脱氧雪腐镰刀菌烯醇和黄曲霉毒素B1单一及联合染毒对小鼠脑组织病理变化、抗氧化性能和紧密连接蛋白表达量的影响

Effects of single and combined exposure of deoxynivalenol and aflatoxin B1 on pathological changes, antioxidant capacity and tight junction protein expression of brain tissue in mice

本试验旨在研究脱氧雪腐镰刀菌烯醇(DON)和黄曲霉毒素B1(AFB1)单一及联合染毒对小鼠脑组织病理变化、抗氧化性能和紧密连接蛋白mRNA表达量的影响。选取96只18日龄昆明系雄性小鼠,随机分为对照组、DON组、AFB1组和AD组(DON+AFB1组),每组分别灌服生理盐水、500μg·kg-1DON、200μg·kg-1AFB1和200μg·kg-1AFB1+500μg·kg-1DON,连续灌服45d。分别于试验的第0、15、30、45天,每组随机选取6只小鼠,麻醉后处死,取脑组织观察病理变化,并检测脑组织氧化与抗氧化指标及紧密连接蛋白ZO-1和OccludinmRNA的表达量。结果显示,与对照组相比,DON组小鼠脑组织超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性显著下降(P<0.05),NO含量显著升高(P<0.05);AFB1组小鼠脑组织中CAT活性显著下降(P<0.05);AD组脑组织总抗氧化能力(T-AOC)、CAT、SOD活性显著下降(P<0.05),丙二醛(MDA)和NO含量显著上升(P<0.05);各染毒组脑组织ZO-1和OccludinmRNA的表达量显著下降(P<0.05)。研究结果表明,DON与AFB1单一及联合染毒均能造成小鼠脑组织不同程度的病理变化,降低抗氧化性能及紧密连接蛋白ZO-1和OccludinmRNA的表达量,且DON与AFB1的联合毒性大于单一毒性。

The present experiment was conducted to evaluate the effects of single and combined exposure of deoxynivalenol (DON) and aflatoxin B 1 (AFB 1) on pathological changes,antioxidant capacity and tight junction protein expression of brain tissues in mice.Ninety-six 18-day-old Kunming(male)mice were randomly divided into control group,DON group,AFB 1 group and AD group (DON+AFB 1 group).Each group was fed with physiological saline,500 μg ·kg-1 DON,200 μg ·kg-1 AFB 1 and 200 μg ·kg-1 AFB 1+500 μg ·kg-1 DON by gavage respectively.The trial was conducted for 45 d.On the days 0,15,30 and 45 of the experiment,six mice in each group were randomly selected and killed after anesthesia,the brain tissues were collected for observing pathological change and measuring the oxidative and antioxidant indexes and the mRNA expression of tight junction protein ZO-1 and Occludin of brain tissue in mice.The results showed that compared with the control group,the activities of superoxide dismutase (SOD) and catalase (CAT) in brain tissues of DON group were decreased significantly ( P <0.05),while the content of NO was increased significantly ( P <0.05).The activity of CAT in brain tissue of AFB 1 group decreased significantly ( P <0.05).The activities of T-AOC,CAT and SOD of brain tissues in the AD group were decreased significantly ( P <0.05).The contents of MDA and NO of brain tissues were increased significantly ( P <0.05).The mRNA expression of ZO-1 and Occludin were decreased significantly in treatment group ( P <0.05).In conclusion,single and combined exposure of DON and AFB 1 can lead to different degrees of pathological changes,as well as reduce antioxidant capacity in mouse brain tissue,produce oxidative damage,while decrease the mRNA expression of ZO-1 and Occludin .DON and AFB 1 exhibit a significant interaction with synergistic effects.