In situ determination by surface chemiluminescence of temporal relationships between evolving warm ischemia-reperfusion injury in rat liver and phagocyte activation and recruitment

Liver ischemia-reperfusion is characterized by an increased oxygen-dependen t free radical chain-reaction rate and an increased steady-state concentrat ion of reactive oxygen species. The aim of this study was to evaluate the i n situ generation of reactive oxygen species and its relationship with phag ocyte activation and recruitment in reperfused rat liver. Rat livers were s ubjected to 2 hours of selective lobular ischemia and reperfusion for up to 12 hours. The following parameters were determined: in situ liver chemilum inescence, understood to reflect the tissue steady-state concentration of s inglet oxygen (O-1(2)); myeloperoxidase tissue activity; the number of neut rophils; and the degree of necrosis. An early chemiluminescence burst was m easured after 30 minutes of blood reflow (early phase of oxidative stress), followed by a relapse and a further increase after 4 to 12 hours of reperf usion (late phase of oxidative stress). Both early and late phases were mod ified by pretreatment with gadolinium chloride (GdCl3), pointing to a key r ole of the Kupffer cells. Neutrophils infiltrated into the liver, myelopero xidase activity, in situ chemiluminescence, and necrosis were found to be s trongly correlated over the 4- to 12-hour reperfusion period (r = .960; ave rage of the 4 correlation coefficients). Together with resident phagocytes, neutrophil recruitment and activation appear to provide a major contributi on to the increase of oxygen-dependent free-radical reactions and amplifica tion of liver reperfusion damage. Surface chemiluminescence appears to prop erly describe the in situ and in vivo progressive organization of the acute inflammatory response with phagocyte-mediated liver injury.