2-Amino-5-chlorophenol toxicity in renal cortical slices from Fischer 344 rats: effect of antioxidants and sulfhydryl agents.
2-Amino-5-chlorophenol toxicity in renal cortical slices from Fischer 344 rats: effect of antioxidants and sulfhydryl agents.
复制标题
Fischer 344 大鼠肾皮质切片中的 2-氨基-5-氯酚毒性：抗氧化剂和巯基药物的影响。
DOI：
10.1006/taap.1999.8784
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Rankin,GO
中科院分区：
文献类型：
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作者：
Valentovic,M;Meadows,MK;Harmon,RC;Ball,JG;Hong,SK;Rankin,GO
2-氨基-5-氯苯酚具有肾毒性，其机制尚未确定。本研究检查了Fischer 344大鼠肾皮质切片中2-氨基-5-氯苯酚的体外毒性，并专门评估了脂质过氧化和肾谷胱甘肽耗竭的诱导。肾皮质切片暴露于0，0.25，0.5，和1 mM 2-氨基-5-氯苯酚表现出浓度和时间依赖性增加乳酸脱氢酶（LDH）泄漏。丙酮酸指导的神经元异生减少浓度依赖性的方式与0，0.25，0.5，和1 mM的2-氨基-5-氯苯酚孵育90分钟后。相对于对照组织，肾切片中的1 mM 2-氨基-5-氯苯酚在60分钟内诱导脂质过氧化。总谷胱甘肽（GSH）水平降低到低于对照值在30分钟内暴露于0.5和1 mM 2-氨基-5-氯苯酚。这些结果表明，GSH水平下降之前出现LDH泄漏增加和膜完整性降低。在从用丁噻鲁胺亚砜亚胺（BSO，890 mg/kg ip）预处理的动物中分离的肾切片中，2-氨基-5-氯苯酚毒性增加。用酚类抗氧化剂N，N′-二苯基-1，4-苯二胺（DPPD，50 μM）或铁螯合剂去铁胺预处理肾切片，未降低2-氨基-5-氯苯酚的细胞毒性。这些结果表明，2-氨基-5-氯苯酚的毒性不是通过铁依赖性机制介导的。2-氨基-5-氯苯酚的细胞毒性通过与2 mM抗坏血酸盐预孵育15分钟或与含巯基试剂GSH（1 mM）或二硫苏糖醇（1 mM，DTT）预孵育30分钟而降低。GSH，DTT，或抗坏血酸预处理减少2-氨基-5-氯苯酚诱导的LDH泄漏和脂质过氧化物的产生。这些结果表明，2-氨基-5-氯苯酚的细胞毒性涉及自由基的产生，通过铁的非依赖性机制。通过抗氧化剂抗坏血酸盐的存在或通过添加谷胱甘肽来降低毒性。
2-Amino-5-chlorophenol is nephrotoxic through an unidentified mechanism. This study examined the in vitro toxicity of 2-amino-5-chlorophenol in renal cortical slices from Fischer 344 rats and specifically assessed induction of lipid peroxidation and depletion of renal glutathione. Renal cortical slices exposed to 0, 0.25, 0.5, and 1 mM 2-amino-5-chlorophenol exhibited a concentration- and time-dependent increase in lactate dehydrogenase (LDH) leakage. Pyruvate-directed gluconeogenesis was diminished in a concentration-dependent manner following a 90-min incubation with 0, 0.25, 0.5, and 1 mM 2-amino-5-chlorophenol. Lipid peroxidation was induced within 60 min by 1 mM 2-amino-5-chlorophenol in renal slices relative to control tissue. Total glutathione (GSH) levels were decreased below control values within 30 min of exposure to 0.5 and 1 mM 2-amino-5-chlorophenol. These results indicated that GSH levels were decreased prior to the appearance of increased LDH leakage and diminished membrane integrity. 2-Amino-5-chlorophenol toxicity was increased in renal slices isolated from animals pretreated with buthionine sulfoximine (BSO, 890 mg/kg ip). Pretreatment of renal slices with the phenolic antioxidant N,N′-diphenyl-1,4-phenylenediamine (DPPD, 50 μM) or the iron chelator deferoxamine did not reduce 2-amino-5-chlorophenol cytotoxicity. These results suggest that 2-amino-5-chlorophenol toxicity was not mediated through an iron-dependent mechanism. 2-Amino-5-chlorophenol cytotoxicity was reduced by a 15-min pre-incubation with 2 mM ascorbate or a 30-min preincubation with the thiol-containing agents GSH (1 mM) or dithiothreitol (1 mM, DTT). Pretreatment with GSH, DTT, or ascorbate reduced LDH leakage and lipid peroxide generation induced by 2-amino-5-chlorophenol. These results suggest that 2-amino-5-chlorophenol cytotoxicity involved free radical generation through an iron-independent mechanism. Toxicity was reduced by the presence of the antioxidant ascorbate or by addition of glutathione.