中文摘要：

采用静态水质接触染毒法，研究不同作用时间和不同暴露浓度下除草剂阿特拉津对鲫鱼肝脏、肾脏和肌肉过氧化氢酶（CAT）活性的影响。结果表明：阿特拉津对鲫鱼各个组织器官CAT活性均产生了较强的影响。24d连续暴露后，在低浓度（0．1～1．0mg·L^-1）范围内，阿特拉津对鲫鱼肝脏、肾脏和肌肉CAT活性均产生了诱导作用；而高浓度（5．0～10.0mg·L^-1）范围内则对这些组织器官CAT活性均产生了抑制作用。从时间效应看，低浓度（1．0mg·L^-1）时，在所有作用时间下，阿特拉津对鲫鱼肝脏、肾脏和肌肉CAT活性均产生了强烈的诱导作用；诱导作用随着暴露时间的延续均先增强后减弱，并最终使CAT含量维持在某一浓度水平；且在染毒后10d．阿特拉津对鲫鱼肝脏、肾脏和肌肉CAT活性的诱导作用达到最大，最大诱导率分别为93．96％、75．39％和62．86％。高浓度（10、0mg·L^-1）时，仅在暴露的第3d，阿特拉津对鲫鱼肝脏CAT活性产生了诱导作用，除此之外，在任何时间下，阿特拉津对鲫鱼各组织器官的CAT活性均表现为抑制作用．且抑制作用随着暴露时间的延续均先增强后减弱，并最终使CAT含量维持在某一浓度水平。试验显示，低浓度阿特拉津暴露即可引起鱼体产生较强的氧化压力，从而会影响鱼类的正常生长发育；同时，鱼体CAT活性变化的显著性及其与阿特拉津之间所存在的剂量-效应和时间-效应关系，说明CAT有望成为一种敏感的分子生物标志物来监测水体中阿特拉津污染。

英文摘要：

Atrazine is one of the most commonly used herbicides in China and the world. Due to its long persistence, it had been present in many surface and ground waters, contaminating non-target organisms such as fish and threatening drinking water of human beings. An ex- periment was conducted on crucian to study effect of atrazine on catalase （CAT） activity. Groups of fish were exposed to atrazine varying in concentration, i.e. 0, 0.1, 0.5, 1.0, 5.0 and 10.0 mg .L^-1, respectively. The CAT activities in liver, kidney and muscle of crucian exposed to 1.0 and 10.0 mg.L^-1 were measured after day 3, 6, 10, 14, 19 and 24, respectively, to study the time-response relationship between atrazine and CAT activities in these organs. At the end of experiment （24 days）, CAT activities in the three organs of crucian exposed to all the concentrations were evaluated to explore the dose-response relationships between atrazine and CAT activities in these brgans. Results indicated that atrazine had strong influences on CAT activities in the three organs. After 24 days continuous exposure, CAT activities in liver, kidney and muscle were induced at low concentrations of 0.1-1.0 mg·L^-1, however, they were inhibited at high concentrations of 5.0-10.0 mg·L^-1. CAT activities in liver, kidney and muscle were induced strongly at concentration of 0.1 mg·L^-1 during the experiment, and the inducement effect increased firstly and then decreased with exposure time prolonging, which made the CAT activities maintain at a level finally. Inducement effect reached the peak after 10 days, with the biggest inducement rate being 93.96%,75.39% and 62.86% in liver, kidney and muscle, respectively. Except that the hepatic CAT activity was induced after 3 days exposure, the CAT activities in all organs were inhibited at any other time when the exposure concentration was 10.0 mg·L^-1, maintained at a level just finally, and the inhibition effect increased firstly and then decreased with exposure time prolonging. Low concentration of atrazine exposu