核黄素对高脂血症所致内皮损伤的保护作用

目的　探讨核黄素对高脂血症所致血管内皮损伤的保护作用。方法　实验用家兔随机分为 3组 :正常对照组 (NC ,n =8)、高脂组 (HL ,n =8)、核黄素组 (RF ,n =8) ,均以普通颗粒饲料喂养 ,后两组加喂胆固醇和猪油 ,其中RF组增喂核黄素 2 0mg/天。饲前取血测血脂 ,尔后每周在HL组及RF组随机抽样复查。饲 5周后 ,取血样测血脂、vWF、NO、MDA水平 ;取主动脉弓制作光镜标本 ,观察血管组织形态学改变。取胸主动脉制作 3～ 4mm长的血管环 ,用于血管张力的测定。结果　饲前各组血脂水平无差异 ,2周后 ,NC组血脂水平无变化 ,HL组与RF组血脂水平升高 ,以LDL C和TC为甚。 5周后 ,HL组、RF组血清TC、TG、LDL C水平明显高于NC组 (P <0 .0 5或P <0 .0 1) ,但RF组明显低于HL组 (P <0 .0 5 ) ;HL组血浆vWF、MDA水平高于NC组 ,NO水平低于NC组 (P <0 .0 5或P <0 .0 1) ,RF组除MDA显著高于NC组 (P <0 .0 5 )外 ,其他指标与NC组无明显差异 ;HL组、RF组胸主动脉血管环对ACh舒张反应、对NE的缩血管反应明显小于NC组 (P <0 .0 5 ,或P <0 .0 1) ,但RF组显著大于HL组 (P <0 .0 1或P <0 .0 5 ) ;光镜下各组均未见明显的主动脉壁结构异常。结论　核黄素对高脂血症所致的血管内皮损伤有明显的保护作用 ,其机制可能与调节血脂代谢和提高?

Protective effects of riboflavin on vascular endothelial dysfunction induced by hyperlipemia

Objective\ To observe the protective effects of riboflavin on endothelial dysfunction induced by hyperlipemia.Methods\ 24 rabbits,weighing 2.0～2.5 kg,were randomly divided into three groups: normal control group (NC,n=8),hyperlipemia group (HL,n=8),riboflavin group (RF,n=8),and then fed with different diets.After 5 weeks,blood samples were collected from all of the rabbits for detecting serum lipids,plasma von willebrand factor (vWF),nitric oxide (NO),malonyldialelyde (MDA).Thoracic aortas were harvested for measurement of the response to norepinephine (NE) and acetycholine (ACh),aortic arches for observing histopathological changes.Results\ Compared with HL group,serum total cholesterol,low density lipoprotein cholesterol,triglyceride,plasma vWF,MDA concentrations in RF group markedly decreased (P<0.05 or P< 0.01). Plasma NO levels significantly increased (P<0.05).The response of ACh induced relaxation and NE induced vasoconstriction of thoracic aortas in RF group were enhanced as compared with HL group (P<0.05 or P<0.01) but reduced compared with NC group (P<0.05).No obvious structural injuries of aortic arch were found in the three groups.Conclusion\ Riboflavin has protective effects on vascular endothelial dysfunction induced by hyperlipemia,which might be attributed to its capacity to regulate lipid metabolism and reinforce antioxidation.