摘要
本文报道了过氧化氢诱发原代培养大鼠肝细胞毒性作用的可能机理．过氧化氢（０．２～１．０ｍｍｏｌ·Ｌ－１）温育６ｈ可以引起大鼠肝细胞坏死性损伤，导致谷丙转氨酶释放增加及细胞存活率下降，加入过氧化氢酶（２５０～１５００Ｕ·ｍＬ－１）及抗氧化剂五味子乙素（１０～１００μｍｏｌ·Ｌ－１）均可降低过氧化氢的毒性作用．加入过氧化氢（０．６和１．０ｍｍｏｌ·Ｌ－１）可在６ｍｉｎ内使大鼠肝细胞内钙从１８０ｎｍｏｌ·Ｌ－１明显持续升高至７００ｎｍｏｌ·Ｌ－１以上（约３．５倍）．过氧化氢与肝细胞作用３０ｍｉｎ至１ｈ既可导致细胞膜脂质过氧化，表现为丙二醛蓄积及膜流动性下降，明显早于肝细胞发生坏死性损伤的时间．肝细胞胞浆中还原型谷胱甘肽（ＧＳＨ）含量在加入过氧化氢３０ｍｉｎ后明显降低，可推测肝细胞在后面的温育中对过氧化氢毒性的敏感性增加．以上结果证实过氧化氢诱发的原代培养大鼠肝细胞致死性损伤可能与细胞内钙迅速持续增高，细胞膜脂质过氧化及ＧＳＨ含量下降有关．
The aim of this study was to investigate the possible mechanism of H 2 O 2 -induced cytotoxicity to primary cultured rat hepatocytes. After 6 h incubation, H 2 O 2 (0.2-1.0 mmol·L -1 ) induced lethal injury to the hepatocytes expressed in the increase of glutamic-pyruvic transaminase release into the culture medium and the decrease of cell viability. The toxic effect of H 2 O 2 could be suppressed by the addition of catalase (250-1500 U·mL -1 ) or pretreatment of the cells with an antioxidant compound schisandrin B (10-100 μmol·L -1 ). An obvious and sustained increase of intracellular Ca 2+ concentration ([Ca 2+ ] i ) of the rat hepatocytes from 180 nmol·L -1 to a level over 700 nmol·L -1 (about 3.5 fold) was observed within 6 min after the addition of H 2 O 2 (0.6 and 1.0 mmol·L -1 ). The results suggest that H 2 O 2 -induced [Ca 2+ ] i alternation may be a cause of its toxicity to the hepatocytes. Membrane peroxidation, as measured by the formation of malondialdehyde (MDA) and the decline of membrane fluidity in hepatocytes, took place about 30 min to 1 h after exposure to H 2 O 2 and preceded the time of cell lethal injury happened. In addition, the reduced glutathione (GSH) content in hepatocyte cytosol was decreased obviously after 30 min incubation with H 2 O 2 , which may render the hepatocytes much more susceptible to the toxicity of H 2 O 2 for the later incubation. All the results indicate that H 2 O 2 induced lethal injury to rat hepatocytes may be related to the quick and sustained rise of [Ca 2+ ] i , the membrane peroxidation, and the decline of cytosolic GSH level.
出处
《中国药理学与毒理学杂志》
CAS
CSCD
北大核心
1996年第4期260-266,共7页
Chinese Journal of Pharmacology and Toxicology
关键词
过氧化氢类
毒性
肝细胞
hydrogen peroxide
toxicity
calcium
lipid peroxidation
glutathione
hepatocyte
