Effects Of Oxidative Stress On The Intestinal Oxidative Injury And Barrier Function Of Broiler Chickens

A broiler intestinal acute oxidative stress model was established by infuse Fe2+and VC. On thisfoundation, we investigated the effect of oxidative stress on broiler intestinal oxidative injury and barrierfunction. Futher more, we studied the effect of VE and Gln on broiler intestinal oxidative injury and barrierdisfunction which was induced by oxidative stress. At last, we investigated the effect of LPS stress onbroiler intestinal oxidative injury and barrier function, and the role of Gln, Thr, BCAA diet in the LPSstress.Trial1, thirty-two1day old Arbor Acres broilers were assigned randomly to4groups. Group A and Bwere infused with VE0mg, Group C and E were infused with VE20mg.1h later, A and C were infusedwith distilled water, B and E were infused with Fe2+and VC.4h later, all broilers were killed. We foundoxidative stress cause significant oxidative injury by increased MDA level of serum and jejunum. VEameliorates the oxidative injury. Oxidative stress significantly decreased the mRNA expression of ZO-2,occludin and EGFR, increased the mRNA expression of HB-EGF. VE significantly decreased the mRNAexpression of ZO-2and HB-EGF.Trial2, on the base of trial1, Gln was added. Sixty-four1day old Arbor Acres broilers were assignedrandomly to8groups, all were treated with0%Gln or2%Gln for48h, then the broliers were treated astrial1. The results showed that, oxidative stress significantly increased the MDA level of jejunum, the8-OHdG level of serum and jejunum. VE significantly decreased the MDA level of jejunum. Glnsignificantly increased the activity of jejunum GSH-PX and CAT, decreased the protein carbonyl level ofjejunum. Oxidative stress significantly decreased the mRNA expression of occludin, increased HB-EGF.VE significantly decreased the mRNA expression of ZO-2and HB-EGF. Gln, VE and oxidative stress hadno effect on the protein expression of jejunal occludin and ZO.Trial3, the broilers were feed with one of the followed diets for10days: control diet, Gln diet, Thr diet,BCAA diet. At the age of10, chose16broilers from each diet and divided into2groups, one was injectedwith LPS(5mg/kg), the other one was injected with distilled water.6h later, all broilers were killed. We found LPS significantly increased8-OHdG level of serum, decreased the activity of serum GSH-PX,decreased the activity of jejunum SOD and CAT, decreased the mRNA expression of occludin. Gln dietsignificantly increased the activity of jejunum SOD, serum GSH-PX, the mRNA expression of HB-EGF,decreased the8-OHdG level of jejunum, the mRNA expression of EGFR. Thr diet significantly increasedthe activity of jejunum CAT, decreased the activity of serum SOD and CAT, decreased the mRNAexpression of HB-EGF and EGFR. BCAA diet significantly decreased the8-OHdG level of jejunum,increased the activity of jejunum SOD.Consider all the result, we can conclude that:1. A broiler intestinal acute oxidative stress model was established by infuse Fe2+and VC.2. Both VE and Gln ameliorates the oxidative injury caused by oxidative stress. Gln and VE willcomplementary each other on the remission of oxidative injury.3. Neither Oxidative stress VE nor VE and Gln will affect the tight junction of jejunum.5. Inject LPS will induce significantly nucleic acid injury, decrease the ability of anti-oxidative injejunum. LPS will damage the tight junction of jejunum.6. The anti-oxidative ability will increased by Gln, Thr and BCAA diet. But according to the mRNAexpression of ZO-2and occludin, they have no effect on the tight junction of jejunum.