饲料中添加壳寡糖对仿刺参肠、触手、体壁、体腔液免疫指标的影响

Effect of adding chitooligosaccharide on immunological indexes of intestine, tentacles, body wall and coelomic fluid of sea cucumber(Aposticopus japonicus)

为了研究不同添加量壳寡糖对仿刺参(Apostichopus japonicus)各组织和体腔液免疫指标的影响,试验选取225头体重为(4.5±0.5)g的海参,随机分为对照且和0.3%、0.5%壳寡糖组,每组设3个平行,每个平行25头海参,进行28 d的投喂试验。采用体细胞计数法、氮蓝四唑(NBT)还原法对体腔细胞的吞噬率和吞噬活性进行测定,采用紫外分光光度法对仿刺参肠、触手、体壁、体腔液的免疫指标——酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、溶菌酶(LSZ)、超氧化物歧化酶(SOD)活性进行测定,每隔7 d测定1次。结果表明:壳寡糖添加量为0.3%和0.5%时均能显著提高仿刺参体腔细胞的吞噬活性、活性氧(ROS)水平以及ACP、AKP、LSZ、SOD等的活性,但在不同组织和体腔液中免疫酶类应答的情况不同。LSZ活性在触手和体壁组织中升高最快,AKP和ACP活性在肠组织中变化较快,SOD活性变化在体腔液中最明显且活性最高,各免疫指标几乎都在前3周活性达到最高,随后有所降低。在整个试验过程中,0.5%壳寡糖组的免疫指标总体高于0.3%壳寡糖组,说明添加0.5%壳寡糖的免疫效果比添加0.3%壳寡糖的免疫效果好。

In this study,225 sea cucumbers(Apostichopus japonicus,A.japonicus)weighing(4.5±0.5)g were randomly divided into 3 groups,each with 3 parallel,with 25 individuals,for a 28 d chitooligosaccharide(COS)feeding test.The phagocytosis rate and phagocytosis activity of coelomocytes were determined by somatic cell count method and nitrogen blue tetrazole(NBT)reduction method.Ultraviolet spectrophotometry was used to detect the activities of acid phosphatase(ACP),alkaline phosphatase(AKP),lysozyme(LSZ),and superoxide dismutase(SOD)in the intestine,tentacles,body walls,and coelomic fluid every 7 d.The results showed that dietary supplemented with 0.3%or 0.5%COS could significantly boost the phagocytic activity,reactive oxygen species(ROS),ACP,AKP,LSZ,and SOD while the immune responses in different tissues were different.The activity of LSZ increased most rapidly in the tentacle and body wall tissues,and the activity of AKP and ACP changed rapidly in the intestinal tissues.The activity changes of SOD were most notable in coelomic fluid and it was the highest compared with other tissues.Almost all the immunization indexes were highest in the first 3 weeks and subsequently decreased.However,the immunizaton indexes of the 0.5%COS group were higher than the 0.3%COS group during the whole experiment period.It indicates that 0.5%of COS adding is relatively better than 0.3%.