在蛛网膜下腔出血灵长类动物模型中，内皮型一氧化氮合酶的内源性抑制剂不对称二甲基-L-精氨酸的脑脊液水平与脑血管痉挛之间的关联。

Association between cerebrospinal fluid levels of asymmetric dimethyl-L-arginine, an endogenous inhibitor of endothelial nitric oxide synthase, and cerebral vasospasm in a primate model of subarachnoid hemorrhage.

作者信息

Jung Carla S, Iuliano Brian A, Harvey-White Judith, Espey Michael G, Oldfield Edward H, Pluta Ryszard M

机构信息

National Institute of Neurological Disorders and Stroke, and National Institute of Alcohol Abuse and Alcoholism; and National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.

出版信息

J Neurosurg. 2004 Nov;101(5):836-42. doi: 10.3171/jns.2004.101.5.0836.

DOI:10.3171/jns.2004.101.5.0836

PMID:15543672

Abstract

OBJECT

Decreased availability of nitric oxide (NO) has been proposed to evoke delayed cerebral vasospasm after sub-arachnoid hemorrhage (SAH). Asymmetric dimethyl-L-arginine (ADMA) inhibits endothelial NO synthase (eNOS) and, therefore, may be responsible for decreased NO availability in cases of cerebral vasospasm. The goal of this study was to determine whether ADMA levels are associated with cerebral vasospasm in a primate model of SAH.

METHODS

Twenty-two cynomolgus monkeys (six control animals and 16 with SAH) were used in this study. The levels of ADMA, L-arginine, L-citrulline, nitrites, and nitrates in cerebrospinal fluid (CSF) and serum were determined on Days 0, 7, 14, and 21 following onset of SAH. Cerebral arteriography was performed to assess the degree of vasospasm. Western blot analyses of the right and left middle cerebral arteries (MCAs) were performed to assess the expression of eNOS, type I protein-arginine methyl transferase (PRMT1) and dimethylarginine dimethylaminohydrolase (DDAH2). Cerebrospinal fluid levels of ADMA remained unchanged in the control group (six animals) and in animals with SAH that did not have vasospasm (five animals; p = 0.17), but the levels increased in animals with vasospasm (11 animals) on Day 7 post-SAH (p < 0.01) and decreased on Days 14 through 21 (p < 0.05). Cerebrospinal fluid levels of ADMA correlated directly with the degree of vasospasm (correlation coefficient = 0.7, p = 0.0001; 95% confidence interval: 0.43-0.83). Levels of nitrite and nitrate as well as those of L-citrulline in CSF were decreased in animals with vasospasm. Furthermore, DDAH2 expression was attenuated in the right spastic MCA on Day 7 post-SAH, whereas eNOS and PRMT1 expression remained unchanged.

CONCLUSIONS

Changes in the CSF levels of ADMA are associated with the development and resolution of vasospasm found on arteriograms after SAH. The results indicate that endogenous inhibition of eNOS by ADMA may be involved in the development of delayed cerebral vasospasm. Inhibition of ADMA production may provide a new therapeutic approach for cerebral vasospasm after SAH.

摘要

目的

有人提出一氧化氮（NO）可用性降低会引发蛛网膜下腔出血（SAH）后的迟发性脑血管痉挛。不对称二甲基-L-精氨酸（ADMA）会抑制内皮型一氧化氮合酶（eNOS），因此可能是脑血管痉挛时NO可用性降低的原因。本研究的目的是确定在SAH的灵长类动物模型中，ADMA水平是否与脑血管痉挛相关。

方法

本研究使用了22只食蟹猴（6只对照动物和16只患有SAH的动物）。在SAH发作后的第0、7、14和21天，测定脑脊液（CSF）和血清中ADMA、L-精氨酸、L-瓜氨酸、亚硝酸盐和硝酸盐的水平。进行脑血管造影以评估血管痉挛的程度。对左右大脑中动脉（MCA）进行蛋白质印迹分析，以评估eNOS、I型蛋白质精氨酸甲基转移酶（PRMT1）和二甲基精氨酸二甲胺水解酶（DDAH2）的表达。对照组（6只动物）和未发生血管痉挛的SAH动物（5只动物；p = 0.17）的脑脊液中ADMA水平保持不变，但发生血管痉挛的动物（11只动物）在SAH后第7天水平升高（p < 0.01），在第14至21天降低（p < 0.05）。脑脊液中ADMA水平与血管痉挛程度直接相关（相关系数 = 0.7，p = 0.0001；95%置信区间：0.43 - 0.83）。发生血管痉挛的动物脑脊液中亚硝酸盐、硝酸盐以及L-瓜氨酸水平降低。此外，SAH后第7天，右侧痉挛性MCA中DDAH2表达减弱，而eNOS和PRMT1表达保持不变。