神经节苷脂治疗新生大鼠缺血缺氧性脑损伤的研究

Effect of Gangliosides in the Treatment of Hypoxic Ischemic Brain Damage in Neonatal Rats

摘要:

目的：观察神经节苷脂(GM1)对缺氧缺血(HI)新生大鼠的治疗作用及对凋亡相关基因Bax/Bcl-2表达的影响。方法：应用生后第7天的SD大鼠，制备缺血缺氧性脑病(HIE)模型。用TUNEL法检测细胞凋亡，用免疫组织化学SABC法检测Bax/Bcl-2的表达。结果：新生大鼠HI后脑细胞存在凋亡。GM1治疗能减少细胞凋亡。治疗组皮质凋亡细胞数为55.75±6.71，较HI组75.25±4.94下降(P<0.01)；治疗组海马凋亡细胞数较对照组也有下降(47.25±6.6 vs 32.14±4.88)，P<0.01。各组Bax和Bcl-2表达皆为阳性，但在HI对照组，Bax表达更强，而Bcl-2表达较弱。结论：应用GM1治疗HI脑损伤可减少脑细胞凋亡，GM1治疗对凋亡相关基因Bax/Bcl-2表达有一定的影响，HI脑损伤后细胞凋亡可能与这两种基因相关。

Abstract:

OBJECTIVE: To observe the effect of gangliosides (GM1) on the apoptosis and expression of Bax and Bcl-2, two genes involved in apoptosis. METHODS: An HIE model was produced in 7day old SpragueDawley (SD) rats by unilateral carotid artery ligation followed by hypoxic insult (8% oxygen) for 2.5 hours. Six of these HIE rats were treated promptly with GM1 (30 mg/kg daily for 3 days) and 6 were not given any treatment as the controls. Apoptosis was examined using terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labelling (TUNEL) staining and the expression of Bax and Bcl-2 was detected by the immunohistochemical streptoavidinbiotinperoxidase complex (SABC) method in all neonatal rats. RESULTS: Apoptosis was noted in the cerebral neurons of the neonatal rats after HI injuries. Apoptosis secondary to HI could be eliminated with prompt treatment with GM1 after the HI insult. The number of apoptotic cells in the cortex and hippocampus decreased from 75.25±4.94 and 47.25±6.6 to 55.75±6.71 and 32.14±4.88 respectively (P<0.01). Bax and Bcl-2 were expressed in all neonatal rats. Bax was expressed to a greater extent and Bcl-2 to a lesser extent in HIE neonatal rats compared with neonatal rats with prompt treatment with GM1(P<0.05). CONCLUSIONS: Prompt treatment with GM1 after HI injuries in neonatal rats results in decreased neuronal apoptosis. GM1 could partly affect the expression of Bax and Bcl-2. The results suggest that neonatal neuronal apoptosis after HI injuries may be related to changes in the expression of these two genes.