The Principles Of The Changes Of Nitric Oxide And Nitric Oxide Synthase In The Rabbits Infected With E.stiedai And Their Roles In Anti-parasite

The rabbits infected with E.stiedai were injected with the substrate of NOS—L–Arg and the inhibitor of iNOS—L–AG through the abdominal cavity. Then study the concentration of NO in the serum, the activity of iNOS in the liver and the pathological changes and etc of rabbits in each group then to approach the effect of NO and NOS of the rabbits infected with E.stiedai.The results showed that when the rabbits were infected with E.stiedai, the activity of iNOS in the liver and the concentration of NO in the serum gradually increased and they both reached the peak after 12 days in the control group , L–Arg and L–AG groups. Then they gradually decreased and reached the level before infection about 23 days later. L–Arg can enhance the activity of iNOS and promote the production of NO so as to improve the inhibition on E.stiedai and weaken the pathological changes caused by E.stiedai. On the contrary, L–AG can decrease the activity of iNOS and reduce the amount of NO produced in the body . The clinical signs,gross and histologic lesions and coccidiosis in L-AG treated group were exacerbated. The rabbit of infective control groups showed typical pathological changes of infected by E.stiedai. These results indicated that L-Arg might successfully activate the NO production in serum and the iNOS activity of the liver and L-AG might inhibit the iNOS activity of the liver then influence the NO production in serum.The results indicate that NO and NOS participate in the process of anti–parasite, so NO is proved to be an effector molecule in anti–E.stiedai infection.