摘要
目的观察非选择性一氧化氮合酶抑制剂L-硝基精氨酸（L-NA）对大鼠局灶性脑缺血诱导的神经元凋亡的影响，探讨L-NA对脑缺血的保护作用及其机制。方法健康雄性SD大鼠，体重250—300g，随机分为假手术组（SH组）、缺血组（IS组）、L-NA治疗组（L-NA组）。IS和L-NA组按缺血后时间分为三个亚组：2h、6h、12h。每组6只大鼠。LNA组每次按20mg／kg，ip给药，每日2次，连续3d。IS组给等容量的生理盐水。插线法制备大鼠大脑中动脉阻断模型。采用流式细胞仪（FCM）检测脑组织细胞凋亡率，Westem blot法和免疫组化法检测Caspase-3蛋白的表达，FCM和免疫组化法检测Bcl-2和Bax蛋白的表达。结果大鼠脑缺血后，细胞凋亡率、Caslmse-3和Bax蛋白表达明显升高，Bcl-2蛋白表达差异无显著性，Bcl-2／Bax降低，缺血12h治疗3d时。L-NA组中细胞凋亡率、Caspase-3和Bax蛋白表达显著低于相应的IS组．Bcl-2蛋白表达、Bcl-2／Bax高于IS组，缺血2、6h治疗3dL-NA组中细胞凋亡率、Caspase-3 、Bcl-2、Bax蛋白表达和Bcl-2／Bax与IS组比，差异无显著性。结论缺血后期应用L-NA对脑缺血有治疗作用，可能与降低Capase-3、增加Bcl-2表达、降低Bax蛋白表达、调节Bcl-2／Bax蛋白平衡有关。
Objective By evaluating the effect of NG-nitro-L-arginine （L-NA） on neuronal apoptosis induced by transient focal cerebral ischemia in rats, to investigate the effect of L-NA on cerebral ischemic injury and the possible mechanism. Methods Male SD mrs （weighing 250- 290 g） were randomly divided into 3 groups：sham operation group （SH）, ischemie group （IS） and L-NA group （ L-NA）. IS and L-NA group were timber divided into 3 subgroups （ n = 6 each） according to the duration of ischemia 2 h, 6 or 12 h. In L-NA group, L-NA （20 mg/kg, ip） was administrated, twice a day, for 3 consecutive days. Saline was administrated in IS group. The focal cerebral ischemic model （MCAO） with thread embolism of left middle cerebral artery was made. In sham operation group, the external carotid artery was surgically prepared for insertion of the filament, but the filament was not inserted. Rats were killed at the scheduled time. Apoptosis was detected by FCM. The expression of Caspase-3 protein was observed by Western blot and immunohistochemistry. The expression of Bcl-2 and Bax protein was measured by immunohistocbemistry and FCM. Results After MCAO, the apoptotic rate of cells, the expression of Caspase-3 and Bax protein was increased significantly.The ratio of Bcl-2/Bax was decreased. The differenee of Bcl-2 protein was not significant. In L-NA 12 h group, the percentage of apoptotie cells,the expression of Caspase-3 and Bax protein was decreased.The expression of Bcl-2 and the ratio of Bcl-2/Bax was increased. There was no significant difference in the percentage of apoptotie cells, the expression of Caspase-3, Bax, Bcl-2 protein and Bcl-2/Bax between L-NA 2,6 h group and IS group. Conclusion L- NA has beneficial effect on ischemie rat brain at ischemie later stage. The possible protective mechanism is that administration of L-NA could reduce the expression of Caspase-3 and Bax, protein, increase the expression of Bcl-2 protein, and regulate the balance between Bcl-2 and Bax protein.
出处
《河北医药》
CAS
2006年第3期163-165,共3页
Hebei Medical Journal
基金
河北省自然科学基金资助课题
No.C2005000840
