The effects of N-acetylcysteine and anti-intercellular adhesion molecule-1 monoclonal antibody against ischemia-reperfusion injury of the rat steatotic liver produced by a choline-methionine-deficient diet

Abstract

Abundant fat in the liver has been implicated in poor outcome after liver transplantation or liver surgery, but the reasons for this association are still unclear. The aim of the present study was to examine mechanisms that may be involved in hepatic dysfunction after ischemia-reperfusion (I/R) of the steatotic rat liver. Steatosis was produced by a choline-methionine-deficient (CMDD) diet. In the first experiment, isolated perfused rat livers, subjected to 24-hour cold storage followed by 120-minute reperfusion, were used to investigate hypothermic I/R injury of the steatotic rat liver. In the second experiment, livers were subjected to 60-minute partial left lobar vascular clamping to allow study of normothermic I/R injury. In the first experiment, compared with normal nonsteatotic liver, steatotic livers showed significantly greater injury, as assessed by amounts of hepatic enzymes released into the perfusate, bile production, the concentrations of reduced glutathione (GSH) in the perfusate, as well as in the livers themselves, and electron microscopic findings of sinusoidal microcirculatory injury. The addition of N-acetylcysteine (NAC), a precursor of glutathione, to the liver before cold storage significantly improved these parameters in steatotic livers. The second experiment showed that, compared with nonsteatotic livers, steatotic livers had lower concentrations of GSH and impaired rates of bile production. There was also evidence of increased oxidative stress in polymorphonuclear leukocytes (PMNLs) in liver or peripheral blood of rats with fatty livers. An anti-rat intercellular adhesion molecule-1 (ICAM-1) monoclonal antibody inhibited neutrophil infiltration into pericentral sinusoids and improved these parameters in the steatotic rats. We conclude that sinusoidal microcirculatory injury is involved in hypothermic I/R injury, that oxidative stress produced by PMNLs is involved in normothermic I/R injury, and that NAC and anti-rat ICAM-1 monoclonal antibody restore liver integrity in I/R injury.

Oxidative Stress in Fatty Livers of Obese Zucker Rats: Rapid Amelioration and Improved Tolerance to Warm Ischemia With Tocopherol

“…Support for this concept is provided by previous observations of decreased liver phospholipids and increased lipid peroxidation products, in rat fatty livers, during reperfusion following warm ischemia. 8,9,34 Further support is provided by the significant increase in survival of animals in antioxidant groups I and III, groups that received additional TOC following reperfusion. TOC protects membranes from free radical attack and, in the process, becomes oxidized to tocopheroxyl radical.…”

Steatosis Reversibly Increases Hepatocyte Sensitivity to Hypoxia-Reoxygenation Injury

“…For example, hepatic warm ischemia in obese Zucker rats had a much more pronounced effect on animal survival and led to more hepatocyte necrosis, microvascular disruption, and oxidative damage than in lean animals (8). Rats fed a choline-and methioninedeficient diet (CMDD) exhibited more functional impairment after ischemia-reperfusion in situ, and increased oxidative stress compared to animals fed a normal diet (8,9). Studies using the same animal model on the effect of cold storage of liver followed by rewarming and perfusion also show more extensive damage in fatty livers than in lean livers, and a reduced "safe" preservation time before transplantation with steatotic livers (9,10).…”

Soluble Thrombomodulin Ameliorates Ischemia-Reperfusion Injury of Liver Grafts by Modulating the Proinflammatory Role of High-Mobility Group Box 1

“…Bile production, which reflects liver function (Nakano et al 1997;Taneja et al 1998), was significantly higher in the HB and 5 mg ART groups than in the CD group (Fig. 2).…”

“…Bile production was measured for 1 h to examine liver function (Nakano et al 1997;Taneja et al 1998;Miyagi et al 2004). Bile was collected through the cannulated common bile duct.…”