论文部分内容阅读
目的探讨异丙酚对大鼠局灶性脑缺血-再灌注损伤后神经型一氧化氮合酶(nNOS)表达的影响及其可能的脑保护机制。方法78只雄性Wistar大鼠随机分为3组:假手术组(S组,n =6);缺血-再灌注组(I-R组,n=36);异丙酚干预组(P组,n=36)。I-R组和P组按不同再灌注时间又随机分为三个亚组:1 h亚组、3 h亚组、6 h亚组(n=12)。采用右侧大脑中动脉线栓法(MCAO)建立大鼠局灶性脑缺血-再灌注模型。S组行假手术操作,但不行线栓法阻断血流及药物干预;I-R组于缺血2 h后再灌注时即刻右侧侧脑室注射生理盐水(1 mg/kg);P组于缺血2 h后再灌注时即刻右侧侧脑室注射1%异丙酚(1 mg/kg)。所有大鼠于再灌注前进行神经学功能评分;分别于各再灌注时间点断头取脑组织,TTC染色法测定脑梗死灶(n=6);苏木精-伊红(HE)染色观察脑组织病理学变化(n=6);免疫组织化学方法测定nNOS蛋白表达(n=6)。结果与I-R组比较,P组神经学功能评分降低(P<0.05)。在I-R组内,与1h亚组比较,3 h亚组和6 h亚组脑梗死灶明显增大(P<0.05);P组3 h亚组、6 h亚组与I-R组同时间亚组比较,脑梗死灶减小( P<0.05)。S组神经细胞结构完整;I-R组神经细胞结构破坏,有核分裂及核溶解;与I-R组比较,P组脑组织病理学改变减轻。S组仅有少量nNOS蛋白表达;在I-R组内,nNOS蛋白在1h亚组表达升高,在3 h亚组表达到高峰,6 h亚组与3 h亚组比较表达降低(P<0.05);P组3 h亚组、6 h亚组与I-R组同时间亚组比较,nNOS蛋白表达减少(P<0.05)。结论异丙酚抑制大鼠局灶性脑缺血-再灌注后nNOS蛋白的表达,可能是其脑保护作用机制之一。
Objective To investigate the effect of propofol on the expression of neuronal nitric oxide synthase (nNOS) after focal cerebral ischemia-reperfusion injury in rats and its possible mechanism of brain protection. Methods 78 male Wistar rats were randomly divided into 3 groups: sham operation group (n = 6 in S group); ischemia-reperfusion group (n = 36 in IR group) = 36). Group I-R and group P were randomly divided into three subgroups according to different reperfusion time: 1 h subgroup, 3 h subgroup and 6 h subgroup (n = 12). A rat model of focal cerebral ischemia - reperfusion was established by right middle cerebral artery occlusion (MCAO). Group S was sham-operated, but the blood flow and drug intervention were not blocked by thread occlusion. The rats in IR group were injected normal saline (1 mg / kg) right ventricle immediately after reperfusion 2 h after ischemia; Immediately after reperfusion at 2 h after blood injection, 1% propofol (1 mg / kg) was injected into the right lateral ventricle. All rats were scored for neurological function before reperfusion. Brain tissue was decapitated at each time point of reperfusion, cerebral infarction was detected by TTC staining (n = 6), hematoxylin and eosin (HE) staining The histopathological changes (n = 6) and the expression of nNOS protein were detected by immunohistochemistry (n = 6). Results Compared with I-R group, neurological score of P group decreased (P <0.05). In the IR group, compared with the 1-hour subgroup, the cerebral infarction size in the 3-h and 6-h subgroups was significantly increased (P <0.05) In comparison, cerebral infarction was decreased (P <0.05). S group neuronal structure integrity; I-R group nerve cell structure destruction, mitosis and nucleolysis; compared with the I-R group, P group of brain tissue pathological changes reduced. Only a small amount of nNOS protein was expressed in S group. In IR group, the expression of nNOS protein increased in 1h subgroup and peaked in 3h subgroup, and decreased in 6h subgroup and 3h subgroup (P <0.05) (P <0.05). Compared with IR group, the expression of nNOS protein in 3 h, 6 h, P group decreased significantly (P <0.05). Conclusion Propofol inhibits the expression of nNOS protein after focal cerebral ischemia-reperfusion in rats and may be one of the mechanisms of its neuroprotection.