论文部分内容阅读
目的肺表面活性物质蛋白D(SP-D)被认为是急性肺损伤(ALI)和急性呼吸窘迫综合征(ARDS)有价值的生物指标,但在急性肺损伤早期,肺组织SP-D的变化特征仍不清楚。该研究旨在探究脂多糖(LPS)诱导的SD幼鼠急性肺损伤时SP-D,SP-D mRNA的时序变化及肺泡Ⅱ型上皮细胞及板层小体的超微结构的变化。方法腹腔内注射LPS建立急性肺损伤模型。注射后6,12,24,36,48,72 h各处死8只大鼠。W estern b lot和RT-PCR方法测定肺组织SP-D和SP-D mRNA的含量。透射电子显微镜研究肺泡Ⅱ型上皮细胞超微结构的变化。结果LPS注射12 h后SP-D和SP-D mRNA含量均开始下降。SP-D mRNA于注射LPS后24~36 h降到最低。SP-D在48 h达最低点。透射电镜显示急性肺损伤组板层小体出现多样变形,特别是在注射后48 h。LPS导致板层小体的体积增大、数量减少,伴有大量空泡样变。结论在LPS诱导的急性肺损伤的早期SP-D的波动变化呈时间依赖性。肺组织SP-D在48 h时水平最低,此时伴有肺泡Ⅱ型上皮细胞严重的多形性变。在ALI发病初期,肺组织低水平的SP-D与较差的临床预后有关。
Objective SP-D is considered as a valuable biomarker of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). However, in the early stage of acute lung injury, changes of SP-D in lung tissue Features are still not clear. The aim of this study was to investigate the temporal changes of SP-D and SP-D mRNA and ultrastructural changes of type II alveolar epithelial cells and lamellar bodies in acute lung injury induced by lipopolysaccharide (LPS). Methods Acute lung injury model was established by intraperitoneal injection of LPS. Eight rats were sacrificed at 6, 12, 24, 36, 48 and 72 h after injection. The contents of SP-D and SP-D mRNA in lung tissue were determined by Western blot and RT-PCR. TEM study on the ultrastructure of alveolar type Ⅱ epithelial cells. Results The content of SP-D and SP-D mRNA began to decrease after LPS injection for 12 h. SP-D mRNA was reduced to the lowest 24-36 h after LPS injection. SP-D reached the lowest point in 48 h. Transmission electron microscopy showed a variety of lamina propria in the acute lung injury group, especially at 48 h after injection. LPS lead to lamellar body volume increases, the number decreases, accompanied by a large number of vacuolar changes. Conclusion The fluctuation of SP-D in the early stage of LPS-induced acute lung injury is time-dependent. The level of SP-D in lung tissue was the lowest at 48 h, with severe pleomorphic change of type II alveolar epithelial cells. In the early stages of ALI, low levels of lung SP-D are associated with poorer clinical outcomes.