内皮依赖性超极化因子的研究进展

Research progress in the endothelium-derived hyperpolarizing factor

血管内皮通过释放血管活性物质来调节血管紧张度,包括舒张性和收缩性两类,内皮依赖性超极化因子(endothelium-de-pendent hyperpolarizing factor,EDHF)是继一氧化氮(NO)和前列环素(PGI2)后在血管平滑肌舒张反应过程中发现的内皮释放的第三类舒血管因子,尽管其作用机制有几种不同类型,但都包括了细胞内Ca2+浓度的升高、钙依赖性钾通道(calcium-activatedpotassium channels,KCa)的开放及内皮细胞(endothelial cell)的超极化,最终导致了血管平滑肌细胞(smooth muscle cell,SMC)的超极化。SMC的超极化可以由直接接触机制(包括缝隙连接和细胞间隙的K+)和可扩散性化学活性物质机制完成,两种机制不具有排他性,可同时存在于某些血管。

The endothelium controls vascular tone not only by releasing nitric oxide（NO） and prostacyclin（PGI2）,the two best characterized endothelium-derived relaxing factors,but also by releasing EDHF,the third factor which is considered to play an important role in the regulation of vascular tone by causing hyperpolarization and subsequent relaxation of the underlying smooth muscle cells,accompany with stimulating calcium-activated potassium channels（KCa） on the endothelium.More recent evidence suggests that several mechanisms have been proposed to involved in this EDHF-mediated response.