L－精氨酸抑制兔肺动脉巨噬细胞平滑肌细胞增殖

DIETARY L-ARGININE ATTENUATES MACROPHAGE INFILTRATION AND SMOOTH MUSCLE CELL PROLIFERATION IN THE PULMONARY ARTERY OF HYPERCHOLESTEROLEMIC RABBITS

目的：观察Ｌ－精氨酸是否通过抑制巨噬细胞浸润和平滑肌细胞增殖而起抗动脉粥样硬化作用。方法：２０只成年雄性新西兰兔随机分为ＡＣ组（ｌ％胆固醇＋饮水含２．２５％Ｌ－精氨酸）；ＭＣ组（１％胆固醇＋饮水含０．９％蛋氨酸；Ｃ组（１％胆固醇）和ＮＣ组（普通饲料和自来水）；每组各５只。１０周后采血标本，处死兔取主肺动脉作形态学和免疫组织化学研究。统计学采取ｔ检验和方差分析。结果：Ｌ－精氨酸使肺动脉内膜增生明显减轻（１．９４至０．６７，Ｐ＜０．０５），巨噬细胞浸润及平滑肌细胞增殖显著减少（分别为７５％～１３％，和６８％～２１％，Ｐ均＜０．０１）；而蛋氨酸却无此作用。结论：Ｌ－精氨酸能抑制高胆固醇兔肺动脉粥样硬化，其机理主要与抑制巨噬细胞浸润和平滑肌细胞增殖有关。

Objective:The purpose of this study is to determine whether the anti-atherogenic effect of L-arginine is due to an inhibition of rnacrophage infiltration and smooth muscle cell(SMC) proliferation in the pulmonary artery of hypercholesterolemic rabbits. Methods:Twenty male New Zealand white rab-bits were randomized into four treatment groups:Group AC with 1%cholesterol diet supplemented with 2.25% L-arginine HCl in the drinking water(AC,n=5),Group MC with 1%cholesterol diet supplemented with 0.9%methionine in the drinbing water(MC,n=5),Group C with 1%cholesterol dietonly(c,n=5),and Group NC with normal diet(NC,n=5).After 10 weeks the blood samples were collected for biochemical studies,and the main pulmonary arteries were harvested for histomor-phometry and immunohistochemical studies. Comparison between two means are analyzed using the Student’s test.Comparison of more than two means is performed using analysis of variance. Results:The results showed that dietary L-arginine supplernentation reduced the intimal thickness(from 1. 94 to 0.67mm2)and accumulation of macrophages(75%～13%, P <0. 01),and inhibited the SMC prolif-eration(68%～21.3%,P <0.01)significantly in association with anti-atherogenesis without affecting plasma cholesterol level; Supplementation of methionine did not produce such effects(75%vs 73.3%and 68 vs 70.8%).Conclusion : Dietary supplementation of L-arginine can inhibit atherogenesis in hy-percholesterolemic rabbits,The anti-atherogenic effect of L-arginine is largely due to the inhibition ofmacrophage infiltration and SMC proliferation.