同型半胱氨酸与兔脑动脉损伤的关系及维生素B6、B12、叶酸对其预防作用的探讨

目的探讨高蛋氨酸(Met)喂饲兔引发高同型半胱氨酸(Hcy)血症与脑动脉损伤的关系,同时观察补充VitB6、VitB12、叶酸对血Hcy水平和动脉损伤的影响.方法采用纯种雄性新西兰兔26只,分为三组对照组、高蛋氨酸组、干预组,分别喂以普通兔饲料每只200g/d、普通饲料添加0.5%Met、普通饲料每天每只兔添加0.5%Met、叶酸2.5mg、VitB6 10mg、VitB12 200mg,喂养6个月,测定血浆总Hcy(tHcy),光镜检测脑动脉组织学改变.结果实验前血浆tHcy浓度三组间无明显差异,实验后断食2 h和7 h血tHcy浓度高Met组明显高于对照组(P＜0.01),而干预组血tHcy浓度明显低于高Met组(P＜0.01),但仍高于对照组.光镜组织学检测发现高Met组和干预组脑动脉可见内皮细胞坏死、脱落、溃疡形成,附壁血栓,中膜平滑肌散乱疏松.结论高Met引发高Hcy血症对脑动脉有损伤,且VitB6、VitB12、叶酸的补充可以降低高Met引发的高Hcy浓度的水平.

The Relation Between Homocysteine with Cerebral Arteries Lesions in Rabbits and the Prevention of Vitamin B6, Vitamin B12 and Folate

Objective To investigate the relation between hyperhomocysteinemia caused by excessive Methionine (Met) diets in rabbits with cerebral arteries injuries, and observe the effects of vitamin B6, vitamin B12 and folate on the total homocysteine (Hey) content in serum and on cerebral arteries injuries. Methods 26 Zewsland rabbits were randomly divided into 3 groups: the control group (CG, n = 8), the high Met group (HG, n = 10) and the intervention group (IG, n = 8), which were fed with normal diets, normal diets enriched with 0.5% Met and normal diets enriched with 0.5% Met plus 2.5 mg folate, 10 mg vitamin B6 and 200 mg vitamin B12 respectively every day for six months. The total homocysteine (Hey) content in serum were measured. The histological changes of cerebral arteries were examined under light microscope. Results There were no differences between three groups before experiment. The homocysteine content in serum at 2 hours and 7 hours after the end of diets application in HG were higher than that in CG ( P < 0. 01). In IG group, the levels of homocysteine at 2 hours and 7 hours after experiment decreased comparing with HG, but it was higher than that in CG, especially at 2 hcurs. The lesions of cerebral arteries in HG and IG were endothelial cell scaling and necrosis, ulccration, mural thrombosis, with some media smooth muscle scattering and loosing. Conclusions Hyperhomocysteinemia causing by excessive Met diets can induce cerebral arteries injuries. Vitamin B6 , B12 and folate may decrease the homocysteine content in serum.