内毒素对培养人脐静脉内皮细胞的损伤作用

Effects of Endotoxin on Culturing Human Umbilical Vein Endothelial Cells

目的研究内毒素对内皮细胞的直接损伤作用，以便对烧伤早期入血的内毒素对血管内皮细胞的影响作出初步评价。方法以培养的原代人脐静脉内皮细胞（ＨＵＶＥＣ）为模型，加入不同浓度内毒素，观察在不同时相点培养液中乳酸脱氢酶（ＬＤＨ）活性变化，前列腺环素（ＰＧＩ２）代谢产物６－酮－前列环素Ｆ１ａ（６－酮－ＰＧＦ１ａ）含量和内皮细胞中的Ｆ－肌动蛋白丝（Ｆ－ａｃｔｉｎ）含量与细胞形态学变化。结果ＬＤＨ活性在内毒素达到０．４μｇ／ｍｌ并作用１２小时后才有显著升高（Ｐ＜０．０５），而６－酮－ＰＧＦ１ａ含量在各组内毒素损伤中变化均不显著。内皮细胞中Ｆ－ａｃｔｉｎ含量在各组中均有明显下降（Ｐ＜０．０１），但程度略有不同，细胞形态也有相应变化。结论内毒素直接损伤血管内皮细胞（ＶＥＣ）须较大浓度（＞０．４μｇ／ｍｌ），但在较低浓度下（０．１μｇ／ｍｌ）可直接引起内皮细胞的一些形态学变化和Ｆ－ａｃｔｉｎ含量的变化。

Aim To investigate the direct effects of endotoxin on culturing human umbilical vein endothelial cells (HUVECs) and evaluate the role of endotoxin invasion into blood at the early stage after burn.Methods The confluent primary HUVECs were cultured for 48 72 hours and different concentrated endotoxin was incubated with HUVECs for 3, 6 and 12 hours. The lactate dehydrogenase (LDH), the product of prostacyclin (PGI 2), 6 keto PGF content and F actin in the HUVECs were measured at different time points. The HUVECs morphologic changes were also observed with microscope and scanning electron microscope. Results The LDH activity in medium increased obviously when the endotoxin reached 0.4μg/ml and incubated over 12 hours ( P <0.05). The content of F actin in cytoplasm of HUVECs decreased significantly in all groups at 12 hours' point ( P <0.01). The 6 keto PGF had no obviously change. Conclusions At least 0.1μg/ml of endotoxin can induce the morphologic changes and the decrease of F actin in HUVECs. Endotoxin can injury HUVECs only when its concentration reaches 0.4μg/ml and incubates over 12 hours. It suggests there is a different molecule mechanism in VEC from the endotoxin CD 14 pathway in CD 14 positive cells.