Akademik Veri Yönetim Sistemi
Turkish Journal of Biochemistry, cilt.36, sa.2, ss.143-148, 2011 (SCI-Expanded)
Aim: Jaundice in newborn is caused by neonatal changes in bilirubin metabolism resulting in increased bilirubin production, decreased bilirubin clearance and increased enterohepatic circulation. Although bilirubin is reported to have antioxidant effects in low concentrations, it is toxic at high levels. At high concentration, bilirubin leads to marked alterations in the membrane content of the several classes of phospholipids and cholesterol, which can render the cells more susceptible to lysis and shorten their lifespan. One of the most important properties of coenzyme Q10 (CoQ10) is its antioxidant activity; it protects cells from free radicals and increases membrane stability of erythrocytes. For that reason in this study, we aimed to investigate any possible relation between serum bilirubin and CoQ10 concentrations in jaundiced newborns in intermediate risk zone. Materials and Methods: Totally, 44 term jaundiced newborns with elevated indirect bilirubin levels were included to the study. Based on the recommendations of American Academy of Pediatrics newborns were divided into two groups according to their day of age and serum bilirubin concentrations: Group I (n:24); newborns in low intermediate risk zone (low-intermediate) and Group II (n:20); newborns in high intermediate risk zone (high-intermediate). Total serum bilirubin levels were obtained at the time of the routine examination in all newborns. Bilirubin concentrations in serum samples were measured spectrophotometrically and total CoQ10 concentration in the same sample of all subjects was measured by HPLC. Results: Mean total serum bilirubin levels of the Group I and Group II were 11.88±2.58 mg/dL and 17.22±1.69 mg/dL, respectively. Mean serum CoQ10 concentration of newborns in Group II was significantly lower according to the newborns in Group I (p<0.001). In addition, a significant negative correlation between serum CoQ10 concentration and bilirubin was found (r=-0.676, p<0.001). Conclusions: The results obtained from 44 fullterm jaundiced newborns indicate that, newborns with higher total serum bilirubin levels in high-intermediate risk group have lower CoQ10 concentrations when compared to low-intermediate risk group. Indeed, increase in bilirubin level is correlated with a decrease in serum CoQ10 concentration. Low serum CoQ10 content in newborns might increase serum bilirubin concentration by leading oxidative stress induced damage to erythrocytes or oxidative and cytotoxic effects of bilirubin might decrease serum CoQ10 concentration. © 2011 TurkJBiochem.com.