Reddan J R, Giblin F J, Dziedzic D C, Wirebaugh B M, Peters J L
Department of Biological Sciences, Oakland University, Rochester, Michigan 48309-4401.
Invest Ophthalmol Vis Sci. 1995 Feb;36(2):289-99.
To investigate the effect of hydrogen peroxide on the epithelial cells of cultured rabbit lenses.
Lenses were cultured in minimum essential medium containing a single dose of 0.03, 0.1, or 0.2 mM H2O2. Three hours later the medium was replaced with peroxide-free minimum essential medium. Lenses were also treated with 0.5 mM 1,3-bis(2-chloroethyl)-1 nitrosourea (BCNU) to lower the activity of glutathione reductase and then exposed to 0.03 mM H2O2 maintained nearly constant by glucose oxidase. After H2O2 treatment, lenses were fixed and whole mounts of the epithelium were prepared or lenses were processed for electron microscopy.
Cells exposed to a single dose of 0.03 mM H2O2 appeared normal; 0.1 mM H2O2 was not cytotoxic. Exposure to 0.2 mM H2O2 elicited swelling in cells in the pre-equatorial region (30 minutes) followed by the formation of islands of cells in the pre-equatorial region at 1 hour. Central epithelial cells appeared normal at 1 hour, were swollen at 3 hours and dead at 24 hours. By 48 hours, dead cells were found in the pre-equatorial and central regions. Cells in the peripheral region of the epithelium did not exhibit cytotoxicity. If lenses were pretreated with BCNU and then challenged with a maintained level of 0.03 mM H2O2, cytotoxicity was induced in the central and pre-equatorial regions. Cells in the peripheral region survived BCNU-H2O2 treatment.
Cells in the peripheral region of cultured lenses were more resistant to H2O2 cytotoxicity than cells in the central and pre-equatorial regions. The antioxidant defense or repair systems for H2O2-induced damage do not appear to be uniformly distributed in subpopulations of the lens epithelium.
研究过氧化氢对培养的兔晶状体上皮细胞的影响。
将晶状体培养于含有单剂量0.03、0.1或0.2 mM过氧化氢的最低必需培养基中。三小时后，将培养基换成不含过氧化氢的最低必需培养基。晶状体还先用0.5 mM 1,3-双（2-氯乙基）-1亚硝基脲（BCNU）处理以降低谷胱甘肽还原酶的活性，然后暴露于由葡萄糖氧化酶维持在近恒定水平的0.03 mM过氧化氢中。过氧化氢处理后，将晶状体固定并制备上皮细胞的整装片，或对晶状体进行电子显微镜处理。
暴露于单剂量0.03 mM过氧化氢的细胞看起来正常；0.1 mM过氧化氢无细胞毒性。暴露于0.2 mM过氧化氢会导致赤道前区域的细胞在30分钟时肿胀，随后在1小时时赤道前区域形成细胞岛。中央上皮细胞在1小时时看起来正常，在3小时时肿胀，在24小时时死亡。到48小时时，在赤道前和中央区域发现了死亡细胞。上皮细胞周边区域的细胞未表现出细胞毒性。如果晶状体先用BCNU预处理，然后用维持在0.03 mM水平的过氧化氢攻击，则在中央和赤道前区域会诱导细胞毒性。周边区域的细胞在BCNU-过氧化氢处理后存活。
培养的晶状体周边区域的细胞比中央和赤道前区域的细胞对过氧化氢细胞毒性更具抗性。过氧化氢诱导损伤的抗氧化防御或修复系统似乎在晶状体上皮细胞亚群中分布不均。
