Kupffer cells generate superoxide anions and modulate reperfusion injury in rat livers after cold preservation

✍ Scribed by H Shibuya; N Ohkohchi; K Seya; S Satomi

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 239 KB
• Volume: 25
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.510250217

✦ Synopsis

HIROSHI SHIBUYA, NOBUHIRO OHKOHCHI, KAZUHIKO SEYA, and SUSUMU SATOMI ies, we have demonstrated that the susceptibility of hepato-This study was designed to determine the source of cytes to lipid peroxidation increases with the duration of cold reactive oxygen species (ROS) and whether Kupffer cells ischemia 7 and that neutrophils cause lipid peroxidation by modulate the injury of perfused rat liver after cold presreleasing superoxide in the perfused rat liver after cold preservation. The livers of male Lewis rats pretreated with ervation. 8 In addition, many investigators have demonschizophyllan glucan (SPG) (10 mg/kg, SPG group) or strated that scavengers for ROS and allopurinol, an inhibitor gadolinium chloride (5 mg/kg; Gd group) and untreated of xanthine oxidase, have a protective effect against ischemia/ rats (control group) were preserved in University of Wisreperfusion injury. 9,10 Another concern has been the identificonsin solution for 0, 12, and 24 hours at 4ЊC and then cation of the primary source of ROS. Several reports have perfused for 60 minutes with oxygenated Krebs-Henseimplicated xanthine oxidase as a major source of ROS during leit bicarbonate buffer. Real-time chemiluminescence reperfusion. 9,11 Other investigators have proposed neutro-(CL) of the liver during perfusion was measured using phils or Kupffer cells as the primary source of ROS. 12,13 Rea sensitive photomultiplier, and reperfusion injury was cent studies, however, have questioned whether the quantity assessed by measuring lipid peroxidation and lactate deof ROS generated during reperfusion is sufficient to cause hydrogenase release. CL intensity reached a peak within direct injury through lipid peroxidation. 14 Alternatively, ROS 5 minutes of reperfusion, and superoxide dismutase acts in signal transduction for subsequent injurious events. 15 completely inhibited this CL in all groups. In the control Thus, the source of ROS and its impact on the pathogenesis group, the total CL intensity was high after 24 hours of of reperfusion injury remain controversial. preservation. It significantly (P õ .05 vs. control group)

Little has been reported about direct measurement of ROS increased in the SPG group, while it decreased in the in a whole organ after cold preservation. Chemiluminescence Gd group after 12 and 24 hours of preservation. The total (CL) is used as a direct method for measuring ROS. A lumi-CL intensity decreased by 70% when diphenyliodonium nol-enhanced CL technique has been reported to be useful to chloride (100 mmol/L; an NADPH oxidase inhibitor) was determine ROS in the perfused rat liver during warm ischadded to the perfusate before preservation of untreated emia/reperfusion. 16,17 However, luminol CL is not a specific rats. Lipid peroxidation and lactate dehydrogenase reindicator of superoxide generation, since luminol would react lease significantly (P õ .05) deteriorated in the SPG with a wide variety of oxidants. 18 Recently, 2-methyl-6-[pgroup, while they ameliorated in the Gd group after 24 methoxyphenyl]-3,7-dihydroimidazo[1,2-a]pyrazin-3-one (MCLA) hours of preservation. These results demonstrate that has been shown to be a very sensitive and specific lumines-Kupffer cells primarily generate superoxide anions and cence probe to detect superoxide anions generated by leukomodulate the organ injury in the initial phase of reperfucytes 19 and Kupffer cells. 18 sion after cold preservation. (HEPATOLOGY 1997;25:356-In this study, we examined the hypothesis that Kupffer 360.) cells are the primary source of superoxide anions using a blood-free perfused rat liver model and whether Kupffer cells Ischemia/reperfusion injury is one of the most important modulate reperfusion injury. causes of graft nonfunction and an important determinant

Methods

of successful liver transplantation. 1 Many efforts have been made to clarify the mechanisms of this injury. Recent studies

The experiments were conducted according to the ''Guide for the have shown that Kupffer cells are activated on reperfusion 2 Care and Use of Laboratory Animals,'' prepared by the National and that inactivation of Kupffer cells contributes to the pre-Academy of Sciences and published by the National Institutes of Health. Male Lewis rats weighing 220 to 280 g were allocated to vention of reperfusion injury 3-5 while improving survival after three groups: (1) the control group, in which rats were not pretreated; orthotopic liver transplantation in rats. 6 (2) the SPG group, in which rats were administered 10 mg/kg (iv) of A possible mechanism of ischemia/reperfusion injury is the schizophyllan glucan (SPG; Kaken Pharmaceutical Co. Ltd., Tokyo, production of reactive oxygen species (ROS). In previous stud-Japan), which is a soluble glucan, to activate Kupffer cells 20 24 hours before liver procurement; (3) the Gd group, in which rats were administered 5 mg/kg (iv) of gadolinium chloride (GdCl 3 ; Wako Pure Chemical Industries, Osaka, Japan) to inactivate Kupffer cells 21 24 hours Abbreviations: ROS, reactive oxygen species; CL, chemiluminescence; MCLA, 2-Methylbefore the procurement. 6-[p-methoxyphenyl]-3,7-dihydroimidazo[1,2-a]pyrazin-3-one; SPG, schizophyllan glucan; Under anesthesia with pentobarbital sodium (50 mg/kg, intraperi-BOF 4272, sodium (-)-8-(3-methoxy-4-phenylsulfinylphenyl) pyrazolo[1,5-a]-1,3,5-triazinetoneally), the liver was flushed with cold Ringer's lactate and Univer-4-olate monohydrate; PMNs, polymorphonuclear leukocytes. sity of Wisconsin cold-storage solution (DuPont Pharmaceuticals,