几种免疫促进剂对中国对虾血细胞数量、形态结构以及酚氧化酶产量和活性的影响

Effects of several immunostimulants on the number, ultrastructure of hemocytes and the yield,activities of phenoloxidase in Penaeus chinensis

为了弄清免疫促进剂增强对虾自身免疫力的作用机理,利用脂多糖(LPS)、β 葡聚糖(β 1,3 glucan)、灭活哈维氏弧菌和灭活鳗弧菌对中国对虾血细胞的数量、形态结构以及酚氧化酶(phenoloxidase,PO)的产量与活性在刺激前后的变化进行了研究。研究结果表明,经β 葡聚糖、脂多糖、灭活哈维氏弧菌和灭活鳗弧菌刺激后,中国对虾总血细胞的数量分别增多了83.4%、52.0%、73.4%和111.3%,其中,小颗粒细胞的数量分别增多了100.4%、67.3%、57.2%和102.9%,大颗粒细胞的数量分别增多了47%、10%、127%、和173%;同时,PO的产量分别提高了81.3%、104.7%、29.2%和40.4%,但PO的单位酶活性在刺激前后没有显著变化。透射电镜(TEM)观察结果显示,中国对虾血细胞的超微结构在免疫刺激前后发生了不同程度的变化。在β 葡聚糖和脂多糖刺激下,小颗粒细胞和大颗粒细胞内糙面内质网(RER)和游离核糖体数量明显增多,线粒体数量增加,细胞内分泌颗粒的数量大幅度减少;而透明细胞的超微结构在多糖刺激前后除RER及线粒体数量略有增加、核孔复合体数量明显增加外没有显著差异。经灭活哈维氏弧菌刺激后,对虾大颗粒细胞中RER增生显著并发生泡状化,核质比明显降低;小颗粒细胞中的RER也发生增生且呈泡状化,核质比略有降低;透明细胞中RER数量明显增加,

To study the stimulating mechanisms of immunostimulants in shrimp autogenous immunocompetence,the immunostimulating effects of β-glucan,lipopolysaccharide (LPS),inactivated Vibrio harveyi and Vibrio anguillarum on the hemocytes and phenoloxidase (PO) from shrimp,Penaeus chinensis,were investigated in this study.After shrimps stimulated with lipopolysaccharide (LPS),β-glucan,inactivated Vibrio harveyi and inactivated Vibrio anguillarum,the number of their overall hemocytes increased 83.4%,52.0%,73.4% and 111.3% respectively,in which the number of semigranular cells increased 100.4%,67.3%,57.2% and 102.9%,and the number of granular cells increased 47%,10%,127% and 173%,respectively.And the amount of PO increased 104.7%,81.3%,30.1% and 40.4%,respectively,whereas the unit activity of PO remains almost the same before and after stimulation.Under the stimulation of β-glucan or LPS,the amount of rough endoplasmic reticulum (RER) of semigranular cells and granular cells increased greatly and with swelled cristae.And the number of free ribosomes and mitochondria increased obviously and the number of secretary vesicles decreased greatly.However,the ultrastructure of hyaline cells changed less before and after stimulation.Under the stimulation of inactivated Vibrio anguillarum,the amount of RER in semigranular cells and granular cells increased greatly.And the number of free ribosomes increased obviously in granular and hyaline cells.The number of mitochondria increased obviously and its nucleoplasmic ratio decreased in hyaline cells.Under the stimulation of inactivated Vibrio harveyi,the amount of RER and the number of mitochondria increased greatly and nucleoplasmic ratio decreased obviously in semigranular cells and granular cells.The amount of RER and the number of mitochondria increased obviously and nucleoplasmic ratio decreased in hyaline cells.Among the four kind of immunostimulants,β-glucan and LPS acted mainly on semigranular cells and granular cells,whereas inactivated Vibrio harveyi and Vibrio anguillarum acted on semigranular cells,granular cells and also hyaline cells.Therefore,it can be concluded that 1) the enhancement of shrimp autogenous immunocompetence is finally realized via increase of OP production instead of PO unit activity,2) the enhancing mechanisms of polysaccharides and inactivated vibros are different,3) the enhancement of shrimp autogenous immunocompetence is finally realized via inducing RER hyperplasia in granular cells to increase PO production after stimulation by β-glucan and LPS,4) the enhancement of shrimp autogenous immunocompetence is finally realized via stimulating the proliferation of granular cells to increase PO production after stimulation by inactivated Vibrio harveyi and Vibrio anguillarum,and 5) the immunostimulating effect of polysaccharides is much better than that of inactivated vibrios.