丹参对大鼠持续局灶性脑缺血后神经元 cyclin G1 蛋白表达的影响

目的:观察大鼠局灶性脑缺血后神经元内细胞周期蛋白G1(cyclin G1)的蛋白表达与神经细胞凋亡的关系以及丹参对其的影响.方法:采用线栓法大鼠大脑中动脉持续栓塞模型,应用免疫组化和TUNEL染色方法观察缺血组、丹参组和对照组神经元阳性细胞染色数量和分布情况.结果:缺血组cyclin G1蛋白自缺血后1h开始表达增加,缺血后3h达高峰,72h恢复至对照组水平;凋亡细胞自缺血后12h开始表达,缺血后72h达高峰.丹参组仅在缺血12h时间点cyclin G1蛋白表达较缺血组明显增加(P＜0.01);凋亡细胞在缺血后12,24和48h均减少(P＜0.05),缺血后72h明显减少(P＜0.01).相邻切片可见cyclin G1蛋白表达和凋亡细胞染色区域基本相同.结论:cyclin G1蛋白在缺血后神经元内表达增加与缺血性神经细胞的凋亡无关,而可能与缺血神经细胞的自我保护适应性和损伤修复有关;丹参可能通过增加cyclin G1的表达,增加神经细胞的缺血损伤适应性,从另一方面发挥其神经细胞的保护作用.

Effects of radix salviae miltiorhizae (RMS) on the expression of cyclin G1 protein in rats with induced focal cerebral ischemia

Objective:To investigate the effects of RMS on expression of cyclin G1 and neuronal apoptosis in different intervals following permanent focal cerebral ischemia in rats. Methods: A rat' s model of MACO (middle cerebral artery ischemia) was created with intraluminal filament occlusion. Immunohistochemstry and tunnel staining technique were sued to observe the quantity and distribution of cyclin Gl protein and neuronal apoptosis in brain tissues in ischemic, RMS and sham operation groups. Results; In ischemic group, the level of cyclin Gl protein started to increase 1h after ischemia, reached to peak level 3h after ischemia,and returned to the level of sham operation group 72h after ischemia; the neuronal apoptosis started to express 12 h after ischemia and reached to peak 72h after ischemia. In RMS group, the expression of cyclin Gl protein significantly increased compared with is-chemic group only at 12h time point after ischemia (P<0. 01); neuronal apoptosis decreased 12,24, and 48h after ischemia,and significantly decreased 72h after ischemia (P <0.01). Conclusion:There was no relationship between increased expression of cyclin Gl protein and neural apoptosis after ischemia , perhaps related to an adoptive response to cellular stress induced by focal cerebral ischemia and the repairing mechanism of ischemic neural cells. RMS could protect the ischemic neurons via up-regulating the expression of cyclin Gl protein.