Caspase-3抑制剂z-DEVD-fmk治疗兔外伤性视神经损伤的研究

目的 观察半胱氨酸天冬氨酸蛋白酶3(Caspase-3)抑制剂z-DEVD-fmk对兔外伤性视神经损伤的治疗效果.方法 实验研究.选取2～3月龄中国白兔52只(104只眼),4只(8只眼)作为空白对照,48只(96只眼)应用液压冲击颅脑损伤仪建立兔外伤性视神经损伤模型,左眼玻璃体腔注射2%二甲基亚砜5μl为对照组(A组);右眼玻璃体腔注射Capase-3抑制剂z-DEVD-fmk 5μl为实验组(B组).给药后1 d、4 d、7 d、10 d、14 d、21 d行闪光视觉诱发电位(F-VEP),视网膜病理学检查,并应用免疫组织化学方法检测视网膜中Caspase-3表达.所得数据采用t检验、单因素方差分析、q检验及直线相关分析进行统计学处理.结果 给药后7 d,实验组的F-VEP P1波潜伏(90.50±7.61)ms与对照组(113.59±12.92)ms相比缩短(t=4.060,P＜0.05),视网膜神经节细胞计数实验组(237.62±8.50)较对照组(207.03±11.04)有所增多(t=-5.843,P＜0.05),均可持续至给药后21 d,实验组的F-VEP P1波潜伏(67.97±7.93)ms与对照组(134.22±8.50)ms相比缩短(t=13.950,P＜0.05);视网膜神经节细胞计数实验组(207.13±12.21)较对照组(156.32±8.45)增多(t=-10.307,P＜0.05).Caspase-3的A值于给药后7 d,实验组(0.396±0.023)低于对照组(0.458±0.024),差异有统计学意义(t=6.200,P＜0.05).F-VEP P1波潜伏期与Caspase-3 A值呈正相关(r=0.95,P＜0.05).结论 z-DEVD-fmk通过抑制视网膜Caspase-3的表达,对兔外伤性视神经损伤具有治疗作用,可促进神经功能的恢复.

Experimental study on treatment of rabbits optic nerve injury with Caspase-3 inhibitor z-DEVD-fmk

Objective To observe the effects of caspase-3 inhibitor z-DEVD-fmk on optic nerve injury of rabbits. Methods It was an experimental study. Two to three month-old rabbits were used in this study. The rabbit model of optic nerve injury was created by fluid percussion brain injury device (FPI).DMSO (5μl 2% solution) was injected intravitreally to the left eyes (control group). Caspase-3 inhibitor z-DEVD-fmk (5 μl) was injected intravitreally to the right eyes (experimental group). Flash-visual evoked potential (F-VEP) and histopathological examination of the retina were used to check the variations in optic nerve injury at 1,4, 7, 10, 14, and 21 days after the treatment. Immunohistochemistry was used to detect the expression of caspase-3 in the retina. T-test, variance analysis, q-test and linear correlation analysis were used to analyze these data. Results At the 7th day after treatment, the latency of F-VEP P1 in experimental group was shorter than that in the control group (90.50 ± 7.61 ) ms vs (113.59 ±12. 92) ms, t = 4. 060, P ＜ 0. 05]and the number of retinal ganglion cells (RGC) in the experimental group was greater than that in the control group ( 237. 62 ± 8. 50 vs 207. 03 ± 11. 04, t = - 5. 843, P ＜0. 05). Both of these trends continued to the 21st day after treatment (67.97 ±7.93) ms vs. ( 134. 22 ±8.50) ms, t=13.950, P＜0. 05; 156.32±8.45 vs. 207.13±12.21, t= -10.307, P＜0. 05]. The absorbency (A) of caspase-3 in the experimental group (0. 396 ±0. 023) was lower than that in the control group (0. 458 ± 0. 024 ) and this difference was statistically significant ( t= 6. 200, P ＜ 0. 05 ) at the 7th day after treatment. The latency of F-VEP P1 and the absorbency of caspase-3 in the retina were positively correlated with each other(r=0. 95,P＜0. 05). Conclusion z-DEVD-fmk is effective in treating rabbit optic nerve injury by inhibiting the expression of caspase-3 in the retina. It can promote the recovery of optic nerve function.