摘要
目的:研究大鼠糖尿病性白内障(diabetic cataract,DC)晶状体中Ca^2+含量及晶状体上皮细胞(lens epithelial cells,LECs)钙蛋白酶Ⅱ(m—calpain,calpain-2)、水通道蛋白-1(aquaporin-1,AQP1)表达水平的变化情况。方法:链脲佐菌素(streptozotocin,STZ)60mg/kg体重一次性注射大鼠尾静脉复制糖尿病模型,定期摘取各模型组及对照组大鼠的双侧眼球,后路取出一侧晶状体,用SpectrAA-40型原子吸收光谱仪测定Ca^2+浓度;将另一侧眼球制成石蜡切片,应用免疫组织化学方法和计算机图像分析技术对LECs表达calpain-2、AQP1进行检测。结果:在晶状体浑浊之前,其Ca^2+浓度和LECs胞浆calpain-2表达增加。随着糖尿病发展,晶状体Ca^2+浓度逐渐增加,除DCⅡ期外,calpain-2表达亦逐渐增加。相反,在晶状体浑浊之前,LECs胞膜AQP1表达减少,且随着糖尿病发展逐渐减少。结论:糖尿病大鼠晶状体中Ca^2+浓度增加、晶状体上皮细胞calpain-2的活性表达增加及AQP1的活性表达减少与DC的发生、发展关系密切。
Objective: To investigate the change of total Ca2. level in lenses and the expression of calpain-2 and aquaporin-1 ( AQP1 ) in lens epithelial cells (LECs) of rat diabetic cataract( DC). Methods: An animal model of diabetes was prepared by intravenous injection of streptozotocin ( 60 mg/kg body weight) in 2-month-old Wistar rats. The eyeballs of both sides were extracted periodically from each experimental groups and control group. The lenses of one side were isolated and the concentration of Ca^2+ was determined by a SpectrAA--40 atomic absorption spectrophotometer. The eyeballs of other side were made into paraffin sections. Immunohistochemical techniques and computer-imaging analysis were used to localize and semi-quantify the expression of calpain-2 and AQP1 in LECs. Results: The increased ion concentration of Ca^2+ in lenses and the elevated level of calpain-2 in cytoplasm of LECs were observed before lens opacification began. The concentration of Ca^2+ increased gradually with the diabetes development and the expression of calpain-2 did so except DC If. On the contrary, the expression of AQP1 on the cell membrane decreased significantly before the DC occurred and decreased gradually with the diabetes development. Conclusions: Increased ion concentration of Ca^2+ in lens, elevated and activated expression of calpain-2 and decreased expression in LECs were closely correlated with DC formation and development.
出处
《实用医学进修杂志》
2008年第4期205-212,共8页
Journal of Practical Training of Medicine