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Tocopherol in inborn errors of intermediary metabolism
D Moyano1, M A Vilaseca, M Pineda
1Serveis de Bioquímica, Hospital Universitari Sant Joan de Déu, Barcelona, Spain.
Summary
Children with mitochondrial defects show lower red blood cell tocopherol (vitamin E) levels due to increased oxidative stress. Supplementation with vitamin E effectively corrects this antioxidant deficiency.
Area of Science:
- Biochemistry
- Pediatric Medicine
- Nutritional Science
Background:
- Inborn errors of intermediary metabolism can lead to cellular dysfunction and oxidative stress.
- Red blood cell tocopherol (vitamin E) serves as a crucial antioxidant, protecting against lipid peroxidation.
Purpose of the Study:
- To assess peroxidative damage in children with mitochondrial versus cytosolic defects.
- To evaluate the potential need for vitamin E supplementation in these patient groups.
Main Methods:
- Tocopherol levels in red blood cells were quantified using High-Performance Liquid Chromatography (HPLC) with UV detection.
- Measurements were standardized to protein content (nmol/g protein).
- Statistical analysis included the Mann-Whitney test for group comparisons.
Main Results:
- Untreated patients with mitochondrial defects exhibited significantly lower red blood cell tocopherol levels compared to those with cytosolic defects and healthy controls (P < 0.001).
- Patients with cytosolic enzyme or transport defects showed normal tocopherol levels.
- Vitamin E treatment effectively normalized the antioxidant status in deficient patients.
Conclusions:
- Mitochondrial enzyme deficiencies, including amino/organic acidurias and energy metabolism defects, appear to induce excessive free radical production, depleting tocopherol.
- Cytosolic enzyme defects, as studied, do not present with a similar depletion of tocopherol.
- Vitamin E supplementation is a viable strategy to address antioxidant deficiencies in children with specific metabolic disorders.