INCREASED OXYRADICAL PRODUCTION DURING REOXYGENATION OF PERFUSED-RAT-LIVER - SIGNAL VERSUS INJURY

Despite general agreement on the importance of oxyradicals in mediatin g ''reperfusion'' injury, the precise event(s) mediated by increased f ree radical production remain unclear. In this study we describe for t he first time a model of unenhanced chemiluminescence of isolated perf used rat liver demonstrating a marked increase in oxyradical productio n after reoxygenation. Using aspartate aminotransferase and purine nuc leoside phosphorylase release as measures of liver injury, there was n o direct link between oxyradical production and hepatic injury However , there was an abrupt increase in neutrophil chemotaxis activity in th e perfusate at the time of reoxygenation with a subsequent decrement, following the pattern of oxyradical production. These data suggest tha t free radical formation during hepatic reperfusion may mel diate sign al transduction, as opposed to direct cell injury, as a primary mechan ism of action.