脑白质缺血性损伤与维生素B_(12)

Ischemic lesion of cerebral white matter and vitamin B_(12)

目的:一些研究已证实维生素B12对脑缺血后少突胶质细胞、髓鞘及髓鞘碱性蛋白的损伤有促进修复的作用。脑白质的缺血性损伤可导致痴呆和缺血性脑血管病,探讨给予维生素B12治疗后临床症状好转的效应途径。资料来源:应用计算机检索中国期刊全文数据库1994-01/2004-10与脑白质缺血性损伤相关文献,检索词“维生素B12,脑缺血,脑白质”,并限定文献为中文;同时检索ElsevierScience1995-01/2004-10与脑白质缺血性损伤相关文献,检索词“vitaminB12,cerebralischemia,whitematterleision”,并限定文献语种为English。资料选择:就检索到的500余篇文献进行筛选,选择以脑白质、维生素B12为主要研究内容的文献70多篇,其中研究内容相似的,以近5年且发表在较权威杂志者优先。资料提炼:将筛选到的21篇按维生素B12与少突胶质细胞、髓鞘及髓鞘碱性蛋白的关系,维生素B12与痴呆和缺血性脑血管病的关系分类:其中9篇与少突胶质细胞、髓鞘及髓鞘碱性蛋白相关,12篇与痴呆和缺血性脑血管病相关。资料综合:21篇文献共包括720只动物,550例患者,分别对维生素B12的治疗作用及作用机制予以评价。①在中枢神经系统内起作用的维生素B12主要是甲基维生素B12和腺苷维生素B12。甲基维生素B12是中枢神经系统内很多甲基化反应的惟一甲基提供者,是S-腺苷甲硫氨酸合成所必须的辅助因子,髓鞘碱性蛋白的甲基化对髓鞘结构的稳定性和致密性非常重要。②脑缺血后少突胶质细胞的缺血性损伤可使髓鞘碱性蛋白的甲基化发生障碍,甲基维生素B12用于治疗脑白质缺血性损伤与其促进髓鞘形成、降低血中同型半胱氨酸水平密切相关。结论:维生素B12参与了髓鞘形成过程,在中枢神经系统白质损伤的恢复以及脑缺血后痴呆和锥体系病变的恢复方面显示了良好疗效。

OBJECTIVE： Some study has confirmed that vitamin B12 can make renovation on oligodendroeyte, myelin and myelin basic protein. Dementia and ischemia cerebral vessels disease can be induced by ischemia injury of brain white matter. Study is done to discuss the feasibility of using vitamin B12. DATA SOURCES： Using the terms vitamin B12, cerebral ischemia, cerebral white matter, we searched the China Journal Full-text Database （CJFD） with language limited to Chinese from January 1994 to October 2004 by computer. Meanwhile, the related docUments were searched in Elsevier Science using the terms vitamin B12, cerebral ischemia, and cerebral white matter from January 1994 to October 2004 with language limited to English. STUDY SELECTION： More than 70 documents studied on cerebral white matter and vitamine B12 were selected from the searched 500 documents. Among similar documents the articles published in the latest five years and the more authoritative articles were included. DATA EXTRACTION： The 21 selected documents were classified according to the relation of vitamin B12 and oligodendrocyte, myelin and myelin basic protein, the relation of vitamin B12, dementia, and ischemia cerebro-vascular disease, including 9 related to the vitamin B12 and oligodendrocyte, myelin and myelin basic protein, 11 related to the vitamin B12 and dementia, cerebral vascular diseases. DATA SYNTHESIS： Totally 21 articles were selected including 720 rats, 550 patients,in which, the treatment and mechanism of vitamin B12 were evaluated. ① Methyl vitamin B12 and adenosine vitamin B12 played an important role in central nervous system. Methyl vitamin B12 was the only methyl provider in methylation response in central nervous system, assistant factor of s-adenosine methionine synthesis. Methylation of myelin sheath alkali protein had stability on myelin sheath structure. ② Ischemia injury of oligodendrocyte could make obstacle on methylation of myelin sheath alkali protein after cerebral ischemia. Methyl vitamin B12 had a close correlation with the treatment of the injury of cerebral white matter, and the formation of myelinization and reduction of homocysteine. CONCLUSION： Vitamin B12 takes part in the process of myelinization, and plays an important role in the recovery of white matter injury, dementia induced by cerebral ischemia and cone architecture lesion.