钼镉联合诱导对麻鸭白细胞免疫功能及脾脏MT基因mRNA表达的影响

Effects of co-exposure to molybdenum and cadmium on immune function of leukocyte and mRNA expression of spleen MT in duck

探讨钼镉联合诱导对麻鸭白细胞免疫功能及脾脏MT基因mRNA表达的影响。挑选360只11日龄健康"江南2号"麻鸭随机分为对照组、低钼组、高钼组、镉组、低钼镉组和高钼镉组。对照组喂基础日粮,试验组在每公斤基础日粮中添加钼、镉分别为:低钼15 mg、高钼100 mg、镉4 mg、低钼15 mg+镉4 mg和高钼100 mg+镉4 mg,以(NH_4)_6Mo_7O_(24)·4H_2O和3Cd SO_4·8H_2O作为钼源和镉源,试验期120 d。结果表明,与对照组比较,第120天脾脏指数和白细胞数高钼镉组显著降低(P<0.05);粒细胞比率:第90、120天,除低钼组外,其余各组显著升高(P<0.05或P<0.01);淋巴细胞比率:第90、120天钼镉联合组极显著降低(P<0.01);中间细胞比率先显著升高后显著降低;并且这些变化趋势,钼镉联合组比钼镉单独组更加明显。MT mRNA表达量:第60,120天,除低钼组外,其余各组显著高于对照组(P<0.05或P<0.01)。结果显示:钼镉联合诱导可影响麻鸭脾脏的生长发育和白细胞免疫功能,上调脾脏MT mRNA表达量,钼镉呈协同关系。

In order to explore the effects of co-exposure to molybdenum （Mo） and cadmium （Cd） on immune function of leukocyte and mRNA expression level of MT in duck spleen,360 ll-day-old healthy ducks were randomly divided into 6 groups which were control group, low Mo group （LMo）,high Mo group （HMo）,Cd group （Cd）,low Mo combined with Cd group （LMo＋Cd）, high Mo combined with Cd group （HMo＋Cd） ,respectively. Ducks in control group were fed with basic ration,different dosages of Mo and Cd were added into basal diet based on feed weight,LMo （15 mg/kg Mo）,HMo （100 mg）,Cd （4 mg）,LMo＋Cd （15mg Mo,4 mg Cd）,HMo＋Cd （100 mg Mo,4 mg Cd）. （NH4）6Mo7O24 · 4H20 and 3CDSO4 ·8H20 were used as the sources of Mo and Cd,respectively,the experiment period lasted 120 days. Results showed that spleen index and leu- kocyte count on 120 day in HMo^-Cd group were significantly reduced in comparison with control group （P~ 0. 05）. granulocyte neutrophile ratio of experimental groups were significantly in- creased on 90 day and 120 day except LMo group （P〈0.05 or P〈0.01） while leukomonocyte were highly significantly declined of combination groups （P〈0.01）. Intermediate cell rate was significantly increased in earlier experiment stage, then declined significantly later. All those condi- tions were more obvious in Mo combined with Cd groups than that in single groups treated with Mo or Cd. Except LMo group,the mRNA expression level of MT on 60 day and 120 day in experimental groups were significantly increased compared to control groups （P〈0.05 or P〈0. 01）. In conclusion,co-exposure to Mo and Cd affected growth and development of spleen,immune function of ducks, up-regulated the mRNA expression level of spleen MT at the same time. Mo combined with cadmium might have synergistic toxic effect on ducks.