Dorszewska Jolanta, Winczewska-Wiktor Anna, Sniezawska Aleksandra, Kaczmarek Izabela, Steinborn Barbara
Pracownia Neurobiologii Katedry Neurologii Uniwersytetu Medycznego im. Karola Marcinkowskiego, Poznań.
Przegl Lek. 2009;66(8):448-52.
Homocysteine (Hcy) is a thyol amino acid resulting from demethylation of methionine. It is metabolized through two pathways: remethylation and trassulfuration, which use as cofactors folate, vitamin B6 and vitamin B12. Hyperhomocysteinemia (hHcy) is a risk factor for cerebrovascular disease, dementia, inborn defects, impaired cognitive function. Several drugs may change metabolic pathways of Hcy, leading to an alteration of plasma Hcy levels. HHcy has been documented in epileptic patients after chronic treatment with antiepileptic drugs (carbamazepine, valproate). HHcy may lead to increase of the level of asymmetric dimethylarginine (ADMA). ADMA has been identified as a potential risk factor for cardiovascular disease and endothelial dysfunction. ADMA is a product of methylation of L-arginine and endogenous nitric oxide (NO) synthase inhibitor, and regulator of NO production. NO plays a role in the convulsant effect. Supplementation of B vitamins, folate and L-arginine is a strategy to reduce Hcy levels in patients with epilepsy treatment antiepileptic drugs.
同型半胱氨酸（Hcy）是一种由甲硫氨酸去甲基化产生的含硫氨基酸。它通过两条途径代谢：再甲基化和转硫化，这两条途径将叶酸、维生素B6和维生素B12用作辅助因子。高同型半胱氨酸血症（hHcy）是脑血管疾病、痴呆、先天性缺陷、认知功能受损的一个危险因素。几种药物可能会改变Hcy的代谢途径，导致血浆Hcy水平改变。在癫痫患者长期使用抗癫痫药物（卡马西平、丙戊酸盐）治疗后已证实存在hHcy。hHcy可能导致不对称二甲基精氨酸（ADMA）水平升高。ADMA已被确定为心血管疾病和内皮功能障碍的一个潜在危险因素。ADMA是L-精氨酸甲基化的产物，是内源性一氧化氮（NO）合酶抑制剂，也是NO生成的调节剂。NO在惊厥作用中起作用。补充B族维生素、叶酸和L-精氨酸是降低癫痫患者使用抗癫痫药物治疗时Hcy水平的一种策略。
