Results 121 to 130 of about 10,448 (137)

Repeated Peripheral Administration of 6R-L-Erythro-5,6,7,8-tetrahydrobiopterin Alters the Binding Activities of 5-HT1Aand 5-HT2Receptors in Rat Brain

Biochemical and Biophysical Research Communications, 1996
Repeated peripheral administration of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (R-THBP) induced significant changes in the binding activities of serotonergic receptors in the rat brain. The increase in the hippocampus and the decrease in the visual cortex of [3H]8-hydroxy-N,N-dipropyl-2-aminotetralin ([3H]8-OH-DPAT) binding (5-HT1A binding site) were ...
Keiko Muguruma, Kazuyuki Imamura, Yasuyoshi Watanabe   +2 more
openaire   +4 more sources

H₂O₂ increases de novo synthesis of (6R)‐L‐erythro‐5,6,7,8‐tetrahydrobiopterin via GTP cyclohydrolase I and its feedback regulatory protein in vitiligo

Journal of Inherited Metabolic Disease, 2008
SummaryPatients with vitiligo accumulate up to 10−3 mol/L concentrations of H2O2 in their epidermis, which in turn affects many metabolic pathways in this compartment, including the synthesis and recycling of the cofactor (6R)‐l‐erythro‐5,6,7,8‐tetrahydrobiopterin (6BH4).
Bhaven Chavan, Hartmut Rokos, Hartmut Rokos, Karin U. Schallreuter, Karin U. Schallreuter, Wayne D. Beazley, John M. Wood, Hiroshi Ichinose   +7 more
openaire   +3 more sources

The Effects of 6R-L-Erythro-5,6,7,8-Tetrahydrobiopterin on Ethanol-Induced Sleep Time and Ethanol Elimination in Inbred Strains of Mice with Different Alcohol Preference

Neuropsychobiology, 1997
6R-L-erythro-5,6,7,8-tetrahydrobiopterin (6R-BH4) is a coenzyme for tyrosine, tryptophan and phenylalanine hydroxylases. Male C57BL/6J and DBA/2J mice were given 6R-BH4 (0, 12.5, 25.0 and 50.0 mg/kg of body weight, i.v.) or saline, and then 4 h later, all animals were injected with ethanol (EtOH) (4.0 g/kg, i.p.), which causes them to lose the righting
T Yoshida, Kanji Yoshimoto, Shuichi Ueda, Yoshihiro Takeuchi   +3 more
openaire   +4 more sources

Enhancement of in Vivo Dopamine Release from the Rat Striatum by 6R-L-Erythro-5,6,7,8-Tetrahydrobiopterin as Studied by Brain Dialysis

1990
6R-L-erythro-5,6,7,8-Tetrahydrobiopterin (6R-BH4) is a natural cofactor for tyrosine hydroxylase, a rate-limiting enzyme for biosynthesis of catecholamines (Nagatsu et al., 1964). Since the concentration of 6R-BH4 in the brain (Fukushima and Nixon, 1980) is low compared with Km values of tyrosine hydroxylase (Nelson and Kaufman, 1987), tissue levels of
Yasuyoshi Watanabe, Ken Lee, Motohatsu Fujiwara, Kunio Koshimura, Soichi Miwa   +4 more
openaire   +3 more sources

Photophysics of 5,6,7,8-tetrahydrobiopterin on a femtosecond time-scale

Journal of Photochemistry and Photobiology B: Biology
Varvara G. Kubenko, Vladimir A. Pomogaev, Andrey A. Buglak, Alexei I. Kononov   +3 more
openaire   +2 more sources

6R-L-Erythro-5,6,7,8-Tetrahydrobiopterin (R-THBP, SUN 0588) Acts on the Brain Muscarinic and Nicotinic Cholinergic Receptors as Evaluated by Positron Emission Tomography (PET) in Rhesus Monkey

Advances in Experimental Medicine and Biology, 1993
6R-L-erythro-5,6,7,8-tetrahydrobiopterin (R-THBP) is the natural cofactor for phenylalanine, tyrosine and tryptophan monooxygenases, the latter two enzymes catalyses the rate-limiting reactions in the synthesis of catecholamines and serotonin, respectively.
Tomochika Ohno, Yasuyoshi Watanabe, Göran Westerberg, Takafumi Ishihara, Per Hartvig, Anders Lilija, Jesper L. R. Andersson, Bengt Långström, Tadashi Kanai, Yoshihiro Tani   +9 more
openaire   +4 more sources

Positron Emission Tomography (PET) Study: The Effects of 6R-L-Erythro-5,6,7,8-Tetrahydrobiopterin (R-THBP, SUN 0588) on the Central Dopamine D1, D2 and D3 Receptors in Rhesus Monkey

Advances in Experimental Medicine and Biology, 1993
Among the brain imaging techniques, X-ray computed tomography (CT) and magnetic resonance imaging (MRI) give morphological images, but positron emission tomography (PET), which gives functional images, allows monitoring non-invasively of energy metabolism, local blood flow, some enzyme reactions and several types of receptor bindings1. The developments
Tomochika Ohno, Yasuyoshi Watanabe, Hirotaka Onoe, Anders Lilija, Bengt Långström, Tadashi Kanai, Göran Westerberg, Jesper L. R. Andersson, Yoshihiro Tani, Takafumi Ishihara, Per Hartvig   +10 more
openaire   +4 more sources

Pterins. VIII. The absolute configuration at C 6 of natural 2-Amino-6-[(1'R,2'S)- 1',2'-dihydroxypropyl]-5,6,7,8-tetrahydropteridin-4(3H)-one (L-erythro-5,6,7,8-tetrahydrobiopterin)

, 1982
The conformation of the side chain of 5,6,7,8-tetrahydrobiopterint (6) in 0.5 M DCl/D2O is predominantly quasi-equatorial (deduced from 3J (13C4a, 1H6) 1.1 HZ), and is the same as that of the methyl group in 2-methyl-1,2,3,4-tetrahydroquinoxaline and in ...
W. Armarego, P. Waring, B. Paal
semanticscholar   +1 more source

The (6R) 5,6,7,8 tetrahydrobiopterin/6-biopterin redox cycle controls melanogenesis and viability in human melanocytes

Melanoma Research, 1994
C. Koerner, J. M. Wood, Mark R. Pittelkow, K. U. Schallreuter, G. Buttner   +4 more
openaire   +3 more sources

Pterins. IX. The conformations of (6R)- and (6S)-2-Amino-6-[(1'R,2'S)-1',2'- dihydroxypropyl]-5,6,7,8-tetrahydropteridin-4(3H)-one [L-erythro-5,6,7,8-Tetrahydrobiopterin] hydrochlorides and their tetraacetyl derivatives

, 1984
Catalytic reduction of biopterin (1) in trifluoroacetic acid gives, after acetylation, a 1 : 3 mixture of (6S)- and (6R)- (4) tetraacetyl-5,6,7,8-tetrahydrobiopterin. Catalytic reduction of triacetylbiopterin (2) in ethanol yields, after acetylation, a 3
W. Armarego, D. Randles, H. Taguchi, M. J. Whittaker   +3 more
semanticscholar   +1 more source