scholarly journals Renal ischemia in the rat stimulates glomerular nitric oxide synthesis

2001 ◽  
Vol 280 (3) ◽  
pp. R771-R779 ◽  
Author(s):  
José M. Valdivielso ◽  
Carlos Crespo ◽  
José R. Alonso ◽  
Carlos Martı́nez-Salgado ◽  
Nelida Eleno ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Structural Damage ◽  
Renal Damage ◽  
Protective Role ◽  
Renal Ischemia ◽  
No Production ◽  
Ischemia And Reperfusion ◽  
Nitric Oxide Synthesis ◽  
Cgmp Production ◽  
Synthesis Activity

Renal ischemia in humans and in experimental animals is associated with a complex and possibly interrelated series of events. In this study, we have investigated the glomerular nitric oxide (NO) production after renal ischemia. Unilateral or bilateral renal ischemia was induced in Wistar rats by clamping one or both renal arteries. NO production was assessed by measuring glomerular production of nitrite, a stable end product of NO catabolism, and NO-dependent glomerular cGMP production and by assessing the glomerular NADPH diaphorase (ND) activity, an enzymatic activity that colocalizes with NO-synthesis activity. Furthermore, we determined the isoform of NO synthase (NOS) implicated in NO synthesis by Western blot and immunohistochemistry. Glomeruli from rats with bilateral ischemia showed elevated glomerular nitrite and cGMP production. Besides, glomeruli from this group of rats showed an increased ND activity, whereas glomeruli from the ischemic and nonischemic rats with unilateral ischemia did not show this increase in nitrite, cGMP, and ND activity. In addition, glomeruli from ischemic kidneys showed an increased expression of endothelial NOS without changes in the inducible isoform. Addition ofl-NAME in the drinking water induced a higher increase in the severity of the functional and structural damage in rats with bilateral ischemia than in rats with unilateral ischemia and in sham-operated animals. We can conclude that after renal ischemia, there is an increased glomerular NO synthesis subsequent to an activation of endothelial NOS that plays a protective role in the renal damage induced by ischemia and reperfusion.

scholarly journals Pretreatment of Nicorandil Protects the Heart from Exhaustive Exercise-Induced Myocardial Injury in Rats

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Lei Lv ◽  
Lin Li ◽  
Yiyong Zhu ◽  
Anwar Azhar ◽  
Yao Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Structural Damage ◽  
Myocardial Injury ◽  
Protective Role ◽  
Exhaustive Exercise ◽  
High Dose ◽  
No Production ◽  
Protective Effects ◽  
Sprague Dawley

Objective. Nicorandil has been widely used for the treatment of angina pectoris and myocardial infarction. The purpose of this study was to investigate whether nicorandil plays a protective role in exhaustive exercise (EE)-induced myocardial injury. Methods. Here, we applied the rat EE model and treated them with exercise preconditioning (EP, reported to protect the heart) or different doses of nicorandil gavage, respectively, to explore whether there are protective effects of single EP or nicorandil or a combination of both and the potential mechanism. Forty-nine male Sprague Dawley rats were randomly divided into control, EE, EP + EE, nicorandil (with low, middle, and high dose) + EE, and EP + nicorandil (middle dose) + EE. Blood samples and myocardial tissues were collected to analyze the myocardial injury-related index. Results. EE induced myocardial structural damage and altered the myocardial injury markers, which were partially reversed by pretreatment of nicorandil. In addition, oxidative stress and inflammation lead to the accumulation of reactive oxygen species (ROS) products and further damage to the myocardium, while pretreatment of nicorandil reduces the oxidative stress response and inflammation. Moreover, nicorandil suppressed the myocardial apoptosis induced by EE, as indicated by a decrease of Bax and caspase-3 expression and an increase of Bcl-2 expression. Finally, the pathway in which nicorandil plays a role may be involved in the endothelial nitric oxide synthase (eNOS)/nitric oxide (NO) pathway. Pretreatment of nicorandil increased the protein level of myocardial eNOS and NO production. Conclusion. Our result demonstrated that nicorandil has protective effects in EE-induced myocardial injury with dose-dependent effects. A combination of nicorandil and EP can further improve the protective effects. Taken together, nicorandil can be potentially used as an intervention method in EE-induced myocardial injury.

Losartan Increases No Production from the Bovine Aortic Wall That is Stimulated by Angiotensin II

2003 ◽  
Vol 1 (3) ◽  
pp. 113-117 ◽  
Author(s):  
M. Myronidou ◽  
B. Kokkas ◽  
A. Kouyoumtzis ◽  
N. Gregoriadis ◽  
A. Lourbopoulos ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Angiotensin Ii ◽  
Aortic Wall ◽  
Vascular Wall ◽  
Protective Role ◽  
Normal Function ◽  
No Production ◽  
Chemical Inactivation

In these studies we investigated if losartan, an AT1- receptor blocker has any beneficial effect on NO production from the bovine aortic preparations in vitro while under stimulation from angiotensin II. Experiments were performed on intact specimens of bovine thoracic aorta, incubated in Dulbeco's MOD medium in a metabolic shaker for 24 hours under 95 % O2 and 5 % CO2 at a temperature of 37°C. We found that angiotensin II 1nM−10 μM does not exert any statistically significant action on NO production. On the contrary, angiotensin II 10nM increases the production of NO by 58.14 % (from 12.16 + 2.9 μm/l to 19.23 + 4.2 μm/l in the presence of losartan 1nM (P<0.05). Nitric oxide levels depend on both rate production and rate catabolism or chemical inactivation. Such an equilibrium is vital for the normal function of many systems including the cardiovascular one. The above results demonstrate that the blockade of AT1-receptors favors the biosynthesis of NO and indicate the protective role of losartan on the vascular wall.

scholarly journals Adenosine Regulates Renal Nitric Oxide Production in Hypothyroid Rats

1999 ◽  
Vol 10 (8) ◽  
pp. 1681-1688
Author(s):  
MARTHA FRANCO ◽  
EDILIA TAPIA ◽  
FLAVIO MARTÍNEZ ◽  
MA. EUGENIA DAVILA ◽  
JUANA INÉS GRIMALDO ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Renal Function ◽  
Urinary Excretion ◽  
Kidney Function ◽  
Normal Values ◽  
Inhibitory Effect ◽  
No Production ◽  
Nitric Oxide Production ◽  
Nitric Oxide Synthesis ◽  
Oxide Production

Abstract. In the hypothyroid kidney, exogenous adenosine (ADO) produces vasodilation and restores renal function to near-normal values. This study evaluates whether this response is mediated by nitric oxide synthesis stimulated by adenosine. GFR and urinary excretion of NO2-/NO3- (UNO2-/NO3-) were measured in normal (NL) and hypothyroid (HTX) rats under basal conditions and during infusion of: intra-aortic ADO, intravenously, 1,3-dipropyl-8p-sulfophenylxanthine (DPSPX), 8-cyclopentyl-1,3-dipropyl xanthine (DPCPX), Nω-nitro-L-arginine methylester (L-NAME) + ADO, L-NAME + PSPX, L-NAME + DPCPX, and intrarenal (IR) ADO or DPCPX + IR ADO. Intra-aortic ADO induced a fall in GFR and increased UNO2-/NO3- slightly in NL rats; in HTX rats, both GFR and UNO2-/NO3- increased significantly. DPSPX and DPCPX increased UNO2-/NO3- excretion in NL animals with minor changes in GFR; the blockers increased both GFR and UNO2-/NO3- in HTX rats. L-NAME completely blocked the increase in NO2-/NO3- induced by ADO, DPSPX, and DPCPX. The intrarenal infusion of ADO at 1, 10, and 35 nmol/kg per min progressively decreased GFR with a slight increase in UNO2-/NO3- in NL rats; in the HTX, GFR increased with the highest dose and UNO2-/NO3- progressively increased. DPCPX prevented the fall in GFR induced by intrarenal ADO in NL rats, with no further changes in UNO2-/NO3-; in HTX rats, intrarenal ADO under A1 blockade further increased GFR and UNO2-/NO3-. Arterial and venous ADO concentrations were lower in the HTX rats. In the HTX kidney, NO production was stimulated by ADO, most likely through activation of A2 or A3 receptors, whereas A1 receptors had an inhibitory effect. Thus, ADO receptors are involved in the regulation of kidney function in pathophysiologic conditions.

scholarly journals Protective Role of Bacillus anthracis Exosporium in Macrophage-Mediated Killing by Nitric Oxide

2007 ◽  
Vol 75 (8) ◽  
pp. 3894-3901 ◽  
Author(s):  
John Weaver ◽  
Tae Jin Kang ◽  
Kimberly W. Raines ◽  
Guan-Liang Cao ◽  
Stephen Hibbs ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Bacillus Anthracis ◽  
Protective Role ◽  
No Production ◽  
Activated Macrophages ◽  
Macrophage Infection ◽  
Positive Bacterium ◽  
Microbicidal Activity ◽  
Murine Macrophages

ABSTRACT The ability of the endospore-forming, gram-positive bacterium Bacillus anthracis to survive in activated macrophages is key to its germination and survival. In a previous publication, we discovered that exposure of primary murine macrophages to B. anthracis endospores upregulated NOS 2 concomitant with an ·NO-dependent bactericidal response. Since NOS 2 also generates O2·−, experiments were designed to determine whether NOS 2 formed peroxynitrite (ONOO−) from the reaction of ·NO with O2·− and if so, was ONOO− microbicidal toward B. anthracis. Our findings suggest that ONOO− was formed upon macrophage infection by B. anthracis endospores; however, ONOO− does not appear to exhibit microbicidal activity toward this bacterium. In contrast, the exosporium of B. anthracis, which exhibits arginase activity, protected B. anthracis from macrophage-mediated killing by decreasing ·NO levels in the macrophage. Thus, the ability of B. anthracis to subvert ·NO production has important implications in the control of B. anthracis-induced infection.

scholarly journals Activation of Endothelial Nitric Oxide Synthase by the Angiotensin II Type 1 Receptor

Endocrinology ◽  
2006 ◽  
Vol 147 (12) ◽  
pp. 5914-5920 ◽  
Author(s):  
Hiroyuki Suzuki ◽  
Kunie Eguchi ◽  
Haruhiko Ohtsu ◽  
Sadaharu Higuchi ◽  
Sudhir Dhobale ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Angiotensin Ii ◽  
Endothelial Dysfunction ◽  
Enos Gene ◽  
No Production ◽  
Hypertrophic Response ◽  
Cgmp Production ◽  
At1 Antagonist

Enhanced angiotensin II (AngII) action has been implicated in endothelial dysfunction that is characterized as decreased nitric oxide availability. Although endothelial cells have been reported to express AngII type 1 (AT1) receptors, the exact role of AT1 in regulating endothelial NO synthase (eNOS) activity remains unclear. We investigated the possible regulation of eNOS through AT1 in bovine aortic endothelial cells (BAECs) and its functional significance in rat aortic vascular smooth muscle cells (VSMCs). In BAECs infected with adenovirus encoding AT1 and in VSMCs infected with adenovirus encoding eNOS, AngII rapidly stimulated phosphorylation of eNOS at Ser1179. This was accompanied with increased cGMP production. These effects were blocked by an AT1 antagonist. The cGMP production was abolished by a NOS inhibitor as well. To explore the importance of eNOS phosphorylation, VSMCs were also infected with adenovirus encoding S1179A-eNOS. AngII did not stimulate cGMP production in VSMCs expressing S1179A. However, S1179A was able to enhance basal NO production as confirmed with cGMP production and enhanced vasodilator-stimulated phosphoprotein phosphorylation. Interestingly, S1179A prevented the hypertrophic response similar to wild type in VSMCs. From these data, we conclude that the AngII/AT1 system positively couples to eNOS via Ser1179 phosphorylation in ECs and VSMCs if eNOS and AT1 coexist. However, basal level NO production may be sufficient for prevention of AngII-induced hypertrophy by eNOS expression. These data demonstrate a novel molecular mechanism of eNOS regulation and function and thus provide useful information for eNOS gene therapy under endothelial dysfunction.

scholarly journals Protective Role of Nitric Oxide inStaphylococcus aureus Infection in Mice

1998 ◽  
Vol 66 (3) ◽  
pp. 1017-1022 ◽  
Author(s):  
Sanae Sasaki ◽  
Tomisato Miura ◽  
Shinsuke Nishikawa ◽  
Kyogo Yamada ◽  
Mayuko Hirasue ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Spleen Cell ◽  
Cell Cultures ◽  
Protective Role ◽  
Inos Mrna ◽  
No Production ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACT This study was carried out to determine the role of nitric oxide (NO) in Staphylococcus aureus infection in mice. NO production in spleen cell cultures was induced by heat-killed S. aureus. Expression of mRNA of the inducible isoform of NO synthase (iNOS) was induced in the spleens and kidneys of S. aureus-infected mice. When mice were treated with monoclonal antibodies (MAbs) against tumor necrosis factor alpha (TNF-α) or gamma interferon (IFN-γ) before S. aureus infection, the induction of iNOS mRNA expression in the kidneys was inhibited. These MAbs also inhibited NO production in spleen cell cultures stimulated with heat-killed S. aureus. NO production in the spleen cell cultures and levels of urinary nitrate plus nitrite were suppressed by treatment with aminoguanidine (AG), a selective inhibitor of iNOS. The survival rates of AG-treated mice were significantly decreased by either lethal or sublethal S. aureusinfections. However, an effect of AG administration on bacterial growth was not observed in the spleens and kidneys of mice during either type of infection. Production of TNF-α and IFN-γ was not affected by AG treatment in vitro and in vivo. These results suggest that NO plays an important role in protection from lethality by the infection, but the protective role of NO in host resistance against S. aureusinfection was not proved. Moreover, our results show that TNF-α and IFN-γ regulate NO production while NO may not be involved in the regulation of the production of these cytokines during S. aureus infection.

scholarly journals Nitric oxide synthase-mediated early nitric oxide-burst alleviates drought-induced oxidative damage in ammonium supplied-rice roots

2018 ◽  
Author(s):  
Cao Xiaochuang ◽  
Zhu Chunquan ◽  
Zhong Chu ◽  
Zhang Junhua ◽  
Zhu Lianfeng ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Oxidative Damage ◽  
Protective Role ◽  
Antioxidant Defenses ◽  
No Production ◽  
No Donor ◽  
Rice Roots ◽  
Nos Inhibitor ◽  
Oxide Synthase

AbstractAmmonium (NH4+) can enhance rice drought tolerance in comparison to nitrate (NO3-). The mechanism underpinning this relationship was investigated based on the time-dependent nitric oxide (NO) production and its protective role in oxidative stress of NH4+-/NO3--supplied rice under drought. An early burst of NO was induced by drought 3h after root NH4+ treatment but not after NO3- treatment. Root oxidative damage induced by drought was significantly higher in NO3- than in NH4+-treatment due to its reactive oxygen species accumulation. Inducing NO production by applying NO donor 3h after NO3- treatment alleviated the oxidative damage, while inhibiting the early NO burst increased root oxidative damage in NH4+ treatment. Application of nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) completely suppressed NO synthesis in roots 3h after NH4+ treatment and aggravated drought-induced oxidative damage, indicating the aggravation of oxidative damage might have resulted from changes in NOS-mediated early NO burst. Drought also increased root antioxidant enzymes activities, which were further induced by NO donor but repressed by NO scavenger and NOS inhibitor in NH4+-treated roots. Thus, the NOS-mediated early NO burst plays an important role in alleviating oxidative damage induced by drought by enhancing antioxidant defenses in NH4+-supplied rice roots.HighlightNOS-mediated early NO burst plays an important role in alleviating oxidative damage induced by water stress, by enhancing the antioxidant defenses in roots supplemented with NH4+

scholarly journals Nitric Oxide-Dependent Mechanisms Underlying MK-801- or Scopolamine-Induced Memory Dysfunction in Animals: Mechanistic Studies

2021 ◽  
Vol 22 (22) ◽  
pp. 12282
Author(s):  
Paulina Cieślik ◽  
Anna Siekierzycka ◽  
Adrianna Radulska ◽  
Agata Płoska ◽  
Grzegorz Burnat ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nmda Receptor ◽  
Chronic Administration ◽  
Receptor Expression ◽  
No Production ◽  
Memory Dysfunction ◽  
Mk 801 ◽  
Cgmp Production ◽  
The Impact ◽  
The Brain

MK-801, an NMDA receptor antagonist, and scopolamine, a cholinergic receptor blocker, are widely used as tool compounds to induce learning and memory deficits in animal models to study schizophrenia or Alzheimer-type dementia (AD), respectively. Memory impairments are observed after either acute or chronic administration of either compound. The present experiments were performed to study the nitric oxide (NO)-related mechanisms underlying memory dysfunction induced by acute or chronic (14 days) administration of MK-801 (0.3 mg/kg, i.p.) or scopolamine (1 mg/kg, i.p.). The levels of L-arginine and its derivatives, L-citrulline, L-glutamate, L-glutamine and L-ornithine, were measured. The expression of constitutive nitric oxide synthases (cNOS), dimethylaminohydrolase (DDAH1) and protein arginine N-methyltransferases (PMRTs) 1 and 5 was evaluated, and the impact of the studied tool compounds on cGMP production and NMDA receptors was measured. The studies were performed in both the cortex and hippocampus of mice. S-nitrosylation of selected proteins, such as GLT-1, APP and tau, was also investigated. Our results indicate that the availability of L-arginine decreased after chronic administration of MK-801 or scopolamine, as both the amino acid itself as well as its level in proportion to its derivatives (SDMA and NMMA) were decreased. Additionally, among all three methylamines, SDMA was the most abundant in the brain (~70%). Administration of either compound impaired eNOS-derived NO production, increasing the monomer levels, and had no significant impact on nNOS. Both compounds elevated DDAH1 expression, and slight decreases in PMRT1 and PMRT5 in the cortex after scopolamine (acute) and MK-801 (chronic) administration were observed in the PFC, respectively. Administration of MK-801 induced a decrease in the cGMP level in the hippocampus, accompanied by decreased NMDA expression, while increased cGMP production and decreased NMDA receptor expression were observed after scopolamine administration. Chronic MK-801 and scopolamine administration affected S-nitrosylation of GLT-1 transport protein. Our results indicate that the analyzed tool compounds used in pharmacological models of schizophrenia or AD induce changes in NO-related pathways in the brain structures involved in cognition. To some extent, the changes resemble those observed in human samples.

scholarly journals Nitric Oxide Participates in IFN-γ-Induced HUVECs Hyperpermeability

2016 ◽  
pp. 1053-1058 ◽  
Author(s):  
C. T. NG ◽  
L. Y. FONG ◽  
Y. Y. LOW ◽  
J. BAN ◽  
M. N. HAKIM ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Barrier Function ◽  
Cell Monolayer ◽  
Guanosine Monophosphate ◽  
Endothelial Barrier ◽  
No Production ◽  
Endothelial Barrier Function ◽  
No Donor ◽  
Cgmp Production ◽  
Ifn Γ

The endothelial barrier function is tightly controlled by a broad range of signaling cascades including nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway. It has been proposed that disturbances in NO and cGMP production could interfere with proper endothelial barrier function. In this study, we assessed the effect of interferon-gamma (IFN-γ), a pro-inflammatory cytokine, on NO and cGMP levels and examined the mechanisms by which NO and cGMP regulate the IFN-γ-mediated HUVECs hyperpermeability. The flux of fluorescein isothiocyanate-labeled dextran across cell monolayers was used to study the permeability of endothelial cells. Here, we found that IFN-γ significantly attenuated basal NO concentration and the increased NO levels supplied by a NO donor, sodium nitroprusside (SNP). Besides, application of IFN-γ also significantly attenuated both the basal cGMP concentration and the increased cGMP production donated by a cell permeable cGMP analogue, 8-bromo-cyclic GMP (8-Br-cGMP). In addition, exposure of the cell monolayer to IFN-γ significantly increased HUVECs basal permeability. However, L-NAME pretreatment did not suppress IFN-γ-induced HUVECs hyperpermeability. L-NAME pretreatment followed by SNP or SNP pretreatment partially reduced IFN-γ-induced HUVECs hyperpermeability. Pretreatment with a guanylate cyclase inhibitor, 6-anilino-5,8-quinolinedione (LY83583), led to a further increase in IFN-γ-induced HUVECs hyperpermeability. The findings suggest that the mechanism underlying IFN-γ-induced increased HUVECs permeability is partly related to the inhibition of NO production.

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