气管滴注大肠杆菌对肉仔鸡肺部抗氧化性能的影响

Effect of Intratracheal Installation of Escherichia coli on Antioxidant Activities in Lung Tissue of Broilers

试验通过对肉仔鸡气管滴注大肠杆菌研究大肠杆菌对肺部抗氧化性能的影响。选取体重一致、健康状况良好的固始肉仔鸡30只,随机分为两组。对照组气管滴注无菌培养液1 m L,试验组气管滴注1×10~9cfu/m L大肠杆菌的培养液1 m L,2 h后进行解剖,观察肺部变化,取肺部组织做组织匀浆,用于测定脂多糖（LPS）和丙二醛（MDA）含量,以及谷胱甘肽过氧化酶（GSH-Px）和超氧化物歧化酶（SOD）活性。结果显示：试验组肉仔鸡肺部有出血斑和出血点,血液中的LPS有升高趋势（P=0.072）,肺组织中的LPS含量显著升高（P〈0.05）,MDA含量有升高趋势（P=0.063）,SOD活性极显著降低（P〈0.01）,GSH-Px活性有降低趋势（P=0.076）。结果表明：气管滴注大肠杆菌可显著降低肉仔鸡肺部抗氧化性能。

The effect of Escherichia coli （E. coli）on antioxidant properties of respiratory tract of chicken was studied in this paper. 30 7-day-age broilers were randomly divided into two groups, one experimental group and one control group, l xl09 cfu E.coli was given to broilers in the experimental group by intratracheal instillation,respectively. Aliquots of agar were administered in the same protocol in the control group. The broilers in each group were sacrificed for blood and lung tissue sample on 2 h after instillation. The concentration of lipopolysaccharides （LPS） in the blood was measured, and the samples of lung were used to detect the concentration of malondialdehyde （MDA） and LPS, the activities of glutathione peroxidase （GSH-Px）and superoxide dismutase （SOD）. The results showed that the concentration of LPS in lung was significantly increased by E. coli （P〈0.05）. There was an increasing tendency in the concentration of LPS in blood （P=0.072） and MDA in lung tissue （P=0.063） of broilers in the experimental group compared with the control. The activities of SOD were significantly decreased （P〈0.05） and GSH-Px （P=0.076） showed a decreasing tendency in the E. coil-treated broilers. The results suggested that the antioxidant ability of lung tissue in broilers would be significantly decreased by intratracheal instillation with E. coll.