高同型半胱氨酸和非对称性二甲基精氨酸对大鼠脑血管的影响及干预的研究

Injured effect of hyperhomocysteinemia and asymmetric dimethylarginine on rats cerebral vascular and efficacy of combined drug regimens

目的研究高同型半胱氨酸（HHcy）、非对称性二甲基精氨酸（ADMA）对大鼠脑血管结构的影响，并探讨普罗布考、叶酸及维生素B12对其干预的效果。方法70只雄性SD大鼠随机分为7组：对照组、HHcy模型组、普罗布考（低剂量、中剂量、高剂量）组、叶酸＋维生素B12（两药联合）组、叶酸＋维生素B12＋普罗布考（3药联合）组。正常对照组给予普通饲料喂养予蒸馏水灌胃；其他6组给予2％蛋氨酸饲料喂养，并分别给予蒸馏水、不同剂量普罗布考（340、510、680mg·kg^-1·d^-1）、叶酸＋维生素B12、叶酸＋维生素B12＋普罗布考灌胃。于实验开始、第8及12周末采用高压液相荧光检测法测定大鼠血浆Hcy、ADMA水平；于第12周末采用电镜观察各组大鼠脑血管结构的改变。结果高蛋氨酸饮食8周后，正常对照组Hcy水平为（7．1±1．4）μmol／L，低于HHCY模型组（60．4±11．9）μmol／L；HHCY模型组ADMA为（1．3±0．4）μmol／L，高于正常对照组（0．4±0．1）μmol／L。12周末，血浆Hcy、ADMA水平低剂量组为（49．9±11．4）μmol／L和（1．0±0．2）μmol／L、中剂量组（46．8±10．9）μmol／L和（0．9±0．1）μmol／L、高剂量组（44．3±11．4）μmol／L和（0．9±0．1）μmol／L、两药联合组（16．3±4．9）μmol／L和（0．7±0．2）μmol／L，较HHCY模型组（69．5±11．4）μmol／L和（1．6±0．5）μmol／L降低，但高于正常对照组（6．7±1．3）μmol／L和（0．5±0．1）μmol／L，差异有统计学意义（P〈0．05）。3药联合组Hey、ADMA水平分别为（8．9±1．9）μmol／L和（0．6±0．2）μmol／L，较HHCY模型组下降（P〈0．05），但与正常对照组比较差异无统计学意义（P〉0．05）。相关分析显示血浆Hcy与ADMA呈正相关（P〈0．05）。电镜下HHCY模型组大鼠脑动脉及大脑皮质结构均可见损伤，应用普罗布考、叶酸及维生素B12干预后大鼠脑血管结构损伤较HHCY模型组减轻，3药联合组减轻更明显。结论HHcy、ADMA能够对大鼠脑血管结构造成损伤；普罗布考、叶酸及维生素B12可通过降低Hcy、ADMA水平，减轻脑血管的损伤，且3种药物联合效果更显著。

Objective To study the damage of hyperhomocysteinemia （HHcy） and asymmetric dimethylarginine （ADMA） on the structure of rats cerebral vessels, and to explore the treatment effect of probucol, folic acid and vitamin B12. Methods Totally, 70 male Sprague Dawley（SD） rats were randomly divided into seven groups： normal control （A）, HHcy model （B）, low-dose- probucol （C）, middle-dose- probucol （D）, high-dose-probucol （E）, folic-acid plus vitamin B12 （F）, folic-acid plus vitamin B12 plus probucol（G）group. Group A was fed plain feedstuff and water. Other groups were fed homomethionin feedstuff and water, probucol （340, 510, 680 mg·kg^-1·d^-1）, folic acid and vitamin B12, folio acid plus vitamin B12 plus probucol respectively. The plasma concentrations of homocysteine（Hey） and ADMA were assayed by high-performance liquid chromatography method （HPLC） at the beginning, and at the end of 8 and 12 weeks. The analysis of rats cerebral vessels was performed with electron microscope at the end of 12 weeks. Results （1） After adding high concentrations of methionine feedstuff for 8 weeks, the levels of Hcy in group B （60.4±11.9） μmol/ L were significantly raised compared with group A（7.1±1. 4）μmol/L. Meanwhile, ADMA levels in group B（1.3±0. 4）μmol/L were higher than group A（0. 4±0.1） μmol/L ] At the end of 12 week, the levels of Hcy and ADMA were lower in groups C〈（49.9±11.4）μmol/L, （1.0±0.2）μmol/L3, D （（46.8±10.9）μmol/L,（0.9±0.1）μmol/L3, E[（44.3±11.4）μmol/L,（0.9±0.1）μmol/L3, F （16.3 ± 4.9 ）μmol/L, （0.7 ± 0.2 ）μmol/L3 compared with group B[（69.5 ± 11.4 ）μmol/L, （1.6 ± 0.5）μmol/L], but higher than group A[（6.7±1.3）μmol/L, （0.5±0.1）μmol/L]. The levels of Hcy and ADMA in group G[（8. 9±1. 9） μmol/L, （0.6±0.2） μmol/L）were also lower than those in group B （ P〈0. 053 , but they did not show statistically significant differences compared with group A（P〉 0. 05）. （2） According to correlative analysis, Hcy levels were positively correlated with ADMA levels （P〈0.05）. （3） On electron microscope, we observed that the cerebral artery and cerebral cortex of group B were seriously damaged. After the intervention with probucol, folic acid and vitamin B12, the structure of rats cerebral vessels were improved in group C,D,E,F and G as compared with group B, and group G were especially improved more obviously. Conclusions The HHcy and ADMA could damage the structure of rats cerebral vessels. Probucol, folic acid and vitamin B12 may alleviate the cerebral vascular damage by decreasing the levels of Hcy and ADMA, and the effect is more significant by the combined drug regimens of Probucol, folic acid and vitamin B12.