Related Experiment Video

Updated: Jul 4, 2026

A High-performance Liquid Chromatography Measurement of Kynurenine and Kynurenic Acid: Relating Biochemistry to Cognition and Sleep in Rats
07:04

A High-performance Liquid Chromatography Measurement of Kynurenine and Kynurenic Acid: Relating Biochemistry to Cognition and Sleep in Rats

Published on: August 19, 2018

Cognitive functions and the antioxidant system in phenylketonuric patients

Rosa Gassió1, Rafael Artuch, Maria Antonia Vilaseca

  • 1PKU Follow-up Unit, Neuropediatrics Department, Hospital Sant Joan de Deu, Universitat de Barcelona, Spain. rgassio@hsjdbcn.org

Neuropsychology
|July 2, 2008
PubMed

Insights

Phenylketonuria (PKU) patients have lower selenium and higher oxidative stress, impacting cognitive functions. Selenium levels correlate with attention deficits, highlighting the need for nutritional monitoring beyond phenylalanine control.

Area of Science:

  • Biochemistry
  • Neuroscience
  • Pediatrics

Background:

  • Phenylketonuria (PKU) is a metabolic disorder requiring strict dietary management.
  • Oxidative stress and antioxidant status may influence cognitive function in PKU.
  • Early and continuous treatment aims to mitigate neurological complications.

Purpose of the Study:

  • To investigate the relationship between the antioxidant system and cognitive functions in PKU patients.
  • To assess levels of antioxidant cofactors, free radical damage markers, and antioxidant enzymes.
  • To evaluate cognitive performance using neuropsychological tests.

Main Methods:

  • Studied 36 early-treated PKU patients and 29 controls.
  • Measured plasma antioxidants (selenium, retinol, tocopherol, coenzyme Q10) and malondialdehyde.
  • Assessed red blood cell antioxidant enzymes (glutathione peroxidase, catalase, superoxide dismutase).
  • Administered neuropsychological tests, including the Conner's Continuous Performance Test.

Main Results:

  • PKU patients exhibited lower selenium, coenzyme Q10, and catalase levels, with higher malondialdehyde.
  • A significant negative correlation was found between plasma selenium and measures of attention on the Conner's Continuous Performance Test.
  • Selenium deficiency was associated with impaired attention, response consistency, and reaction time in PKU patients.

Conclusions:

  • Selenium status is significantly associated with attention functions in PKU patients.
  • Nutritional management in PKU should include monitoring of selenium levels, not solely phenylalanine.
  • Addressing antioxidant status may be crucial for optimizing cognitive outcomes in PKU.

More Related Videos

Semi-Targeted Ultra-High-Performance Chromatography Coupled to Mass Spectrometry Analysis of Phenolic Metabolites in Plasma of Elderly Adults14:39

Semi-Targeted Ultra-High-Performance Chromatography Coupled to Mass Spectrometry Analysis of Phenolic Metabolites in Plasma of Elderly Adults

Published on: April 22, 2022

Related Concept Videos

Oxidation of Phenols to Quinones01:17

Oxidation of Phenols to Quinones

In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Inborn Errors of Metabolism01:20

Inborn Errors of Metabolism

Phenylketonuria (PKU) is a protein metabolism disorder characterized by high blood levels of the amino acid phenylalanine. This results from a mutation in the gene responsible for phenylalanine hydroxylase, an enzyme that converts phenylalanine into tyrosine. When this enzyme is deficient, phenylalanine builds up in the blood, leading to symptoms such as vomiting, rashes, seizures, growth deficiency, and severe mental retardation. An early diagnosis and a diet restricting phenylalanine intake...
Pharmacokinetics in Pediatric Patients: Drug Metabolism01:24

Pharmacokinetics in Pediatric Patients: Drug Metabolism

In pediatric care, understanding the nuances of hepatic drug metabolism is crucial, as it significantly differs from that of adults. This divergence is primarily due to the developmental stage of drug-metabolizing enzymes, which affects how medications are processed in the body. In neonates, for instance, the activity of Phase I enzymes—critical for the initial breakdown of drugs—is markedly reduced, functioning at just 20–40% of the levels seen in adults. This reduction poses a challenge in...
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase01:27

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...
Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems01:19

Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems

Phase I biotransformation reactions are integral to drug metabolism, predominantly involving oxidative, reductive, and hydrolytic transformations. Chief among these are oxidative reactions, which enhance the hydrophilicity of xenobiotics and introduce polar functional groups to facilitate their elimination from the body.
Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into...
Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test01:22

Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test

In clinical practice, the direct measurement of hepatic blood flow to evaluate liver function presents significant challenges due to the intricate and specialized nature of the necessary techniques. Consequently, healthcare professionals often rely on empirical estimates derived from thorough patient examinations and liver function tests to gauge liver health. Among the tools at their disposal, the Child–Pugh and MELD scoring systems stand out for their ability to categorize and assess the...