HYDROGEN-PEROXIDE IN THE RABBIT ANTERIOR-CHAMBER - EFFECTS ON GLUTATHIONE, AND CATALASE EFFECTS ON PEROXIDE KINETICS
HYDROGEN-PEROXIDE IN THE RABBIT ANTERIOR-CHAMBER - EFFECTS ON GLUTATHIONE, AND CATALASE EFFECTS ON PEROXIDE KINETICS
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DOI：
10.3109/02713688709044503
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发表时间：
1987-12-01
影响因子：
2
通讯作者：
GREEN, K
中科院分区：
文献类型：
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作者：
CSUKAS, S;COSTARIDES, A;GREEN, K
幼兔（t1/2，93 秒）的前房内过氧化氢（H2O2）清除速度比成年兔（t1/2，109 秒）更快。外推的 H2O2 零时浓度在成人中为 3.3 mM，在年轻人中为 3.2 mM。与成年动物相比，幼年动物中 H2O2 消失速度更快，与虹膜 (35%) 和角膜内皮 (50%) 中过氧化氢酶水平较高相关。已发现3-氨基-1H-1,2,4-三唑(3AT)以剂量相关的方式降低眼组织中的过氧化氢酶水平，静脉注射3M溶液高达6ml/kg。虹膜和睫状突显示出随剂量的线性降低，而角膜内皮、肝脏和肺的过氧化氢酶活性分别在2、4和6ml/kg时达到接近最大降低。 3AT 引起前房 H2O2 清除率的显着剂量依赖性延长，这与过氧化氢酶损失直接相关。成年动物中 H2O2 消失的 t1/2 从无 3AT 时的 109 秒增加到 2 ml/kg 3M 3AT 后的 147 秒，增加到 4 ml/kg 3M 3AT 后的 161 秒，以及 6 ml/kg 3M 3AT 后的 184 秒。前房内注射过氧化氢后，角膜内皮氧化谷胱甘肽水平短暂升高。考虑到眼前节所有组织的总和，静脉注射3AT产生的过氧化氢酶的特异性增量减少导致H2O2从前房清除的t1/2变长，而除晶状体上皮外的眼前节组织的减少能力与3AT的全身剂量明显相关。保护眼前节组织免受氧化剂的影响取决于氧化剂的浓度、还原型谷胱甘肽的可用性和过氧化氢酶的活性之间的相互作用。
Intracameral hydrogen peroxide (H2O2) is cleared at a faster rate in young (t1/2, 93 seconds) than in adult (t1/2, 109 seconds) rabbits. Extrapolated zero time concentrations of H2O2 were 3.3 mM in adults and 3.2 mM in young. The more rapid disappearance of H2O2 correlated with greater catalase levels in iris (35%) and corneal endothelium (50%) in young as compared to adult animals. Catalase levels have been found to be reduced in ocular tissues with 3-amino-lH-1,2,4-triazole (3AT) in a dose-related manner up to 6 ml/kg of an intravenous 3M solution. Iris and ciliary processes showed a linear reduction with dose, while corneal endothelium, liver and lung reached near maximal decreases in catalase activity at 2, 4, and 6 ml/kg, respectively. 3AT caused a significant dose-sependent extension of the rate of clearance of H2O2 from the anterior chamber, that was directly related to catalase loss. The t1/2 for H2O2 disappearance in adult animals increased from 109 seconds with no 3AT, to 147 seconds after 2 ml/kg 3M 3AT, to 161 seconds after 4 ml/kg 3M 3AT and 184 seconds after 6 ml/kg 3M 3AT. Corneal endothelial oxidized glutathione levels were transiently increased after intracameral hydrogen peroxide. Considering the sum total of all tissues of the anterior segment, specific incremental decreases of catalase generated by intravenous 3AT caused the t1/2 of H2O2 clearance from the anterior chamber to become longer, while the reducing power of anterior segment tissues excluding lens epithelium is related clearly to the systemic dose of 3AT. Protection of anterior segment tissues from oxidants depends on the interplay between the concentration of the oxidant, the availability of reduced glutathione and the activity of catalase.