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Sample records for biopterin

  1. Radioimmunoassay for biopterin

    International Nuclear Information System (INIS)

    Nagatsu, Toshiharu; Yamaguchi, Tokio; Kato, Takeshi; Sugimoto, Takashi; Matsuura, Sadao.

    1979-01-01

    Specific antibodies against biopterin, neopterin, and 6,7-dimethylpterin were prepared and a new type of radioimmunoassay, to which these pterins were subjected was developed. This new type of radioimmunoassay was used to determine biopterin in human urine. Specific antiserum against biopterin did not crossreact significantly with tetrahydro-biopterin, dihydro-biopterin, neopterin, 6,7-dimethylpterin, pterin, or folic acid and showed 30% binding of biopterinyl-caproyl- ( 125 I ) tyramide at a dilution of 1:800. The antisera against neopterin and dimethylpterin also showed a high specificity and did not cross-react significantly with the other pterins. The sensitivity of the radioimmunoassay was increased about ten-fold by pre-incubating the antiserum with 6,7-dimethylpterinyl-caproyl to remove antibodies against the caproic acid moiety of the biopterin conjugate. The recovery of biopterin or tetrahydro-biopterin added human urine was nearly 100% according to this type of radioimmunoassay, and the biopterin concentrations in the urine that were obtained by means of this type of radioimmunoassay showed a fairly good agreement with the values obtained by means of bioassay. The biopterin contents per milliliter of human urine showed considerable variations depending on the subjects, but those per milligram of creatinine were found to be fairly constant in normal subjects. Therefore, biopterin concentrations per milligram of creatinine in human urine may be a good indicator of biopterin metabolism in clinical chemistry. This new type of radioimmunoassay is simple, highly specific, and reproducible. Therefore, it may be very useful for the screening of atypical phenylketonuria due to biopterin deficiency and also for the study of the pathogenesis of various biopterin metabolic diseases. (J.P.N.)

  2. Radioimmunoassay for biopterin

    Energy Technology Data Exchange (ETDEWEB)

    Nagatsu, T; Yamaguchi, T; Kato, T [Tokyo Inst. of Tech. (Japan); Sugimoto, T; Matsuura, S

    1979-06-01

    Specific antibodies against biopterin, neopterin, and 6,7-dimethylpterin were prepared and a new type of radioimmunoassay, to which these pterins were subjected was developed. This new type of radioimmunoassay was used to determine biopterin in human urine. Specific antiserum against biopterin did not crossreact significantly with tetrahydro-biopterin, dihydro-biopterin, neopterin, 6,7-dimethylpterin, pterin, or folic acid and showed 30% binding of biopterinyl-caproyl- ( /sup 125/I ) tyramide at a dilution of 1:800. The antisera against neopterin and dimethylpterin also showed a high specificity and did not cross-react significantly with the other pterins. The sensitivity of the radioimmunoassay was increased about ten-fold by pre-incubating the antiserum with 6,7-dimethylpterinyl-caproyl to remove antibodies against the caproic acid moiety of the biopterin conjugate. The recovery of biopterin or tetrahydro-biopterin added human urine was nearly 100% according to this type of radioimmunoassay, and the biopterin concentrations in the urine that were obtained by means of this type of radioimmunoassay showed a fairly good agreement with the values obtained by means of bioassay. The biopterin contents per milliliter of human urine showed considerable variations depending on the subjects, but those per milligram of creatinine were found to be fairly constant in normal subjects. Therefore, biopterin concentrations per milligram of creatinine in human urine may be a good indicator of biopterin metabolism in clinical chemistry. This new type of radioimmunoassay is simple, highly specific, and reproducible. Therefore, it may be very useful for the screening of atypical phenylketonuria due to biopterin deficiency and also for the study of the pathogenesis of various biopterin metabolic diseases.

  3. Biopterin-deficient hyperphenylalaninemia: Diagnosis and treatment

    Directory of Open Access Journals (Sweden)

    E. A. Nikolaeva

    2015-01-01

    Full Text Available The term phenylketonuria encompasses some genetically heterogeneous diseases from a group of hereditary amino acid metabolic disorders, the key biochemical sign of which is a steady increase in blood phenylalanine levels – hyperphenylalaninemia. Phenylketonuria is a most common disease of the above group; its rate in the Russian Federation is 1:7140 neonates. The rare causes of hyperphenylalaninemia include the cofactor (biopterin-deficient forms associated with tetrahydrobiopterin deficiency, leading to the blocked metabolic pathways for converting phenylalanine to tyrosine and for synthesizing catecholamine and serotonin precursors (L-dopa and 5-hydroxytryptophan. The distinguishing feature of all cofactor forms of hyperphenylalaninemia is the inefficiency of an isolated low-protein diet. Cofactor therapy with sapropterin in combination with correction of neuromediatory disorders is used in the combination treatment of these patients. The paper presents a case history of a child with severe biopterin-deficient hyperphenylalaninemia resulting from a defect in the PTS gene. The clinical example illustrates difficulties associated with the diagnosis of cofactor hyperphenylalaninemia and with long individual dosage adjustments for medications. 

  4. Serum Biopterin and Neopterin Levels as Predictors of Empty Follicles

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    Akihiro Hamuro

    2015-01-01

    Full Text Available Objective This study measured serum and follicular fluid (FF levels of biopterin, neopterin, vascular endothelial growth factor (VEGF, and macrophage colony-stimulating factor (M-CSF in patients receiving mild ovarian stimulation for oocyte retrieval. Patients and Methods Infertile patients who underwent ovarian stimulation were divided into the following: Group 1, no oocyte retrieval ( n = 12, and Group 2, retrieval of more than four oocytes ( n = 13. Median total gonadotropin dose in both groups was 150 IU. Biopterin and neopterin levels were measured using high-performance liquid chromatography. VEGF and M-CSF levels were measured by enzyme-linked immunosorbent assay. Results Compared to Group 2, serum and FF levels of neopterin and VEGF and serum levels of M-CSF were significantly increased, and serum and FF levels of biopterin were significantly decreased in Group 1 ( P < 0.05 each. Conclusion Biopterin and neopterin levels showed similar differences in FF and serum of patients with empty follicles. Decreased biopterin and increased neopterin in serum could predict poor oocyte retrieval.

  5. Determination of marker pteridins and biopterin reduced forms, tetrahydrobiopterin and dihydrobiopterin, in human urine, using a post-column photoinduced fluorescence liquid chromatographic derivatization method

    International Nuclear Information System (INIS)

    Canada-Canada, Florentina; Espinosa-Mansilla, Anunciacion; Munoz de la Pena, Arsenio; Mancha de Llanos, Alicia

    2009-01-01

    A liquid chromatographic method for the simultaneous analysis of marker pteridins and biopterin reduced forms, in urine samples is proposed. A Zorbax Eclipse XDB-C18 column was used for the chromatographic separation, using a 98/2 (v/v), citrate buffer (pH 5.5)-acetonitrile mobile phase, in isocratic mode. A post-column photoderivatization was carried out with an on-line photoreactor, located between a diode array detector (DAD) and a fast scanning fluorescence detector (FSFD). Neopterin (NEO), biopterin (BIO), pterin (PT) and dihydrobiopterin (BH2) were determined by measuring native fluorescence, using the photoreactor in OFF-mode, and tetrahydrobiopterin (BH4) was determined by measuring of the induced fluorescence of the generated photoproducts, using the photoreactor in ON-mode. In addition, Creatinine (CREA), as a reference of metabolites excrection in urine, was simultaneously determined using the DAD detector. Detection limits were 0.2, 13.0, 0.3, 0.3 and 3.5 ng mL -1 , for NEO, BH2, BIO, PT and BH4, respectively, and 0.4 μg mL -1 for CREA. Ratio values for NEO/CREA, PT/CREA, BH4/CREA, BH2/CREA, NEO/BIO and BIO total /CREA, in urine samples, of healthy children and adults, phenylketonuric children and infected mononucleosis children, are reported. A comparative study, about the mean values obtained for each of the compounds, by the present procedure and by the classical iodine oxidation method (Fukushimas method), has been performed, in urine samples belonging to healthy volunteers. The values obtained were BH4/CREA: 0.41, BH2/CREA: 0.31 and BIO total /CREA: 0.73, by the proposed method, and BH4/CREA: 0.35, BH2/CREA: 0.20 and BIO total /CREA: 0.48, by iodine oxidation method.

  6. Determination of marker pteridins and biopterin reduced forms, tetrahydrobiopterin and dihydrobiopterin, in human urine, using a post-column photoinduced fluorescence liquid chromatographic derivatization method

    Energy Technology Data Exchange (ETDEWEB)

    Canada-Canada, Florentina, E-mail: floricanada@gmail.com [Department of Analytical Chemistry, University of Extremadura, 06071 Badajoz (Spain); Espinosa-Mansilla, Anunciacion; Munoz de la Pena, Arsenio; Mancha de Llanos, Alicia [Department of Analytical Chemistry, University of Extremadura, 06071 Badajoz (Spain)

    2009-08-19

    A liquid chromatographic method for the simultaneous analysis of marker pteridins and biopterin reduced forms, in urine samples is proposed. A Zorbax Eclipse XDB-C18 column was used for the chromatographic separation, using a 98/2 (v/v), citrate buffer (pH 5.5)-acetonitrile mobile phase, in isocratic mode. A post-column photoderivatization was carried out with an on-line photoreactor, located between a diode array detector (DAD) and a fast scanning fluorescence detector (FSFD). Neopterin (NEO), biopterin (BIO), pterin (PT) and dihydrobiopterin (BH2) were determined by measuring native fluorescence, using the photoreactor in OFF-mode, and tetrahydrobiopterin (BH4) was determined by measuring of the induced fluorescence of the generated photoproducts, using the photoreactor in ON-mode. In addition, Creatinine (CREA), as a reference of metabolites excrection in urine, was simultaneously determined using the DAD detector. Detection limits were 0.2, 13.0, 0.3, 0.3 and 3.5 ng mL{sup -1}, for NEO, BH2, BIO, PT and BH4, respectively, and 0.4 {mu}g mL{sup -1} for CREA. Ratio values for NEO/CREA, PT/CREA, BH4/CREA, BH2/CREA, NEO/BIO and BIO{sub total}/CREA, in urine samples, of healthy children and adults, phenylketonuric children and infected mononucleosis children, are reported. A comparative study, about the mean values obtained for each of the compounds, by the present procedure and by the classical iodine oxidation method (Fukushimas method), has been performed, in urine samples belonging to healthy volunteers. The values obtained were BH4/CREA: 0.41, BH2/CREA: 0.31 and BIO{sub total}/CREA: 0.73, by the proposed method, and BH4/CREA: 0.35, BH2/CREA: 0.20 and BIO{sub total}/CREA: 0.48, by iodine oxidation method.

  7. Biopterin status in dogs with myxomatous mitral valve disease is associated with disease severity and cardiovascular risk factors

    DEFF Research Database (Denmark)

    Reimann, Maria Josefine; Häggström, J.; Mortensen, Alan

    2014-01-01

    BACKGROUND: Endothelial dysfunction (ED) has been suggested to be associated with myxomatous mitral valve disease (MMVD) in dogs. Tetrahydrobiopterin (BH4) is an important cofactor for production of the endothelium-derived vasodilator nitric oxide (NO). Under conditions of oxidative stress, BH4...... is oxidized to the biologically inactive form dihydrobiopterin (BH2). Thus, plasma concentrations of BH2 and BH4 may reflect ED and oxidative stress. OBJECTIVE: To determine plasma concentrations of BH2 and BH4 in dogs with different degrees of MMVD. ANIMALS: Eighty-four privately owned dogs grouped according...... to ACVIM guidelines (37 healthy control dogs including 13 Beagles and 24 Cavalier King Charles Spaniels [CKCSs], 33 CKCSs with MMVD of differing severity including 18 CKCSs [group B1] and 15 CKCSs [group B2], and 14 dogs of different breeds with clinical signs of congestive heart failure [CHF] because...

  8. Tetrahydrobiopterin restores endothelial dysfunction induced by an oral glucose challenge in healthy subjects

    DEFF Research Database (Denmark)

    Ihlemann, Nikolaj; Rask-Madsen, Christian; Perner, Anders

    2003-01-01

    (n = 10) and SNP (n = 8). On different days (6R)-5,6,7,8-tetrahydro-l-biopterin dihydrochloride (6R-BH4; n = 10), the active cofactor of eNOS or its stereoisomer (6S)-5,6,7,8-tetrahydro-l-biopterin sulfate (6S-BH4; n = 10), which is inactive as a cofactor, was added 10 min (500 microg/min) before...... and during the 1-h postchallenge serotonin dose-response study. In vitro studies showed that 6R-BH4 and 6S-BH4 were equipotent antioxidants. Serotonin response was reduced by 24 +/- 7% (at the highest dose) at 1 h postchallenge compared with fasting (P = 0.001) and was restored 2 h postchallenge...

  9. Vitamin C deficiency reduces muscarinic receptor coronary artery vasoconstriction and plasma tetrahydrobiopterin concentration in guinea pigs

    DEFF Research Database (Denmark)

    Skovsted, Gry Freja; Tveden-Nyborg, Pernille; Lindblad, Maiken Marie

    2017-01-01

    Vitamin C (vitC) deficiency is associated with increased cardiovascular disease risk, but its specific interplay with arteriolar function is unclear. This study investigates the effect of vitC deficiency in guinea pigs on plasma biopterin status and the vasomotor responses in coronary arteries...... exposed to vasoconstrictor/-dilator agents. Dunkin Hartley female guinea pigs (n = 32) were randomized to high (1500 mg/kg diet) or low (0 to 50 mg/kg diet) vitC for 10-12 weeks. At euthanasia, coronary artery segments were dissected and mounted in a wire-myograph. Vasomotor responses to potassium......-1 were unaffected by vitC status. The study shows that vitC deficiency decreases tetrahydrobiopterin concentrations and muscarinic receptor mediated contraction in coronary arteries. This attenuated vasoconstrictor response may be linked to altered production of vasoactive arachidonic acid...

  10. Sample preparation and UHPLC-FD analysis of pteridines in human urine.

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    Tomšíková, H; Solich, P; Nováková, L

    2014-07-01

    Elevated levels of pteridines can indicate the activation of cellular immune system by certain diseases. No work dealing with the simultaneous determination of urinary neopterin, biopterin and their reduced forms has been published. Therefore, a new SPE-UHPLC-FD method for the analysis of these compounds has been developed. The main emphasis was put on the stability of dihydroforms during the sample processing and storage. As a stabilizing agent, dithiothreitol, at various concentrations, and various pH values (3.8-9.8) of working solutions were tested. Chromatographic separation was performed under HILIC isocratic conditions on BEH Amide column. The method was linear for the calibration standard solutions in the range of 10-10,000 ng/ml (dihydroforms) and 0.5-1000 ng/ml (oxidized forms), and for real samples in the range of 25-1000 ng/ml (dihydroforms) and 1-100 ng/ml (oxidized forms). The development of a new SPE sample preparation method was carried out on different types of sorbents (based on a mixed-mode cation exchange, porous graphitic carbon and a polymer comprising hydrophilic and hydrophobic components). Final validation was performed on a MCAX SPE column. Method accuracy ranged from 76.9 to 121.9%. The intra- and inter-day precision did not exceed 10.7%. The method provided high sensitivity for the use in routine clinical measurements of urine (LLOQ 1 ng/ml for oxidized forms and 25 ng/ml for dihydroforms). Average concentrations of biopterin, neopterin, and dihydrobiopterin found in urine of healthy persons were related to the mol of creatinine (66.8, 142.3, and 257.3 μmol/mol of creatinine, respectively) which corresponded to the literature data. The concentration of dihydroneopterin obtained using our method was 98.8 μmol/mol of creatinine. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. High dose sapropterin dihydrochloride therapy improves monoamine neurotransmitter turnover in murine phenylketonuria (PKU).

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    Winn, Shelley R; Scherer, Tanja; Thöny, Beat; Harding, Cary O

    2016-01-01

    Central nervous system (CNS) deficiencies of the monoamine neurotransmitters, dopamine and serotonin, have been implicated in the pathophysiology of neuropsychiatric dysfunction in phenylketonuria (PKU). Increased brain phenylalanine concentration likely competitively inhibits the activities of tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH), the rate limiting steps in dopamine and serotonin synthesis respectively. Tetrahydrobiopterin (BH4) is a required cofactor for TH and TPH activity. Our hypothesis was that treatment of hyperphenylalaninemic Pah(enu2/enu2) mice, a model of human PKU, with sapropterin dihydrochloride, a synthetic form of BH4, would stimulate TH and TPH activities leading to improved dopamine and serotonin synthesis despite persistently elevated brain phenylalanine. Sapropterin (20, 40, or 100mg/kg body weight in 1% ascorbic acid) was administered daily for 4 days by oral gavage to Pah(enu2/enu2) mice followed by measurement of brain biopterin, phenylalanine, tyrosine, tryptophan and monoamine neurotransmitter content. A significant increase in brain biopterin content was detected only in mice that had received the highest sapropterin dose, 100mg/kg. Blood and brain phenylalanine concentrations were unchanged by sapropterin therapy. Sapropterin therapy also did not alter the absolute amounts of dopamine and serotonin in brain but was associated with increased homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA), dopamine and serotonin metabolites respectively, in both wild type and Pah(enu2/enu2) mice. Oral sapropterin therapy likely does not directly affect central nervous system monoamine synthesis in either wild type or hyperphenylalaninemic mice but may stimulate synaptic neurotransmitter release and subsequent metabolism. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Estrogen Therapy, Independent of Timing, Improves Cardiac Structure and Function in Oophorectomized mRen2.Lewis Rats

    Science.gov (United States)

    Jessup, Jewell A.; Wang, Hao; MacNamara, Lindsay M.; Presley, Tennille D.; Kim-Shapiro, Daniel B.; Zhang, Lili; Chen, Alex F.; Groban, Leanne

    2013-01-01

    Objective mRen2.Lewis Rats exhibit exacerbated increases in blood pressure, left ventricular (LV) remodeling, and diastolic impairment following the loss of estrogens. In this same model, depletion of estrogens has marked effects on the cardiac biopterin profile concomitant with suppressed nitric oxide (NO) release. With respect to the establishment of overt systolic hypertension after oophorectomy (OVX), we assessed the effects of timing chronic 17 β-estradiol (E2) therapy on myocardial function, structure, and the cardiac NO system. Methods Oophrectomy (OVX; n=24) or sham-operation (Sham; n=13) was performed in 4-week-old, female mRen2.Lewis rats. Following randomization, OVX rats received E2 immediately (OVX + early E2; n=7), E2 at 11 weeks of age (OVX + late E2 N=8), or no E2 at all (OVX N=9). Results Early E2 was associated with lower body weight, less hypertension-related cardiac remodeling, and decreased LV filling pressure compared to OVX rats without E2 supplementation. Late E2 similarly attenuated the adverse effects of ovarian hormone loss on tissue-Doppler derived LV filling pressures and perivascular fibrosis, and significantly improved myocardial relaxation, or mitral annular velocity (e′). Early and late exposure to E2 decreased dihydrobiopterin, but only late E2 yielded significant increases in cardiac nitrite concentrations. Conclusions Although there were some similarities between early and late E2 treatment on preservation of diastolic function and cardiac structure after OVX, the lusitropic potential of E2 was most consistent with late supplementation. The cardioprotective effects of late E2 were independent of blood pressure and may have occurred through regulation of cardiac biopterins and NO production. PMID:23481117

  13. Guinea pig ascorbate status predicts tetrahydrobiopterin plasma concentration and oxidation ratio in vivo.

    Science.gov (United States)

    Mortensen, Alan; Hasselholt, Stine; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2013-10-01

    Tetrahydrobiopterin (BH₄) is an essential co-factor of nitric oxide synthases and is easily oxidized to dihydrobiopterin (BH₂) which promotes endothelial nitric oxide synthase uncoupling and deleterious superoxide production. Vitamin C has been shown to improve endothelial function by different mechanisms, some involving BH₄. The hypothesis of the present study was that vitamin C status, in particular low levels, influences biopterin redox status in vivo. Like humans, the guinea pig lacks the ability to synthesize vitamin C and was therefore used as model. Seven day old animals (n = 10/group) were given a diet containing 100, 250, 500, 750, 1000, or 1500 ppm vitamin C until euthanasia at age 60-64 days. Blood samples were drawn from the heart and analyzed for ascorbate, dehydroascorbic acid (DHA), BH₄ and BH₂ by high-performance liquid chromatography. Plasma BH₄ levels were found to be significantly lower in animals fed 100 ppm vitamin C compared to all other groups (P < .05 or less). BH₂ levels were not significantly different between groups but the BH₂-to-BH₄ ratio was higher in the group fed 100 ppm vitamin C (P < .001 all cases). Significant positive correlations between BH4 and ascorbate and between BH₂-to-BH₄ ratio and DHA were observed (P < .0001 both cases). Likewise, BH₂-to-BH₄ ratio was negatively correlated with ascorbate (P < .0001) as was BH₄ and DHA (P < .005). In conclusion, the redox status of plasma biopterins, essentially involved in vasodilation, depends on the vitamin C status in vivo. Thus, ingestion of insufficient quantities of vitamin C not only leads to vitamin C deficiency but also to increased BH₄ oxidation which may promote endothelial dysfunction. © 2013 Elsevier Inc. All rights reserved.

  14. Impaired systemic tetrahydrobiopterin bioavailability and increased dihydrobiopterin in adult falciparum malaria: association with disease severity, impaired microvascular function and increased endothelial activation.

    Directory of Open Access Journals (Sweden)

    Tsin W Yeo

    2015-03-01

    Full Text Available Tetrahydrobiopterin (BH₄ is a co-factor required for catalytic activity of nitric oxide synthase (NOS and amino acid-monooxygenases, including phenylalanine hydroxylase. BH4 is unstable: during oxidative stress it is non-enzymatically oxidized to dihydrobiopterin (BH₂, which inhibits NOS. Depending on BH₄ availability, NOS oscillates between NO synthase and NADPH oxidase: as the BH₄/BH₂ ratio decreases, NO production falls and is replaced by superoxide. In African children and Asian adults with severe malaria, NO bioavailability decreases and plasma phenylalanine increases, together suggesting possible BH₄ deficiency. The primary three biopterin metabolites (BH₄, BH₂ and B₀ [biopterin] and their association with disease severity have not been assessed in falciparum malaria. We measured pterin metabolites in urine of adults with severe falciparum malaria (SM; n=12, moderately-severe malaria (MSM, n=17, severe sepsis (SS; n=5 and healthy subjects (HC; n=20 as controls. In SM, urinary BH₄ was decreased (median 0.16 ¼mol/mmol creatinine compared to MSM (median 0.27, SS (median 0.54, and HC (median 0.34]; p<0.001. Conversely, BH₂ was increased in SM (median 0.91 ¼mol/mmol creatinine, compared to MSM (median 0.67, SS (median 0.39, and HC (median 0.52; p<0.001, suggesting increased oxidative stress and insufficient recycling of BH2 back to BH4 in severe malaria. Overall, the median BH₄/BH₂ ratio was lowest in SM [0.18 (IQR: 0.04-0.32] compared to MSM (0.45, IQR 0.27-61, SS (1.03; IQR 0.54-2.38 and controls (0.66; IQR 0.43-1.07; p<0.001. In malaria, a lower BH₄/BH₂ ratio correlated with decreased microvascular reactivity (r=0.41; p=0.03 and increased ICAM-1 (r=-0.52; p=0.005. Decreased BH4 and increased BH₂ in severe malaria (but not in severe sepsis uncouples NOS, leading to impaired NO bioavailability and potentially increased oxidative stress. Adjunctive therapy to regenerate BH4 may have a role in improving NO

  15. Muscle-directed gene therapy for phenylketonuria (PKU): Development of transgenic mice with muscle-specific phenylalanine hydroxylase expression

    Energy Technology Data Exchange (ETDEWEB)

    Harding, C.O.; Messing, A.; Wolff, J.A. [Univ. of Wisconsin, Madison, WI (United States)

    1994-09-01

    Phenylketonuria (PKU) is an attractive target for gene therapy because of shortcomings in current therapy including lifelong commitment to a difficult and expensive diet, persistent mild cognitive deficits in some children despite adequate dietary therapy, and maternal PKU syndrome. Phenylalanine hydroxylase (PAH) is normally expressed only in liver, but we propose to treat PKU by introducing the gene for PAH into muscle. In order to evaluate both the safety and efficacy of this approach, we have a developed a trangenic mouse which expresses PAH in both cardiac and skeletal muscle. The transgene includes promoter and enhancer sequences from the mouse muscle creatine kinase (MCK) gene fused to the mouse liver PAH cDNA. Mice which have inherited the transgene are healthy, active, and do not exhibit any signs of muscle weakness or wasting. Ectopic PAH expression in muscle is not detrimental to the health, neurologic function, or reproduction of the mice. Pah{sup enu2} hyperphenylalaninemic mice, a model of human PAH deficiency, bred to carry the transgene have substantial PAH expression in cardiac and skeletal muscle but none in liver. Muscle PAH expression alone does not complement the hyperphenylalaninemic phenotype of Pah{sup enu2} mice. However, administration of reduced tetrahydrobiopterin to transgenic Pah{sup enu2} mice is associated with a 25% mean decrease in serum phenylalanine levels. We predict that ectopic expression of PAH in muscle along with adequate muscle supplies of reduced biopterin cofactor will decrease hyperphenylalaninemia in PKU.

  16. Administration of secretin for autism alters dopamine metabolism in the central nervous system.

    Science.gov (United States)

    Toda, Yoshihiro; Mori, Kenji; Hashimoto, Toshiaki; Miyazaki, Masahito; Nozaki, Satoshi; Watanabe, Yasuyoshi; Kuroda, Yasuhiro; Kagami, Shoji

    2006-03-01

    We evaluated the clinical effects of intravenously administered secretin in 12 children with autism (age range: 4-6 years, median age: 9 years, boy:girl=8:4). In addition, we investigated the association between improvement in symptoms and changes in the cerebrospinal fluid (CSF) homovanillic acid (HVA),5-hydroxyindole-3-acetic acid (5-HIAA), and 6R-5,6,7,8-tetrahydro-L-biopterin (BH(4)) levels after administration. After administration of secretin, the Autism Diagnostic Interview-Revised (ADI-R) score improved in 7 of the 12 children. However, the score deteriorated in 2 of the 12 children (in the item of 'restricted and repetitive, stereotyped interests and behaviors'). The HVA and BH(4) levels in CSF were increased in all children with improvement in the ADI-R score. In contrast, no patient without the elevation of the BH(4) level showed improvement in the score. These findings suggest that secretin activated metabolic turnover of dopamine in the central nervous system via BH(4), improving symptoms.

  17. Influence of various forms of dialyzable leukocyte extracts on rat adjuvant arthritis

    International Nuclear Information System (INIS)

    Stancikova, Maria; Rovensky, Jozef; Blazickova, Stanislava; Pekarek, J.; Cech, Karel

    1994-01-01

    Adjuvant-induced arthritis in rats is a chronic inflammatory disease, widely as an animal model for rheumatoid arthritis. In our study the effect of various fractions of dialyzable leukocyte extract (DLE): DLE I-molecular weight below 10 kDa (commercial preparation), DLE II-molecular weight below 5 kDa (suppressor fraction), DLE III-molecular weight 5-10 kDa on rat adjuvant-induced arthritis was studied. The adjuvant arthritic (AA) rats were treated with DLE fractions i.p. in solutions containing an active substance isolated from 12.5 x 10 6 and 6.25 x 10 6 leukocytes from day 1 (adjuvant injected) through day 18, every second day (total 9 times). Various markers in inflammation, immune function and joint destruction were evaluated: hind paw volume, serum hyaluronic acid, serum albumin and biopterin in urine. All these markers showed a significant improvement after using fraction DLE II in comparison with AA controls. Fractions DLE I and DLE III influenced only some markers of inflammation and immune function. Our results demonstrated a therapeutical effect of fraction DLE II on rat adjuvant-induced arthritis. (author). 22 refs, 2 figs, 2 tabs

  18. Is tetrahydrobiopterin a therapeutic option in diabetic hypertensive patients?

    Directory of Open Access Journals (Sweden)

    Alberto Francisco Rubio-Guerra

    2010-09-01

    Full Text Available Alberto Francisco Rubio-Guerra1, Hilda Vargas-Robles2, Luz Maria Ramos-Brizuela1, Bruno Alfonso Escalante-Acosta21Metabolic Clinic, Hospital General de Ticomán SS DF, Mexico; 2Department of Molecular Biomedicine, Centro de Investigacion y de Estudios Avanzados del IPN, MexicoAbstract: Nitric oxide (NO is an important regulator of vascular tone, and is also an antithrombotic, anti-inflammatory, antiproliferative, and antiatherogenic factor. Endothelial function is altered in patients with coronary artery disease, stroke, and peripheral artery disease, and endothelial dysfunction correlates with the risk factor profile for a patient. Hypertension and type 2 diabetes are risk factors for vascular disease, and are both pathologies characterized by loss of NO activity. Indeed, endothelial dysfunction is usually present in diabetic and/or hypertensive patients. Tetrahydrobiopterin is an essential cofactor for the NO synthase enzyme, and insufficiency of this cofactor leads to uncoupling of the enzyme, release of superoxide, endothelial dysfunction, progression of hypertension, and finally, proatherogenic effects. Tetrahydrobiopterin is also an important mediator of NO synthase regulation in type 2 diabetes and hypertension, and may be a rational therapeutic target to restore endothelial function and prevent vascular disease in these patients. The aim of this paper is to review the rationale for therapeutic strategies directed to biopterins as a target for vascular disease in type 2 diabetic hypertensive patients.Keywords: tetrahydrobiopterin, endothelial dysfunction, diabetes, hypertension, oxidative stress, nitric oxide, eNOS synthase uncoupling

  19. Cell metabolomics reveals the neurotoxicity mechanism of cadmium in PC12 cells.

    Science.gov (United States)

    Zong, Li; Xing, Junpeng; Liu, Shu; Liu, Zhiqiang; Song, Fengrui

    2018-01-01

    The heavy metals such as cadmium (Cd) can induce neurotoxicity. Extensive studies about the effects of Cd on human health have been reported, however, a systematic investigation on the molecular mechanisms of the effects of Cd on central nervous system is still needed. In this paper, the neuronal PC-12 cells were treated with a series of concentrations of CdCl 2 for 48h. Then the cytotoxicity was evaluated by MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. The IC 15 value (15% inhibiting concentration) was selected for further mechanism studies. After PC-12 cells incubated with CdCl 2 at a dose of IC 15 for 48h, the intracellular and extracellular metabolites were profiled using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS)-based cell metabolomics approach. As found, the effects of the heavy metal Cd produced on the PC-12 cell viability were dose-dependent. The metabolic changes were involved in the glycolysis and gluconeogenesis, biopterin metabolism, tryptophan metabolism, tyrosine metabolism, glycerophospholipid metabolism, and fatty acids beta-oxidation. These could cause the perturbation of cell membrane, redox balance, energy supply, cellular detoxification, further affecting the cellular proliferation and apoptosis and other cellular activities. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Elevated phenylalanine on newborn screening: follow-up testing may reveal undiagnosed galactosaemia.

    Science.gov (United States)

    Shakespeare, Lynette; Downing, Melanie; Allen, Joyce; Casbolt, Ann-Marie; Ellin, Sheila; Maloney, Martin; Race, Gillian; Bonham, Jim

    2010-11-01

    Introduction Newborn screening for phenylketonuria (PKU) can reveal other conditions which lead to an increased blood spot phenylalanine (Phe) concentration. We have investigated the proportion of blood spot samples that gave a positive screen due to clinically significant conditions other than PKU, compared the positive predictive value (PPV) of our referral Phe cut-off with that recommended by the UK Newborn Screening Programme Centre (UKNSPC) (>210 and >240 μmol/L, respectively) and evaluated the effectiveness of reflex testing for galactosaemia using a lower blood spot Phe cut-off concentration of 130 μmol/L. All blood spot samples that screened positive, for an increased Phe concentration, between April 2001 and March 2008, were identified from the records of the Sheffield Newborn Screening Laboratory and the diagnoses noted. In addition, all cases of galactosaemia detected in or notified to our screening laboratory within this time were also examined and the screened Phe concentrations compared. Out of 438,674 babies who were screened, 67 had Phe concentration >210 μmol/L (15 per 100,000). Of these, 40 had PKU or persistent hyperphenylalaninaemia with a Phe concentration identified by screening between 270 and 2350 μmol/L. A further 11 were diagnosed with another clinically significant disorder: galactosaemia (n = 8), biopterin defects (n = 2), tyrosinaemia Type 1 (n = 1). In addition, 16 had transient elevations in Phe. In total, nine cases of galactosaemia were identified, of whom, three had Phe concentrations 240 μmol/L) will not affect the detection rate of classical PKU, but will improve the PPV from 76% to 80%. The use of a lower cut-off (130 μmol/L) for reflex galactosaemia testing enables the timely identification of asymptomatic cases that benefit particularly from early treatment, without prompting any unnecessary clinical referrals or delaying any referrals. This intervention may reduce mortality in this vulnerable group.

  1. Simultaneous detection of six urinary pteridines and creatinine by high-performance liquid chromatography-tandem mass spectrometry for clinical breast cancer detection.

    Science.gov (United States)

    Burton, Casey; Shi, Honglan; Ma, Yinfa

    2013-11-19

    Recent preliminary studies have implicated urinary pteridines as candidate biomarkers in a growing number of malignancies including breast cancer. While the developments of capillary electrophoresis-laser induced fluorescence (CE-LIF), high performance liquid chromatography (HPLC), and liquid chromatography-mass spectroscopy (LC-MS) pteridine urinalyses among others have helped to enable these findings, limitations including poor pteridine specificity, asynchronous or nonexistent renal dilution normalization, and a lack of information regarding adduct formation in mass spectrometry techniques utilizing electrospray ionization (ESI) have prevented application of these techniques to a larger clinical setting. In this study, a simple, rapid, specific, and sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method has been developed and optimized for simultaneous detection of six pteridines previously implicated in breast cancer and creatinine as a renal dilution factor in urine. In addition, this study reports cationic adduct formation of urinary pteridines under ESI-positive ionization for the first time. This newly developed technique separates and detects the following six urinary pteridines: 6-biopterin, 6-hydroxymethylpterin, d-neopterin, pterin, isoxanthopterin, and xanthopterin, as well as creatinine. The method detection limit for the pteridines is between 0.025 and 0.5 μg/L, and for creatinine, it is 0.15 μg/L. The method was also validated by spiked recoveries (81-105%), reproducibility (RSD: 1-6%), and application to 25 real urine samples from breast cancer positive and negative samples through a double-blind study. The proposed technique was finally compared directly with a previously reported CE-LIF technique, concluding that additional or alternative renal dilution factors are needed for proper investigation of urinary pteridines as breast cancer biomarkers.

  2. Manipulation of dopamine metabolism contributes to attenuating innate high locomotor activity in ICR mice.

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    Yamaguchi, Takeshi; Nagasawa, Mao; Ikeda, Hiromi; Kodaira, Momoko; Minaminaka, Kimie; Chowdhury, Vishwajit S; Yasuo, Shinobu; Furuse, Mitsuhiro

    2017-06-15

    Attention-deficit hyperactivity disorder (ADHD) is defined as attention deficiency, restlessness and distraction. The main characteristics of ADHD are hyperactivity, impulsiveness and carelessness. There is a possibility that these abnormal behaviors, in particular hyperactivity, are derived from abnormal dopamine (DA) neurotransmission. To elucidate the mechanism of high locomotor activity, the relationship between innate activity levels and brain monoamines and amino acids was investigated in this study. Differences in locomotor activity between ICR, C57BL/6J and CBA/N mice were determined using the open field test. Among the three strains, ICR mice showed the greatest amount of locomotor activity. The level of striatal and cerebellar DA was lower in ICR mice than in C57BL/6J mice, while the level of L-tyrosine (L-Tyr), a DA precursor, was higher in ICR mice. These results suggest that the metabolic conversion of L-Tyr to DA is lower in ICR mice than it is in C57BL/6J mice. Next, the effects of intraperitoneal injection of (6R)-5, 6, 7, 8-tetrahydro-l-biopterin dihydrochloride (BH 4 ) (a co-enzyme for tyrosine hydroxylase) and L-3,4-dihydroxyphenylalanine (L-DOPA) on DA metabolism and behavior in ICR mice were investigated. The DA level in the brain was increased by BH 4 administration, but the increased DA did not influence behavior. However, L-DOPA administration drastically lowered locomotor activity and increased DA concentration in several parts of the brain. The reduced locomotor activity may have been a consequence of the overproduction of DA. In conclusion, the high level of locomotor activity in ICR mice may be explained by a strain-specific DA metabolism. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Vitamin C Deficiency Reduces Muscarinic Receptor Coronary Artery Vasoconstriction and Plasma Tetrahydrobiopterin Concentration in Guinea Pigs

    Directory of Open Access Journals (Sweden)

    Gry Freja Skovsted

    2017-07-01

    Full Text Available Vitamin C (vitC deficiency is associated with increased cardiovascular disease risk, but its specific interplay with arteriolar function is unclear. This study investigates the effect of vitC deficiency in guinea pigs on plasma biopterin status and the vasomotor responses in coronary arteries exposed to vasoconstrictor/-dilator agents. Dunkin Hartley female guinea pigs (n = 32 were randomized to high (1500 mg/kg diet or low (0 to 50 mg/kg diet vitC for 10–12 weeks. At euthanasia, coronary artery segments were dissected and mounted in a wire-myograph. Vasomotor responses to potassium, carbachol, sodium nitroprusside (SNP, U46619, sarafotoxin 6c (S6c and endothelin-1 (ET-1 were recorded. Plasma vitC and tetrahydrobiopterin were measured by HPLC. Plasma vitC status reflected the diets with deficient animals displaying reduced tetrahydrobiopterin. Vasoconstrictor responses to carbachol were significantly decreased in vitC deficient coronary arteries independent of their general vasoconstrictor/vasodilator capacity (p < 0.001. Moreover, in vitC deficient animals, carbachol-induced vasodilator responses correlated with coronary artery diameter (p < 0.001. Inhibition of cyclooxygenases with indomethacin increased carbachol-induced vasoconstriction, suggesting an augmented carbachol-induced release of vasodilator prostanoids. Atropine abolished carbachol-induced vasomotion, supporting a specific muscarinic receptor effect. Arterial responses to SNP, potassium, S6c, U46619 and ET-1 were unaffected by vitC status. The study shows that vitC deficiency decreases tetrahydrobiopterin concentrations and muscarinic receptor mediated contraction in coronary arteries. This attenuated vasoconstrictor response may be linked to altered production of vasoactive arachidonic acid metabolites and reduced muscarinic receptor expression/signaling.

  4. Clinical efficacy of melittin in the treatment of cats infected with the feline immunodeficiency virus.

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    Hartmann, Anja D; Wilhelm, Natalie; Erfle, Volker; Hartmann, Katrin

    2016-12-05

    The bee venom melittin shows an antiviral efficacy against the human immunodeficiency virus in cell culture. It was shown to be non-toxic for cats. Aim of this pilot study was to investigate the clinical efficacy and side-effects of melittin in cats naturally infected with feline immunodeficiency virus (FIV). The study was performed as a prospective, placebo-controlled double-blinded trial. Twenty cats were included, of which 10 cats each were treated with either melittin (500 µg/kg body weight) or phosphate-buffered saline (placebo) subcutaneously twice per week. During the treatment period of 6 weeks, the cats' general health status, determined by the Karnofsky's score, and the severity of clinical signs (conjunctivitis and stomatitis) using a clinical scoring system were evaluated. Haematology, biochemistry profiles, lymphocyte subpopulations, CD4/CD8 ratio, and pterines (biopterine, 7-xanthopterine) as surrogate parameters were also compared. The general health status and the clinical scores for conjunctivitis and stomatitis improved in cats treated with melittin. A statistically significant improvement however could only be detected for conjunctivitis in cats treated with melittin compared to cats treated with placebo which was likely due to different scores between both groups at the beginning. No influence on the lymphocyte subpopulations, CD4/CD8 ratio, and pterine concentrations was observed. No side effects occurred in this study. In the protocol used in the present study, no significant efficacy of melittin could be detected. However, efficacy of melittin, especially if applied in a higher dosage as in the present study or for a longer period, could be evaluated in further studies. Synergistic effects if used in combination with classic antiretroviral drugs could be an interesting future approach.

  5. Folinic acid treatment for schizophrenia associated with folate receptor autoantibodies.

    Science.gov (United States)

    Ramaekers, V T; Thöny, B; Sequeira, J M; Ansseau, M; Philippe, P; Boemer, F; Bours, V; Quadros, E V

    2014-12-01

    Auto-antibodies against folate receptor alpha (FRα) at the choroid plexus that block N(5)-methyltetrahydrofolate (MTHF) transfer to the brain were identified in catatonic schizophrenia. Acoustic hallucinations disappeared following folinic acid treatment. Folate transport to the CNS prevents homocysteine accumulation and delivers one-carbon units for methyl-transfer reactions and synthesis of purines. The guanosine derivative tetrahydrobiopterin acts as common co-factor for the enzymes producing dopamine, serotonin and nitric oxide. Our study selected patients with schizophrenia unresponsive to conventional treatment. Serum from these patients with normal plasma homocysteine, folate and vitamin B12 was tested for FR autoantibodies of the blocking type on serial samples each week. Spinal fluid was analyzed for MTHF and the metabolites of pterins, dopamine and serotonin. The clinical response to folinic acid treatment was evaluated. Fifteen of 18 patients (83.3%) had positive serum FR auto-antibodies compared to only 1 in 30 controls (3.3%) (χ(2)=21.6; pfolate flux to the CNS, which explained low CSF folate values in 6 and normal values in 7 patients. The mean±SD for CSF MTHF was diminished compared to previously established controls (t-test: 3.90; p=0.0002). A positive linear correlation existed between CSF MTHF and biopterin levels. CSF dopamine and serotonin metabolites were low or in the lower normal range. Administration of folinic acid (0.3-1mg/kg/day) to 7 participating patients during at least six months resulted in clinical improvement. Assessment of FR auto-antibodies in serum is recommended for schizophrenic patients. Clinical negative or positive symptoms are speculated to be influenced by the level and evolution of FRα antibody titers which determine folate flux to the brain with up- or down-regulation of brain folate intermediates linked to metabolic processes affecting homocysteine levels, synthesis of tetrahydrobiopterin and neurotransmitters