大剂量氨溴索对大鼠肺缺血再灌注损伤的保护作用及机制研究

目的：评价大剂量盐酸氨溴索（沐舒坦）对肺缺血再灌注损伤（Lungischemiareperfusioninjury，LIRI）的保护作用及其机制。方法：实验选取sD大鼠36只，分为三组：缺血再灌注损伤组；沐舒坦干预组；手术对照组。对大鼠进行左侧开胸并阻断左肺门根部60min，然后进行再灌注6h。沐舒坦干预组再灌注开始时，经股静脉持续6h输入沐舒坦溶液（3．75mg·kg-1．h-1）。分别检测大鼠动脉血氧分压，肺组织湿／干重比值，氧化应激因子（MDA，SOD，GSH-PX）含量，髓过氧化物酶（MPO）活力，细胞因子（TNF-α、MCP-1、TGF-β1）基因mRNA的表达水平，光镜下观察病理组织学改变。结果：（1）大剂量沐舒坦干预后，肺间质水肿、炎症细胞浸润、肺泡内出血、渗出等较再灌注损伤组明显改善（P〈O．05）；肺组织湿／干重比值显著降低（P〈0．05）；动脉血氧分压明显改善（P〈0．05）。（2）大剂量沐舒坦干预后，肺组织MDA、SOD、和GSH—PX含量基本降至正常水平；MPO活力降至手术对照组水平；差异均明显低于缺血再灌注损伤组（P〈0．05）。（3）沐舒坦干预组的TNF-α，MCP-1，TGF．B1基因mRNA表达水平在药物干预后虽未能恢复至正常水平，但是较缺血再灌注损伤组明显降低。结论：大剂量沐舒坦可参与下调肺组织的MDA、SOD、GSH．PX的含量和MPO活力，并通过下调TNF-α、MCP．1、TGF-β1基因rnRNA的表达水平达到减轻LIRI损伤程度的目的。本研究结果表明，沐舒坦通过调控uRJ在形成过程中相关基因的表达来抑制氧化应激损伤，从而有效的减轻肺缺血再灌注损伤。

Effects of Large Dose Ambroxol Hydrochloride on the Protection of Lung Ischemia Reperfusion Injury in Rats

Objective： To evaluate the effects of ambroxol hydrochloride with a large dose on the protection of lung ischemia reperfusion injury in rats and to analyze the possible therapeutic mechanism. Methods： 36 adult male Spragne-Dawley rats （n=36, 200-250g） were selected and divided into three groups： ischemia reperfusion group, ambroxol intervention group, sham operation group. All the rats were operated with the thoracic posterolateral approach. The left lung ischemia of rat was induced by clamping the hilum of the left inflated lung for 60 minutes, and then conducted the reperfusion for six hours. At the beginning of reperfusion, the rats in ambroxol hydrochloride group were infused with ambroxol hydrochloride solution （3.75mg.kgkh-1） via femoral vein for six hours. Then the PaO2, wet-to-dry lung weight ratio, oxidative stress factor （MDA, SOD and GSH-PX）, myeloperoxidase （MPO） activity, mRNA expressions of cytokines （TNF-α, MCP-1, TGF-β1） were analyzed and the histopathological changes were observed under light microscope. Results： （1） Histological examination of ischemia reperfusion group has showed lung injury with interstitial edema and intm-alveolar hemorrhage and exsudation in the alveolar space and septum, while large dose of ambroxol could markedly reduce such damage in lung tissue; The wet-to-dry lung weight ratio in ambroxol hydrochloride group was decreased and PaO2 was elevated significantly （P〈0.05）. （2） In the am- broxol intervention group, the MDA, MPO activity, hydroxyproline contents and the mRNA expressions of TNF-α, MCP-1, TGF-β1 were up-regnlated in lung tissues, but SOD and GSH-PX activity were down-regulated in lung tissue when compared with the control group （P〈0.05）. （3） In ambroxol intervention group, the MDA, MPO activity, hydroxyproline content, the mRNA expression of TNF-α, MCP-I, TGF-β1 were significantly decreased, while the SOD and GSH-PX activities in lung tissues were increased when compared with LIPd group （P〈0.05）. Conclusion： Large dose of ambroxol could alleviate damages to the lung by down-regulating the expression of MDA, SOD and GSH-PX content and the activity of MPO. In addition, the mRNA expressions of TNF-α, MCP-1 and TGF-β1 could be down-regulated by large dose of ambroxol hydrochloride, which contributed to alleviation of the LIRI damage. The results of this study indicated that large dose of ambroxol hydrochlorid might apply gene regulation and fresh pharmacological effect during the formation of lung ischemia reperfusion.injury.