Bernareggi M, Radice S, Rossoni G, Oriani G, Chiesara E, Berti F
Department of Pharmacology, Chemotherapy and Medical Toxicology E. Trabucchi, University of Milan, Italy.
Br J Pharmacol. 1999 Feb;126(3):794-800. doi: 10.1038/sj.bjp.0702354.
This study investigates the microvascular permeability changes in tracheal tissue of rats exposed to hyperbaric oxygen (HBO). Rats, following exposure to HBO or ambient air (control animals) for 1.5, 3 and 6 h, were prepared for recording of nitric oxide exhaled (FENO) in air using a chemiluminescence analyser. The level of FENO was not statistically different in the two groups. Plasma exudation, evaluated by measuring the leakage of Evans blue (EB) dye into the tracheal tissue, was significantly elevated (48, 86 and 105% at 1.5, 3 and 6 h, respectively) in HBO-treated rats. Plasma exudation in the trachea of control rats was significantly increased (42%, P<0.05) by NG-nitro-L-arginine methyl ester (L-NAME), whereas it was significantly reduced (31%, P<0.05) in rats exposed to HBO for 3 h. N-acetylcysteine (NAC) and flunisolide significantly prevented the increase in plasma leakage in HBO-treated rats. In contrast, indomethacin was devoid of anti-exudative activity in these experiments. Western immunoblot showed a significant increase in the level of inducible nitric oxide synthase (iNOS) protein in the tracheal homogenates of HBO-treated rats, as compared to basal levels. These results indicate that nitric oxide (NO) is involved in the maintenance of microvascular permeability in tracheal tissue of rats. The protective effect observed with the steroid seems to support this hypothesis. Furthermore, the beneficial action of NAC underlines that reactive oxygen species participate in the microvascular permeability changes observed in tracheal tissue of rats exposed to HBO.
本研究调查了暴露于高压氧（HBO）的大鼠气管组织中的微血管通透性变化。将大鼠暴露于HBO或环境空气（对照动物）1.5、3和6小时后，使用化学发光分析仪准备记录呼出空气中的一氧化氮（FENO）。两组的FENO水平无统计学差异。通过测量伊文思蓝（EB）染料渗入气管组织来评估血浆渗出，在接受HBO治疗的大鼠中显著升高（在1.5、3和6小时分别升高48%、86%和105%）。NG-硝基-L-精氨酸甲酯（L-NAME）使对照大鼠气管中的血浆渗出显著增加（42%，P<0.05），而在暴露于HBO 3小时的大鼠中显著降低（31%，P<0.05）。N-乙酰半胱氨酸（NAC）和氟尼缩松显著阻止了HBO治疗大鼠血浆渗漏的增加。相比之下，在这些实验中吲哚美辛没有抗渗出活性。蛋白质免疫印迹显示，与基础水平相比，HBO治疗大鼠气管匀浆中诱导型一氧化氮合酶（iNOS）蛋白水平显著增加。这些结果表明，一氧化氮（NO）参与维持大鼠气管组织中的微血管通透性。观察到的类固醇的保护作用似乎支持这一假设。此外，NAC的有益作用强调活性氧参与了暴露于HBO的大鼠气管组织中观察到的微血管通透性变化。
