休克／再灌注肝损伤中氧自由基的作用

ROLE OF OXYGEN FREE RADICALS ON LIVER IN SHOCK/REPERFUSION HEPATIC INJURY

采用电子自旋共振（ｅｌｅｃｔｒｏｎｓｐｉｎｒｅｓｏｎａｎｃｅ，ＥＳＲ）及自旋捕捉技术直接测定兔休克／再灌注不同时限肝组织内氧自由基（ｏｘｙｇｅｎｆｒｅｅｒａｄｉｃａｌｓ，ＯＦＲ）含量的变化，同时观察肝组织内脂质过氧化物（ｌｉｐｉｄｐｅｒｏｘｉｄｅ，ＬＰＯ）含量，超氧化物岐化酶（ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ，ＳＯＤ）及血清ＡＬＴ活性的变化。结果示，ＯＦＲ易被自由基捕捉剂ＰＢＮ（α－ｐｈｅｎｙｌ－ｔｅｒｔ－ｂｕｔｙｌｎｉｔｒｏｅｎｅ）捕捉，并可通过ＥＳＲ而检测。ＯＦＲ在休克１．５小时后即有明显增高，再灌注１５和３０分钟后增高更为显著，ＬＰＯ、ＳＯＤ于再灌注后才分别有显著增高和降低，ＡＬＴ休克１．５小时后即有大幅度增高。ＬＰＯ、ＡＬＴ与ＯＦＲ有良好的线性正相关，ＳＯＤ与ＯＦＲ有良好的线性负相关，提示兔休克／再灌注肝损伤可能由ＯＦＲ介导。

Oxygen free radicals(OFR)of rabbit liver tissue following shock/reperfusion weremeasured by electron spin resonance(ESR) and spin trapping.Lipid peroxide (LPO)andsuperoxide dismutase(SOD)in liver tissue and serum ALT were also investigated.Theexperimental results showed that OFR could be trapped by free radical trapping agent PBN)and could be measured with ESR.At the end of l.5 hours of shock,OFR of liver tissueincreased significantly and increased further after reperfusion for l5 minutes and 30 minutes.LPO and SOD did not change markedly till after reperfusion, but ALT began to risesignificantly after l.5hr of shock.The results also showed that there was a linear positivecorrelation between OFR, LPO and ALT, and a negative correlation between OFR and SOD.All of these suggest that OFR might play an important role in ischemia/reperfusion injury of the liver.