Latest research on Tetrahydrobiopterin

Tetrahydrobiopterin or BH4 is a cofactor in the synthesis of nitric oxide. It is also essential in the conversion of phenylalanine to tyrosine by the enzyme phenylalanine-4-hydroxylase; the conversion of tyrosine to L-dopa by the enzyme tyrosine hydroxylase; and conversion of tryptophan to 5-hydroxytryptophan via tryptophan hydroxylase. [Wikipedia]

Latest findings

In addition, exogenous supplementation of the NOS substrate L-Arginine or the cofactor Tetrahydrobiopterin (BH4) is shown to increase insulin sensitivity [63, 64]. [source, 2016]
These orphan drugs are Imiglucerase, sapropterin dihydrochloride, recombinant coagulation Factor VIII, coagulation factor VIIa, human coagulation Factor VIII, human prothrombin complex concentrate, bosentan, Iloprost, ambrisentan, recombinant human Growth hormone, Busulfan, teniposide, Mitoxantrone, Imatinib, Dasatinib, nilotinib, meisoindigo, Arsenious Acid, homoharringtonine, rituximab, sorafenib, Danazol, Riluzole and poractant alfa. [source, 2016]
Endothelial cells synthetize Nitric oxide (NO), a potent vasodilator that is generated by NO synthases (NOS; i.e., the L-arginine/NO pathway), following the oxidation of L-arginine in a process that depends on the bioactivity of several cofactors, including Tetrahydrobiopterin (BH4) [13–15]. [source, 2016]
A similar consideration should be made for the cofactor Tetrahydrobiopterin (BH4). [source, 2016]
This enzyme is the rate-limiting enzyme in Tetrahydrobiopterin (BH4) biosynthesis and modulation of its activity would in turn influence BH4 related pathways such as Nitric oxide metabolism and endothelial function, and the one-carbon pool by Folate pathway (see Supplementary Table S1). [source, 2016]
The biosynthesis also requires various cofactors like flavin mononucleotide (FMN), flavin ADENINE dinucleotide (FAD), and Tetrahydrobiopterin (BH4) [4]. [source, 2016]
Increased uncoupling of eNOS due to different factors—elevated levels of ADMA [53, 54], reduced association with Hsp90 [55], decreased Tetrahydrobiopterin levels [56], oxidation of tetrathiolate cluster by hydrogen peroxide, Nitric oxide or peroxynitrite [57–59]—reduce consumption of Arginine through the NO pathway leading to vasoconstriction in pulmonary artery [54, 60]. [source, 2016]
Tetrahydrobiopterin, which has been reported to limit the superoxide generation from NOS and chemically reduce superoxide, fails to reduce neurological deficits 24 h after ICH in mice [131]. [source, 2016]
Data from pursuant research suggested that these effects were mediated by secretin activating the metabolic turnover of Dopamine in the central nervous system via Tetrahydrobiopterin, resulting in the improvement of ASD symptoms [16]. [source, 2015]
NADPH, Tetrahydrobiopterin, NG-nitro-l-arginine methyl ester (L-NAME), diphenyleneiodonium (DPI) and other reagents were purchased from Sigma unless otherwise indicated. [source, 2015]