亚硒酸钠对刺参免疫反应中体腔液酶活力的影响

Effect of sodium selenite on some enzymes of coelomic fluid to the immune response of holothurian Apostichopus japonicus

为了合理评价硒对水产养殖刺参的作用,实验检测和观察了室内模拟亚硒酸钠处理及病菌感染条件下刺参体腔液免疫酶的变化、组织病理变化和相对保护率。结果表明,随着亚硒酸钠处理强度的增加,刺参体腔液中超氧物岐化酶(SOD)、谷胱甘肽过氧化物酶(GPX)、溶菌酶(LYZ)、酚氧化酶(PO)及碱性磷酸酶(ALP)活性升高;在同时感染病菌的情况下,SOD、GPX及LYZ活性表现为先升高后下降的趋势,PO和ALP活性则持续上升,但随亚硒酸钠浓度升高,ALP活性增加的幅度减少,而较高亚硒酸钠浓度时累计发病率上升,相对保护率下降。研究结果表明,适宜浓度的亚硒酸钠可增强刺参对病菌感染的免疫力,而病菌感染可以加剧亚硒酸钠胁迫对刺参造成的免疫功能损伤,所以适度利用硒可减轻刺参养殖病害的发生。

The aquaculture of the sea cucumber Apostichopus japonicus（Echinodermata,Holothuroidea）has been growing rapidly over recent years in China in response to increasing consumer demand.Indeed,it has become an important sector of the marine industry in Northern China.However,with rapid growth and the use of non-standard practices and culture techniques,epidemic diseases of A.japonicus now pose increasing problems to the industry.Therefore,the healthy aquaculture of A.japonicus is important.For a reasonable evaluation of selenium effect on sea cucumber aquaculture,using laboratory tests to simulate the sodium selenite treatment and virus infection conditions,the detection and observation of the sea cucumber body cavity fluid immune enzyme changes,pathological changes and the relative rate of protection were made.The results showed that：the change of immune enzymes in coelomic fluid of sea cucumbers under simulated sodium selenite treatments and bacteria infected conditions was tested in order to reasonably evaluate the influence of selenium on aquaculture diseases.Results indicated that the activities of superoxide dismutase（SOD）,glutathione peroxidase（GPx）,lysozyme（LYZ）,phenoloxidase（PO）and alkaline phosphatase（ALP）in coelomic fluid rose after sodium selenite treatments were enhanced.However,SOD,GPX and LYZ activities first ascended and then declined,and PO and ALP activities showed continued rise under additional pathogen injection into sea cucumbers,but the increasing extent of ALP activity was reduced along with increased sodium selenite concentration,and total diseased incidence rose and relative percent survival decreased under the severe sodium selenite treatment.This suggested that applying sodium selenite with moderate concentration could enhance immunity of sea cucumber to bacterial infection,but infecting also aggravated immune damage of sea cucumber by sodium selenite stress.Therefore,the diseases of cultured sea cucumber can be alleviated by optimized use of selenium.