肌肽对H9N2亚型猪流感病毒致小鼠肺部组织SOD、MDA、iNOS和NO的影响
Effect of Carnosine on SOD, MDA, iNOS and NO in Mice Lung Tissue Infected with H9N2-SIV

探讨肌肽（carnosine）对H9N2亚型猪流感病毒（H9N2-SIV）致小鼠肺部损伤时肺组织的超氧化物歧化酶（SOD）、丙二醛（MDA）、诱导型一氧化氮合酶（iNOS）和一氧化氮（NO）的影响。选用6～8周龄SPF级雌性BALB/c小鼠150只，随机分为对照组、模型组和肌肽组，每组50只，分别给予正常鸡胚尿囊液、H9N2-SIV和肌肽+H9N2-SIV。试验第2、4、6、8和14天分别观察小鼠的临床表现，统计死亡率，每个观测时间每组处死8只小鼠，检测肺组织匀浆中SOD、MDA、iNOS和NO。肌肽可减轻H9N2-SIV造成的小鼠临床症状，降低死亡率，在试验第6、8天显著提高肺组织的SOD活性（P＜0.05），显著降低MDA含量、iNOS活性和NO含量（P＜0.05）。肌肽通过提高肺部SOD活性，降低iNOS活性、MDA含量和NO含量，抑制由H9N2-SIV造成的自由基和脂质过氧化反应，改善肺组织的水肿程度，减轻小鼠肺损伤的程度、降低死亡率。
To investigate the effect of carnosine on the change in SOD, MDA, iNOS and NO of mice lung which was infected with H9N2-SIV. One hundred and fifty BALB/c SPF female mice (6 to 8 weeks old) were divided randomly into control group, ALI group and carnosine group with 50 mice each, each group were treated with normal allantoic fluid, H9N2-SIV and carnosine plus H9N2-SIV. On the 2nd,4th, 6th, 8th and 14th day , clinical symptom and mortality rate were observed, and eight mice of each group were executed at the same time to detect SOD, MDA, iNOS and NO of lung homogenate. Carnosine could alleviate clinical symptom and reduce mortality rate affected by H9N2-SIV. On the 6th and 8th day of experiment, SOD activity of lung tissue was raised apparently（P＜0.05）, MDA content were reduced obviously（P＜0.05), and the same to iNOS activity and NO content （P＜0.05). Carnosine could inhibit free radicals and lipid peroxidation reaction, ameliorate edema degree, alleviate damage degree of lung as well as cut down mortality rate affected by H9N2-SIV through increasing SOD activity as well as reducing iNOS activity, MDA and NO content.