Mansoori Somayh, Moosavi Seyed Mostafa Shid, Ketabchi Farzaneh
Department of Physiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Iran J Med Sci. 2017 May;42(3):284-291.
The mechanism of hypoxic pulmonary vasoconstriction (HPV) is still debatable. It has been proposed that reactive oxygen species (ROS) might be involved in HPV. However, there is no special transporter for superoxide anion in the cell membrane and it may release from the cells via anion exchanger. Therefore, the aim of this study was to investigate the interaction of ROS and anion exchanger in acute HPV.
The present study was performed in the isolated rabbit lung. After preparation, the lungs were divided into four hypoxic groups of control, Trolox (antioxidant)-treated, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS, anion exchanger inhibitor)-treated, and Trolox+DIDS-treated. Pulmonary artery pressure, left atrial pressure, and lung weight were continuously registered and PVR was then calculated. PO, PCO, HCO, pH, and NO metabolites of the perfusate were measured during steady-state and at the end of experiments (30 minutes). All data were compared with ANOVA and -test and significance was considered when P<0.05.
Ventilation of the lungs with hypoxic gas induced HPV in the control group. DIDS did not have a further effect on HPV compared with the control group. The combination of Trolox and DIDS decreased HPV rather than Trolox per se at 5 minutes. Furthermore, HPV was abolished in both the Trolox and Trolox+DIDS groups at 30 minutes. Concentrations of NO metabolites in the Trolox+DIDS group were more than other groups.
The present study indicates a possible interaction between ROS and anion exchanger in acute HPV. It also suggests the modulatory effect of NO at above condition.
低氧性肺血管收缩（HPV）的机制仍存在争议。有人提出活性氧（ROS）可能参与HPV。然而，细胞膜上没有超氧阴离子的特殊转运体，它可能通过阴离子交换器从细胞中释放出来。因此，本研究的目的是探讨急性HPV中ROS与阴离子交换器的相互作用。
本研究在离体兔肺上进行。制备完成后，将肺部分为四组低氧组，分别为对照组、曲洛司坦（抗氧化剂）处理组、4,4'-二异硫氰酸芪-2,2'-二磺酸（DIDS，阴离子交换器抑制剂）处理组和曲洛司坦+DIDS处理组。连续记录肺动脉压、左心房压和肺重量，然后计算肺血管阻力（PVR）。在稳态和实验结束时（30分钟）测量灌注液的氧分压（PO）、二氧化碳分压（PCO）、碳酸氢根（HCO）、pH值和一氧化氮代谢产物。所有数据采用方差分析和t检验进行比较，当P<0.05时认为具有统计学意义。
低氧气体通气诱导对照组出现HPV。与对照组相比，DIDS对HPV没有进一步影响。曲洛司坦和DIDS联合使用在5分钟时降低HPV的作用比单独使用曲洛司坦更明显。此外，在30分钟时，曲洛司坦组和曲洛司坦+DIDS组的HPV均被消除。曲洛司坦+DIDS组中一氧化氮代谢产物的浓度高于其他组。
本研究表明急性HPV中ROS与阴离子交换器之间可能存在相互作用。它还提示了在上述条件下一氧化氮的调节作用。
