Partial liver ischemia is followed by metabolic changes in the normally perfused part of the liver during reperfusion.

BACKGROUND: Temporary vascular in- and outflow occlusion is an effective technique for bleeding control during liver resection. However, occlusion can result in ischemia/reperfusion (I/R) injury to the liver. The aim of this study in a porcine model was to investigate the effect of in- and outflow occlusion of part of the liver on the metabolism of the normally perfused parenchyma of the same liver measured by microdialysis. METHODS: Eight pigs underwent laparotomy. A microdialysis catheter was inserted into in the left and right part of the liver, respectively. Microdialysis samples were collected every 30 min. Occlusion of the left part of the liver was achieved for 60 min, followed by 5 h of reperfusion. Samples were analyzed for glucose, lactate, pyruvate and glycerol. Blood samples were drawn to determine standard liver and biochemical parameters. RESULTS: Comparing the ischemic part of the liver with the normally perfused part, significant differences in the levels of lactate, pyruvate and glycerol were found. During reperfusion, similar and continuous decreases below baseline levels were observed for lactate and pyruvate in both the ischemic and normally perfused part of the liver. No significant changes in liver parameters or blood glucose levels were seen. CONCLUSIONS: Partial ischemia of the liver is without effects on metabolism in the normally perfused part. Metabolic changes in the ischemic part of the liver were reversible. However, partial liver ischemia was followed by similar continuous decreases in lactate and pyruvate levels in the whole liver, even though the ischemic insult was not detectable in transaminase levels.

Cytokine changes during warm ischemia and reperfusion of the pig liver with or without preconditioning.

BACKGROUND: Hepatic inflow occlusion results in ischemia-reperfusion injury. The aim of the present porcine study was to investigate whether the pro- and anti-inflammatory cytokine response is involved in mediating the protective effect of ischemic preconditioning (IPC) during, and after warm liver ischemia. METHODS: Fifteen randomized pigs--7 non-IPC and 8 (IPC)--underwent laparotomy followed by 60 min of total ischemia with or without IPC continued by 3 h of reperfusion. Plasma cytokines (IL-6, IL-8, IL-10, and TNF-alpha) were measured during the study period as well as liver parameters (alanine-aminotransferase, alkaline phosphatase, bilirubin, and prothrombin time). RESULTS: In the IPC group, IL-6 increased significantly during reperfusion compared to baseline and the non-IPC group. TNF-alpha increased nonsignificantly in the non-IPC group, while the levels remained stable in the IPC group. IL-8 and IL-10 increased in both groups after reperfusion. Only minor differences were observed in liver parameters. CONCLUSIONS: Warm liver ischemia with or without IPC activates inflammatory cytokines. IL-6 increased significantly in the IPC group compared to the non-IPC group, while the opposite was observed for TNF-alpha. These cytokine changes may be involved in the hepatoprotective mechanism induced by IPC.