壳聚糖对大鼠动脉粥样硬化的影响及其机制探讨

目的:研究壳聚糖对大鼠动脉粥样硬化斑块及一氧化氮合酶(NOS)的影响。方法:40只Wistar大鼠均分为:A组(正常对照组);B组:饲以高脂饲料(不含维生素D3);C组:一次性给予大鼠维生素D3(30万U/kg体重)肌肉注射,以球囊损伤主动脉内皮和饲以含维生素D3(1.25×106U/kg)的高脂饲料;D组在C组的基础上饲料中加入5%壳聚糖。90 d后检测主动脉动脉粥样硬化斑块形成及NOS的活性。结果:(1)90 d后C组大鼠胸主动脉形成了明显的动脉粥样硬化斑块,而仅饲以高脂饲料的大鼠胸主动脉结构未见改变,D组大鼠胸主动脉未形成动脉粥样硬化斑块;(2)血管中内皮型一氧化合酶(eNOS)后三组较A组均活性下降(P<0.01),而三者之间无统计学差异;(3)诱导型一氧化氮合成酶(iNOS):B组较A组无差异,而C组较A、B两组表达和活性均显著增加(P<0.05~<0.01),较之C组,D组的水平下降(P<0.01),但仍高于A、B组(P<0.01);(4)较之A组,B、C组的TC、TG、LDL-C水平上升(P<0.05~<0.01),D组的较C组下降(P<0.05~<0.01);B、C组的HDL-C水平较A组明显下降(P<0.01)。结论:壳聚糖可通过抑制胆固醇、甘油三酯等的吸收而发挥抗动脉粥样硬化作用,并通过对血脂的作用而间接发挥对NOS的影响。

Effects of chitosan on atherosclerosis plaques in rats

Objective:To observe the effects and mechanisms of chitosan on atherosclerosis plaques in rats.Methods:All the 40 Winstar rats were divided into four groups:group A:the rats were fed with normal diet,group B:the rats were fed with only high-cholesterol diet(no vitamin D3),group C:the rats were treated with one intramuscularly injection of vitamin D3(300 000 U/kg) and were denudated of endothelium,followed by high-cholesterol diet,group D:the rats were treated with 5% chitosan added into the diet besides treatment as group C.Ninety days later,the formation of atherosclerosis plaques and the activities of nitric oxide synthase in aortas in the four group rats were investigated.Results:After 90 days,(1)The aorta structure of rats fed with only high-cholesterol diet(no vitamin D3) was normal.Distinct atherosclerosis plaques were formed in the thoracic aortas of rats in group C,structure of aortas in group D was almost normal;(2)Compared with rats in group A,rats in group B,group C and group D had lower activities of endothelial nitric oxide synthase(P<0.01),there was no differences among later three groups;(3)With inducible nitric oxide synthase(iNOS),there was no differences between group A and group B;whereas the activities of that of rats in group C were more higher than that of group A and B(P<0.01);compared with group C,iNOS decreased in group D,but it was still more than that of group A,group B and C(P<0.01);(4)Compared with group A,the levels of TC,TG,LDL-C increased(P<0.05~<0.01) in group B and C;compared with group C,the levels of TC,TG,LDL-C significantly decreased(P<0.05~<0.01) in group D;compared with group A,the HDL-C level of group B and C decreased(P<0.01).Conclusion:Chitosan has role of anti-atherosclerosis through restraining absorb of cholesterol and triglyceride,and has indirect influence on NOS via role on serum cholesterol and triglyceride.