Togashi H, Shinzawa H, Yong H, Takahashi T, Noda H, Oikawa K, Kamada H
Second Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Arch Biochem Biophys. 1994 Jan;308(1):1-7. doi: 10.1006/abbi.1994.1001.
Using electron spin resonance (ESR) spectroscopy, we examined whether reactive oxygen intermediates (ROIs) are produced after reperfusion of isolated, perfused rat livers subjected to global ischemia (10, 30, 60, and 90 min of ischemia). A few drops of effluent (200 microliters) flowed from reperfused liver was mixed immediately with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO, final concentration 1 M), and ESR measurements were then performed. Immediately after reperfusion, a small amount of ascorbic acid radical and DMPO-OOH, which was formed by the reaction of superoxide with DMPO, was detected. The amount of ascorbic acid radical peaked immediately after reperfusion, but became hardly detectable at 6 min after reperfusion, irrespective of the period of ischemia. Six minutes after reperfusion, not only DMPO-OOH but also DMPO-OH, which was formed by the reaction of hydroxyl radical with DMPO, was detected. Thereafter, DMPO-OOH and DMPO-OH gradually declined and became hardly detectable at 40 min after reperfusion. In accordance with the duration of ischemia, the concentrations of DMPO-OOH and DMPO-OH were highest after 60 min of ischemia, and then after 30, 90, and 10 min of ischemia in decreasing order. These results directly demonstrate that the production of ROIs occurs at an early stage of reperfusion in ischemic liver and that the amount of ROI production is closely related to the duration of ischemia.
我们运用电子自旋共振（ESR）光谱法，检测了经历全脑缺血（缺血10、30、60和90分钟）的离体灌注大鼠肝脏再灌注后是否产生活性氧中间体（ROIs）。将再灌注肝脏流出的几滴流出液（200微升）立即与5,5-二甲基-1-吡咯啉-N-氧化物（DMPO，终浓度1 M）混合，然后进行ESR测量。再灌注后立即检测到少量抗坏血酸自由基以及由超氧化物与DMPO反应形成的DMPO-OOH。抗坏血酸自由基的量在再灌注后立即达到峰值，但无论缺血时间长短，在再灌注后6分钟时几乎检测不到。再灌注6分钟后，不仅检测到DMPO-OOH，还检测到由羟基自由基与DMPO反应形成的DMPO-OH。此后，DMPO-OOH和DMPO-OH逐渐下降，在再灌注后40分钟时几乎检测不到。根据缺血持续时间，DMPO-OOH和DMPO-OH的浓度在缺血60分钟后最高，然后依次为缺血30、90和10分钟后。这些结果直接表明，ROIs的产生发生在缺血肝脏再灌注的早期阶段，并且ROIs的产生量与缺血持续时间密切相关。
