Disease relevance of Deoxypyridoxine-P

• Relationship of dietary folate and vitamin B6 with coronary heart disease in women [1].
• Perinatal hypophosphatasia: tissue levels of vitamin B6 are unremarkable despite markedly increased circulating concentrations of pyridoxal-5'-phosphate. Evidence for an ectoenzyme role for tissue-nonspecific alkaline phosphatase [2].
• Plasma folate, vitamin B6, vitamin B12, homocysteine, and risk of breast cancer [3].
• Effects of dietary vitamin B6 at levels ranging from deficiency to megadoses on the development of herpes simplex virus type 2-transformed (H238) cell-induced tumors and on in vitro responses relating to cell-mediated immunity were examined [4].
• Vitamin B6 in management of gyrate atrophy of choroid and retina [5].

Psychiatry related information on Deoxypyridoxine-P

• Coenzyme Q10, iron, and vitamin B6 in genetically-confirmed Alzheimer's disease [6].
• Vitamin B6 intake, alcohol consumption, and colorectal cancer: a longitudinal population-based cohort of women [7].
• Effects of vitamin B6 on averaged evoked potentials in infantile autism [8].
• Vitamin B6 treatment in acute neuroleptic-induced akathisia: a randomized, double-blind, placebo-controlled study [9].
• The aim of this study was to examine whether vitamin B6 therapy influences psychotic symptoms in patients suffering from schizophrenia and schizoaffective disorder [10].

High impact information on Deoxypyridoxine-P

• Puffs induced by treatment with vitamin B6 at locus 2-48BC in salivary gland cells of Drosophila hydei were isolated by micromanipulation, and the puff RNA was analyzed electrophoretically [11].
• Pyridoxal kinase converts vitamin B6 derivatives into pyridoxal phosphate (PLP), the coenzyme of many enzymes involved in amino acid and neurotransmitter metabolism [12].
• INTERVENTION: Participants were randomly assigned to receive a combination of folic acid (1 mg/d), vitamin B12 (cyanocobalamin, 400 micro g/d), and vitamin B6 (pyridoxine hydrochloride, 10 mg/d) (n = 272) or placebo (n = 281) for 6 months [13].
• Relationship of dietary folate and vitamin B6 with coronary heart disease in women [14].
• Vitamin B6 appears useful in treating choroid disorder [15].

Chemical compound and disease context of Deoxypyridoxine-P

• Markedly increased circulating pyridoxal-5'-phosphate levels in hypophosphatasia. Alkaline phosphatase acts in vitamin B6 metabolism [16].
• Methionine and vitamin B6 intake and risk of pancreatic cancer: a prospective study of Swedish women and men [17].
• These laboratory findings confirmed the clinical observations in these two patients that penicillin-streptomycin therapy should be used in vitamin B6-dependent streptococcal endocarditis [18].
• Gyrate atrophy of the choroid and retina: characterization of mutant ornithine aminotransferase and mechanism of response to vitamin B6 [19].
• Vitamin B6 repletion in cirrhosis with oral pyridoxine: failure to improve amino acid metabolism [20].

Biological context of Deoxypyridoxine-P

• BACKGROUND & AIMS: Vitamin B6 has a crucial role in 1-carbon metabolism, which involves DNA synthesis and DNA methylation [7].
• Refractory postpartum anemia due to vitamin B6 deficiency [21].
• Cloning of the mutated gene revealed that rsr4-1 carries a point mutation in a member of the PDX1/SOR1/SNZ (for Pyridoxine biosynthesis protein 1/Singlet oxygen resistant 1/Snooze) family that leads to reduced vitamin B6 content [22].
• Crystal structure of glutamate-1-semialdehyde aminomutase: an alpha2-dimeric vitamin B6-dependent enzyme with asymmetry in structure and active site reactivity [23].
• A highly conserved sequence is a novel gene involved in de novo vitamin B6 biosynthesis [24].

Anatomical context of Deoxypyridoxine-P

• The present studies suggest an important role for the low pH values resulting from gastric acid secretion in the normal absorption of dietary PLP, and raise questions about the implications of widespread use of acid-lowering therapeutic modalities on vitamin B6 nutritional status [25].
• We conclude that fibroblast levels of CBS are only partially effective as prognosticators of disease severity and that it is important to test the in vivo response to vitamin B6 in all cases of homocystinuria, including those in which the mutations lead to the absence of the enzyme in cultured fibroblasts [26].
• These findings are discussed in terms of tumor nutrition and vitamin B6 metabolism in a rat hepatoma cell line [27].
• Kinetic analysis and chemical modification of vitamin B6 phosphatase from human erythrocytes [28].
• However, TE monolayers from vitamin B6-deficient animals were unable to effect such a maturation of T lymphocytes [29].

Associations of Deoxypyridoxine-P with other chemical compounds

• CONCLUSION: These results suggest that intake of folate and vitamin B6 above the current recommended dietary allowance may be important in the primary prevention of CHD among women [30].
• In four affected children, urinary excretion of the PLP degradation product, 4-pyridoxic acid, was unremarkable during consumption of normal quantities of dietary vitamin B6 [16].
• We have carried out a randomised clinical trial of a 12-month course of isoniazid plus vitamin B6 versus vitamin B6 alone in Port-au-Prince, Haiti, to assess the efficacy of isoniazid in preventing active tuberculosis in symptom-free HIV-infected individuals [31].
• Simple, inexpensive, nontoxic therapy with folic acid, vitamin B6, and vitamin B12 reduces plasma homocyst(e)ine levels [32].
• The metabolic fate of homocysteine is linked to vitamin B12, reduced folates, vitamin B6 and sulfur amino acids [33].

Gene context of Deoxypyridoxine-P

• Tpn1p, the plasma membrane vitamin B6 transporter of Saccharomyces cerevisiae [34].
• We also provide evidence that of the highly conserved SNZ and SNO genes in S. cerevisiae, only the protein encoded by SNZ1 is required for vitamin B6 biosynthesis [34].
• Deletion and linker scanning analyses of the VHT1 promoter revealed the palindromic 18-nucleotide sequence AATCA-N(8)-TGAYT as the vitamin H-responsive element [35].
• RESULTS: Holo-transcobalamin II levels were normal or supranormal in all patients and showed a linear association with albumin (r = 0.205, P = 0.025) and with vitamin B12 (r = 0.778, P = 0.001), but not with age, creatinine, body mass index, tHcy, ln-tHcy, vitamin B6, plasma folate, and red blood cell folate concentration [36].
• We report that pdxA, which is required for de novo biosynthesis of pyridoxine (vitamin B6) and pyridoxal phosphate, belongs to an unusual, multifunctional operon [37].

Analytical, diagnostic and therapeutic context of Deoxypyridoxine-P

• STUDY SELECTION: Prospective studies and major retrospective epidemiologic studies evaluating the association between homocyst(e)ine levels and cardiovascular disease and the association between blood levels or dietary intake of folate, vitamin B6, and vitamin B12 and cardiovascular disease [32].
• We have used site-directed mutagenesis to examine the function of three putative active site residues (C278, G279, and G281) of the vitamin B6 enzyme D-serine dehydratase [38].
• The effect of high doses of vitamin B6 on autistic children: a double-blind crossover study [39].
• RT-PCR and direct sequence analyses were used to define mutations in the cystathionine beta-synthase (CBS) gene in two unrelated male patients with vitamin B6 nonresponsive homocystinuria [40].
• All of these results indicate that uremic patients are vitamin B6 deficient and that those undergoing hemodialysis may have decreased amounts of the EGOT apoenzyme [41].

References