ENHANCED LUMINESCENCE STUDY OF LIVER HOMOGENATE RESPONSE TO OXIDATIVESTRESS

An enhanced luminescence technique was used to monitor the response of liver homogenates stressed with sodium perborate. Rat liver homogenat es were subjected to oxidative stress with sodium perborate, and the l ight signals, generated by a suitable system, containing luminol and c ompounds producing enhancement of light emission such as sodium benzoa te and indophenol, were detected by a luminometer. The intensity of li ght emission (E) was found dependent on homogenate concentration (C). When C increased, E at first increased as well and, then, decreased ra pidly. The graphic expression of this phenomenon resulted as a curve t hat can be described by the equation: E = a . C/exp(b . C). It is prop osed that the a value represents the capacity of the tissue to catalyz e the production of . OH radical species. The b value might be related to the capacity of the tissue to scavenge such radicals, since it inc reases when homogenates are supplemented with antioxidants and decreas es when homogenates are treated with prooxidant The results obtained b y supplementing homogenates with iron containing substances, or using model systems, suggest that cell substances catalyzing the luminescent reaction, such as the hemoproteins, are ''scavengers'' as well as rad ical producers. The concentration-emission curve obtained with suitabl e model system is described by the equation: E = a . C/exp(b . C-k). I t is suggested that,using the k value, information can be obtained on the relative capacity of hemoproteins and antioxidant systems to inter act with . OH radicals.