反复肺炎支原体肺部感染大鼠肺组织中碱性成纤维细胞生长 …

目的 探讨反复肺炎支原体肺部感染大鼠肺组织中碱性成纤维细胞生长因子（ｂＦＧＦ）ｍＲＮＡ表达的变化。方法将８只大鼠于２４周内反复９次经超声雾化吸入肺炎支原体以复制其慢性肺部感染模型，另以４只为对照，随后用ｂＦＧＦｃＤＮＡ核酸探针行核酸分子原位杂交及定量图像分析，观察肺组织ｂＦＧＦｍＲＮＡ表达的变化。结果 （１）感染组动物（４只）支气管肺泡灌洗液肺炎支原体－聚合酶链反应（ＰＣＲ）检测均为阳性，而对照组

mRNA expression of basic fibroblast growth factor in the pulmonary tissues from rats repeatedly infected with mycoplasma pneumoniae

OBJECTIVE: To investigate changes in mRNA expression of basic fibroblast growth factor (bFGF) in pulmonary tissues from rats repeatedly infected with Mycoplasma pneumoniae (MP). METHODS: Rats were infected with MP for 9 times during a period of 24 weeks by ultrasonic nebulizing inhalation to establish animal models of chronic pulmonary MP infection. In situ hybridization was performed with bFGF cDNA probe and results were quantitatively analysed to measure the changes of bFGF mRNA expression in lung tissues. RESULTS: (1) MP polymerase chain reaction (PCR) tests showed positive results in the bronchoalveolar lavage fluid (BALF) from MP infected animals (n = 4) while results were negative for BALF from the control rats (n = 4) and rats infected with MP but treated with erythromycin (n = 4). Bacterial cultures of the bronchial and the lung tissues were negative in all three groups. Observation with transmission electron microscope showed that interalveolar septa were widened with increased amount of collagen in the MP infected rats while there were no obvious abnormalities in the other two groups. (2) Positive expression of bFGF mRNA were found in alveolar walls of MP infected rats. No expression of bFGF mRNA was found in control animals. In the rats infected with MP but treated with erythromycin positive expression of bFGF mRNA was found to be scarcely distributed in alveolar walls. Quantitative analysis showed that the optical densities of bFGF mRNA expression were 41.32 +/- 10.44 in the MP infected rats (n = 4), which were significantly higher than those in the control group (0.30 +/- 0.13, n = 4, P < 0.01) and those in the MP infected and erythromycin treated rats (6.03 +/- 2.41, n = 4, P < 0.01). CONCLUSIONS: Repeated pulmonary infection with MP can lead to up-regulation of bFGF mRNA expression, which suggests that bFGF might play a role in the pathogenesis of pulmonary interstitial fibrosis after repeated MP infection.