Immunotoxicological evaluation of fish neutrophil exposed with chemical contaminations

(1)从罗非鱼鱼囊分离出中性粒细胞，用氯化镉染毒3h，测定中性粒细胞的酵母多糖吞噬活性和活性氧。对感染迟发性艾美耳球虫的青竹和斑马鱼暴露于氯化镉(1×10~(-4)~(-4)M)后的死亡率进行了监测。罗非鱼中性粒细胞在氯化镉浓度下的存活率分别为98%、86%、95%和96%。死亡细胞常表现为胞核碎裂。吞噬活性在暴露组(1x10；-4；M)统计上较低，在所有三个暴露组中，大约10%的活性氧下降。(2)将幼鱼(孵化后4天)暴露于两种浓度(A)废水标准和(B)氯化镉和铬(III)环境标准中96h后，再用迟发性艾美耳球虫攻击，以评价重金属的免疫毒理效应。暴露在环境标准(0.01ppm)氯化镉和废水(2.0ppm)和环境标准(0.2ppm)铬的鱼在受到迟发性肺炎病毒攻击后，开始与对照鱼在相同的时间范围内死亡。死鱼鳃上皮细胞呈典型固缩，抗E.迟发性抗体染色。

(1) Neutrophil isolated from tilapia swim bladder was exposed with cadmium chloride for three hours and zymosan phagocytic activity and active oxygen of the neutrophil was measured. Mortality was monitored on challenged medaka and zebrafish with E. tarda after exposing to cadmium chloride (1x10^<-4> M). Tilapia neutrophil survival rates in the concentrations of cadmium chloride were 98% (0 M), 86% (1x10^<-4> M), 95% (1x10^<-5> M) and 96% (1x10^<-6> M). Dead cells frequently showed fragmented nuclei. Phagocytic activity was statistically lower in the group (1x10^<-4> M)and approximately 10% of active oxygen declined in all three exposed groups. No mortality rate was observed in medaka and zebra fish infected with E. tarda after the exposure to cadmium chloride.(2) Juvenile fish (4 days after hatch) was exposed in two concentrations (a)waste water standard and (b)environmental standard of cadmium chloride and chromium(III) for 96 hours, then challenged with E. tarda to evaluate immunotoxicological effect of heavy metals. Fish exposed with the concentrations of the environmental standard (0.01 ppm) of cadmium chloride and waste water (2.0 ppm) and environmental standards (0.2 ppm) of chromium started dying at the same time range with control fish after challenged with E tarda. Gill epithelium cells in dead fish showed typical pycnosis and same degree of E. tarda cell numbers detecting with anti-E. tarda antibody staining.