Studies On The Brain Tissue Oxidative Caused By High Copper In Chickens

360 one-day-old Avian chickens were randomly divided into six groups,and fed on diets as follows:controls(Cu 10.89mg/kg) and high copper(Cu 100mg/kg,high copper groupⅠ;Cu 200mg/kg,high copper groupⅡ;Cu 400mg/kg,high copper groupⅢ;Cu 600mg/kg,high copper groupⅣ;Cu 800mg/kg,high copper groupⅤ) for six weeks.The growth velocity in high copper groupsⅠandⅡwere stepped up,while those were lowed in high copper groupsⅢ,ⅣandⅤ.Clinical symptom were appeared in the third week and death were happened in high copper group V.Pathological changes were appeared in high copper groupⅤwhen compared with those in control group.The chondriosome were intumesce in nerve cell,the medullary sheath were vacuolization and apoptosis cells were found in nerve cell of cerebellum ultrastructurally.The copper content in brain and serum were much higher in high copper groupsⅢ,ⅣandⅤthan in control gomp(P＜0.01). The brain tissue Cu-Zn-SOD and GSH-Px were significantly increased in high copper groupsⅠandⅡ,and decreased in high copper groupsⅢ,ⅣandⅤcompared with those of control group.The MDA,NO contents and NOS,hydroxy radical,monoamine oxidase(MAO) avtivities in brain tissue were much higher in high copper groupsⅢ,ⅣandⅤthan in control group.The brain tissue catalase(CAT) and choline esterase(CHE) activities were much lower in high copper groupsⅢ,ⅣandⅤthan in control group. The percentage of apoptotic brain cells was significantly increased in high copper groupsⅢ,ⅣandⅤcompared with that of control group.The serum copper protein(CP), copper-zinc-superoxide dismutase(Cu-Zn-SOD) and glutathione peroxidase activities (GSH-PX) were decreased in high copper groupsⅢ,ⅣandⅤcompared with those of control group,and increased significantly in high copper groupsⅠandⅡ.The serum malonaldehyde(MDA),nitrogen monoxidum(NO) contents and nitricoxide synthase (NOS) activity were much higher in high copper groupsⅢ,ⅣandⅤthan in control group,and the serum hydrogen peroxidase(CAT) activity were significantly decreased in high copper groupsⅢ,ⅣandⅤcompared with that of control group.The percentage of positive cells of Bax was increased in high copper groupsⅠ,Ⅱ,Ⅲ,ⅣandⅤ,and the percentage of positive cells of Bcl-2 decreased(p＜0.05 or p＜0.01) in high copper groupsⅣandⅤin comparison with those of control group.The results showed that the brain tissue antioxygen function was decreased and the percentage of apoptotic brain cells was increased under the dietary Cu in excess of 400mg/kg diet.