氨氮对中华绒螯蟹仔蟹肝组织RNA/DNA及肝细胞结构的影响

以中华绒螯蟹（Eriocheir sinesis）仔蟹为研究对象。采用静水试验法,温度在20℃左右,用氨氮与过滤海水分设5个质量浓度组（2.04、6.35、9.04、11.75和19.13 mg.L-1）,同时以过滤海水为对照组（氨氮质量浓度为0.30 mg.L-1）,每一个质量浓度组设3个平行样本,对中华绒螯蟹仔蟹进行6 d胁迫试验。每2 d观察仔蟹的蜕壳情况,并分别于实验后的2、4和6 d取仔蟹肝组织样,应用激光共聚焦技术分析测定RNA/DNA荧光相素比,同时用透射电镜观察6 d后,最高浓度组和对照组仔蟹肝细胞结构的变化情况。试验结果表明;对于氨氮的胁迫,仔蟹的变态率随染毒浓度的增高而降低,同时变态蜕壳的时间也会产生延迟现象。氨氮的胁迫会引起仔蟹的肝组织细胞内的DNA和RNA的质量分数逐渐降低,导致RNA/DNA比率的不断下降。在高质量浓度氨氮的胁迫下,使得仔蟹肝细胞线粒体部分解体、胞质空泡化和染色质浓缩、转运泡数量增多,体积增大,细胞出现许多空泡和微绒毛消失等一系列的损伤变化。破坏了仔蟹自身机能正常的代谢和生长水平。

Subchronic effects of ammonia-N on RNA/DNA ratio and ultrastructure of Liver of Eriocheir sinensis larvae

This paper studied the subchronic effects of ammonia-N on Eriocheir sinensis larvae.The crabs were allocated to six treatment groups with different NH3-N levels：2.04 mg·L-1（low concentration group）,6.35 mg·L-1 and 9.04 mg·L-1（two middle concentration groups） and 11.75 mg·L-1and 19.13 mg·L-1（two high concentration groups）,which were obtained by diluting different concentration NH4C1（Guaranteed reagent）,and the control groups（basic concentration of 0.30 mg·L-1）.The tissues of liver were sampled randomly from each groups at the time intervals of 2,4,6 d,respectively.Laser scanning co focal microscopy was used to analyze the relative RNA/DNA radio of the tissues.The pathological changes of the tissues were examined by transmission electron microscopy.The results indicated that high levels of ammonia-N have significant effects on the metamorphosis rate.As the ammonia-N concentration increased,metamorphosis rate decreased gradually,and metamorphosis time of the two high concentration groups was delayed to the control groups.The RNA/DNA radio had decreased significantly after exposed to ammonia-N.And ammonia-N can affected the histological structure of liver.The increased intercellular space,cholestasis,infiltration of inflammatory cell,presence of lipid droplets and increasing of lysosome in hepatocytes were observed.