褪黑素对油酸致大鼠急性肺损伤的防护作用及其机制研究

目的：研究油酸（OA）致大鼠急性肺损伤（ALI）时,P-选择素（Ps）、细胞间粘附分子-1（ICAM-1）和核因子-κB（NF-KB）在肺组织中的表达及褪黑素（MT）对肺组织的保护作用及其机制。方法：将48只SD大鼠随机分为4组（n=12）,对照组（Control）、油酸组（OA）、MT＋OA组,SB203580＋OA组。采用尾静脉注射油酸的方法建立大鼠Au的模型,测定肺系数,光镜下观察大鼠肺组织形态学改变,并通过免疫组织化学染色技术观察肺组织中Ps、ICAM-1和NF-κB的表达变化。结果：与control组相比,OA组大鼠肺系数明显升高（P〈0．05）;肺组织损伤严重,肺泡间隔明显增宽,肺泡腔及肺间质弥漫性炎细胞浸润;Ps、ICAM-1和NF-κB的阳性表达信号明显增强（P〈0．05）;应用MT和SB203580均显著缓解上述变化（P〈0．05）。结论：MT对ALI时的肺组织起明显的保护作用,其保护机制可能与抑制Ps、ICAM-1和NF-κB的表达有关。

Protective function of melatonin to acute lung injury and its mechanisms in rats caused by oleic acid

Objective： To observe the expression of P-selectin（Ps ）, intercellular adhesion molecule-1 （ ICAM-1 ） and nuclear factor-kappa B （NF-κB） in lung tissues of acute lung injury（ALI） rat model induced by oleic acid （OA） and to explore the protective effects of melatonin （MT） in lung tissues in rats. Methods： All rats were randomly divided into four groups： control group, OA group, MT ＋ OA group and SB203580 ＋ OA group. Rat model of ALI was established by intravenous injection of oleic acid（OA）. Lung coefficient was measured, lung tissues were imbedded by paraffin to observe morphological changes and the expression of Ps, ICAM- 1 and NF-κB in lung tissues by means of immunoh/stochemistry staining. Results： Compared with control group, the lung coefficient increased significantly in OA group（ P 〈 0.05）. Alveolar septum thickened significantly in OA group, there had many infiltrated inflammatory cells and collapsed alveoli of lung; positive expression of Ps, ICAM-1 and NF-κB were very obvious（P 〈 0.05） ; the administration of MT and SB203580 mitigated above changes significantly（ P 〈 0.05）. Conclusion： MT possesses obviously protective effect on lung tissues during ALI, its protective mechanism might be related to the inhibition of the expression of Ps, ICAM-1 and NF-κB.