scholarly journals Modulation of Renal Blood Flow and Vascular Tone by Neuronal Nitric Oxide Synthase-Derived Nitric Oxide

2011 ◽  
Vol 48 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Noboru Toda ◽  
Tomio Okamura
1995 ◽  
Vol 15 (5) ◽  
pp. 774-778 ◽  
Author(s):  
Qiong Wang ◽  
Dale A. Pelligrino ◽  
Verna L. Baughman ◽  
Heidi M. Koenig ◽  
Ronald F. Albrecht

The nitric oxide synthase (NOS) inhibitors, nitro-L-arginine, its methyl ester, and N-monomethyl-L-arginine, have been shown to attenuate resting CBF and hypercapnia-induced cerebrovasodilation. Those agents nonspecifically inhibit the endothelial and neuronal NOS (eNOS and nNOS). In the present study, we used a novel nNOS inhibitor, 7-nitroindazole (7-NI) to examine the role of nNOS in CBF during normocapnia and hypercapnia in fentanyl/N2O-anesthetized rats. CBF was monitored using laser-Doppler flowmetry. Administration of 7-NI (80 mg kg−1 i.p.) reduced cortical brain NOS activity by 57%, the resting CBF by 19–27%, and the CBF response to hypercapnia by 60%. The 60% reduction was similar in magnitude to the CBF reductions observed in previous studies in which nonspecific NOS inhibitors were used. In the present study, 7-NI did not increase the MABP. Furthermore, the CBF response to oxotremorine, a blood–brain barrier permeant muscarinic agonist that induces cerebrovasodilation via endothelium-derived NO, was unaffected by 7-NI. These results confirmed that 7-NI does not influence eNOS; they also indicated that the effects of 7-NI on the resting CBF and on the CBF response to hypercapnia in this study were solely related to its inhibitory action on nNOS. The results further suggest that the NO synthesized by the action of nNOS participates in regulation of basal CBF and is the major, if not the only, category of NO contributing to the hypercapnic CBF response.


2008 ◽  
Vol 43 (4) ◽  
pp. 313-321 ◽  
Author(s):  
Anthony S. de Buys Roessingh ◽  
Pascal de Lagausie ◽  
Taline Ibrahima ◽  
Sy Duong-Quy ◽  
Jean-Christophe Schneider ◽  
...  

Author(s):  
Nymphaea Arora ◽  
Vikash Prashar ◽  
Tania Arora ◽  
Randeep Sidhu ◽  
Anshul Mishra ◽  
...  

Introduction: Nitric oxide (NO) is a diatomic free radical gaseous molecule that is formed from L-arginine through NOS (Nitric oxide synthase) catalyzed reaction. NO controls vascular tone (hence blood pressure), insulin secretion, airway tone, and peristalsis and is involved in angiogenesis (growth of new blood vessels) and in the development of the nervous system. In the CNS, NO is an important messenger molecule, which is involved in various major functions in the brain. NOS has been classified into three isoforms which include nNOS (neuronal NOS), eNOS (endothelial NOS), and iNOS (inducible NOS). NOS1 is localized on chromosome 12, consisting of 1434 amino acids and 161 KDa molecular weight. nNOS is involved in synaptic transmission, regulating the tone of smooth muscles, penile erection. We studied NOS1 gene and protein network analysis through in silico techniques as human nNOS sequence was fetched from GenBank, and its homologous sequences were retrieved through BLAST search. Moreover, the results of this study exploit the role of NOS1 in various pathways, which provide ways to regulate it in various neurodegenerative diseases. Background: Previous research has revealed the role of Nitric Oxide (NO) formed from L-arginine through NOS (Nitric Oxide Synthase) as a physiological inter/intracellular messenger in the central as well as the peripheral nervous system. The diverse functions of NOS include insulin secretion, airway tone, vascular tone regulation, and in the brain, it is involved in differentiation, development, synaptic plasticity, and neurosecretion. Objective: The objective of this study is to unravel the role of neuronal Nitric Oxide Synthase (nNOS) in different pathways and its involvement as a therapeutic target in various neurodegenerative disorders, which can surely provide ways to regulate its activity in different aspects. Materials and Methods: In this study, we employed various bioinformatics tools and databases, initiating the study by fetching the neuronal Nitric Oxide Synthase (nNOS) sequence(GenBank) to find its homologous sequences(BLAST) and then exploring its physical properties and post-translational modifications, enhancing the research by network analysis(STRING), leading to its functional enrichment(Panther). Results : The results positively support the hypothesis of its role in various pathways related to neurodegeneration., Its interacting partners are the probable therapeutic targets of various neurodegenerative diseases focusing on specifically multi-target analysis. Conclusion: This study considered the evolutionary trend of physical, chemical, and biological properties of NOS1 through different phyla. The neuronal Nitric Oxide Synthase (nNOS), being one of the three isoforms of NOS (Nitric Oxide Synthase), is found to be involved in more pathways than just forming Nitric Oxide. This research provides the base for further neurological research.


2005 ◽  
Vol 183 (3) ◽  
pp. 257-262 ◽  
Author(s):  
L. Jansson ◽  
P.-O. Carlsson ◽  
B. Bodin ◽  
A. Andersson ◽  
O. Kallskog

2002 ◽  
Vol 97 (6) ◽  
pp. 1528-1533 ◽  
Author(s):  
Franz Kehl ◽  
Hui Shen ◽  
Carol Moreno ◽  
Neil E. Farber ◽  
Richard J. Roman ◽  
...  

Background Despite intense investigation, the mechanism of isoflurane-induced cerebral hyperemia is unclear. The current study was designed to determine the contributions of neuronal nitric oxide synthase, prostaglandins, and epoxyeicosatrienoic acids to isoflurane-induced cerebral hyperemia. Methods Regional cerebral cortical blood flow was measured with laser Doppler flowmetry during stepwise increases of isoflurane from 0.0 to 1.2, 1.8, and 2.4 vol% end-tidal concentration in alpha-chloralose-urethane-anesthetized, C57BL/6 mice before and 45 min after administration of the neuronal nitric oxide synthase inhibitor 7-nitroindazole (7-NI, 40 mg/kg, intraperitoneal), the cyclooxygenase inhibitor indomethacin (INDO, 10 mg/kg, intravenous), and the cytochrome P450 epoxygenase inhibitor N-methylsulfonyl-6-(2-proparglyoxyphenyl)hexanoic acid (PPOH, 20 mg/kg, intravenous). Results Isoflurane increased regional cerebral cortical blood flow by 9 +/- 3, 46 +/- 21, and 101 +/- 26% (SD) at 1.2, 1.8, and 2.4 vol%, respectively. The increases in regional cerebral cortical blood flow were significantly (*P < 0.05) smaller after 7-NI (5 +/- 6, 29 +/- 19*, 68 +/- 15%*) or PPOH (4 +/- 8, 27 +/- 17*, 67 +/- 30%*), but not after administration of INDO (4 +/- 4, 33 +/- 18 [NS], 107 +/- 35% [NS]). The effect of combined treatment with 7-NI, PPOH, and INDO was not additive and was equal to that of either 7-NI or PPOH alone (5 +/- 5, 30 +/- 12*, 76 +/- 24%*). Chronic treatment of mice for 5 days with 7-NI (2 x 40 mg/kg, intraperitoneal) produced similar decreases in regional cerebral cortical blood flow as those seen with acute administration. Neither PPOH nor INDO conferred a significant additional block of the hyperemia in these animals. Conclusions Nitric oxide and epoxyeicosatrienoic acids contribute to isoflurane-induced hyperemia. However, only approximately one third of the cerebral hyperemic response to isoflurane is mediated by autacoids. The remaining part of this response appears to be mediated by a direct action of isoflurane on smooth muscle by some yet-unknown mechanism.


1998 ◽  
Vol 43 ◽  
pp. 62-62 ◽  
Author(s):  
Robyn L Rairigh ◽  
Laurent Storme ◽  
Timothy D Le Cras ◽  
Marilee P Horan ◽  
Steven H Abman

1995 ◽  
Vol 15 (5) ◽  
pp. 766-773 ◽  
Author(s):  
Paul A. T. Kelly ◽  
Isobel M. Ritchie ◽  
Gordon W. Arbuthnott

The novel nitric oxide synthase inhibitor 7-nitroindazole (7-NI) is relatively specific for the neuronal isoform of the enzyme and in this study we have used this compound to investigate the physiological role of perivascular nitric oxide-containing nerves in the cerebrovascular bed. Following injection of 7-NI (25 or 50 mg/kg, i.p.), cerebral blood flow and glucose utilization were measured in the conscious rat using the fully quantitative [14C]iodoantipyrine and 2-[14C]deoxyglucose techniques, respectively. Neither dose of the drug produced any change in arterial blood pressure, confirming a lack of effect upon the endothelial isoform of the enzyme, although there was a pronounced decrease in heart rate (−28% by 10 min postinjection). Throughout the brain 25 mg/kg 7-NI i.p. resulted in decreases in blood flow of between −20% in the hippocampus and −58% in the substantia nigra. Increasing the dose to 50 mg/kg resulted in a further generalized decrease, to almost −60% in parts of the thalamus and hippocampus, but in every animal this higher dose of 7-NI also produced randomly distributed areas of relative hyperaemia, which were most commonly found in those areas where the most intense hypoperfusion was otherwise in evidence. Despite these changes in blood flow, in all but a very few areas of the brain no significant decrease in glucose use was measured at either of the two doses of 7-NI. Thus despite the greater specificity of 7-NI for neuronal nitric oxide synthase, the cerebrovascular effects of the drug in vivo are very similar to that reported for the arginine analogues. However, these data do suggest that nitric oxide-releasing neurones in the brain may have an important role to play in the regulation of cerebral blood flow.


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