Effects of hypoxia-reoxygenation on isolated liver nonparenchymal cells

Abstract

To clarify the relationship between Kupffer cells (KC) and hepatocytes in hepatic ischemia-reperfusion injury, isolated liver nonparenchymal cells (NPC), including a large proportion of KC, from C3H/HeN and C3H/HeJ mice were utilized in an in vitro hypoxia-reoxygenation system which enabled precise control of the oxygen concentration in the circumferential air during incubation. The viability of NPC, concentrations of cytokines and superoxides released from NPC, and the effects of antioxidants on hypoxiareoxygenation were investigated. The results were: (1) The deterioration of NPC was slow under hypoxia, but a significant decrease in their viability was observed with reoxygenation. These results were virtually identical in C3H/HeN and C3H/HeJ mice. (2) The concentration of tumor necrosis factor (TNF)-α from NPC of C3H/HeJ was much lower than that from NPC of C3H/HeN, and production of O2− was lower in the NPC of C3H/HeJ than in C3H/HeN, but changes in the viability of NPCs which were reoxygenated following various intervals of hypoxia were almost identical in both types of mice. (3) Viability after reoxygenation was improved by the addition of catalase or superoxide dismutase (SOD), and further improved with the combined use of catalase and SOD. These results suggested that the changes in KC function after reoxygenation decreased the viability of the cells, due predominantly to the release of reactive oxygen metabolites, not to the release of TNF-α.