Brass C A, Immenschuh S, Song D X, Liem H H, Eberhard U M
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, USA.
Biochem Biophys Res Commun. 1998 Jul 30;248(3):574-7. doi: 10.1006/bbrc.1998.9023.
Hemopexin is a plasma protein with exceptionally high affinity for heme. During liver transplantation heme is released via lysis of transfused blood. This heme may catalyze peroxidative reactions that contribute to "reperfusion" injury of the organ. Using a rat liver model of cold storage and reperfusion we tested the potential anti-oxidant effects of hemopexin. After 3 h of cold storage rat liver was reperfused with warm oxygenated buffer. Spontaneous liver chemiluminescence, which is a parameter of oxyradical production, was measured during reperfusion and expressed as an index of free radical production (IFRP). Chemiluminescence reached a maximum within 5 min of reperfusion and decreased to baseline within 30 min. Addition of hemopexin to the perfusate (5 microM) significantly decreased the IFRP. By contrast, the control proteins albumin and gamma-globulin (10 microM) had a smaller non-significant effect. The data suggest that heme could be complexed by hemopexin during reperfusion, thus inhibiting heme mediated cellular injury.
血红素结合蛋白是一种对血红素具有极高亲和力的血浆蛋白。在肝移植过程中，血红素通过输入血液的溶解而释放。这种血红素可能催化过氧化反应，从而导致器官的“再灌注”损伤。我们使用大鼠肝脏冷保存和再灌注模型，测试了血红素结合蛋白的潜在抗氧化作用。冷保存3小时后，用温热的含氧缓冲液对大鼠肝脏进行再灌注。在再灌注过程中测量自发肝脏化学发光，这是氧自由基产生的一个参数，并表示为自由基产生指数（IFRP）。化学发光在再灌注后5分钟内达到最大值，并在30分钟内降至基线。向灌注液中添加血红素结合蛋白（5微摩尔）可显著降低IFRP。相比之下，对照蛋白白蛋白和γ-球蛋白（10微摩尔）的作用较小且无统计学意义。数据表明，在再灌注过程中，血红素结合蛋白可与血红素结合，从而抑制血红素介导的细胞损伤。
