研究背景： 生物标志物能够有效指示机体的疾病状态及其他的生理状态， 目前研究较多关于血液中生物标志物开展。相较血液而言，尿液更易大量、无 创、多次采集且其中生物标志物成分更为稳定，是研究生物标志物的良好来源。 研究目的： 实验通过对大鼠腹腔注射大肠杆菌菌液，研究注射后大鼠尿液 蛋白质组成分的变化，并后续分析含量变化的蛋白质所引起的生物过程与通 路的变化， 为现有的疾病标志物的研究作为补充并为尿液蛋白质组数据库的 建立积累数据。 实验方法： 本实验使用动物为 Wistar 140g 雄性大鼠 8 只。随机选取 4 只为实验组，其余 4 只为对照组。实验组大鼠腹腔内注射 2 ml Escherichia coli (DH5α 1×108CFU/mL)，对照组不做处理， 实验采取自身对照的方法。 收集尿液，适应环境 3 天后注射大肠杆菌，注射大肠杆菌起 0h， 24h， 72h， 分别收集实验组尿液。每次收尿之前称量并记录全部大鼠的体重，收尿时长持 续 12h。 收集尿液并使用乙醇沉淀法提取蛋白，并使用液相色谱分离串联质谱 (LC-MS/MS)进行分析。 实验结果及结论：经过筛选，在整个实验过程中一共找到 49 个差异蛋白， 其中四种蛋白在注射后 12 小时、注射后 84 小时重复出现，并且含量均有上 升。 对大鼠腹腔注射大肠杆菌后， 大鼠尿蛋白质成分发生变化。 尿蛋白可有效 区分出注射在同一部位不同种类的细菌、真菌、癌细胞造成的影响，也可以区 分出不同器官的同种细菌感染。

BACKGROUND: Biomarkers can effectively indicate the disease status and other physiological status of the body. At present, there are many studies on biomarkers in blood. Compared with blood, urine is easier to be collected in large quantities, non-invasively and many times, and its biomarker composition is more stable, which is a good source for the study of biomarkers. OBJECTIVE: To study the changes of proteins in rat urine after intraperitoneal injection of Escherichia coli, and to analyze the changes of biological processes and pathways caused by the changes of protein content in rat urine, so as to supplement the research of disease markers and accumulate data for the establishment of urine proteome database. METHODS: Eight Wistar 150g male rats were used in this experiment. Four were randomly selected as the experimental group and the other four as the control group. The rats in the experimental group were intraperitoneally injected with 2 ml Escherichia coli (DH5alpha 1 *108 CFU/mL), while the rats in the control group were not treated. The urine of the experimental group was collected by self-control method. After 3 days of adaptation to the environment, E. coli was injected into the urine of the experimental group for 0 h, 24 h and 72 h. The weight of all rats was4 weighed and recorded before each urination. The duration of each urination lasted 12 hours. Urine was collected and protein was extracted by ethanol precipitation and analyzed by LC-MS/MS. EXPERIMENTAL RESULTS AND CONCLUSIONS: After screening, 49 differential proteins were found in the whole experiment, which were repeated 12 hours after injection and 84 hours after injection, and the contents of the four proteins were increased. The urinary protein composition of rats was changed after intraperitoneal injection of Escherichia coli. Urinary protein can effectively distinguish the effects of different kinds of bacteria, fungi and cancer cells injected into the same site, and can also distinguish the same bacterial infection in different organs.