天然及氧化修饰高密度脂蛋白对内皮细胞部分分泌功能的影响

目的 研究天然高密度脂蛋白（N-HDL）及氧化修饰高密度脂蛋白（OX-HDL）对培养人脐静脉内皮细胞（HUVEC）部分分泌功能的影响。方法 采用培养人脐静脉内皮细胞，以0．01mol／L PBS为空白对照，以N-HDL为正常对照，分别加入不同质量浓度OX-HDL（5mg／L，10mg／L，50mg／L）共同孵育24h后，观察培养基中内皮细胞分泌一氧化氮（NO）、一氧化氮合酶（NOS）、组织型纤溶酶原激活物（tPA）和纤溶酶原激活物抑制剂（PAI-1）水平的变化。结果 和空白对照相比，N-HDL组NO的量（P＜0．05）和NOS活性（P＜0．01）明显升高，tPA和PAI-1的差异没有统计学意义（P均＞0．05）；OX-HDL组NO的量和NOS活性均显著下降，并呈剂量依赖关系，PAI-1活性也显著升高（P＜0．05），tPA的水平差异无统计学意义。结论 N-HDL可以明显提高培养人脐静脉内皮细胞分泌NO的量并提高NOS活性，对tPA和PAI-1的产生则没有显著影响；而OX-HDL明显抑制内皮细胞NO合成和NOS活性，它不影响tPA的水平，却增加内皮细胞PAI-1活性。

The Effect of High Density Lipoprotein and Oxidized High Density Lipoprotein on Some Secretive Functions of Endothelial Cells

Objective To investigate the effect of high density lipoprotein and oxidized high density lipoprotein on the synthesis of NO,the activity of NOS,and the secretion of tPA and PAI-1 by cultured human umbilical vein endothelial cells(HUVEC). Methods With the 0.01 mol/L PBS and N-HDL of 50 mg/L as control, OX-HDL of 5 mg/L,10 mg/L,50 mg/L were co-incubated with HUVEC for 24 h in vitro. The levels of NO, the activity of NOS, and the levels of tPA and PAI-1 in the medium were detected after the incubation. Results Compared with the 0.01 mol/L PBS control, the synthesis of NO(P<0.05) and the activity of NOS(P<0.01) were significantly increased in the N-HDL group,but the change of tPA and PAI-1 displayed no statistical significance(both P>0.05). In the OX-HDL group, the synthesis of NO and the activity of NOS were significantly decreased in a dose-dependent way; the PAI-1 activity(P<0.05) was increased, but the secretion of tPA(P>0.05) was not affected. Conclusion N-HDL significantly increased the synthesis of NO and the activity of NOS secreted by HUVEC,but it had no influence on the generation of tPA and PAI-1. On the contrary,OX-HDL significantly decreased the synthesis of NO and the activity of NOS; it significantly increased PAI-1 activity ,but had no effect on the secretion of tPA.