Effects Of Deoxynivalenol On Serum Indexes And Small Intestine Mechanical Barrier Of Mice

Deoxynivalenol(DON),a toxoid belonging to the trichothecenes family.In this experiment,80 SPF-grade Kunming mice aged 4 weeks and weighing 18～22 g were randomLy divided into 4 groups,and groups 1,2,and 3 were administered with 1.0 mg/kg BW and 1.5 mg/kg respectively.BW and 2.5 mg/kg BW DON for 21 days,the control group was given the same amount of normal saline.The ELISA method was used to study the effects of DON on serum and small intestinal antibody levels and antioxidant function,and HE staining,immunohistochemistry and Real-time qPCR methods were used to study the effects of DON on the small intestine microstructure and intestinal epithelial tight junction related protein mRNA.And the influence of PCNA protein expression.The test results showed that with the increase in the level of DON,the average daily gain and daily feed intake of mice in the middle and high-dose groups were significantly lower than those in the control group(P<0.05),and there was no difference in the low-dose group.Significant(P>0.05).Serum IgA levels in the middle-dose group increased significantly(P<0.05),while the high-dose group increased significantly(P<0.01).The serum IgG level in the high-dose group was significantly increased(P<0.05).The level of sIgA in the duodenum of the high-dose group was significantly lower than that of the control group(P<0.05).The jejunum sIgA levels of each group were not significantly different(P>0.05).In the ileum,the level of sIgA decreased with the increase of DON concentration.The middle-dose group was significantly lower than the control group(P<0.05),and the high-dose group was extremely significantly lower than the control group(P<0.01).Different levels of DON reduced the activity of T-AOC and SOD in serum.The T-AOC activity of each experimental group was significantly reduced(P<0.05),and the high-dose group was extremely significantly reduced(P<0.01);the SOD activity of the high-dose group was significantly reduced(P<0.05);the GSH-Px and MDA activities of each experimental group were compared with The changes in the control group were not significant(P>0.05).The T-AOC and GSH-Px levels of each intestinal segment in the high-dose group were significantly reduced(P<0.05).The middle dose of DON significantly reduced the activity of GSH-Px in the jejunum and ileum(P<0.05).Gavage of high-dose DON significantly reduced SOD activity(P<0.05);the duodenum and ileum SOD activity of the middle-dose group were significantly reduced(P<0.05);the low-dose group ileum SOD activity was significantly reduced(P<0.05)).DON in the test group significantly increased the MDA activity of the duodenum(P<0.05).High doses of DON significantly increased the MDA activity of the jejunum(P<0.05).It can be seen that DON reduces the immune function and intestinal antioxidant performance of mice,and it is dose-dependent.The small intestine structure of the control group is complete,the length of the villi is longer and tightly arranged compared with the test groups;the low-dose group has lighter damage,and some villi are damaged and lost;the middle and high-dose groups have obvious villi broken,the villi length becomes shorter and thinner,and the ileum is injured The most obvious.The expression of Claudin-1 mRNA in the three segments of the small intestine in the low-dose group was not significantly different(P>0.05),the expression in the duodenum and jejunum of the middle-dose group was significantly different(P<0.05),and the expression in the ileum was extremely different(P<0.01),the difference in the high-dose group was extremely significant(P<0.01);the expression of β-catenin gene mRNA showed that the difference in the duodenum in the low-dose group was not significant(P>0.05),and the difference in the jejunum was significant(P<0.05),the ileum was extremely different(P<0.01),the duodenum was not significantly different in the middle and high-dose groups(P>0.05),and the jejunum and ileum were extremely different(P<0.01);the Occludin gene in the low-dose group There was no significant difference in mRNA expression in each intestinal segment(P>0.05),the difference in the middle-dose group was significantly reduced(P<0.05),and the difference in the high-dose group was extremely significant(P<0.01).The positive reaction intensity of PCNA in the three segments of the small intestine of the test group decreased,and the IOD value was significantly decreased(P<0.01).It can be seen DON damages the mechanical barrier of small intestinal epithelial cells and inhibits the repair of barrier function by inhibiting the expression of PCNA protein and Occludin,Claudin-1,and β-catenin mRNA in the small intestine of mice.