Arginase, nitrik oxide, some antioxidant enzymes and levels of lipid peroxidation in tissues of blood and liver in sheep infected with fasciola hepatica and biochemical properties of arginase enzyme in liver

92 7. SUMMARY Fasciola hepatica is a parasiter disease which is often seen in sheep and causes liver injury. In the study of sheep with cirrhosis and fibrosis which is come into being by chronic fasciolasis; -Levels of arginase enzyme in erythrocyte and liver and biochemical features of arginase enzyme in liver, -Levels of lipid peroxidation in plasma and liver as an indication of free radical damage, -Levels of total nitrit in serum and liver as an indication of nitric oxide, -Enzyme activity levels of catalase and glutathione peroxidase which are from antioxidant defence system are measured. The method of Griess was used for measuring levels of nitrit; Tiyosemicarbazide-Diasetilmonoxim-Urea (TDMU) method for activity of arginase; Aebi method for activity of catalase; Beutler method for activity of glutathione peroxidase; a modified method of Satoh and Yagi for plasma levels of MDA; the Ohkawa et al. method for tissue levels of MDA; The Lowry method for protein concentration and siyanomethemoglobin method for concentration of hemoglobin. In the conclusion; -Any differences can not be found between erythrocyte arginase, catalase, glutathione peroxidase and plasma malondialdehyde and levels of serum nitrit of healty sheep (P > 0.05). There is no difference between healty sheep and sheep with fasciolasis for biochemical features of liver arginase enzyme. It was determined that presence of 1 mM Mn+2 ions, 1 5-minute-preincubation at 65 °C and 10 minute- incubation at 37 °C are necessary for activation of arginase in liver tissue of sheep. The most suitable buffer for enzyme of arginase in liver tissue is bicarbonate buffer and it was found about optimal pH:10. Km which is against L-arginine-substrat of enzyme- was found by the method of Michaelis-Menten and Lineweaver-Burk and it is about 4 mM.93 -While levels of arginase, catalase enzyme activity and nitrit and malondialdehyde in liver with faciolasis decrease, glutathione peroxidase activity increases (p< 0.01). Decrease in lipid peroxidation can be come into being decreasing pollyunsaturated fatty acids in structure of cell membrane as a result of excessive fibrosis. Decrease in activities of arginase and catalase can be come into existence from increasing of fibrotic tissue in liver. Decrease in level of nitrit in liver can be come into being from damage endothelial cells and hepatocytes in liver. Increase in activity of glutathione peroxidase can be come into being from liver injury..--