URINARY 8-HYDROXYDEOXYGUANOSINE IN INFANTS AND CHILDREN

Several diseases of prematurity are thought to be related to oxidative injury and many of the available markers are unsatisfactory. An assay was developed using HPLC with electrochemical detection for the quant itation of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a proposed indicator for oxygen-derived free radical injury to DNA in preterm inf ants. A median value of 3.79 mu mol/mol creatinine was obtained for no rmal children (2-15 years old, n=14). Urinary 8-OHdG excretion in neon ates ranged from 0-99 mu mol/mol creatinine. There were no gestation o r birthweight related differences in urinary 8-OHdG, and no correlatio n with urinary malondialdehyde. Mean 8-OHdG excretion increased with p ostnatal age (r = 0.80, p < 0.0001, n = 15), mirroring the growth velo city curve. These changes could also be due to changes in the activity of the enzyme responsible for 8-OHdG excision. Urinary 8-OHdG levels are unlikely to accurately reflect oxygen derived free radical activit y given the strength of the relationship with growth.