杞贞胶囊对视网膜神经节细胞保护作用及其作用机制的实验研究

Neuroprotective effects and its mechanism of Qizhen on retinal ganglion cells in rat optic nerve crush model

目的探索杞贞胶囊对大鼠视神经夹伤模型视网膜神经节细胞的保护作用及其作用机制。设计实验研究。研究对象SPF级SD大鼠72只。方法 72只SD大鼠随机分为2组:用药组36只;对照组36只。两组大鼠右眼行视神经夹伤,于球后2mm处用40 g微型视神经夹夹伤视神经60 s。左眼作为正常对照。夹伤后2小时及此后每日予以灌胃给药一次。用药组给予20%杞贞溶液2.5 ml/kg,对照组给予生理盐水2.5 ml/kg。给药第28天取眼球标本,用药组和对照组各取24只行HE染色﹑Tunel试剂盒染色﹑Caspase-3免疫组化染色;剩余每组12只分离视网膜提取m RNA,测定Bax和Bcl-2基因的表达量。主要指标视网膜厚度﹑Bax和Bcl-2基因表达量。结果用药组视网膜厚度平均为(109.0±4.4)μm;对照组视网膜厚度为(101.8±7.6)μm(F=29.497,P=0.028)。两组间Bax基因表达差异具有统计学意义(t=1.089,P=0.028);Bcl-2基因表达差异未见统计学意义(t=0.553,P=0.692)。结论杞贞胶囊对大鼠视神经夹伤后的视网膜神经节细胞具有保护作用,可能通过下调Bax基因表达和抑制Caspase蛋白活性从而减少视网膜神经节细胞凋亡。

Objective To investigate the protective effect and its mechanism of Qizhen capsule on the retinal ganglion cell （RGCs） of the rat optic nerve crush model. Design Experimental study. Participants 72 healthy adult male SD rats. Methods The 72 rats were divided randomly into two groups： treatment group （36 rats） and control group （36 rats）. All the right eyes were selected as the experimental eyes, using a micro optic nerve forceps with the clipping pressure of 40 g to crush the exposed optic nerve for 60 s at 2 mm from the optic disc. The left eyes served as normal controls. The rats were given drug by gastric perfusion 2 h after the crushing, and then once daily. The rats of treatment group were given 20% Qizhen solution with a dose of 2.5 ml/kg; control group rats were given saline with same does for consecutive four weeks. At the 28 days after injury, the rats were sacrificed, HE staining, the expression of Caspase-3 protein and Tunel were detected with 24 rats of each group. The rest 12 rats each group were used to detect the expression of Box and Bcl-2. Main Outcome Measures The thickness of retina, the expression of Box and Bcl-2. Results The average thickness of retina in Qizhen treatment group was （109.0±4.4） μm, and （101.8±7.6） μm in the control group （P=0.028）. The difference of the expression of Bax was significant （t=1.089,P=0.028）, but there was no significant difference of Bcl-2 （t=O.553,P=0.692） between the two groups. Conclusion Qizhen plays a protective role for RGCs in rat optic nerve crush model, decreasing the apoptosis of RGCs may through reducing the expression of Bax and Caspase-3.