放射性肺损伤小型猪肺表面活性物质相关蛋白A、DmRNA的表达

目的：通过建立巴马小型猪放射性肺损伤模型，探讨肺组织在放射损伤后的不同时间点病理和表面活性物质相关蛋白A、D（pulmonarysurfactant—associatedproteinAandD，SP—A，SP—D）mRNA表达的变化。方法：健康雄性巴马小型猪30只随机分为空白对照组（空白组）和单纯照射组（单照组），行。。C07射线右胸野照射，单照组单次照射剂量为15Gy，空白组为0Gy。于照射后4，8，12周取右肺组织行HE染色，实时荧光定量PCR法（qPCR）检测肺组织中SP—AmRNA和SP—DmRNA的表达量。结果：HE染色结果表明照射4周后，肺泡中有炎性细胞渗出，间质水肿，第8周，肺泡壁增厚，肺泡结构破坏，第12周，肺组织实变，肺间质出现胶原纤维；qPCR检测结果发现单照组肺组织SP—AmRNA和SP-DmRNA的表达量与空白组各时间点相比都明显降低（P〈0．01），单照组各时间点SP—AmRNA和SP—DmRNA的表达量均随时间的推移进行性降低（P〈0．01），以第4周下降最明显。结论：SP—A、SP—D参与了放射性肺损伤的发生、发展过程，可为放射性肺损伤的发病机制及早期预测提供一定的实验依据。

EXPRESSION OF PULMONARY SURFACTANT-ASSOCIATED PROTEIN A AND D IN A MINIATURE PIG MODEL OF RADIATION INDUCED LUNG INJURY

Objective：To investigate the changes in pathology and expression of pulmonary surfactant associ- ated protein A and D （SP-A and SP-D） at different time points of radiation induced lung injury by establis- hing a model of Bama miniature pigs. Methods： Thirty male miniature pigs were randomly divided into con- trol and radiation groups, and each pig in the radiation group received 6~Co gamma-rays at a dose of 15 Gy, while control group 0 Gy. Pathological change of lung tissues was examined by HE staining and SP-A mR- NA, SP-D mRNA expression levels were determined by qPCR in the right lung tissues of the miniature pigs after 4, 8, 12 weeks of radiation. Results： HE staining showed that the alveolar spaces after 4 weeks of radiation had inflammatory cells exudation, followed by interstitial edema. The structure of alveolar de- structed and the walls incrassated at the 8＇h week. Pulmonary mesenchyme showed full of collagen fibers and local consolidation at the 12th week. The expression of SP-A mRNA and SP-D mRNA by qPCR was significantly lower in radiation group than in control group in each time point of the test （ P d0. 01）, and that decreased successively at the 4th, 8th and 12th weeks （ P d0.01）, of which the 4th week showed the fas- test descent rate. Conclusion： SP-A and SP-D participate in the progress of radiation induced pulmonary in- jury, which can provide experimental basis for further investigation of the pathogenesis and early predic-