Abstract: Objective　To investigate the effects on release of blood-serum cytokines and lung tissues by inhibition of complement activation with cobra venom factor(CVF)in septic rats. Methods　One hundred and forty-four SD rats(clean, male,250-300g) were randomly divided into three groups(each n=48):group A(sham group); group B(sepsis group):sepsis was induced by cecal ligation and puncture (CLP) ; group C(CVF pretreatment):sepsis was induced by CLP after pretreatment with CVF，rats were given a dose of 50μg/kg CVF before operation, an equal volume of saline solution in group A and group B. MPO contents, levels of TNF-α、IL-6 and IL-10 were measured at 6 hours points. Lung tissues were observed the changes of histopathology. Results The manifestations of sepsis were severe in group B than that of group A. The levels of TNF-αand IL-6 were higher in group B than that of group A（P< 0.05 ，P< 0.01）. MPO contents of lung tissues were higher in group B than that of group A（P< 0.05 ,P< 0.01）.The degree of histological damage were much severe in group B than in group A. However, after injection CVF in group C, the manifestations of sepsis were much lighter, the levels of TNF-a、IL-6 and MPO were decreased obviously (P< 0.05,P< 0.01), and the histologic damage ameliorated in CVF group compared to that of group B. Conclusion CVF could lessen the systemic inflammatory response and provide pulmonary protection in septic rats.

Key words: sepsis, complement, cobra venom factor, cytokines, lung, protective effects