【摘要】 目的　探讨L 精氨酸 (L Arg)对蛛网膜下腔出血 (SAH)后内皮素 1(ET 1)的影响。 方法　应用脑底动脉环血管内穿刺法建立大鼠SAH模型 ,将动物随机分为假手术组 (SO组 )、SAH组和SAH +L Arg组。动态检测 2 4h内大脑顶叶皮层局部脑血流量 (rCBF) ,测定不同时间点血清NO(NO-2 /NO-3 )水平和血浆及脑组织ET 1含量。结果　假手术对rCBF ,NO ,ET 1无显著影响。SAH组术后rCBF迅速降低 ,1h达最低值 ,持续 2 4h ;在术后 1～ 2 4h ,血清NO水平较SO组为低 ;血浆和脑组织ET 1水平均显著高于SO组。与SAH组比较 ,SAH +L Arg组rCBF下降的速度减慢、程度减轻 ;血清NO水平下降的幅度减小 ,血浆和脑组织ET 1增加的程度减轻。结论　L Arg通过增加NO产生、抑制ET 1生成而减轻SAH后继发性脑缺血更多还原

【Abstract】 OBJECTIVETo investigate the effect of extraneous L-arginine on endothelin-1 levels in plasma and brain tissue following sub arachnoid hemorrhage (SAH).METHODSNoncraniotomy models of S AH using endovascular perforating method in Wistar rats were used and the animal s were divided into sham-operated group,SAH group and SAH+L-arginine group.The dynamic changes of regional cerebral blood flow (rCBF) within 24 hours were mea sured using a laser Doppler flowmeter (LDF) probe.The levels of NO (nitrite/nitr ate) in serum and levels of endothelin-1 both in plasma and in brain tissue at different time within 24 hours were also determined by an activated cadmium redu ction method and a radioimmunoassay respectively.RESULTSSha m operation had no obvious effect on rCBF,nitric oxide and endothelin-1.In SAH group,rCBFs reduced immediately after induction of SAH,reaching their nadir at 1 h,persisting within 24 h,as compared with sham operated group.The serum NO leve ls were decreased significantly from 1h to 24 h after operation.Both plasma and brain endothelin-1 levels were increased statistically from 1 h to 24 h after S AH.Above pathological alterations in SAH+L-arginine group were less obvious than those in SAH group.CONCLUSIONL-arginine elevated nitric oxide levels in serum and decreased endothelin-1 levels in both plasma and brain tissue,and thus may have a protective effect on secondary cerebral isc hemia following SAH.更多还原