丹参酮ⅡA对脑缺血再灌注损伤大鼠脑组织及血清中NO含量及NO

1、丹参酮A对脑缺血再灌注损伤大鼠脑组织及血清中NO含量及NOS、iNOS活性的影响 11-05-06 15:14:00 作者：李浩,刘开祥,俸军林编辑：studa20【摘要】 目的 观察丹参酮A(Tan A)对脑缺血再灌注损伤大鼠脑组织及血清中一氧化氮(NO)含量、一氧化氮合酶(NOS)及诱导型一氧化氮合酶(iNOS)活性的影响,探讨其对脑缺血再灌注损伤保护作用的可能机制。方法 将大鼠随机分为假手术组、缺血再灌注组、Tan A低、高剂量组,线栓法建立局灶性脑缺血再灌注模型。Tan A高、低剂量组于术前连续灌胃给予高、低剂量Tan A 3 d,每日1次。各组于脑缺血90 min再灌注24 h后进行

2、HE染色,观察病理形态学变化,检测脑组织和血清中NO含量和NOS、iNOS活性的变化。结果 Tan A高、低剂量组脑组织缺血损伤病理学改变明显轻于缺血再灌注组,Tan A高剂量组缺血改变亦轻于低剂量组。与假手术组比较,缺血再灌注组脑组织和血清中NO含量和NOS、iNOS活性明显升高；与缺血再灌注组比较,Tan A高、低剂量组脑组织和血清中NO含量和NOS、iNOS活性均明显降低,高、低剂量组之间差异具有统计学意义(P0.05)。结论 Tan A可减轻神经元损伤程度,对缺血再灌注脑损伤具有保护作用,其机制可能与降低NOS、iNOS活性,减少NO含量有关。 【关键词】 缺血再灌注损伤；一氧化氮；一

3、氧化氮合酶；诱导型一氧化氮合酶；丹参酮A；大鼠 Abstract：Objective To study effect of Tanshinone A (Tan A) on the content of NO and the activities of NOS and iNOS in cerebral ischemia reperfusion (I/R) injury rats, and explore its protective mechanism. Methods Rats were randomly divided into 4 groups, which were sham opera

4、ted group, I/R group, low dose Tan A treated group and high dose Tan A treated group. The focal middle cerebral arterymocclusion (MCAO) model was made by suture-occluded method. Rats were pretreated with Tan A, ig for 3 d before MCAO. After 90 min MCAO following 24 h of reperfusion, pathomorphologic

5、 changes was investigated with HE staining. The content of NO and the activities of NOS and iNOS was also determined. Result The change of ischemic impairment in low or high dose Tan A treated group was lighter than that of I/R group, and high dose Tan A treated group was lighter than that of low do

6、se Tan A treated group. Compared with sham operated group, the content of NO and the activities of NOS and iNOS increased at 24 h of reperfusion in the ischemic territory (P0.05). Compared with I/R group, low and high dose Tan A treated group reduced the content of NO and the activities of NOS and i

7、NOS dose-dependently (P0.05). Conclusion Tan A has protective effect on cerebral I/R injury by reducing the content of NO and the activities of NOS and iNOS dose-dependently. Key words：ischemiareperfusion injury；NO；NOS；iNOS；Tanshinone A；rat 一氧化氮(NO)是机体内重要的信使分子和效应分子,为神经传递、血管舒张、调节神经功能的内源性介质,与神经系统的生理和病

8、理过程关系密切1,而一氧化氮合酶(NOS)是NO生物合成的限速酶。丹参为唇形科鼠尾草属植物,具有活血化瘀、宁心安神等功效,目前在缺血性脑血管病的治疗中广为应用。有研究发现,丹参能下调缺血所致的NOS表达,使NO合成减少,减轻缺血性脑损伤2。本实验采用大鼠局灶性脑缺血再灌注模型,研究丹参酮A(Tanshinone A,Tan A)对大鼠脑缺血再灌注损伤脑组织和血清中NO含量和NOS、诱导型一氧化氮合酶(iNOS)活性变化的影响,探讨其保护作用的可能分子生物学机制。1 材料与方法1.1 动物 健康Wistar大鼠,雄性,清洁级,共40只,体质量(25030) g,广西医科大学动物实验中心提供。1.

9、2 分组及给药 将大鼠随机分为假手术组、缺血再灌注组、Tan A低剂量组及Tan A高剂量组,每组10只。TanA低剂量组(15 mg/kg)和高剂量组(30 mg/kg)均于术前连续灌胃给药3 d,每日1次,假手术组和缺血再灌注组给予等量的生理盐水灌胃。第3 日给药后1 h建立局灶性脑缺血90 min再灌注24 h动物模型。1.3 造模 参照文献3方法制备大鼠局灶性脑缺血再灌注模型。采用颈外动脉插入线栓法,各组均进行左侧大脑中动脉栓塞。采用石蜡线栓,直径约0.27 mm,插入深度约18 mm,此时线栓头位于大脑中动脉起始部。缺血90 min时,抽提线栓实现再灌注。神经功能缺陷评分按照Longa等3评分标准,分数在13分为模型成功。1.4 HE染色病理形态学观察 再灌注24 h,各组随机取5只大鼠,用生理盐水和多聚甲醛进行心脏灌流固定,断头取脑。在左侧大脑半球距离嗅球尖端711 mm之间冠状切取约5 mm厚脑组织块,固定、脱水、包埋成腊块,连续切片,厚5 m。连取5张作HE染色,观察病理形态学改变。1.5 指标检测 再灌注24 h,大鼠均内眦取血,置于干燥试管中,离心,然后将上清液置于干净EP管中,低温保存,用于测定NO、NOS和iNOS。取血完毕后立即将各组大鼠断头取脑,冰盘上快速取一侧大脑皮层,用冰冷生理盐水冲洗掉血液