摘要:
以仿刺参(Apostichopus japonicus)为受试生物,采用半静水式试验方法,设置3种不同浓度(1/5、1/25、1/125的96 h-LC50)的苯、甲苯、乙基苯、邻-二甲苯、间-二甲苯和对-二甲苯处理健康仿刺参,检测仿刺参过氧化氢酶(CAT)基因在呼吸树、肠组织中的表达和酶活性变化情况。结果发现:在各苯系物处理组的仿刺参呼吸树和肠组织中,cat基因的转录表达变化显著;苯、甲苯、乙基苯、邻-二甲苯对呼吸树中CAT活性具有诱导作用,其中乙基苯的诱导倍数最高,为12.0~19.8倍;6种苯系物对肠组织中CAT活性具有抑制作用,抑制程度大小顺序为:邻-二甲苯 > 乙基苯 > 对-二甲苯 > 甲苯 > 间-二甲苯 > 苯。表明苯系物对仿刺参呼吸树、肠具有氧化胁迫作用,可能造成2种组织的氧化损伤。相关性分析表明:苯系物处理后,仿刺参肠组织中cat m RNA相对表达倍数与CAT活性变化呈显著正相关;仿刺参肠和呼吸树中cat m RNA相对表达倍数变化呈显著正相关。以上结果为苯系物对仿刺参的生物毒性评价提供了基础数据。
Abstract:
The present study is aimed to evaluate the effects of BTEXs on the activities of catalase (CAT) and relative fold changes of cat gene in respiratory tree and intestine of sea cucumber Apostichopus japonicus. Three different concentrations (1/5, 1/25, 1/125 of 96-LC50) of benzene, toluene, ethyl benzene, o-, m-, p-xylene were selected to treat the healthy sea cucumber individuals using semi-static water experimental method. The results showed that the fold changes of cat gene in respiratory tree and intestine were remarkably changed in different BTEXs treatment groups. The activities of CAT in respiratory tree were induced in benzene, toluene, ethyl benzene and o-xylene treatment groups, and the highest relative folds (12.0-19.8 fold) were found in ethyl benzene treatment group. The activities of CAT in intestine were inhibited in BTEXs treatment groups, and the activities in descending order were o-xylene, ethyl benzene, p-xylene, toluene, m-xylene and benzene treatment groups. This suggested that BTEXs have oxidative stress on the respiratory tree and intestine of A. japonicus, and might have oxidative damage on the two tissues. Correlation analysis showed that CAT activities was remarkably positive correlated with the relative fold changes of cat gene in intestine, which was also remarkably positive correlated with that of respiratory tree. These results will provide the basic data for toxic assessment of BTEXs on the sea cucumber.A. japonicus.
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