Changes Of Apoptosis And Pathology In Liver And Kidney Of Chicks After Iron Excess

Iron is an indispensable trace element in the process of life activities and plays an important role in biological metabolism.The "Agricultural Industry Standards of the People’s Republic of China < Chickens feeding standards >" stipulates that the normal iron requirement of chicken is80～100 mg/kg feed,and the tolerance amount is 500 mg/kg feed.The iron content in the body is dynamically balanced,and excessive iron will destroy iron homeostasis and cause pathological damage to tissues and organs.The liver has a first-pass effect of iron absorption,controls the synthesis of hepcidin,and excretes hepcidin by the kidneys,both of which are extremely important for maintaining iron homeostasis balance.In actual production,the amount of iron added is too high or too low,which will lead to organ dysfunction and harm the development of aquaculture.In this study,75 1-day-old chicks were taken as the study subject,and after 10 days of adaptive rearing,the chicks were randomly divided into three groups: control group(CON),iron excess group 1(Iron E1)and iron excess group 2(Iron E2).Chicks of iron excess group 1 and iron excess group were added to the basal diet of ferrous sulfate to 500 and 1000 mg Fe/kg feed,respectively,for three consecutive days.At 1,3,7,14 and 21 days after iron excess,5 chicks were randomly selected from each group,blood was collected from the heart and executed.Take livers,kidneys and serum quickly.Observation of morphological changes in liver and kidney and calculation of organ cofficient;Detection of serum enzyme activity;The q PCR and Western blot method were used to detect the expression of apoptosis related factors;The histopathological changes,hemosiderosin deposition and apoptosis of chicks after iron excess were observed by paraffin sectioning,HE staining,Prussian blue staining and Hoechst staining;Ultrastructural changes were observed by transmission electron microscopy;The apoptosis and phological changes of chick liver and kidney after iron excess were analyzed,and the study results were as follows:(1)After iron excess of chicks,the liver and kidney were engorged,the color became darker,the iron content of tissues was increased,the activity of serum ALT,AST and LDH enzyme was enhanced,and the most significant on the first day after iron excess,and it returns to normal after21 days.It was shown that excessive iron intake affected the physiological function of liver and kidney,and iron metabolism in chicks liver and kidney had a periodicity.(2)After iron excess of chicks,the m RNA expression and protein content of liver and kidney pro-apoptotic factors Caspase-3,Caspase-9 and Bax increased to varying degrees,and the apoptotic factor Bcl-2 decreased to varying degrees.The expression of correlators in the PI3K/AKT/m TOR signaling pathway suppressed.It was shown that excessive iron caused apoptosis in chicks liver and kidney,and apoptosis was regulated by network regulation and signal transduction between factors.(3)After iron excess of chicks,histopathological damage and ultrastructural changes occurred in the liver and kidney.The hepatic lobule structure was destroyed,there was hemorrhage between the liver plates,disorganized hepatocyte cords,massive inflammatory cell infiltration,and hemosiderin deposited in the sinusoidal spaces of the liver;the kidney had hemorrhage in the renal tubular space and glomerular capsule lumen,degenerative necrosis of the renal tubular epithelium,narrowing of the tubular lumen,and hemosiderin deposited mainly in the renal tubular epithelium,etc.The liver and kidney organelles were damaged,with cell nuclei crinkled and nuclear membranes ruptured,and the damage was enhanced with increasing iron excess.It showed that excessive iron was deposited in the liver and kidney tissues of chicks,caused structural damage to liver and kidney,and compared to the two,liver lesions were more obvious.