一氧化氮合酶在实验性动脉瘤中的表达及作用

Expression and Role of Notric Oxide Synthase in Experimental Aneurysms

目的探讨一氧化氮合酶(NOS)在实验性动脉瘤中的表达及其作用。方法在13只家兔上成功复制了动脉瘤,并以正常的兔颈总动脉作为对照。用生物化学方法检测了动脉瘤组织和对照组中总一氧化氮合酶(T-NOS)和诱导型一氧化氮合酶(i-NOS)的活性,并以免疫组化的方法对i-NOS在血管壁中的表达进行了观察定位。结果动脉瘤组织与正常血管相比,T-NOS的活性无显著性差异(P>0.05),但i-NOS显著增加(P<0.01),且i-NOS与T-NOS的比例亦显著升高(P<0.01)。动脉瘤瘤壁肌层结构明显紊乱,可见炎症细胞浸润,细胞外基质明显破坏或消失。动脉瘤组织内i-NOS的表达呈局灶性分布在血管壁,主要集中在炎症细胞浸润的区域。结论提示主要由炎症细胞产生的i-NOS在动脉瘤发生发展的病理过程中可能起重要作用。

Objective To investigate the expression and role of nitric oxide synthase （NOS） in experimental aneurysms. Methods Aneurysms were successfully established in 13 rabbits. The activities of total NOS （T-NOS） and inducible NOS （i-NOS） in the aneurysm tissues and normal common carotid arteries of rabbits were meassured by biochemical method. The expression of i-NOS in the aneurysm tissues and the normal common carotid arteries of the rabbits were determined by immunohistochemistry. Results The activities of T-NOS in the aneurysms（n=10） and the normal common carotid arteries（n=6） were （13.267±2.614）U/g.protein and （11.627±6.272）U/g.protein respectively. There was insignificant difference in the activities of T-NOS between the experimental aneurysms and normal carotid arteries （P〉0.05）. The activity [（4.218±0.692）U/g.protein] of i-NOS and i-NOS to T-NOS ratio （32.29%±5.58%） in aneurysms （n=10） were significant higher than those [（1.933±0.772）U/g.protein and （18.39%±5.74%）] in the normal carotid arteries （P〈 0.01）. The structures of aneurysmal walls were obviously destroyed. Inflammatory cells infiltrated into the aneurysmal walls and their extracellular matrixes were destroyed or disappeared. The expression of i-NOS was detectable in some spot of the aneurysmal walls into which the inflammatory cells infiltrated. Conclusion It is suggested that i-NOS produced mainly by inflammatory cells probably plays an important role in the pathogenesis of the aneurysms.