Nitric oxide from perivascular nerves modulates cerebral arterial pH reactivity

2001 ◽  
Vol 281 (3) ◽  
pp. H1353-H1363 ◽  
Author(s):  
Ute Lindauer ◽  
Alexander Kunz ◽  
Sigrid Schuh-Hofer ◽  
Johannes Vogt ◽  
Jens P. Dreier ◽  
...  

In the isolated rat middle cerebral artery (MCA) we investigated the role of nitric oxide (NO)/cGMP in the vasodilatory response to extraluminal acidosis. Acidosis increased vessel diameter from 140 ± 27 μm (pH 7.4) to 187 ± 30 μm (pH 7.0, P < 0.01). NO synthase (NOS) inhibition by N ω-nitro-l-arginine (l-NNA, 10 μM) reduced baseline diameter (103 ± 20 μm, P < 0.01) and attenuated response to acidosis (9 ± 8 μm). Application of the NO-donors 3-morpholinosydnonimine (1 μM) or S-nitroso- N-acetylpenicillamine (1 μM), or of 8-bromoguanosine 3′,5′-cyclic monophosphate (8-BrcGMP, 100 μM) reestablished pre-l-NNA diameter at pH 7.4 and reversedl-NNA-induced attenuation of the vessel response to acidosis. Restoration of pre-l-NNA diameter (pH 7.4) by papaverine (20 μM) or nimodipine (30 nM) had no effect on the attenuated response to acidosis. Guanylyl cyclase inhibition with 1H-[1,2,4]oxadiazolo[4,3-a]-quinoxalin-1-one (5 μM) or NOS-inhibition with 7-nitroindazole (7-NI, 100 μM) reduced baseline vessel diameter (109 ± 8 or 127 ± 11 μm, respectively) and vasodilation to acidosis, and restoration of baseline diameter with 8-BrcGMP (30 μM) completely restored dilation to pH 7.0. Chronic denervation of NOS-containing perivascular nerves in vivo 14 days before artery isolation significantly reduced pH-dependent reactivity in vitro (diameter increase sham: 48 ± 14 μm, denervated: 14 ± 8 μm), and 8-BrcGMP (30 μM) restored dilation to pH 7.0 (denervated: 49 ± 31 μm). Removal of the endothelium did not change vasodilation to acidosis. We conclude that NO, produced by neuronal NOS of perivascular nerves, is a modulator in the pH-dependent vasoreactivity.

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 277
Author(s):  
Lei Wang ◽  
Hye-Won Yang ◽  
Ginnae Ahn ◽  
Xiaoting Fu ◽  
Jiachao Xu ◽  
...  

In the present study, the in vitro and in vivo anti-inflammatory effects of the sulfated polysaccharides isolated from Sargassum fulvellum (SFPS) were evaluated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and zebrafish. The results indicated that SFPS improved the viability of LPS-stimulated RAW 264.7 macrophages from 80.02 to 86.80, 90.09, and 94.62% at the concentration of 25, 50, and 100 µg/mL, respectively. Also, SFPS remarkably and concentration-dependently decreased the production levels of inflammatory molecules including nitric oxide (NO), tumor necrosis factor-alpha, prostaglandin E2, interleukin-1 beta, and interleukin-6 in LPS-treated RAW 264.7 macrophages. In addition, SFPS significantly inhibited the expression levels of cyclooxygenase-2 and inducible nitric oxide synthase in LPS-treated RAW 264.7 macrophages. Furthermore, the in vivo test results indicated that SFPS improved the survival rate of LPS-treated zebrafish from 53.33 to 56.67, 60.00, and 70.00% at the concentration of 25, 50, and 100 µg/mL, respectively. In addition, SFPS effectively reduced cell death, reactive oxygen species, and NO levels in LPS-stimulated zebrafish. Taken together, these results suggested that SFPS possesses strong in vitro and in vivo anti-inflammatory activities, and could be used as an ingredient to develop anti-inflammatory agents in the functional food and pharmaceutical industries.


Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 420
Author(s):  
Su-Jung Hwang ◽  
Ye-Seul Song ◽  
Hyo-Jong Lee

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.


Author(s):  
Maria Cristina Budani ◽  
Gian Mario Tiboni

Nitric oxide (NO) is formed during the oxidation of L-arginine to L-citrulline by the action of multiple isoenzymes of NO synthase (NOS): neuronal NOS (nNOS), endotelial NOS (eNOS), and inducible NOS (iNOS). NO plays a relevant role in the vascular endothelium, in central and peripheral neurons, and in immunity and inflammatory systems. In addition, several authors showed a consistent contribution of NO to different aspects of the reproductive physiology. The aim of the present review is to analyse the published data on the role of NO within the ovary. It has been demonstrated that the multiple isoenzymes of NOS are expressed and localized in the ovary of different species. More to the point, a consistent role was ascribed to NO in the processes of steroidogenesis, folliculogenesis, and oocyte meiotic maturation in in vitro and in vivo studies using animal models. Unfortunately, there are few nitric oxide data for humans; there are preliminary data on the implication of nitric oxide for oocyte/embryo quality and in-vitro fertilization/embryo transfer (IVF/ET) parameters. NO plays a remarkable role in the ovary, but more investigation is needed, in particular in the context of human ovarian physiology.


2018 ◽  
Vol 60 (No. 8) ◽  
pp. 359-366
Author(s):  
J. Li ◽  
B. Shi ◽  
S. Yan ◽  
L. Jin ◽  
Y. Guo ◽  
...  

The effects of chitosan on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) activity and gene expression in vivo or vitro were investigated in weaned piglets. In vivo, 180 weaned piglets were assigned to five dietary treatments with six replicates. The piglets were fed on a basal diet supplemented with 0 (control), 100, 500, 1000, and 2000 mg chitosan/kg feed, respectively. In vitro, the peripheral blood mononuclear cells (PBMCs) from a weaned piglet were cultured respectively with 0 (control), 40, 80, 160, and 320 &micro;g chitosan/ml medium. Results showed that serum NO concentrations on days 14 and 28 and iNOS activity on day 28 were quadratically improved with increasing chitosan dose (P &lt; 0.05). The iNOS mRNA expressions were linearly or quadratically enhanced in the duodenum on day 28, and were improved quadratically in the jejunum on days 14 and 28 and in the ileum on day 28 (P &lt; 0.01). In vitro, the NO concentrations, iNOS activity, and mRNA expression in unstimulated PBMCs were quadratically enhanced by chitosan, but the improvement of NO concentrations and iNOS activity by chitosan were markedly inhibited by N-(3-[aminomethyl] benzyl) acetamidine (1400w) (P&nbsp;&lt; 0.05). Moreover, the increase of NO concentrations, iNOS activity, and mRNA expression in PBMCs induced by lipopolysaccharide (LPS) were suppressed significantly by chitosan (P &lt; 0.05). The results indicated that the NO concentrations, iNOS activity, and mRNA expression in piglets were increased by feeding chitosan in a dose-dependent manner. In addition, chitosan improved the NO production in unstimulated PBMCs but inhibited its production in LPS-induced cells, which exerted bidirectional regulatory effects on the NO production via modulated iNOS activity and mRNA expression.


2003 ◽  
Vol 31 (11) ◽  
pp. 1337-1346 ◽  
Author(s):  
Jose A. Adams ◽  
James E. Moore, Jr. ◽  
Michael R. Moreno ◽  
Jaqueline Coelho ◽  
Jorge Bassuk ◽  
...  

2004 ◽  
Vol 82 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Norma Marchesini ◽  
Yusuf A Hannun

Ceramide, an emerging bioactive lipid and second messenger, is mainly generated by hydrolysis of sphingomyelin through the action of sphingomyelinases. At least two sphingomyelinases, neutral and acid sphingo myelinases, are activated in response to many extracellular stimuli. Despite extensive studies, the precise cellular function of each of these sphingomyelinases in sphingomyelin turnover and in the regulation of ceramide-mediated responses is not well understood. Therefore, it is essential to elucidate the factors and mechanisms that control the activation of acid and neutral sphingomyelinases to understand their the roles in cell regulation. This review will focus on the molecular mechanisms that regulate these enzymes in vivo and in vitro, especially the roles of oxidants (glu ta thi one, peroxide, nitric oxide), proteins (saposin, caveolin 1, caspases), and lipids (diacylglycerol, arachidonic acid, and ceramide).Key words: sphingomyelinase, ceramide, apoptosis, Niemann-Pick disease, FAN (factor associated with N-SMase activation).


1999 ◽  
Author(s):  
Marcelo Bariatto ◽  
Rogerio Furlan ◽  
Koiti Arakai ◽  
Jorge J. Santiago-Aviles

Abstract Nitric oxide (NO) is known to mediate many beneficial physiology processes, motivating its detection in vivo as well as in vitro. Electrochemical detection provides the required cellular level determination of NO among several other techniques. In this work, electrochemical micro-sensors for both types of detection, in vivo and in vitro, were developed, exploring the silicon planar technology, which presents high yield and reliability and also permits batch fabrication. The developed in vitro sensor features eight detection sites (10 μm × 10 μm microelectrodes), for determination of nitric oxide spatial distribution or multi-species analysis. Different electrochemical methods were applied to provide sensor calibration and chemical reproducibility. For in vivo analysis, the designed structures have a needle shape (40 μm thick) and they were silicon micro-machined by using plasma etching or etch stop techniques. Different configurations were designed and implemented, containing a number of detection microelectrodes that vary from 2 to 10. The amperometric detection of both nitric oxide and nitride (NO2−) — a molecule that causes an interference — were investigated by using the in vitro micro-sensor configuration. The need of a cationic exchanger (Nafion) was demonstrated in order to provide selectivity to NO for low concentrations. Also, the developed sensor has a sensitivity of 500 A/M.cm2 and a detection limit of 10 μM.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Belinda A Di Bartolo ◽  
Sian P Cartland ◽  
Leonel Prado-Lourenco ◽  
Nor Saadah M Azahri ◽  
Thuan Thai ◽  
...  

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.


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