大剂量氨溴索对大鼠肺缺血再灌注损伤的影响

Effects of large dose of ambroxol hydrochloride on lung ischemia reperfusion injury in rats

目的评价大剂量盐酸氨溴索（沐舒坦）对肺缺血再灌注损伤（Lung ischemia reperfusion injury，LIRI）的保护作用及对EphrinAl、缺氧诱导因子1α（HIF-1α）和血管内皮生长因子（VEGF）基因及蛋白表达的影响。方法大鼠左侧开胸，阻断左肺门根部60min，再灌注6h。实验分为缺血再灌注损伤组、沐舒坦干预组及手术对照组和空白对照组。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，IL-1β、TNF—α含量，髓过氧化物酶（MPO）活力，EphrinAl、HIF-1α和VEGF基因及蛋白的表达水平，光镜下观察病理组织学改变。结果（1）大剂量沐舒坦干预后，肺泡间隔水肿、肺泡内出血、渗出等较再灌注损伤组明显改善，肺组织湿／干重比值显著降低，动脉血氧分压明显改善；（2）肺组织IL-1β和TNF—α含量在大剂量沐舒坦干预后，基本降至正常水平，MPO活力降至手术对照组水平，均明显低于缺血再灌注实验组；（3）沐舒坦干预组的EphrinAl、HIF-1α和VEGF基因及蛋白表达水平在药物干预后并未恢复至正常水平，但是较缺血再灌注损伤组明显下降。结论（1）大剂量沐舒坦干预下调肺组织的IL-1β、TNF-α含量和MPO活力，减轻LIRI的损伤程度；（2）大剂量沐舒坦可通过下调EphrinAl、HIF-1α和VEGF基因及其蛋白产物的表达来减轻LIRI。这一观察结果可能提示LIRI形成过程中基因调控的作用以及沐舒坦新的药理效应。

Objective To evaluate the protective effect of large dose of ambroxol hydrochloride on lung ischemia reperfusion injury in rats and analyze the relationship between ambroxol hydrochloride and pulmonary vascular permeability mediators including EphrinAl, HIF-α and VEGF at mRNA and protein levels. Methods Rats were operated by the thoracic posterolateral approach. The left lung ischemia was induced by clamping the hilum of the left inflated lung for 60 minutes, and then followed by a 6-hour reperfusion. Forty rats were divided into ischemia-reperfusion group, ambroxol hydrochloride intervention group, sham operation group and blank control group. At the beginning of reperfusion, rats in ambroxol hydrochloride group were infused with ambroxol hydrochloride solution （3.75 mg · kg^-1 · h^-1 ） via femoral vein for six hours. Then, PaO2, wet-to-dry lung weight ratio, concentrations of IL-1 β and TNF- α, activity of myeloperoxidase （ MPO）, mRNA and protein expressions of EphrinA1, HIF-1α and VEGF were detected. Histopathological changes were observed under light microscope. Results （ 1 ） Histological observation with light microscope showed significant decrease of diffuse alveolar damage consisting of septal edema, intraalveolar hemorrhage and exsudation in ambroxol hydrochloride group compared with ischemia-reperfusion group. The wet-to-dry lung weight ratio in ambroxol hydrochloride group was decreased and PaO2 was elevated significantly. （2） Compared with ischemia-reperfusion group, the concentrations of IL-1 β and TNF-α and activity of MPO in ambroxol hydrochloride group were decreased significantly. （3） The mRNA and protein expressions of EphrinA1, HIF-1 α and VEGF in ambroxol hydrochloride group did not recover to normal but were down-regulated significantly compared with ischemia-reperfusion group. Conclusions （ 1 ） Large dose of ambroxol hydrochloride can alleviate the LIRI damage by down-regulating the expressions of IL-1β and TNF-α and the activity of MPO in the lung parenchyma. （2） The mRNA and protein expressions of EphrinA1, HIF-1 α and VEGF can be down-regulated by large dose of ambroxol hydrochloride, which contributes to alleviation of the LIRI damage. The results indicate possible role of gene regulation and fresh pharmacological effect of ambroxol hydrochloride during forma- tion of LIRI.