Tetrahydrobiopterin Bh4
Mostrando 25-30 de 30 artigos, teses e dissertações.
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25. Superoxide generation by endothelial nitric oxide synthase: The influence of cofactors
The mechanism of superoxide generation by endothelial nitric oxide synthase (eNOS) was investigated by the electron spin resonance spin-trapping technique using 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide. In the absence of calcium/calmodulin, eNOS produces low amounts of superoxide. Upon activating eNOS electron transfer reactions by calcium/calmoduli
The National Academy of Sciences.
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26. Sepiapterin Decreases Acute Rejection and Apoptosis in Cardiac Transplants Independently of Changes in Nitric Oxide and Inducible Nitric-Oxide Synthase Dimerization
Tetrahydrobiopterin (BH4), a cofactor of inducible nitric-oxide synthase (iNOS), is an important post-translational regulator of NO bioactivity. We examined whether treatment of cardiac allograft recipients with sepiapterin [S-(-)-2-amino-7,8-dihydro-6-(2-hydroxy-1-oxopropyl)-4-(1H)-pteridinone], a precursor of BH4, inhibited acute rejection and apoptos
American Society for Pharmacology and Experimental Therapeutics.
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27. Complementation analysis of mutants of nitric oxide synthase reveals that the active site requires two hemes.
For catalytic activity, nitric oxide synthases (NOSs) must be dimeric. Previous work revealed that the requirements for stable dimerization included binding of tetrahydrobiopterin (BH4), arginine, and heme. Here we asked what function is served by dimerization. We assessed the ability of individually inactive mutants of mouse inducible NOS (iNOS; NOS2), each
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28. Effects of ageing and exercise training on eNOS uncoupling in skeletal muscle resistance arterioles
Reduced availability of tetrahydrobiopterin (BH4) contributes to the age-related decline of nitric oxide (NO)-mediated vasodilatation of soleus muscle arterioles. Depending on availability of substrate and/or necessary co-factors, endothelial nitric oxide synthase (eNOS) can generate NO and/or superoxide (O2−). We evaluated the effects of age and chronic e
Blackwell Science Inc.
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29. GTP Cyclohydrolase I: Purification, Characterization, and Effects of Inhibition on Nitric Oxide Synthase in Nocardia Species
GTP cyclohydrolase I (GTPCH) catalyzes the first step in pteridine biosynthesis in Nocardia sp. strain NRRL 5646. This enzyme is important in the biosynthesis of tetrahydrobiopterin (BH4), a reducing cofactor required for nitric oxide synthase (NOS) and other enzyme systems in this organism. GTPCH was purified more than 5,000-fold to apparent homogeneity by
American Society for Microbiology.
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30. Bacterial translocation in cirrhotic rats stimulates eNOS-derived NO production and impairs mesenteric vascular contractility
Nitric oxide (NO) has been implicated in the arterial vasodilation and associated vascular hyporesponsiveness to vasoconstrictors observed in liver cirrhosis. Bacteria, potent activators of NO and TNF-α synthesis, are found in the mesenteric lymph nodes (MLNs) of ascitic cirrhotic rats. Here, we investigated the impact of bacterial translocation (BT) to MLN
American Society for Clinical Investigation.