内毒素对大鼠肺泡Ⅱ型上皮细胞的损伤作用

Effect of lippolysaccharides (LPS) on alveolar type Ⅱ cells (AT-Ⅱ) in rats

目的:研究急性肺损伤时内毒素主要成分脂多糖(LPS)对肺泡Ⅱ型上皮细胞(AT-Ⅱ)的损伤作用。方法:18只SD大鼠随机分为生理盐水对照组、LPS模型组。通过颈外静脉给药4 h后处死动物,收集肺泡灌洗液(BALF)测定表面张力、总磷脂含量(TPL)、乳酸脱氢酶(LDH)、碱性磷酸酶(AKP)、丙二醛(MDA)及总蛋白(TP)含量;取右肺下叶,行HE染色光镜观察。结果:与对照组相比,LPS可增加表面张力[(23.12±2.8)vs(19.6±2.5)mN.m-1,P<0.05],并提高BALF中LDH活性[(8.2±1.9)vs(4.7±1.9)μkat.L-1,P<0.05]以及AKP活性[(256±101)vs(102±81)nkat.L-1,P<0.01];增加TP含量[(85±31)vs(29±16)g.L-1,P<0.01]和MDA含量;降低BALF中TPL含量[(370±57)vs(432±43)μg.kg-1,P<0.05]。同时光镜下发现LPS组呈典型间质性肺水肿表现。结论:LPS可以引起AT-Ⅱ的损伤,并抑制其合成、分泌肺表面活性物质。

Objective. To study the effect of LPS on alveolar type Ⅱ cells （AT- Ⅱ ） inrats. Methods： 18 SD rats were randomly divided into 2 groups, control group and LPS group. The control group were injected physiological saline through jugular vein and the LPS group were injected LPS instead. Four hours later, the rats were killed in order to collect the bronchoalveolar lavage fluid （BALF）. Surface tension, total phospholipids （TPL） , total protein （TP） and maleic dialdehyde （MDA） contents in the BALF were measured; the activities of lactate dehydrogenase （LDH） and alkaline phosphatase（AKP） in BALF were detected. The pathological features of right lungs were observed under an optical microscope. Results： Compared with control group, LPS could increase the surface tension[（23. 12±2. 8） vs （19. 6±2. 5） mN · m^-1 ,P〈0.05 ], the activity of LDH[（8. 2±1.9） vs （4. 7±1. 9）μkat· L^-1 , P〈0.05] and activity of AKPF（256±101） vs （102±81） nkat · L^-1 ,P〈0. 01] ;ihcrease the content of TP [（85±31） vs （29±16） g·L^-1 ,P〈0. 01] and the content of MDA in BALF;decrease the content of TPL[（370±57） vs （432±43）μg · kg^-1 ,P〈0. 05]. We also found the interstitial pulmonary edema in LPS group by the microscopy. Conclusion： LPS can injure the AT-Ⅱ and inhibit the secretion of pulmonary surfactants in acute lung injury.