VitC对兔慢性高同型半胱氨酸血症氧化应激导致内皮功能损伤的保护作用

The protection of VitC to endothelial dysfunction by oxidant stress in hyperhomocysteinemia rabbits

目的 探讨高同型半胱氨酸血症 (HHcy)导致内皮功能损伤时 ,兔血中一氧化氮 (NO)以及谷胱甘肽过氧化物酶 (GSH PX)活性的改变 ,从而观察氧化应激在活体内皮功能损伤中的作用以及抗氧化剂VitC的保护作用。方法 将兔随机分为 3组 ,每组 9只 ,分别喂食正常饲料 (N组 ) ,L 蛋氨酸 (0 .8g·kg-1·d-1)饲料 (M组 ) ,L 蛋氨酸加VitC(1.0g·kg-1·d-1)饲料 (MC组 ) ,然后于第 0、2 0、40、60、80天取血检测NO、GSH PX的活性 ,同时利用高分辨率超声检测其内皮依赖性舒张功能 (EDD)、内皮非依赖性舒张功能 (EID)。结果 慢性HHcy时 ,MC组和M组的EDD均较对照组明显降低 ,P <0 .0 1,而且两组之间也差异显著 ,P <0 .0 1;MC组和M组的EID亦较对照组明显降低 ,P <0 .0 5 ,但两组之间无显著差异。同时 ,M组血浆NO、GSH PX活性较对照组和MC组明显降低 ,P <0 .0 5 ;而MC组和对照组之间无显著差异。结论 HHcy可导致兔血浆NO及GSH PX的活性降低 ,而抗氧化剂VitC可以保护Hcy对兔血管内皮功能的损伤 ,减少NO的灭活 ,而且对GSH

Objectives Through observation of the changes of NO and activity of GSH?PX in plasma of HHcy rabbits to study the effects of oxidant stress in endothelial dysfunction and the protection of the antioxidant ascorbic acid (VitC).Methods Rabbits were randomized into three groups ( n =9 per group),normal control group (N group) received normal diet, methioine group (M group) received methioine rich diet consisted of L methioine 0.8?g· kg -1 ·d -1 ,methioine+VitC group (MC group) received diet consisted of L methioine 0.8?g·kg -1 ·d -1 and VitC 1.0 ?g·kg -1 ·d -1 .Then NO,ET and activity of GSH?PX,SOD in plasma were examined in the 20th,40th,60th,80th day.At the same time,EDD and EID were examined by high resolution ultrasound.Results In chronic hperhomocysteinemia,EDD and EID of external iliac arteries in MC group and M group were reduced significantly compared with N group, P <0.01,and EDD instead of EID in M group was reduced significantly compared with MC group too.At the same time,NO in M group was reduced more significantly than MC group and N group, P <0.05,and there was no difference between MC group and N group.Conclusions In chronic hyperhomocysteinemia,Hcy could lead to endothelia dysfunction in rabbits through oxidant stress.Antioxidant VitC could prevent NO inactivity and protect the activity of GSH?PX.