Cook D R, Howell R E, Gillis C N
Anesth Analg. 1982 Aug;61(8):666-70.
We were interested in determining the effect of lung injury initiated by superoxide anions and hydroxyl radicals on removal of 5-hydroxytryptamine (5-HT) and phenylethylamine by the isolated perfused lung. The rate of removal and percentage of removal of these bioamines was determined before and after lung injury initiated by perfusion of the lung with hypoxanthine (HX) and xanthine oxidase (XO) or xanthine oxidase alone for 10 or 30 minutes; free radicals are generated by such treatment. Because of variation in removal of bioamines among lungs of different animals, the effects of lung injury on bioamine removal were determined by calculating the percentage of inhibition of removal using data from the control and test period for each lung. Perfusion of the lung with HX/XO or XO for 10 or 30 minutes significantly inhibited 5-HT removal by 39.5% and 63.3%, respectively. In contrast, only perfusion of the lung for 30 minutes with HX/XO produced inhibition of phenylethylamine uptake (by 54.8%). As uptake of 5-HT is the rate-limiting step in 5-HT removal, these data demonstrate dose (time)-related depression of active 5-HT uptake by free radicals generated in vitro. The rate-limiting step of phenylethylamine uptake, metabolism by monoamine oxidase, is inhibited only by severe lung injury.
我们感兴趣的是确定超氧阴离子和羟基自由基引发的肺损伤对离体灌注肺清除5-羟色胺（5-HT）和苯乙胺的影响。在用次黄嘌呤（HX）和黄嘌呤氧化酶（XO）或仅用黄嘌呤氧化酶灌注肺10或30分钟引发肺损伤之前和之后，测定这些生物胺的清除率和清除百分比；这种处理会产生自由基。由于不同动物的肺对生物胺的清除存在差异，通过计算每只肺在对照期和测试期的数据得出的清除抑制百分比，来确定肺损伤对生物胺清除的影响。用HX/XO或XO灌注肺10或30分钟分别显著抑制5-HT清除39.5%和63.3%。相比之下，仅用HX/XO灌注肺30分钟会抑制苯乙胺摄取（抑制54.8%）。由于5-HT摄取是5-HT清除的限速步骤，这些数据表明体外产生的自由基会导致活性5-HT摄取出现剂量（时间）相关的降低。苯乙胺摄取的限速步骤，即单胺氧化酶的代谢，仅在严重肺损伤时受到抑制。
