作　　者： ; ; ; ; ; ;

机构地区： 华东师范大学生命科学学院

出　　处： 《中国水产科学》 2007年第3期412-418,共7页

摘　　要： 以中华绒螯蟹(Eriocheir sinensis)为研究对象,蟹初始体质量为(71.25±1.13)g。设计对照组(不额外添加氨氮,水中本底氨氮质量浓度约为1 mg/L)、低浓度组(10 mg/L NH4Cl)、中浓度组(50 mg/L NH4Cl)、高浓度组(100 mg/L NH4Cl)4种不同的氨氮质量浓度,分别于胁迫的第1天、3天、5天、15天抽取血淋巴进行相关免疫指标测定,并观察氨氮胁迫15 d后对肝胰腺组织结构的影响。结果表明:(1)3个处理组的血细胞密度(DHC)在胁迫初期(第1天和第3天)均显著低于对照组(P<0.05);在胁迫第5天,各组血细胞密度均升至最高;但至第15天时,高浓度组的DHC下降,显著低于对照组(P<0.05)。低浓度的氨氮胁迫在短期内可促进超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,高浓度的氨氮胁迫却抑制其活性;随胁迫时间延长,SOD活性变化趋势与DHC相似,CAT活性在胁迫第5天时出现显著下降(P<0.05),且3个氨氮处理组显著低于对照组(P<0.05),而第15天时各组之间差异不显著。丙二醛(MDA)含量随胁迫时间延长而不断增加,不同浓度的氨氮胁迫使MDA增加速度不同,浓度越高,MDA在体内累积量越大;(2)与对照组相比,3个氨氮处理组的中华绒螯蟹在遭受氨氮胁迫15 d后,其肝胰腺B细胞数量均减少,转运泡体积明显增大,细胞核增大且数量增多;而且在高浓度组中,中华绒螯蟹的部分肝小管基膜破裂、细胞结构模糊,少量细胞核解体。结论认为,随着氨氮胁迫浓度的增加和胁迫时间的延长,中华绒螯蟹DHC逐渐下降,MDA含量逐渐增加,机体非特异性免疫防御系统遭到损伤,同时机体细胞和组织受到伤害甚至出现死亡。研究结果从免疫学与形态学的角度阐明了氨氮胁迫对中华绒螯蟹的毒害机制。 In intensive culture system, accumulation of ammonia-N, which is the principal end-product of nitrogenous metabolism, has deleterious effects on aquatic animals. The relationship between ambient ammonia and immunity capacity in aquatic animals is well-documented, but there is a dearth of information relating to the immune and histological alterations induced by ambient ammonia from Eriocheir sinensis. In the present study,the effects of ambient ammonia on the immune response of E. sinensis body weight （71.25 ± 1.13） g,was investigated. The crabs were allocated to four groups with different NH4^＋ -N levels： 10 mg/L （LC group）, 50 mg/L （MC group） and 100 mg/L （HC group） ,which were obtained by diluting 50 g/L NH4Cl,and the control （basic concentration of 1 mg/L NH4 Cl）. The relative immunity indicators of haemolymph were measured on days 1,3,5 and 15 following the stress and histological structure of hepatopancreas was observed on day 15. The results were as follows： （1） After 1 - 3 days treatment with ammonia exposure,density of hemocyte cell （DHC） in these three treatments decreased significantly compared with control（ P 〈 0.05）. With time elapsed, DHC peaked on day 5 and there was no significant difference among different treatments（ P 〉0.05）. However,on day 15 ,DHC in group HC was lower significantly than that in control （ P 〈 0.05）. Within short time （within 1 day） following the stress, superoxide dismutase （SOD） and catalase （CAT） activity were stimulated in LC group while inhibited in HC group. After 5 d, the change of SOD activity was similar to that of DHC. Whereas CAT activity dropped to the lowest on day 5, and significant difference presented in these three treatments compared with control （ P 〈 0.05 ）. Progressive increases in malodiadehyde （MDA） level was observed with time elapsed. Moreover, the augmentation of MDA changed with different concentration of ambient arnmonia-N that the higher concentration, the more augmentation o

关 键 词： 氨氮胁迫 中华绒螯蟹 免疫指标 细胞

领　　域： [生物学]