外源性L-精氨酸对大鼠脑血管痉挛的影响

Effect of extrinsic L-arginine on cerebral vasospasm in rats

目的:探讨L-精氨酸(L-Arg)对蛛网膜下腔出血(SAH)所致脑血管痉挛(CVS)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,将动物分为假手术组(SO组)、SAH组和SAH+L-Arg组。动态检测24h内顶叶皮层局部脑血流量(rCBF),测量基底动脉(BA)管径,并测定不同时点脑组织内皮素-1(ET-1)含量。结果:假手术组对各项指标无显著影响。SAH组术后 rCBF迅速降低,并持续24h;SAH后BA管径明显缩小;脑组织ET-1含量逐渐增加。与SAH组比较,SAH+L-Arg组rCBF下降的速度减慢、程度减轻,BA管径缩小的程度减轻,脑组织ET-1含量增加的幅度减小。结论:L-Arg通过增加NO产生、抑制ET-1生成而缓解SAH后CVS。

OBJECTIVE To investigate the effect of extrinsic L-arginine on cerebral vasospasm (CVS) following subarachnoid hemorrhage (SAH). METHODS SAH models of Wistar rats by endovascular piercing method were used and animals were divided into sham-operated group, SAH group and SAH + L-arginine group. Dynamic changes of regional cerebral blood flow (rCBF) within 24 hours were detected. Diameters of basilar artery (BA) were measured. Endothelin-1 content in brain tissue at different time points within 24 hours were also detected. RESULTS Sham operation did not alter above parameters. However, in SAH group, rCBF reduced immediately after induction of SAH, persisting at low level within 24 h. Diameter of BA significantly decreased 30 min after induction of SAH. Brain endothelin-1 content increased statistically after SAH. Above pathological alterations in SAH+ L-arginine group were less obvious than those in SAH group. CONCLUSIONS L-arginine, that probably enhancing endothelial nitric oxide level and thus decreasing endothelin-1 level,may reverse CVS following SAH.