Page last updated: 2024-10-18

kynurenine and Phenylketonurias

kynurenine has been researched along with Phenylketonurias in 11 studies

Kynurenine: A metabolite of the essential amino acid tryptophan metabolized via the tryptophan-kynurenine pathway.
kynurenine : A ketone that is alanine in which one of the methyl hydrogens is substituted by a 2-aminobenzoyl group.

Phenylketonurias: A group of autosomal recessive disorders marked by a deficiency of the hepatic enzyme PHENYLALANINE HYDROXYLASE or less frequently by reduced activity of DIHYDROPTERIDINE REDUCTASE (i.e., atypical phenylketonuria). Classical phenylketonuria is caused by a severe deficiency of phenylalanine hydroxylase and presents in infancy with developmental delay; SEIZURES; skin HYPOPIGMENTATION; ECZEMA; and demyelination in the central nervous system. (From Adams et al., Principles of Neurology, 6th ed, p952).

Research

Studies (11)

TimeframeStudies, this research(%)All Research%
pre-199010 (90.91)18.7374
1990's0 (0.00)18.2507
2000's0 (0.00)29.6817
2010's1 (9.09)24.3611
2020's0 (0.00)2.80

Authors

AuthorsStudies
Ney, DM1
Murali, SG1
Stroup, BM1
Nair, N1
Sawin, EA1
Rohr, F1
Levy, HL1
FISCHL, J1
RABIAH, S1
Godin, C1
Dolan, G1
Kochen, W4
Byrd, DJ2
Bühner, R3
Bühlen, E1
Bührlen, E2
Jablonska, S1
Stachow, A1
Byrd, D1
Otting, W1
Machill, G1
Haufe, U1
Haufe, F1
Lubs, H1
Vassella, F1
Colombo, JP1
Humbel, R1
Rossi, E1
Heeley, AF1

Clinical Trials (1)

Trial Overview

TrialPhaseEnrollmentStudy TypeStart DateStatus
Phase 2 Study of Glycomacropeptide vs. Amino Acid Diet for the Management of PKU[NCT01428258]32 participants (Actual)Interventional2011-09-30Completed
[information is prepared from clinicaltrials.gov, extracted Sep-2024]

Trial Outcomes

Bone-specific Alkaline Phosphatase (BSAP) Plasma Concentration at Day 22

Plasma concentration of BSAP was determined as a measure of bone turnover. (NCT01428258)
Timeframe: day 22 of each dietary treatment

Interventionmicro gram per liter (Mean)
GMP Diet/GMP Medical Foods17.0
AA Diet/AA Medical Foods17.0

Change in the Plasma Phenylalanine Concentration of PKU Subjects Fed the Glycomacropeptide Diet Compared With the Change When Fed the Amino Acid Diet

Plasma will be collected at each base week and after 3 weeks on each of the dietary treatments, glycomacropeptide and amino acid, following an overnight fast. Plasma phenylalanine concentration (along with the complete profile of free amino acids) will be determined with an amino acid analyzer in the Wisconsin State Lab of Hygiene. Statistical analysis to determine the significance of the change in plasma phe concentration when comparing the 2 diets will consist of ANCOVA with covariates for baseline Phe and dietary Phe intake. The change in plasma Phe concentration from day 22 (final) to day 1 (baseline) was determined after adjusting for baseline Phe level and dietary Phe intake. (NCT01428258)
Timeframe: baseline to day 22 on each diet

Interventionmicro moles per liter plasma (Mean)
GMP Diet/GMP Medical Foods62
AA Diet/AA Medical Foods-85

Comparison of Phe Concentrations in Plasma With Concentrations in Dried Blood Spots

Concentrations of Phe in plasma and in dried blood spots collected simultaneously by subjects will be compared using 2 methodologies, regardless of intervention. At each of the 4 study visits (baseline and final for each dietary treatment): 1) venipuncture was used to collect blood and plasma was isolated and analyzed for Phe with ion exchange chromatography and 2) subjects were asked right after the venipuncture to spot their blood on filter paper for analysis of Phe with tandem mass spectroscopy (MS/MS). The discrepancy in Phe concentrations with these 2 methods was compared for each sample pair using Bland-Altman statistical analysis. Each subject should have had 4 sample pairs, 29 x 4 = 116, but we ended up with only 110 sample pairs, as explained below. (NCT01428258)
Timeframe: 4 times total, 2 per treatment

Interventionmicro moles per liter (Mean)
Phe Concentration in Plasma, Ion Exchange Chromatography731
Phe Concentration in Dried Blood Spots, Tandem Mass Spec514

Dietary Compliance

Compliance with the glycomacropeptide and amino acid dietary treatments will be assessed by comparison of the intake of medical food in grams of protein from medical food per day based on subject completion of 3-day food records prior to the final study visit on day 22. Statistical analysis for a dietary treatment effect will consist of ANOVA. (NCT01428258)
Timeframe: 3 week dietary treatment

Interventiong protein from MF/kg/day (Mean)
GMP Diet0.74
AA Diet/AA Medical Foods0.76

Executive Function Assessed by BRIEF

Completion of a standardized test, the Behavior Rating Inventory of Executive Function (BRIEF), by each subject for the GMP diet and the AA diet. Values are T-scores which have a mean of 50 points and a SD of 10 points. A T score of <50 is considered within the normative range. Data are analyzed with a paired t-test. (NCT01428258)
Timeframe: day 22 of each dietary treatment

InterventionT score (Mean)
GMP Diet/GMP Medical Foods49.0
AA Diet/AA Medical Foods48.8

N-terminal Telopeptide (NTX) Plasma Concentration at Day 22

Plasma concentration of NTX was determined as a measure of bone resorption; higher levels indicate greater bone breakdown (NCT01428258)
Timeframe: day 22 of each dietary treatment

Interventionnmol per liter bone collagen equivalents (Mean)
GMP Diet/GMP Medical Foods17.5
AA Diet/AA Medical Foods17.1

Vitamin D (25-OH) Plasma Concentration at Day 22

Vitamin D was measured as a measure of the capacity for calcium absorption. Higher levels of plasma vitamin D are consistent with higher calcium absorption. (NCT01428258)
Timeframe: day 22 of each dietary treatment

Interventionng per ml (Mean)
GMP Diet/GMP Medical Foods33.8
AA Diet/AA Medical Foods33.6

Trials

1 trial available for kynurenine and Phenylketonurias

ArticleYear
Metabolomic changes demonstrate reduced bioavailability of tyrosine and altered metabolism of tryptophan via the kynurenine pathway with ingestion of medical foods in phenylketonuria.
    Molecular genetics and metabolism, 2017, Volume: 121, Issue:2

    Topics: Adolescent; Adult; Amino Acids; Biological Availability; Caseins; Catecholamines; Cross-Over Studies

2017

Other Studies

10 other studies available for kynurenine and Phenylketonurias

ArticleYear
DETERMINATION OF FREE AND TOTAL INDOLE-3-ACETIC ACID AND OF THE INDOLE INDEX.
    Clinical chemistry, 1964, Volume: 10

    Topics: Friedreich Ataxia; Humans; Indoleacetic Acids; Indoles; Intestines; Kynurenine; Metabolism; Myotonia

1964
Tryptophan metabolism in normal and phenylketonuric rats.
    Biochimica et biophysica acta, 1966, Dec-28, Volume: 130, Issue:2

    Topics: Animals; Carbon Dioxide; Carbon Isotopes; Humans; Indoleacetic Acids; Injections, Intravenous; Kynur

1966
[Studies on tryptophan metabolism in untreated phenylketonuric patients].
    Zeitschrift fur klinische Chemie und klinische Biochemie, 1975, Volume: 13, Issue:1

    Topics: Acetophenones; Adolescent; Adult; Biotransformation; Child; Child, Preschool; Chromatography, Ion Ex

1975
Tryptophan metabolism in untreated phenylketonuria.
    Acta vitaminologica et enzymologica, 1975, Volume: 29, Issue:1-6

    Topics: Adolescent; Adult; Age Factors; Child; Child, Preschool; Humans; Indoles; Kynurenine; Phenylketonuri

1975
[Pseudoscleroderma or scleroderma coexisting with phenylketonuria].
    Annales de dermatologie et de syphiligraphie, 1972, Volume: 99, Issue:3

    Topics: Child; Diagnosis, Differential; Female; Humans; Kynurenine; Phenylketonurias; Scleroderma, Localized

1972
[Proceedings: Tryptophan metabolism in untreated phenylketonuria and in vitamin B6 dependent cramps].
    Zeitschrift fur klinische Chemie und klinische Biochemie, 1972, Volume: 10, Issue:4

    Topics: 3-Hydroxyanthranilic Acid; Adolescent; Adult; Carboxylic Acids; Child; Child, Preschool; Humans; Hyd

1972
[Identification of oxindole and 3-indolecarbaldehyde in the urine of patients with untreated phenylketonuria].
    Hoppe-Seyler's Zeitschrift fur physiologische Chemie, 1972, Volume: 353, Issue:7

    Topics: Aldehydes; Carbamates; Chromatography, Thin Layer; Humans; Indoles; Kynurenine; Mass Spectrometry; N

1972
[Kynureninase activity and pyridoxine elimination in rats with experimental phenylketonuria].
    Acta biologica et medica Germanica, 1971, Volume: 26, Issue:3

    Topics: Animals; Disease Models, Animal; Humans; Hydrolases; Kynurenine; Liver; Phenylketonurias; Pyridoxine

1971
[L-tryptophan metabolism in phenylketonuria].
    Helvetica paediatrica acta, 1968, Volume: 23, Issue:1

    Topics: Adolescent; Adult; Child; Diet Therapy; Female; Humans; Indoles; Kynurenine; Male; Phenylalanine; Ph

1968
The effect of pyridoxine on tryptophan metabolism in phenylketonuria.
    Clinical science, 1965, Volume: 29, Issue:3

    Topics: Child; Child, Preschool; Chromatography, Ion Exchange; Diet Therapy; Humans; In Vitro Techniques; In

1965