血小板激活因子对肺动脉内皮细胞的直接作用

体外传代培养的牛肺动脉内皮细胞用不同浓度的血小板激活因子(PAF)处理后,观察乳酸脱氢酶(LDH)释放率、血管紧张素转换酶(ACE)活性和丙二醛(MDA)含量的变化,并观察受体拮抗剂对PAF效应的影响和PAF对白细胞-内皮细胞粘附的促进作用。结果表明,PAF对细胞LDH释放率无显著影响,ACE活性虽有增高但不显著,细胞MDA含量无显著变化,培养上清液MDA含量低浓度PAF(10~(-10)M,10~(-8)M)组显著低于高浓度PAF组(10~(-6)M)。SKI63-441使细胞内MDA含量显著高于PAF组,而上清液MDA降低。PAF无论是作用于白细胞还是内皮细胞,都能显著增加内皮细胞与白细胞的粘附,提示PAF对内皮细胞没有明显的损伤作用但可激活内皮细胞,促进内皮细胞与白细胞的粘附。

Direct effects of platelet-activating factor on pulmonary artery endothelial cells

Platelet-activating factor(PAF) at different concentrations were added to in vitro cultured bovine=pulmonary artery endothelial cells(BPAEC) when lactate dehydrogenase(LDH) release rate, angiotensin converting enzyme(ACE) activity and malondialdehyde (MDA) content were determined. The influences of specific PAF receptor antagonist on PAF effects and the stimulating effect of PAF on leukocyte-endothelial cell adhesion were also observed. The results showed that when PAF were added to BPAECs, there were no significant change in LDH release rate, ACE activities were only slightly increased. No obvious changes in cellbound MDA, but supernatant MDA content was increased in cells treated with high concentration of PAF (10~(-6)). The PAF receptor antagonist, SRI 63-441 made the cell-bound MDA content higher than that of PAF treated cells, whereas the supernatant MDA became lower. PAF may promote endothelial-leukocyte adhesion either through its effects on endothelial cells or on leukocytes, suggesting that PAF has no obvious damaging effect on endothelial cells but may activate endothelial cells thus promoting endothelialleukocyte adhesion.