方法：取健康清洁级兔的16对离体透明晶状体，将一对晶状体的任意一只为实验组，另一只为对照组，实验组为含浓度依次为5，10，15，20，25，30，35，40mmol/L CaCl₂的1640培养液，对照组含1 640培养液，观察培养36h后晶状体的混浊情况。取健康清洁级兔的24对离体透明晶状体，将一对晶状体的任意一只为实验组，另一只为对照组，实验组为含有CaCl₂(5～30mmmol/L)+E-64d的1 640培养液，对照组为含CaCl₂(5～30mmol/L)的1640培养液，检测两组晶状体的透明度及相对灰度值，用原子吸收分光光度计检测两组晶状体的钙离子(Ca²⁺)含量。采用SPSS 11.9统计学软件进行统计学分析，计量资料采用(-overx)±s表示，采用配对t检验，以P<0.05为差异有统计学意义。

结果：透明晶状体在含有氯化钙的培养液中发生混浊，且随着钙离子浓度的升高，晶状体的混浊程度也提高，当培养液中钙离子浓度为30mmol/L以上时，培养液中的晶状体下方的黑色十字线几乎不能透见，晶状体皮质几乎完全混浊； 含有钙蛋白酶抑制剂E-64d的实验组晶状体的混浊程度较对照组明显减轻，实验组与对照组晶状体灰度值比较，差异有显著统计学意义(t<=3.820，P=0.001<0.01)，但实验组与对照组晶状体钙离子含量比较，差异无统计学意义(t=2.144，P=0.055>0.05)。

结论：晶状体外的高钙环境可以诱导晶状体混浊； 钙蛋白酶抑制剂E-64d不能抑制晶状体对细胞外钙离子的摄入； 钙蛋白酶抑制剂E-64d对高钙诱导的晶状体混浊有保护作用，它可能是直接抑制了钙蛋白酶的活性，进而通过其他途径抑制晶状体蛋白变性或者上皮细胞凋亡及坏死，延缓白内障的发生。

METHODS: Sixteen paired rabbit lens were randomly divide into two groups, the lens of any pair of one was as experimental group, the other for the control group. Experimental group contained concentration of 5, 10, 15, 20, 25, 30, 35, 40mmol/L CaCl₂ 1 640 culture medium, the control group contained 1 640 culture medium, the situation was observed by turbidity after 36h. Twenty-four paired rabbits lens were randomly divided into two groups, the lens of any pair of one was as experimental group, the other for the control group. Experimental group contained CaCl₂(5～30mmol/L)+ E-64d of 1 640 culture medium and control group containd CaCl₂(5～30mmol/L)of 1 640 culture medium. Lens transparency and relative gray values were detected, Atomic absorption spectrophotometer was used to detect lens calcium(Ca^{2 +})content. The data were analyzed with SPSS 13.0 statistical software. Measurement data were expressed (-overx)±s and the differences of two groups were compared by pared- samples t test. P<0.05 was considered statistically significant.

RESULTS: Transparent lens opacity occurred in medium containing CaCl₂, and with the Ca²⁺ concentration increased, degree of lens opacity was also improved. When Ca²⁺ concentration >30mmol/L, black cross line below the lens was hardly seen through in culture medium, and lens cortex was almost completely cloudy. Lens opacity incubated with 1 640 mediun containing E-64d was declined compared with controls. There were significant difference of relative gray scale between experimental group and control group(t=3.820, P=0.001<0.01). However, experimental group and control group had no significant effect on Ca²⁺ uptake by lens(t=2.144, P=0.055>0.05).

CONCLUSION: The high levels of extralenticular calcium can induced cataract. E-64d, an inhibitor of calpain, can inhibit calcium-induced lens opacity, However, E-64d has no significant effect on Ca²⁺ uptake by lens. Its inhibitory effect on lens opacification may be due to a direct action on the activity of calpain. Moreover, maybe it can inhibit degeneration of crystallin or apoptosis and necrosis of epithelial cell by other approaches to delay the occurrence of cataract.