天麻酚类成分对脑缺血模型大鼠海马一氧化氮和一氧化氮合酶的影响

摘要

目的 探讨天麻酚类成分对脑缺血大鼠海马NO和一氧化氮合酶(NOS)的影响.方法 采用双侧颈总动脉永久性结扎法,造成大鼠脑缺血模型.造模6周后,SD大鼠40只随机分为5组,假手术组、模型组、尼莫地平组、天麻酚类成分高剂量组(高剂量组)和天麻酚类成分低剂量组(低剂量组),每组8只.给药3周后,比色法检测海马NO含量和NOS活性,免疫印记法检测大鼠海马NOS 3种亚型(nNOS,iNOS,eNOS)的表达.结果 与假手术组比较,模型组大鼠海马NO含量、NOS活性及nNOS和iNOS表达明显升高,eNOS表达明显降低;与模型组比较,尼莫地平组和高剂量组大鼠海马NO含量、NOS活性及nNOS和iNOS表达明显降低,eNOS表达明显升高;低剂量组大鼠NOS活性和iNOOS表达明显降低,差异有统计学意义(P＜0.05,P＜0.01).结论 天麻酚类成分对脑缺血大鼠海马NO损伤有保护作用.%Objective To investigate the effects of phenolic components of Gastrodia elata Blume (PG) on nitric oxide and nitric oxide synthase in hippocampus of rats with cerebral ischemia. Methods The experimental cerebral ischemia model was established by chronic cerebral hypoperfusion induced by permanent occlusion of bilateral carotid arteries. After six weeks,the rats were randomly divided into five groups:sham operation group,model group,nimodipine group,phenolic components of Gastrodia elata high-dose group and the phenolic components low dose group, n = eight. After three weeks,the content of NO and activity of NOS in hippocampus were determined by colorimetric method. The expression of three subtypes of NOS in hippocampus was determined by Western blot. Results Compared with the sham group,the content of NO,activity of NOS,the expression of nNOS and iNOS in hippocampus was increased, the expression of eNOS was decreased in the model group. Compared with the model group,the content of NO,activity of NOS, the expression of nNOS and iNOS in hippocampus decreased,the expression of eNOS increased in the high-dose and nimodipine groups. The activity of NOS and expression of iNOS in hippocampus decreased in the low-dose group, the difference was statistically significant (P<0. 05 ,P< 0. 01). Conclusions The results suggest that PG can protect against the NO damage in hippocampus of the cerebral ischemic rats.