scholarly journals Selective loss of sarcolemmal nitric oxide synthase in Becker muscular dystrophy.

1996 ◽  
Vol 184 (2) ◽  
pp. 609-618 ◽  
Author(s):  
D S Chao ◽  
J R Gorospe ◽  
J E Brenman ◽  
J A Rafael ◽  
M F Peters ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Muscular Dystrophy ◽  
Nitric Oxide Synthase ◽  
Dystrophin Gene ◽  
Becker Muscular Dystrophy ◽  
Mdx Mice ◽  
Developmental Studies ◽  
Oxide Synthase ◽  
Dystrophin Complex

Becker muscular dystrophy is an X-linked disease due to mutations of the dystrophin gene. We now show that neuronal-type nitric oxide synthase (nNOS), an identified enzyme in the dystrophin complex, is uniquely absent from skeletal muscle plasma membrane in many human Becker patients and in mouse models of dystrophinopathy. An NH2-terminal domain of nNOS directly interacts with alpha 1-syntrophin but not with other proteins in the dystrophin complex analyzed. However, nNOS does not associate with alpha 1-syntrophin on the sarcolemma in transgenic mdx mice expressing truncated dystrophin proteins. This suggests a ternary interaction of nNOS, alpha 1-syntrophin, and the central domain of dystrophin in vivo, a conclusion supported by developmental studies in muscle. These data indicate that proper assembly of the dystrophin complex is dependent upon the structure of the central rodlike domain and have implications for the design of dystrophin-containing vectors for gene therapy.

scholarly journals A nitric oxide synthase transgene ameliorates muscular dystrophy in mdx mice

2001 ◽  
Vol 155 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Michelle Wehling ◽  
Melissa J. Spencer ◽  
James G. Tidball
Keyword(s):  
Nitric Oxide ◽  
Muscular Dystrophy ◽  
Nitric Oxide Synthase ◽  
Muscle Membrane ◽  
Mdx Mice ◽  
No Production ◽  
Dystrophic Muscle ◽  
Membrane Injury ◽  
Oxide Synthase

Dystrophin-deficient muscles experience large reductions in expression of nitric oxide synthase (NOS), which suggests that NO deficiency may influence the dystrophic pathology. Because NO can function as an antiinflammatory and cytoprotective molecule, we propose that the loss of NOS from dystrophic muscle exacerbates muscle inflammation and fiber damage by inflammatory cells. Analysis of transgenic mdx mice that were null mutants for dystrophin, but expressed normal levels of NO in muscle, showed that the normalization of NO production caused large reductions in macrophage concentrations in the mdx muscle. Expression of the NOS transgene in mdx muscle also prevented the majority of muscle membrane injury that is detectable in vivo, and resulted in large decreases in serum creatine kinase concentrations. Furthermore, our data show that mdx muscle macrophages are cytolytic at concentrations that occur in dystrophic, NOS-deficient muscle, but are not cytolytic at concentrations that occur in dystrophic mice that express the NOS transgene in muscle. Finally, our data show that antibody depletions of macrophages from mdx mice cause significant reductions in muscle membrane injury. Together, these findings indicate that macrophages promote injury of dystrophin-deficient muscle, and the loss of normal levels of NO production by dystrophic muscle exacerbates inflammation and membrane injury in muscular dystrophy.

Vasculoprotective Role of Inducible Nitric Oxide Synthase at Inflammatory Coronary Lesions Induced by Chronic Treatment With Interleukin-1β in Pigs in Vivo

Circulation ◽  
1997 ◽  
Vol 96 (9) ◽  
pp. 3104-3111 ◽  
Author(s):  
Yoshihiro Fukumoto ◽  
Hiroaki Shimokawa ◽  
Toshiyuki Kozai ◽  
Toshiaki Kadokami ◽  
Kouichi Kuwata ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Chronic Treatment ◽  
Interleukin 1Β ◽  
Coronary Lesions ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

scholarly journals Angiotensin II is involved in nitric oxide synthase and cyclo-oxygenase inhibition-induced leukocyte-endothelialcell interactions in vivo

2001 ◽  
Vol 132 (3) ◽  
pp. 677-684 ◽  
Author(s):  
Angeles Alvarez ◽  
Laura Piqueras ◽  
Regina Bello ◽  
Amparo Canet ◽  
Lucrecia Moreno ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Angiotensin Ii ◽  
Nitric Oxide Synthase ◽  
Oxide Synthase

Increasing dihydrobiopterin causes dysfunction of endothelial nitric oxide synthase in rats in vivo

2011 ◽  
Vol 301 (3) ◽  
pp. H721-H729 ◽  
Author(s):  
Katsuhiko Noguchi ◽  
Naobumi Hamadate ◽  
Toshihiro Matsuzaki ◽  
Mayuko Sakanashi ◽  
Junko Nakasone ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Control Treatment ◽  
Enos Uncoupling ◽  
Nos Inhibitor ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
First Time

An elevation of oxidized forms of tetrahydrobiopterin (BH4), especially dihydrobiopterin (BH2), has been reported in the setting of oxidative stress, such as arteriosclerotic/atherosclerotic disorders, where endothelial nitric oxide synthase (eNOS) is dysfunctional, but the role of BH2 in the regulation of eNOS activity in vivo remains to be evaluated. This study was designed to clarify whether increasing BH2 concentration causes endothelial dysfunction in rats. To increase vascular BH2 levels, the BH2 precursor sepiapterin (SEP) was intravenously given after the administration of the specific dihydrofolate reductase inhibitor methotrexate (MTX) to block intracellular conversion of BH2 to BH4. MTX/SEP treatment did not significantly affect aortic BH4 levels compared with control treatment. However, MTX/SEP treatment markedly augmented aortic BH2 levels (291.1 ± 29.2 vs. 33.4 ± 6.4 pmol/g, P < 0.01) in association with moderate hypertension. Treatment with MTX alone did not significantly alter blood pressure or BH4 levels but decreased the BH4-to-BH2 ratio. Treatment with MTX/SEP, but not with MTX alone, impaired ACh-induced vasodilator and depressor responses compared with the control treatment (both P < 0.05) and also aggravated ACh-induced endothelium-dependent relaxations ( P < 0.05) of isolated aortas without affecting sodium nitroprusside-induced endothelium-independent relaxations. Importantly, MTX/SEP treatment significantly enhanced aortic superoxide production, which was diminished by NOS inhibitor treatment, and the impaired ACh-induced relaxations were reversed with SOD ( P < 0.05), suggesting the involvement of eNOS uncoupling. These results indicate, for the first time, that increasing BH2 causes eNOS dysfunction in vivo even in the absence of BH4 deficiency, demonstrating a novel insight into the regulation of endothelial function.

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