摘要
采用膜片钳技术以全细胞方式在鼠脑微血管内皮细胞中记录到一种延迟外向电流。机械力作用下可引出一外向电流 ,膜电位为 30mV时其大小为 (5 4 1 2± 5 3 2 3)pA ,6 0mV时为 (1 0 6 1 3± 4 7 4 2 )pA ,90mA时为 (1 5 4 0 1± 5 3 2 2 )mV。说明血管内皮细胞上存在机械敏感性通道 ,并且这种通道不同于以往在内皮细胞上发现的机械力激活的内向整流性通道。不同的流动剪切力对体外培养的人脐静脉内皮细胞c fos和c myc蛋白表达产生不同的影响。c fos蛋白表达在静态时非常低 ,在 4dynes cm2 和 1 0dynes cm2 的剪应力都可诱导c fos蛋白水平迅速增加 ,尤其是 1 0dynes cm2 的剪应力。并随时间的增加而增加 ,到 1 0h时达到高峰 ,随后下降 ,2 5h时接近基础水平。c myc蛋白在静态时表达也非常低 。
Using the whole-cell patch-clamp technique,delayed outward currents are recorded in rat brain microvascular endothelial cells.In the presence of mechanical force,outward currents are increased in amplitude as compared with controls.When potential membrane is 30mV,the current is (54^12±53^23)pA,(106^13±47^42)pA for 60mV and (154^01±53^22)pA for 90mV.The mechanosensitive channel exists on endothelial cells of blood vessel,which is different from previous described mechanosensitive channel induced by mechanical force with characterstic of inward rectifier.The different effects of different fluid shear forces on the expression of proto-oncogenes c-fos and c-myc in cultured human umbilicalvein endothelial cells are rereaded.In the stationary state,c-fos protein levels are very low.The shear stresses of 4dynes/cm+2 and 10 dynes/cm+2 induce the rapid increases of c-fos protein levels,especially when the shear stress is 10 dynes/cm+2.The levels peak at 1^0h,and then began to decrease.They decline to almost basal levels after 2^5h.In the stationary state,the c-myc protein levels are also very low;They increase after the onset of shear stress slowly.
出处
《北京生物医学工程》
2004年第1期30-32,46,共4页
Beijing Biomedical Engineering
基金
国家自然科学基金 ( 3 960 0 0 40
10 172 0 96)
北京市自然科学基金 ( 3 982 0 0 5 )
