| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1994: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1993: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Research Abstract |
The present study is to determine whether neutrophils (PMNs) contribute to the cellular injuries under hepatic ischermia/reperfusion and endotoxemia.
Hepatic warm ischemia/reperfusion-Mate Wistar rats were used and the vessels supplying the median and the left lateral hepatic lobes were occuluded with arterial clamp for 90 min. Five minutes before the occulusion, monoclonal anitibody (mAb) against ICAM-1 (IA29), CD11a (WT-1), CD18 (WT-3) or PBS as the placebo was administered intravenously. After reperfusion, the infiltration of PMNs and the expression of ICAM-1 in the liver were examined histologically. To examine the effect of mAb treatment, hepatic adenosine triphosphate (ATP) and malondialdehyde (MDA) levels were determined as indices of hepatic cellular injury. The number of accumulated PMNs increased continuously up to 24 hours after reperfusion. The expression of ICAM-1 in the liver was enhanced 4 houres after reperfusion. Treatment with the mAbs suppressed the infiltration of PM
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NS by 6 hours, ATP resynthesis by 6,12 and 24 hours, and reduced hepatic MDA level by 12 hours after reperfusion. Then, these mAbs increased the survival rate of rats receiving total hepatic ischemin (90min) / reperfusion.
Endotoxemia-Lipopolysaccharide (LPS : E.coli) was administered to ICR mice intraperitoneally, and lmg/kg antileukocyte adhesion molecule mAb (anti-CD11a : KAB,anti-CD11b : MI/70, anti-CD18 ; C17/16, anti-ICAM-1 : KAT-1, anti-LECAM-1 : MEL-14), 30mg/kg methylprednisolone (MP) as a conventional agent for shock, or PBS as the placebo was administered intravenously, simultancously. In the placebo group, the survival rate of mice 48 houres after LPS administration was 36% (20/55). Treatment with anti-CD11a, antiCD18, anti-LECAM-1 and MP increased the survival rate to 70 (7/10), 62 (8/13), 64 (7/11) and 100% (11/11), respectively. ON the other hand, anti-CD11b and anti-ICAM-1 had no significant effect on the survial rate. FACS analysis using the anti-CD18 mAb revealed that the expression of CD18 on the surfaces of granulocytes increased 12 folds within 30 min, and MP suppressed it significantly for up to 3 hours after LPS administration. The hepatic MDA content increased from 0.50 (untreated mice) to 2.46 nmol/mg protein 4 hours after LPS administration, and anti-CD18 mAb and MP suppressed it to 1.80 and 1.41 nmol/mg protein, respectively.
Leukocytes are concluded to mediate significant roles for oxidative injury causing hapatic cellular damages under hepatic ischemia/reparfuion and endotoxemia. These mAbs can be therapeutic agents preventing such injuries. Less
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