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Serum paraoxonase/arylesterase activities in phenylketonuric patients on diet

K H Schulpis1, A Bartzeliotou, S Tsakiris

  • 1Institute of Child Health, Aghia Sophia Children's Hospital, Athens, Greece.

European Journal of Clinical Nutrition
|January 5, 2007
PubMed

Insights

Phenylketonuria (PKU) patients with high phenylalanine (Phe) levels show reduced paraoxonase/arylesterase (PON-aryl) activities. Dietary control of Phe levels is crucial for restoring PON-aryl enzyme function in PKU.

Area of Science:

  • Biochemistry
  • Clinical Chemistry
  • Metabolic Disorders

Background:

  • Phenylketonuria (PKU) is a genetic disorder characterized by the inability to metabolize phenylalanine (Phe).
  • Elevated Phe levels can lead to neurological damage and other health complications.
  • Paraoxonase/arylesterase (PON-aryl) is an enzyme with antioxidant properties that may be affected by metabolic imbalances.

Purpose of the Study:

  • To investigate the relationship between serum PON-aryl activities and blood Phe concentrations in PKU patients.
  • To compare PON-aryl activities in PKU children with high versus low Phe levels and healthy controls.

Main Methods:

  • Seventeen PKU children (off-diet) and 24 controls were studied.
  • Measurements included serum lipids, lipoproteins, apolipoprotein AI (Apo AI), total antioxidant capacity (TAC), PON-aryl, and Phe levels.
  • PKU patients were assessed before and after 30 days on a special diet.

Main Results:

  • PKU patients off-diet had significantly higher lipids, lipoproteins, and Phe levels compared to when on-diet.
  • Total antioxidant capacity (TAC) was significantly lower in PKU patients off-diet compared to on-diet and controls.
  • Serum PON-aryl activities were significantly reduced in PKU children with high Phe levels compared to those with low Phe levels and controls.

Conclusions:

  • Serum PON-aryl activities are significantly diminished in PKU patients with uncontrolled high phenylalanine levels.
  • PON-aryl enzyme activity demonstrates a strong positive correlation with dietary Phe control in PKU patients.
  • These findings highlight the importance of dietary management in PKU for maintaining antioxidant enzyme function.
Abstract

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