高同型半胱氨酸血症与LDL氧化修饰及动脉粥样硬化的关系

为探讨同型半胱氨酸与LDL氧化修饰及动脉粥样硬化的关系 ,将 32只家兔随机分为甲硫氨酸组(M组 ) 9只 ,胆固醇组 (Ch组 ) 9只 ,甲硫氨酸 +胆固醇组 (M +Ch组 ) 9只和对照组 (C组 ) 5只。M组、Ch组和M +Ch组每日先分别喂予含 3%甲硫氨酸、3 75 %胆固醇和 3%甲硫氨酸 +3 75 %胆固醇的饲料 2 0 g后 ,再喂与C组一样的饲料不限。 16周末 ,取血测有关指标及留胸主动脉行病理学检查。结果显示 ,高甲硫氨酸喂食可使M组和M +Ch组血清同型半胱氨酸、ox LDL和硫代巴比妥酸反应物 (TBARS)分别较C组和Ch组显著增高 (P<0 0 1)。体外研究示 ,同型半胱氨酸诱发LDL体外氧化修饰的程度与LDL和同型半胱氨酸浓度有关 (P <0 0 1)。主动脉病理学显示 ,M组内皮细胞剥脱、内弹力膜和中膜弹力纤维断裂 ;M +Ch组斑块面积占动脉面积的百分比和内膜厚度显著大于Ch组 (P <0 0 1)。

OXIDATIVE MODIFICATION OF LOW DENSITY LIPOPROTEIN AND ATHEROSCLEROSIS INDUCED BY HYPERHOMOCYSTEINAEMIA FOLLOWING ADMINISTRATION HIGH DOSES OF METHIONINE

To observe the relationship between the oxidative modification of low density lipoprotein and atherosclerosis and hyperhomocysteinaemia following administration of high doses of methionine, thirty eight rabbits were randomized as methionine group(group M, n =9), cholesterol group(group Ch, n =9), methionine+cholesterol group(group M+Ch, n =9) and control group(group C, n =5) In groups M, Ch and M+Ch, the animals were fed with food containing 3% methionine, 3 75% cholesterol,and 3% methionine+3 75% cholesterol, respectively By the end of sixteen weeks, the blood and aorta were taken and the measurements were carried out The results showed that, following the administration of high doses of methionine, the levels of homocysteine, ox LDL and TBARS in group M and group M+Ch were much higher than those of group C and group Ch ( P <0 01). The oxidative modification of low density lipoprotein induced by homocysteine in vitro were significantly increased with the concentrations of LDL and homocysteine ( P <0 01) The light microscopy showed that in group M there was intense falling off of endothelial cells, and the internal elastic lamina and elastic fibers of media of aorta were fragmented.In group M+Ch the area of plaque formation and thickness of internal lamina were significantly increased compared with those of group Ch