Affiliations: Institute of Biochemistry, Polytechnic University of
the Marche, Ancona, Italy | Pediatric Clinic Laboratory, Children Hospital Salesi,
Polytechnic University of Marche, Ancona
Note: [] Address for correspondence: Dr. Luca Tiano, Institute of
Biochemisty, Polytechnic University of the Marche, Via Ranieri, 60100 Ancona,
Italy. Tel.: +39 071 2204394; Fax: +39 071 2204398; E-mail:
[email protected]
Abstract: Down syndrome (DS) is a chromosomal abnormality (trisomy 21)
associated with mental retardation and Alzheimer-like dementia, characteristic
change of the individual's phenotype and premature ageing. Oxidative stress is
known to play a major role in this pathology since a gene dose effect leads to
elevated ratio of superoxide dismutase to catalase/glutathione peroxidase
compared to controls in all age categories suggesting that oxidative imbalance
contributes to the clinical manifestation of DS. Hyperuricemia is another
feature of DS that has an interesting relationship with oxidative stress since
uric acid represents an important free radical scavenger. However its formation
is connected to the conversion of Xanthine dehydrogenase (XDH) to Xanthine
oxidase (XO) which leads to concomitant production of free radicals. Here we
report that plasma samples from DS patients in pediatric age, despite an
increased total antioxidant capacity, largely due to elevated Uric acid content
(UA), present significantly elevated markers of oxidative damage such as
increased allantoin levels. Moreover DS plasma samples do not differ from
healthy control ones in terms of Coenzyme Q_{10} and
susceptibility to peroxidative stimuli. On the contrary, lymphocyte and
platelet CoQ_{10} content was significantly lower in DS
patients, a fact that might underlie oxidative imbalance at a cellular level.
Journal: BioFactors, vol. 32, no. 1-4, pp. 161-167, 2008
