邻苯二甲酸二甲酯对小鼠生长性能、免疫性能及小肠组织形态的影响

Effects of Dimethyl Phthalate on Growth Performance,Immune Performance and Small Intestinal Tissue Morphology of Mice

本试验旨在探究小鼠生长发育时期接触邻苯二甲酸二甲酯(DMP)对其生长性能、免疫性能及小肠组织形态的影响及孕鼠妊娠期接触DMP对仔鼠生长发育和免疫性能的影响。试验一:选取3周龄的雌性青年ICR小鼠30只,随机分为3组,每组10只。在饲喂相同基础饲粮条件下,2个试验组分别灌胃1000和2000 mg/(kg·d)DMP(以玉米油按照1 mL/kg的给药量稀释),对照组灌胃等量玉米油,试验期21 d。试验二:选取2月龄雌性ICR小鼠20只,随机分为2组,每组10只。2组小鼠饲喂相同的基础饲粮,DMP组灌胃1000 mg/(kg·d)DMP(以玉米油按照1 mL/kg的给药量稀释),对照组灌胃等量玉米油,从配种成功后第1天开始,直至分娩。试验一结果表明:1)与对照组相比,灌胃2000 mg/(kg·d)DMP使青年小鼠末重和平均日增重(ADG)显著降低(P<0.05);各组平均日采食量(ADFI)没有显著差异(P>0.05)。2)各组之间肝脏、脾脏、胸腺指数没有显著差异(P>0.05);与对照组相比,灌胃1000和2000 mg/(kg·d)DMP均显著降低了血清免疫球蛋白G(IgG)水平(P<0.05),对血清IgM水平没有显著影响(P>0.05)。3)与对照组相比,灌胃1000和2000 mg/(kg·d)DMP对十二指肠、回肠绒毛高度、隐窝深度及十二指肠绒隐比均无显著影响(P>0.05),但显著降低了空肠绒毛高度(P<0.05),显著提高空肠隐窝深度(P<0.05),显著降低了空肠与回肠绒隐比(P<0.05)。试验二结果表明:1)与对照组相比,孕鼠妊娠期灌胃1000 mg/(kg·d)DMP会造成仔鼠初生重降低,但差异不显著(P>0.05),断奶重和8周龄体重显著降低(P<0.05)。2)与对照组相比,孕鼠妊娠期灌胃1000 mg/(kg·d)DMP会造成仔鼠肝脏、脾脏指数显著降低(P<0.05),血清IgG和IgM水平显著降低(P<0.05)。3)DMP组仔鼠与对照组相比十二指肠、空肠、回肠绒毛高度显著降低(P<0.05),十二指肠、空肠、回肠隐窝深度无显著变化(P>0.05),空肠和回肠绒隐比显著降低(P<0.05)。综上所述,DMP对小鼠的正常生长发育有一定的影响,会降低小鼠免疫能力,且对小肠组织形态有一定的损伤。

This experiment was to investigate the effects of exposure to dimethyl phthalate(DMP)on growth performance,immune performance and small intestinal tissue morphology of mice during growth and development,as well as the effects of gestational exposure of pregnant mice to DMP on the growth,development and immune performance of offsprings.In experiment 1:thirty 3-week-old female ICR young mice were randomly divided into 3 groups of 10 mice each.Under the condition of feeding the same basal diet,mice in two experimental groups were gavaged with 1000 and 2000 mg/(kg·d)DMP(diluted with corn oil as the dose of 1 mL/kg)for 21 d,respectively,and mice in control group were gavaged with the same amount of corn oil.In experiment 2:twenty 2-month-old female ICR mice were selected and randomly divided into 2 groups of 10 mice each,and they were fed the same basal diet.Form the first day after successful mating to delivery,mice in DMP group were gavaged with 1000 mg/(kg·d)DMP(diluted with corn oil as the dose of 1 mL/kg),and mice in control group were gavaged with the same amount of corn oil.The results of experiment 1 showed as follows:1)compared with the control group,the final body weight and average daily gain(ADG)of young mice gavaged with 2000 mg/(kg·d)DMP were significantly decreased(P<0.05),and there was no significant difference in average daily feed intake(ADFI)among the groups(P>0.05).2)There were no significant differences in liver,spleen and thymus indices among the groups(P>0.05);compared with the control group,young mice gavaged with 1000 and 2000 mg/(kg·d)DMP significantly decreased serum immunoglobulin G(IgG)level(P<0.05),and had no significant effect on serum immunoglobulin M(IgM)level(P>0.05).3)Compared with the control group,young mice gavaged with 1000 and 2000 mg/(kg·d)DMP had no significant effects on the villus height and crypt depth of duodenum and ileum,and duodenum villus height/crypt depth(VH/CD)(P>0.05),significantly decreased the villus height of jejunum(P<0.05),significantly increased the crypt depth of jejunum(P<0.05),and significantly decreased the VH/CD of jejunum and ileum(P<0.05).The results of experiment 2 showed as follows:1)compared with the control group,pregnant mice gavaged with 1000 mg/(kg·d)DMP during gestation in resulted in reduced but not significant birth weight of filial mice(P>0.05),and the weaning weight and 8-week-old body weight were significantly reduced(P<0.05).2)Compared with the control group,pregnant mice gavaged with 1000 mg/(kg·d)DMP during gestation caused a significant reduction in liver and spleen indices and a significant decrease in serum IgG and IgM levels of filial mice(P<0.05).3)Compared with the control group,the villi height of duodenum,jejunum and ileum of filial mice in the DMP group were significantly reduced(P<0.05),the crypt depth of duodenum,jejunum and ileum had no significant differences(P>0.05),and the VH/CD of jejunum and ileum was significantly decreased(P<0.05).In summary,DMP has a certain impact on the normal growth and development of mice,reduces the immunity of mice,and has certain damage to the small intestinal tissue morphology.