[Estimation of total antioxidant power in the serum of Yusho victims].

Polychlorinated biphenyls (PCB) causes the release of superoxide during the metabolic process. Therefore, Yusho victims are thought to be exposed to oxidative stress caused by PCB, because high concentrations of PCB are still detected in the serum of Yusho victims. Recently, total antioxidant power (TAP) has been proposed as one of excellent markers of defense capacity against oxidative stresses. In order to estimate the antioxidant capacity in Yusho victims, we measured serum TAP in certified Yusho victims and age-matched noncertified subjects. The mean values of serum TAP were 0.479 +/- 0.017 in certified Yusho victims and 0.397 +/- 0.013 microM in non-certified subjects, respectively. There was a significant difference in the serum values of TAP between certified Yusho victims and uncertified subjects. TAP was reported to increase in the case of severe oxidative stress and PCB can give rise to an oxidative stress in Yusho victims. Therefore, it was supposed that TAP could increase in the oxidative stress of Yusho probably by some negative feedback mechanisms. The exact mechanism is still unclear, and further examinations should be conducted in the future.