Results 1 to 10 of about 10,448 (137)
Ratio of 5,6,7,8-tetrahydrobiopterin to 7,8-dihydrobiopterin in endothelial cells determines glucose-elicited changes in NO vs. superoxide production by eNOS [PDF]
American Journal of Physiology-Heart and Circulatory Physiology, 2008 5,6,7,8-Tetrahydrobiopterin (BH4) is an essential cofactor of nitric oxide synthases (NOSs). Oxidation of BH4, in the setting of diabetes and other chronic vasoinflammatory conditions, can cause cofactor insufficiency and uncoupling of endothelial NOS (eNOS), manifest by a switch from nitric oxide (NO) to superoxide production.
Crabtree, M +4 more
europepmc +6 more sources
Effect of Sepiapterin, 7,8-Dihydrobiopterin, 5,6,7,8-Tetrahydrobiopterin and Xanthopterin on Cholesterol and Phospholipid Content and Phospholipid Biosynthesis in vitro [PDF]
Pteridines, 1995 Summary Incorporation of fatty acids into phospholipids has been investigated using samples of rat live tissue homogenate, Krebs-Ringer-phosphate buffer (pH = 7A) containing 0.3% albumin, farry acid mixture and glycerol. The addition of sepiapterin, 7,8-dihydrobiopterin and 5.6.7.8-tetrahydrobiopterin (5 and 30 pmol g wet weight) to incubation medium ...
Gabriele Baier-Bitterlich +4 more
doaj +4 more sources
Effect of 5,6,7,8-Tetrahydrobiopterin (BH4) on γ-Ray-induced Micronucleus Frequency in RAW264.7 Cells [PDF]
pteridines, 2006 Abstract The effect of 5,6,7,8-tetrahydrobiopterin (BH4), an endogenous antioxidant, on γ-ray-induced micronucleus frequency was examined in RAW264.7 cells. Exogenously added BH4 reduced the γ-ray-induced micronucleus frequency. Treatment with 1 mM sepiapterin, a biosynthetic precursor of BH4, also significantly reduced the micronucleus
Shuji Kojima, Mayumi Hori
doaj +4 more sources
6R-L-erythro-5,6,7,8-Tetrahydrobiopterin and Dopamine Release
Pteridines, 1995 We previously reported that intracerebroventricular administration of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (6R-BJL), a cofactor for aromatic amino acid hydroxylases and nitric oxide synthase, induces an increase in DOPA levels (as an index of DA biosynthesis) and in levels of DA metabolites (as an index of DA release) in the rat brain: the increase
Soichi Miwa, Kunio Koshimura
doaj +4 more sources
Modulation of LPS-induced Cell Death by 5,6,7,8-Tetrahydrobiopterin
pteridines, 1999 Summary It has been previously reported that 5,6,7,S-tetrahydrobiopterin (BH4) modulates HL-60 cell death induced by a nitric oxide (NO) donor, S-nitroso-N-acetyl-D, L-penicillamine (SNAP). In this study, the role of endogenous BH4 was investigated in lipopolysaccharide (LPS)-induced apoptotic cell death.
Hiroyuki Iizuka +2 more
doaj +4 more sources
pteridines, 2006 Abstract We investigated the effects of HMG-CoA reductase inhibitors, so-called statins, on 5,6,7,8-tctrahydrobioptcrin (BH4) metabolism in human umbilical vein endothelial cells (HUVEC). The mRNA of GTP cyclohydrolase I (GTPCH), as well as cNOS, was upregulated in HUVEC treated with cerivastatin.
Nobuo Nakanishi, Yoshiyuki Hattori
doaj +4 more sources
Peroxidase catalysed aerobic degradation of 5,6,7,8‐tetrahydrobiopterin at physiological pH [PDF]
European Journal of Biochemistry, 1983 The aerobic degradation of 5,6,7,8‐tetrahydrobiopterin at neutral pH is catalysed by peroxidase (EC 1.11.1.7) and provides quinonoid 7,8‐dihydro(6H)biopterin which readily loses the side chain to yield 7,8‐dihydro(3H)pterin. The latter is in equilibrium with trace amounts of 6‐hydroxy‐5,6,7,8‐tetrahydropterin (covalent hydrate) Which is irreversibly ...
Hiroyasu Taguchi +2 more
openaire +4 more sources
Hyperoxia Depletes (6R)-5,6,7,8-Tetrahydrobiopterin Levels in the Neonatal Retina [PDF]
The American Journal of Pathology, 2015 Retinopathy of prematurity is a sight-threatening complication of premature birth caused by nitro-oxidative insult to the developing retinal vasculature during therapeutic hyperoxia exposure and later ischemia-induced neovascularization on supplemental oxygen withdrawal.
Edgar, Kevin S. +4 more
openaire +5 more sources
6R-L-erythro-5,6,7,8-Tetrahydrobiopterin: A Regulator of Neurotransmitter Release [PDF]
Advances in Experimental Medicine and Biology, 1993 6R-L-erythro-Tetrahydrobiopterin (6R-BH4) is a common natural cofactor for hydroxylases of phenylalanine, tyrosine and tryptophan, and is thought to play an important role in the regulation of monoamine neurotransmitter biosynthesis1. In fact, it is well known that in atypical phenylketonuria, 6R-BH4 deficiency results in severe neurological problems ...
Tetsuya Ohue +3 more
openaire +4 more sources
FEBS Letters, 1995 5,6,7,8‐Tetrahydrobiopterin is an essential cofactor of diverse enzymes. Of the eight possible stereoisomers, only the 6R,1′R,2′S‐configuration is biologically active. Other stereoisomers, as well as other reduced pterins such as, e.g. 5,6,7,8‐tetrahydroneopterin, fail to exhibit significant cofactor activity.
Willibald Estelberger +2 more
openaire +4 more sources