Balance of Superoxide and Nitric Oxide in Hyperoxic Lung Injury

实验1：要研究超氧化物（O-D22-）和硝酸氧化物（NO）在急性肺损伤的病理学中的产生，我们在分离的肺暴露中控制NO的产生到O-D22-通过在体内暴露中的充分氟醚后续L-arginine浓度的alienation在L-arginine concentration在体外暴露中控制脂质体（LPS）。Rats were divided lo three groups （n=6 in each）： （G1） saline+ y D2L D2-Argine（3 mM）、（G2） LPS+ y D2L D2-Argine（3 mM）、（G3） LPS+ y D2L D2-Argine（0.1 mM）。G2和G3中的动物在隔离前接收LPS 6小时。Xathine氧化酶（0.1 U/ml）已被转化为Oy-D22-和2-甲基-6-（对甲基苯基）-3，7-二氢-亚胺（1，2-a）吡嗪-3-one（MCLA; 6 mM），Oy-D22-D2-特定的化学物质检测探针被添加到全氟剂中。We estimated lung injury by measuring the concentration of lactate dehydrogenase （LDH） in the perfusate。Nitrite和Nitrate是用灰色反应来断言的。LPS行政管理增加了O ... More D22-production only slightly.两种NO的生产和LDH浓度明显在G2中，但在G3中没有与G1相比较。在结合，不可能exacerbate ROS介导的急性肺损伤中，实验2：硝酸氧化物（NO）在氧化剂肺损伤中的作用残留不确定。我们研究了两个NO合成酶（NOS）抑制剂的影响，IYD 2L IYD 2-N IYD 16 IYD 1-（1-iminoethyl）赖氨酸（IYD 2L IYD 2-NIL），高度选择性抑制剂的iNOS，和IYD 2L IYD 2-NG-monomethyl arginine （IYD 2L IYD 2-NMMA），非选择性NOS抑制剂对大鼠高氧肺抑制剂的高氧肺抑制剂。Animals received y-D2 L y-D2-NIL，y-D2 L y-D2-NMMA or diluent intraperitoneally every beginning 12 hr之前暴露到100%氧（Oy-D22 y-D2）或空气在一个周期内50小时的空气。NOS抑制剂的吸收被确认为血清中的硝酸盐/硝酸盐集中的变化的测量。我们衡量的湿到干的重量比（W/D）是肺蛋白通量指数和全蛋白质集中在支气管炎阴道液（BALP）中的指数。We also evaluated hyperoxia-induced alternations in inducible NOS （iNOS） and endothelial NOS （eNOS） mRNA expression in lung tissue。OイイD22イエD2 exposure increased W/D， BALP and serum nitrite/nitrate concentration。D2-NIL and D2 L-NMMA attenuated the O-D22-NMMA attenuated the O-D2 induced increases in nit #/nitrate concentration but only D2-NMMA produced further significant increases in W/D and BALP above those with O-D22 exposure。Exposure to 100% O-D22-D2 increased the expression of both iNOS and eNOS mRNA and this effect was not altered by O-D2 L-D2-NIL or O-D2-NMMA，作为竞争NOS inhibitors的行为。In conclusion，y D2L y D2-NMMA but not y D2L y D2-NIL accentuates hyperoxic lung injury suggesting that endogenous endothelial NO play a protective role in pulmonary oxygen toxicity。Less（低）

EXPERIMENT 1: To study the interaction of superoxide (OィイD22ィエD2-) and nitric oxide (NO) production in the pathogenesis of acute lung injury, we controlled NO production in the isolated lung exposed to OィイD22ィエD2- by alienation of the L-arginine concentration in the perfusate following in vivo exposure to lipopolysaccharide (LPS). Rats were divided lo three groups (n=6 in each): (G1) saline+ィイD2LィエD2-Arginine (3mM), (G2) LPS+ィイD2LィエD2-Arginine (3mM), (G3) LPS+ィイD2LィエD2-Arginine (0.1mM). The animals in G2 and G3 received LPS 6 hr before isolation of the lungs. Xathine oxidase (0.1 U/ml) was infused to generate OィイD22ィエD2- and 2-methyl-6-(p-methoxyphenyl)-3,7-dihydro-imiduo (1,2-a) pyrazin-3-one (MCLA; 6mM), OィイD22ィエD2-specific chemiluminescence probe was added to the perfusate. We estimated lung injury by measuring the concentration of lactate dehydrogenase (LDH) in the perfusate. Nitrite and nitrate in the perfusate were assayed using the Griess reaction. LPS administration increased O … More ィイD22ィエD2- production only slightly. Both NO production and LDH concentration increased significantly in G2 but not in G3 compared with G1. In conclusion, excess production of NO may exacerbate ROS mediated acute lung injury.EXPERIMENT 2: The role of nitric oxide (NO) in pathogenesis of oxidant lung injury remains uncertain. We investigated the effect of two NO synthase (NOS) inhibitors, ィイD2LィエD2-NィイD16ィエD1-(1-iminoethyl)lysine (ィイD2LィエD2-NIL), highly selective inhibitor of iNOS, and ィイD2LィエD2-NG-monomethyl arginine (ィイD2LィエD2-NMMA), non-selective NOS inhibitor on hyperoxic lung injury in rats. Animals received ィイD2LィエD2-NIL, ィイD2LィエD2-NMMA or diluent intraperitoneally every 12 hr beginning 12 hr before exposure to 100% oxygen (OィイD22ィエD2) or air for a period of 50 hr. Absorption of the NOS inhibitors was confirmed by measurement of changes in the nitrite/nitrate concentration in serum. We measured wet-to-dry weight ratio (W/D) of lung tissue as an index of pulmonary edema and total protein concentration in bronchoalveolar lavage fluid (BALP) as an index of lung protein flux. We also evaluated hyperoxia-induced alternations in inducible NOS (iNOS) and endothelial NOS (eNOS) mRNA expression in lung tissue. OィイD22ィエD2 exposure increased W/D, BALP and serum nitrite/nitrate concentration. ィイD2LィエD2-NIL and ィイD2LィエD2-NMMA attenuated the OィイD22ィエD2 induced increases in nitrite/nitrate concentration but only ィイD2LィエD2-NMMA produced further significant increases in W/D and BALP above those with OィイD22ィエD2 exposure. Exposure to 100% OィイD22ィエD2 increased the expression of both iNOS and eNOS mRNA and this effect was not altered by ィイD2LィエD2-NIL or ィイD2LィエD2-NMMA, which acts as competitive NOS inhibitors. In conclusion, ィイD2LィエD2-NMMA but not ィイD2LィエD2-NIL accentuates hyperoxic lung injury suggesting that endogenous endothelial NO play a protective role in pulmonary oxygen toxicity. Less