the intensity of phagocytosis in vitro and in vivo. Methanol extract from the whole part of S. kamtschaticum strongly inhibit PGE2 production from lipopolysaccharide-induced RAW 264.7 cells, a mouse macrophage cell line via modulating activity in gene expression of the enzyme cyclooxygenase-2 (COX-2). The methanol extract of plants S. sarmentosum and the major kaempferol glycosides from S. dendroideum have antinociceptive activity. It was noticed that anti-adipogenic activity of extracts from plants S. kamtschaticum were caused by inhibition of peroxisome-proliferator-activated receptor γ (PPARγ) expression and it’s dependent target genes, such as genes encoding adipocyte protein 2 (аР2), lipoprotein lipase (LPL), adiponectin and CD36. Polysaccharides fractions from S. telephium cause inhibition of cell adhesion of human fibroblast (MRC5) to laminin and fibronectin via interfere with integrin-mediated cell behaviour and they contributed to the role of polysaccharides in cell-matrix interaction. The methanol extract of plants S. sarmentosum exhibited a significant inhibitory activity in the chick embryo chorioallantoic membrane angiogenesis in a dose-dependent manner. The crude alkaloid fraction of S. sarmentosum caused a dose-dependent inhibition of cell proliferation on murine hepatoma cell line BNL CL.2 and human hepatoma cell line HepG2 without necrosis or apoptosis. Alkaloids from plants S. sarmentosum may improve survival of hepatoma patients via the inhibition of excessive growth of tumor cells. Plant’s juices have antiviral activity (S. sarmentosum, S. spurium, S. stahlii). Crude ethanol extract S. praealtum have spermicidal activity of the in mice and a relevant inhibitory effect of aqueous extract on human spermatozoa motility as well as an anti-fertilizing activity in rats. Hepatoprotective triterpenes, e.g., δ-amyrone, 3-epi-δ-amyrin, δ-amyrin and sarmentolin were isolated from S. sarmentosum. 2- and 2,6-substituted piperidine alkaloids (e.g., norsedamine, allosedridine, sedamine, allosedamine) are observed in plants S. acre, which in the presence of data on the use of pyridine and piperidine derivatives for treating neurodegenerative diseases (e.g., Alzheimer's disease), points on the promising research in this area. Taking into account that biologically active compounds are accumulated in the aboveground vegetative organs of plants of Sedum, the prospects of further study of the use of Sedum for the purposes of biotechnology and in the pharmaceutical industry becomes apparent. This work extends the existing views regarding the use of plants Sedum.

Appraisal of Immunological Impacts of Melaleuca leucadendra Extract over Macrophage Performance in Vitro

2020 ◽  
Keyword(s):  
Nitric Oxide ◽  
Interleukin 2 ◽  
Dependent Manner ◽  
Reduced Pressure ◽  
Medical Plant ◽  
Dose Dependent ◽  
Level Production ◽  
Melaleuca Leucadendra ◽  
Phagocytic Killing

This trial research was performed to discuss the immune-influence of Melaleuca leucadendra ‘paper-bark tree’ dried leaves which is an important medical plant known in many regions in the world. The leaves were dissolved in a mixture of (ethanol + water) (3:1) mixture, then filtered, evaporated and dried under reduced pressure to obtain leaves extract. The macrophages of blood derived origin were provided from rats and mixed with three different leaves extracts doses in tissue culture plates and incubated then stained with fluorescent acridine orange and examined under fluorescent microscope to assess the phagocytic and killing potency. The wells contents were aspirated and assayed for nitric oxide and interleukin-2 levels. The results displayed an obvious increase in phagocytic, killing performance as well as nitric oxide and IL-2 level production than control in a dose dependent manner. The obtained results suggested the immune-stimulant impact of the paper-bark tree leaves.

Suppressive effects of sulfated polysaccharide ascophyllan isolated from Ascophyllum nodosum on the production of NO and ROS in LPS-stimulated RAW264.7 cells

2020 ◽  
Vol 85 (4) ◽  
pp. 882-889
Author(s):  
Yan Liang ◽  
Shijiao Zha ◽  
Masanobu Tentaku ◽  
Takasi Okimura ◽  
Zedong Jiang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ascophyllum Nodosum ◽  
Sulfated Polysaccharide ◽  
Intracellular Reactive Oxygen Species ◽  
Raw264.7 Cells ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Oxide Synthase ◽  
Dose Dependent ◽  
Inducible Nitric Oxide

ABSTRACT In this study, we found that a sulfated polysaccharide isolated from the brown alga Ascophyllum nodosum, ascophyllan, showed suppressive effects on stimulated RAW264.7 cells. Ascophyllan significantly inhibited expression of inducible nitric oxide synthase mRNA and excessive production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in a dose-dependent manner without affecting the viability of RAW264.7 cells. Ascophyllan also reduced the elevated level of intracellular reactive oxygen species (ROS) in LPS-stimulated RAW264.7 cells. Furthermore, preincubation with ascophyllan resulted in concentration-dependent decrease in ROS production in phorbol 12-myristate-13-acetate-stimulated RAW264.7 cells. Our results suggest that ascophyllan can exhibit anti-inflammatory effects on stimulated macrophages mainly through the attenuation of NO and ROS productions.

Abstract 619: Alpha Keto Acids Decompose Peroxides and Prevents Oxidation of Lipoproteins

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Chandrakala Aluganti Narasimhulu ◽  
Kathryn Young Burge ◽  
Yu Yuan ◽  
Sampath Parthasarathy
Keyword(s):  
Therapeutic Potential ◽  
Lipid Peroxides ◽  
Enzymatic Oxidation ◽  
Raw 264.7 Cells ◽  
Dependent Manner ◽  
Gene Expressions ◽  
Dual Effect ◽  
Keto Acids ◽  
Hydroperoxyoctadecadienoic Acid ◽  
Dose Dependent

Background: Alpha keto acids are unstable and decompose rapidly. In this study, we tested the ability of alpha keto acids to reduce peroxides and inhibit oxidation of lipoproteins. Methods: Keto salicylic acid (KSA) and Keto Octanoicacid (KoA) were synthesized and their ability to reduce hydrogen peroxides as well as lipid peroxides (LOOH) was measured using 13-hydroperoxyoctadecadienoic acid (13-HPODE). Lipoproteins (LDL and HDL) were isolated from human plasma and oxidation of liporproteins was performed using copper and MPO in the presence or absence of the keto compounds. RAW 264.7 cells and HUVECS were incubated with LPS and mm-LDL respectively either in the presence or absence of the keto compounds. RNA was isolated from treated cells and real time PCR was performed to analyze IL-1α, IL-6, MCP-1 and VCAM1 gene expressions. Reactive oxygen species were evaluated using DCF fluorescence in presence and absence of the keto compounds. Results: KSA reduced both H2O2 and 13-HPODE whereas KoA is able to reduce the former but not the latter. Both compounds inhibited the lipoprotein oxidation in a dose dependent manner and were able to reduce ROS production by H2O2. KSA is able to inhibit both LPS as well as mm-LDL induced inflammation. However, KoA showed a dual effect as it induced inflammatory markers in the presence of LPS, but inhibited the mm-LDL-induced inflammatory gene expressions. Conclusion: The results of our studies suggest that these keto compounds a) inhibit both enzymatic and non enzymatic oxidation of lipoproteins; b) reduce peroxides and ROS and c) have inhibitory and inducing effect on inflammatory cytokine/gene production in presence of mm-LDL and LPS respectively. Based on these results, we predict that these keto compounds could have therapeutic potential in reducing CVD/atherosclerosis-associated inflammation.

scholarly journals Dual effect of polyphosphate on mineralization of rat osteoblast ROS17/2.8 cells in a dose-dependent manner

2018 ◽  
Vol 138 (3) ◽  
pp. 209-213 ◽  
Author(s):  
Yoshikazu Mikami ◽  
Daisuke Omagari ◽  
Yusuke Mizutani ◽  
Manabu Hayatsu ◽  
Tatsuo Ushiki ◽  
...  
Keyword(s):  
Dependent Manner ◽  
Dual Effect ◽  
Rat Osteoblast ◽  
Dose Dependent

scholarly journals Endogenous H2S is required for hypoxic sensing by carotid body glomus cells

2012 ◽  
Vol 303 (9) ◽  
pp. C916-C923 ◽  
Author(s):  
Vladislav V. Makarenko ◽  
Jayasri Nanduri ◽  
Gayatri Raghuraman ◽  
Aaron P. Fox ◽  
Moataz M. Gadalla ◽  
...  
Keyword(s):  
Carotid Body ◽  
Time Course ◽  
Channel Blocker ◽  
Primary Site ◽  
Dependent Manner ◽  
Free Medium ◽  
Adult Rats ◽  
Glomus Cells ◽  
Dose Dependent ◽  
Carotid Body Glomus Cells

H2S generated by the enzyme cystathionine-γ-lyase (CSE) has been implicated in O2 sensing by the carotid body. The objectives of the present study were to determine whether glomus cells, the primary site of hypoxic sensing in the carotid body, generate H2S in an O2-sensitive manner and whether endogenous H2S is required for O2 sensing by glomus cells. Experiments were performed on glomus cells harvested from anesthetized adult rats as well as age and sex-matched CSE+/+ and CSE−/− mice. Physiological levels of hypoxia (Po2 ∼30 mmHg) increased H2S levels in glomus cells, and dl-propargylglycine (PAG), a CSE inhibitor, prevented this response in a dose-dependent manner. Catecholamine (CA) secretion from glomus cells was monitored by carbon-fiber amperometry. Hypoxia increased CA secretion from rat and mouse glomus cells, and this response was markedly attenuated by PAG and in cells from CSE−/− mice. CA secretion evoked by 40 mM KCl, however, was unaffected by PAG or CSE deletion. Exogenous application of a H2S donor (50 μM NaHS) increased cytosolic Ca2+ concentration ([Ca2+]i) in glomus cells, with a time course and magnitude that are similar to that produced by hypoxia. [Ca2+]i responses to NaHS and hypoxia were markedly attenuated in the presence of Ca2+-free medium or cadmium chloride, a pan voltage-gated Ca2+ channel blocker, or nifedipine, an L-type Ca2+ channel inhibitor, suggesting that both hypoxia and H2S share common Ca2+-activating mechanisms. These results demonstrate that H2S generated by CSE is a physiologic mediator of the glomus cell's response to hypoxia.

Sign in / Sign up

Export Citation Format

Share Document