The Effect Of Phase Ⅱ Detoxification Enzymes In Regulating The Hazard Control Of Common Mycotoxins In Shrimp(Litopenaeus Vannamei)

T-2 toxin, AFB1, DON and OTA are the toxic metabolite of moulds, they are mycotoxin, and were the common mycotoxins that occured in shrimp feeds. They are highly toxic and not easily detoxified, they are stable. They can cause shrimp disease,production performance descends, and quality decreased and so on. They bring great harm to the development of shrimp industry, lead to large economic loss, and have potential food safety risks at the same time. To effectively control the harm is hotspot issues to be solved.So, according to the principle of biological transformation, we study the expression of phase Ⅱ key detoxification enzymes, in order to achieve goals to reduce the mycotoxin harm.Our study was based on toxicology design principle. 20 days’ accumulation infected,the initial infected doses of T-2, AFB1, DON and OTA were 4.8, 1.2, 6.0 and 1.78mg/kg·feed, respectively, 4 days for a period, increase 1.5 times each period, For another,adopted three inducers(quercetin, rutin and tea polyphenols), and their initial doses in feed were 0.2%, 0.3% and 0.04% respectively, 4 days for a period, increase 2.0 times each period. And set toxins and inducers together in feed, to study the effect of phase Ⅱdetoxification enzymes in regulating the hazard control of common mycotoxins in shrimp(Litopenaeus vannamei).About the damage of mycotoxins, we mainly from the following aspects, compared the harm changes, further proved the endogenous enzymes controlling technology on common mycotoxins in induced shrimpFirst, from the perspective of physiological characteristics(survival rate, increasing weight rate and feeds intake rate and so on), the results showed that four toxins all could lead to the decrease of the shrimp survival rate, weight rate, specific growth rate and feeds intake rate. And AFB1 had the lowest values of these indexes.After 20 days of dose escalation infected assay, the cumulative coefficient of T-2 and DON toxins were 4.26 and 3.76 respectively, medium accumulation. While KAFB1 was 2.24,obvious accumulation. And we can detected toxin residues(T-2, AFB1, DON and OTA) in shrimp tissues using the LC-MS/MS method. Indicated that not only in shrimp therewas material accumulation, but also functional accumulation.Second, on account of the histopathologic changes of shrimp muscle, hepatopancreas and intestine, when shrimp exposed to the mycotoxin(T-2, AFB1, DON and OTA), results indacated that, with the increase of the cumulative infected dose, the more serious the pathological damage in a dose-dependent manner. Mainly in the damage of myofiber,sarcomere, and the spatium intramusculare was increased or fractured, even appeared melt phenomenon; Hepatopancreas basement membrane fall off, the cell compact structure was destroyed, hepatic ductswas damaged and became vacuoles under electronic microscope,cytolysis and hypochromatosis; The epithelium mucosa fold of intestine was reduced, the toxin could cause inflammation of the bowel wall, seriously of the tissue separation,structure unconsolidated, muscular layer became thinner, showed the dissolved state.Third, from the phase Ⅱ key detoxification enzymes change point, we detected the phase Ⅱ enzyme activities in different shrimp tissues in the five stages of four mycotoxins The results showed that, during the 20 days’ exposed period, the four toxins were maily inhibited the activities of Sulfotransferase(SULT) and Arylamine N-Acetyltransferase(AANAT). T-2 toxin inhibited the activity of Glutathione S-transferase(GSTs) in shrimp muscle, but could induced the expression of GSTs in shrimp muscle at the exposed dose of0.5 mg/kg. While the inductive effect of inducers on SULT and AANAT were bigger than that on GSTs, Uridine diphosphate glucuronyl transferase(UGT) and Methyltransferase(MT). Then we found that the toxins and inducers toghther could induced the activities of SULT and AANAT.Fourth, from the correlation analysis of the changes between phase Ⅱ key detoxification enzymes activities and harm change with inducers, using statistical analysis software, find out the inducers that could control the mycotoxin hazard, and reduced the toxin residues,could repair the pathological injury of shrimp exposed to mycotoxins. Different inducers could induce the different enzymes in shrimp.Conclusion:(1) T-2, AFB1, DON and OTA all could lead to the decrease of the shrimp survival rate, weight rate, specific growth rate and feeds intake rate. And AFB1 had the lowest values of these indexes. And they could all lead to the damage of shrimp muscle,hepatopancreas and intestine. With the increased exposed dose of toxin, the spatium intramusculare was increased or fractured, even appeared melt phenomenon; The cell compact structure was destroyed, cytolysis and hypochromatosis; The toxin could cause inflammation of the bowel wall, seriously of the tissue separation, showed the dissolved state.(2) There’s toxins in shrimp after exposed to mytoxins, and the muscle,head and blood had high toxin residue. T-2 and DON were medium accumulation, andAFB1 was obvious accumulation.(3) The mycotoxins could inhibited SULT and AANAT enzyme activities, when added inducers in shrimp feed, the toxin residue in shrimp was reduced and the enzyme activities of SULT and AANAT were also induced. the inducers had repair features in the pathological injury in shrimp exposed to mycotoxins. And the SULT was the main mMetabolic enzymes in shrimp.