Pathomorphology Of Vitamin E Deficiency In Channel Catfish (Ictalurus Punctatus)

The experiment was conducted to study the effect of vitamin E deficiency on morphology changes of channel catfish (Ictalurus punctatus). In this experiment, four hundered and eighty channel catfish which initial weight were 5.11±0.03g were randomly divided into 4 groups, and were fed the semi-purified diet supplemented with vitamin E 0, 5, 25 or 50mg·Kg^-1 respectively for 20 weeks. In this groups,Ⅰ,Ⅱ,Ⅲwere vitamin E defficiency groups and IV was the control group.Results indicated that, vitamin E deficiency had great effect on weight gain. The morbidity and mortality of the test groups were negatively correlated to the level of vitamin E in the diets. The morbidity and mortality were 53.33%, 32.50%, 12.50%, 0% and 25.83%, 14.17%, 7.50%, 2.50% respectively. Some deficiency symptoms such as "thin back" symptom charactered with obvious muscle atrophy, skin depigmentation, antisternum arcuation, exudative diathesis with exophthalmus and ascites were observed in the fishes fed vitamin E deficient diet during the experiment. Clinic anatomise showed transparent ascites, skeletal muscular dystrophy, especially in both sides of the back and whole viscus colour and luster gray. The liver was swollen with yellow color spots. The spleen,kidney and head kidney were swollen with hyperemia and hemorrhage. The heat was enlarged with hemorrhage in epicardium. In the histopathological examination, the skeletal muscles showed denaturalization and necrosis, infiltration with lymphocytes and monocytes, dystrophy of survival muscle fibers and enlargement of the muscle fibers interspaces. The cardiac muscles showed denaturalization and hemorrhage. The hepatocyte gained denaturalization, vacuolation and focal necrosis. The pancreas showed denaturalization and necrosis. The spleen took on dilation, ferric flavin aggradation in parenchyma and lymphocyte count decreased, macrophage licked up a great deal foreign body. The head kidney took on dilation and gore of parenchyma vein antrum and lymphoid tissue relative decrease. In the ultrastructural examination, the kidney showed enlargement of glomerulus, denaturalization in renal tubular epithelial cells; The M-line and Z-membrane of skeletal muscle and cardiac muscle blurred and disappeared; myofibril broke down and dissolved; the mitochondria of the skeletal muscle cells, the cardiac muscle cells, the liver cells and tubular epithelial cells were swollen with disintegration and lysis of caritas, the endoplasmic reticulum expanded and the quantities of glycogen were significantly reduced in the hepatocyte.Vitamin E deficiency lead many tissues and organs of channel catfish to pathological changes especially in skeletal muscle and hepatopancreas which showed degeneration, necrosis and damage of membrane structure represented with mitochondrion, endoplasmic reticulum, nucleus membrane. They casued some pathology characteristics such as "thin back" symptom, exophthalmus, skin depigmentation, antisternum arcuation and so on. Pathological changes of hepatopancreas resulted in loss of growth performance of channel catfish through degrading absorptive function.