成年大鼠持续性脑缺血后TGFβ_1蛋白表达与凋亡的关系

The relationship between the expression of TGFβ_1 protein and neuron apoptosis in adult rats following permanent middle cerebral artery occlusion

目的 :观察成年大鼠持续性局灶脑缺血后 TGFβ1 蛋白表达与缺血后凋亡的关系。方法 :单侧大脑中动脉近端电凝术建立大鼠持续性局灶脑缺血模型。缺血后 1h,实验组经尾静脉注射氟美松 (5 mg/ kg) ,对照组注射相同容积的生理盐水。缺血后 3h～ 12 0 h取材 ,分别用免疫组织化学 SP法和原位末端标记 TUNEL法标记 TGFβ1 蛋白表达细胞和凋亡细胞。结果 :持续性局灶脑缺血后 TGFβ1 蛋白呈双相性 ,主要分布在梗塞灶周围区域。TGFβ1 的表达可被氟美松抑制 ,同时缺血后神经细胞凋亡也加重。结论 :大鼠持续性局灶脑缺血后梗塞灶周围区域 TGFβ1 蛋白表达可能有减轻缺血后神经细胞凋亡的作用。

Objective:To observe the change of TGFβ 1 protein and the relationship between the expression of TGFβ 1 protein and neuron apoptosis in adult rats following permanent middle cerebral artery occlusion. Methods: The rat model of focal cerebral ischemia was established by permanent middle cerebral occlusion. One hour after ischemia, the experiental groups were treated with dexamethasone(5mg/kg) while the control groups were treated with saline. Immunohistochemistry and Tunel methods were used to show the expression of TGFβ 1 protein and apoptosis. Results: The expression time course of TGFβ 1 protein was two phase. The first peak of expression was at 6h; the second was from 24h to 72h. The TUNEL positive apoptotic cells were present from 24h to 5d, localizing at the border zone of infarct. The significant decrease in expression of TGFβ 1 protein and significant increase of the number of TUNEL positive apoptotic cells in rats treated with dexamethasone was observed compared with that of control group. Conclusion: TGFβ 1 protein may antagonize the neuron apoptosis after permanent focal cerebral ischmia