Pathological Study On Thiamphenicol Harming Experimentally In Carp

The harmful effect of different dosages of thiamphenicol on the pathomorphology, biochemical indexes and remains of thiamphenicol in muscle was investigated in carp. The carps, initial body weight 55 to 65 g, were in six groups and fed for 96 days on the standard diet with no thiamphenicol or diets containing 660, 1320 , 2640 and 5280mg thiamphenicol /Kg diet. During the whole trial, the clinical symptom in the tests were appetite descending, emaciation and activities reduction at different degrees. The larger the dose of thiamphenicol, the severer the clinical symptoms. Lesions induced by thiamphenicol in all tissues were examined. All the viscera almost appeared hypoplasia. Head kidney, kidney and liver all displayed tumefaction, brittle and color and luster lighting. Part of liver became green. Cholecyst was filling and expanded to the utmost. The characteristic lesions appeared in the head kidney, spleen, kidney, liver, pancreas and bowel. The first change was the reversible decrease of mature lymphocyte, neutrophil, monocyte, erythrocyte and melanin - macrophage center, and the convertible increase of the reticuloendothelial cell and hemopoietic stem cell in lymphoid tissue in spleen, head kidney and kidney, chromaffin tissue in the head kidney display granular degeneration and vacuolation. The second important lesion was congestion and expanding of the central veins and blood capillary, coagulation necrosis of the hepatocytes around central veins in liver. A great quantity of lymphocytes and monocyte Infiltrated into coagulation necrosisareas, and become the so-called the zone of inflammtion. The lesions in pancreas were swelling, degeneration and lysis of cells, and there were several lytic necrosis areas in which many melanin - macrophage center aggregated in pancreas. Mucus cells in the intestinal mucosa hyperplasia severely. Renal cells appeared cellular swelling, granular degeneration, detachment from the basement membrane, running off of the plasm of cells and becoming reticular formation. Some of renal corpuscles increase and endothelial cells of blood capillarys in renal corpuscles appear hyperplasia and renal tubule regeneration isvirous in later period. About biochemical indexes, the results were as follows: RBC ,WBC,Hb, and T-AA decreased significantly, and there was significant difference contrast to the control(p<0.01). Serum iron and P -N-acetyl aminoglucose increased significantly((p<0.01). There were significant difference between the tests and the control. The changes of ultrastructure appeard breakage , Lysis and extinction of the mitochondrial crista in liver, spleen, kidney and head kidney; the increase of euchromatin in hepatocyte nuclei; nuclear membrane of the erythrocyte in liver and the renal cells and lymphocyte in Interstitial expanding and the gap around the Nuclei broading; microvillus of the renal cells swelling and Shedding; chromatin in the immature leucocyte moving to the edge of the nucleus.