Effects Of Excess Iron On Expression Of Main Inflammatory Factors And Histopathological Changes Of Parenchymal Organs In Sheep

Iron is a necessary trace element in the body and plays an indispensable role in biological metabolism.The iron content in the body is dynamically balanced,and the iron excess will cause damage to the body's tissues and organs.Sheep in domestic animals have the lowest tolerance to iron and are more prone to iron overload and iron poisoning,the National Scientific Research Council(NRC,2005)recommends a maximum tolerance of 500mg/kg to iron for sheep.In this experiment,16 adult sheep were randomly divided into four groups: control group(CON),iron excess group 1(Iron E1),iron excess group 2(Iron E2)and iron excess group 3(Iron E3).50mg/kg,500mg/kg,1000mg/kg and 1500mg/kg iron were added to the base diet and slaughtered after 75 days.Take the hearts,livers,spleens,kidneys and lungs,and the expression changes of organs IL-1?,IL-2,IL-6,TNF-?,IFN-?,NF-?B and TGF-?1 m RNA were detected by Fluorescence Quantitative PCR method;The protein content changes of IL-1?,IL-2,IL-6,TNF-? and IFN-? were detected by ELISA method;The protein content changes of NF-?B and TGF-?1 were detected by Western Blot method.Histopathological changes and hemosiderin distribution were detected by HE staining and Perls staining methods with frozen sections.To investigate the expression of the main inflammatory factors and histopathological changes in the parenchymal organs of sheep after iron excess.The results are as follows:(1)The IL-1?,TNF-? and IFN-? m RNA expression and protein content were decreased and the IL-2,IL-6,NF-?B and TGF-?1 m RNA expression and protein content were increased of heart,liver,spleen,lung and kidney after iron excess in sheep and with the increase of iron dose corresponding to the relationship.The content of these inflammatory factors in parenchymal organs changed significantly or significantly(p<0.05 or p<0.01)after 1500 mg/kg iron was added to the basal diet.Suggesting that iron excess inhibits IL-1?,TNF-? and IFN-? secretion in sheep parenchymal organs and attenuates the inflammatory response induced by iron excess by reducing the content of pro-inflammatory factors.And the IL-2,IL-6,NF-?B and TGF-?1 secretion of sheep parenchymal organs increased after iron excess.While pro-inflammatory factors induce inflammation in the body,the content of pro-inflammatory factors increases against tissue damage.(2)Histopathological injury of liver and spleen was the most serious after iron excess in sheep,hemosiderin deposition was obvious.Kidney and heart also have different degrees of pathological damage,mainly manifested as inflammatory cells infiltration,tissue cells degeneration,tissue cells necrosis and tissue fibrosis.